Patent Application
20130266966
The present invention relates to methods of determining the risk of developing scoliosis, methods of stratifying a subject having a scoliosis, methods for assessing the efficacy of a brace on a subject having a scoliosis, and kits therefor.
The nucleic and amino acid sequences listed in the accompanying sequence listing are shown using standard letter abbreviations for nucleotide bases, and three letter code for amino acids, as defined in 37 C.F.R. 1.822. Only one strand of each nucleic acid sequence is shown, but the complementary strand is understood as included by any reference to the displayed strand. The Sequence Listing is submitted as an ASCII text file named Sequences.txt, created on Feb. 22, 2013, ˜80 KB, which is incorporated by reference herein.
Spinal deformities and scoliosis in particular, represent the most prevalent type of orthopedic deformities in children and adolescents, while adolescent idiopathic scoliosis (AIS) represents the most common form of scoliosis.
The etiology of adolescent idiopathic scoliosis (AIS) remains poorly understood resulting in the traditional paradigm that AIS is a multi-factorial disease with a genetic predisposition.(1-7) The occurrence of a melatonin signaling dysfunction in cells derived from biopsies obtained intraoperatively from affected AIS patients has been reported.8
Unfortunately, there is no proven method or test available to identify children or adolescents at risk of developing AIS or to identify, which of the affected individuals may require treatment due to the risk of progression. Consequently, the application of current treatments, such as bracing or surgical correction, is delayed until a significant deformity is detected or until a significant progression is clearly demonstrated, resulting in a delayed and less optimal treatment.29
The present description refers to a number of documents, the content of which is herein incorporated by reference in their entirety.
More specifically, in accordance with the present invention, there is provided a method for determining the risk for developing a scoliosis comprising monitoring osteopontin (OPN) expression in a sample from a subject over time; wherein an OPN expression that increases in the subject sample over time is indicative that the subject is at risk for developing a scoliosis.
In a specific embodiment, the monitoring begins when the subject is about three years old. In another specific embodiment, the monitoring is performed by measuring OPN expression at a frequency of at least about once per month. In another specific embodiment, the monitoring is performed by measuring OPN expression at a frequency of at least about once per six month. In another specific embodiment, the method further comprises measuring sCD44 expression in a sample from the subject. In another specific embodiment, the monitoring OPN expression is performed using an enzyme-linked immunosorbent assay (ELISA) or radioimmunoassay (RIA).
In accordance with the present invention, there is provided a method for determining the risk for developing a scoliosis comprising measuring osteopontin (OPN) expression in a sample from a subject; wherein an OPN expression that is higher in the subject sample than that in a control sample is indicative that the subject is at risk for developing a scoliosis.
In another specific embodiment, the subject is a likely candidate for developing a scoliosis. In another specific embodiment, the subject is a likely candidate for developing adolescent idiopathic scoliosis. In another specific embodiment, the subject is pre-diagnosed as having a scoliosis.
In another specific embodiment, the subject is pre-diagnosed with adolescent idiopathic scoliosis.
In accordance with another aspect of the present invention, there is provided a method of stratifying a subject having a scoliosis comprising measuring osteopontin (OPN) expression in a sample from the subject; whereby the measuring step enables the stratification of the subject into a scoliosis subgroup.
In accordance with another aspect of the present invention, there is provided a method for assessing the efficacy of a brace on a subject having a scoliosis comprising measuring osteopontin (OPN) expression in a sample from the subject prior to and at least once after bracing the subject, wherein an increase in the OPN expression after as compared to prior to bracing the subject is indicative that the brace is ineffective.
In a specific embodiment, the determining the OPN expression after the bracing is performed at least one month after the bracing. In another specific embodiment, the determining the OPN expression after bracing the subject is performed at least 2 months hours after the bracing. In another specific embodiment, the determining the OPN expression after bracing the subject is performed at least three months after the bracing. In another specific embodiment, the determining the OPN expression after bracing the subject is performed at least six months after the bracing.
In another specific embodiment, the method further comprises measuring soluble CD44 receptor (sCD44) expression in the sample from the subject.
In another specific embodiment, the sample from the subject is a biological fluid from the subject. In another specific embodiment, the biological fluid is selected from the group consisting of blood, urine, tear and saliva. In another specific embodiment, the biological fluid is plasma.
In another specific embodiment, the OPN expression is OPN protein. In another specific embodiment, the determining of the OPN expression is performed with an antibody that specifically binds to OPN. In another specific embodiment, the measuring OPN expression is performed using an enzyme-linked immunosorbent assay (ELISA). In another specific embodiment, the sample is a plasma sample and an OPN expression that is higher than 700 nanograms per milliliter of plasma is indicative that the subject is at risk for developing a scoliosis. In another specific embodiment, the sample is a plasma sample and an OPN expression that is higher than 800 nanograms per milliliter of plasma is indicative that the subject is at risk for developing a scoliosis.
In another specific embodiment, the OPN expression is OPN RNA. In another specific embodiment, the sample from the subject is a paraspinal muscle biopsy and the OPN expression is OPN RNA.
In accordance with another aspect of the present invention, there is provided a method of selecting an agent as a potential candidate for the reduction or prevention of scoliosis comprising contacting a candidate agent with a cell expressing osteopontin (OPN), and detecting the expression of OPN, wherein when the expression of OPN is lower in the presence of the candidate agent as compared to in the absence thereof, the candidate agent is selected.
In accordance with another aspect of the present invention, there is provided a method of selecting an agent as a potential candidate for the reduction or prevention of scoliosis comprising contacting a candidate agent with a cell expressing sCD44, and detecting the expression of sCD44, wherein when the expression of OPN is higher in the presence of the candidate agent as compared to in the absence thereof, the candidate agent is selected.
In another specific embodiment, the cell is a cell derived from a scoliotic patient.
In accordance with another aspect of the present invention, there is provided a method of selecting an agent as a potential candidate for the prevention or reduction of scoliosis comprising administering a candidate agent to a scoliosis model animal before scoliosis has developed in the animal, whereby the candidate is selected when the scoliosis is prevented or reduced in the model animal as compared to in a control animal who was not administered the candidate agent.
In accordance with another aspect of the present invention, there is provided a method of preventing or reducing scoliosis comprising administering to a subject having scoliosis a therapeutically effective amount of an osteopontin inhibitor (OPN) or a selenium rich diet, whereby scoliosis is thereby prevented or treated.
In accordance with another aspect of the present invention, there is provided a method of preventing or reducing scoliosis comprising administering to a subject having scoliosis a therapeutically effective amount of a CD44 inhibitor, whereby scoliosis is thereby prevented or treated.
In accordance with another aspect of the present invention, there is provided a method of preventing or reducing scoliosis comprising administering to a subject having scoliosis a therapeutically effective amount of a sCD44 stimulator, whereby scoliosis is thereby prevented or treated.
In a specific embodiment of the methods of the present invention, the subject is human. In another specific embodiment of the methods of the present invention, the subject is human female. In another specific embodiment of the methods of the present invention, the subject is human male.
In accordance with another aspect of the present invention, there is provided an osteopontin inhibitor for use in the treatment or prevention of scoliosis.
In accordance with another aspect of the present invention, there is provided a CD44 inhibitor for use in the treatment or prevention of scoliosis.
In accordance with another aspect of the present invention, there is provided a sCD44 stimulator for use in the treatment or prevention of scoliosis.
In accordance with another aspect of the present invention, there is provided a use of an osteopontin inhibitor in the manufacture of a medicament for the prevention or the treatment of scoliosis.
In accordance with another aspect of the present invention, there is provided a use of an osteopontin inhibitor for the prevention or the treatment of scoliosis.
In accordance with another aspect of the present invention, there is provided a use of a CD44 inhibitor in the manufacture of a medicament for the prevention or the treatment of scoliosis.
In accordance with another aspect of the present invention, there is provided a use of a CD44 inhibitor for the prevention or the treatment of scoliosis.
In accordance with another aspect of the present invention, there is provided a use of a sCD44 stimulator in the manufacture of a medicament for the prevention or the treatment of scoliosis.
In accordance with another aspect of the present invention, there is provided a use of a sCD44 stimulator for the prevention or the treatment of scoliosis.
In a specific embodiment of the uses of the present invention, the scoliosis is adolescent idiopathic scoliosis.
In accordance with another aspect of the present invention, there is provided a kit for predicting the risk of developing a scoliosis comprising a ligand specific to osteopontin (OPN) and instructions to use the kit for predicting the risk of developing a scoliosis. In a specific embodiment, the kit further comprises a ligand specific to soluble CD44 (sCD44).
Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings.
In the appended drawings:
The involvement of osteopontin (OPN) (also called secreted phosphoprotein 1, bone sialoprotein I, early T-lymphocyte activation 1), a multifunctional cytokine, was investigated in adolescent idiopathic scoliosis (AIS) and plasma OPN concentrations were determined in three populations: patients with AIS, healthy controls without any family antecedent for scoliosis and asymptomatic offspring, born from at least one scoliotic parent, who are considered as at risk (“children at risk”).
A group of 252 consecutive patients with AIS were compared with 35 healthy control subjects without any family history of scoliosis and 70 asymptomatic at risk subjects. All subjects were Caucasians and demographic characteristics are shown in Table 2 below. Plasma OPN, soluble CD44 receptor (sCD44), and hyaluronan (HA) levels were measured by enzyme-linked immunosorbent assays. Pinealectomized chicken and genetically modified bipedal C57Bl/6j mice devoid of either OPN or CD44 receptor, a known OPN receptor, were also studied.
Mean plasma OPN concentration in patients with AIS were significantly higher (p-value <0.001) in patients with AIS having a Cobb's angle >45° (965±414 nanograms per milliliter) than that in healthy controls (570±156 nanograms per milliliter) and than that in AIS patients with a Cobb's angle <45° (799±284 nanograms per milliliter). Diagnostic sensitivity and specificity of OPN for AIS was 84.4 percent and 90.6 percent respectively (cut-off value 800 nanograms per milliliter). Subgroup analysis showed that 47.9 percent of children at risk had OPN values higher than 800 nanograms per milliliter as opposed to only 8.6 percent for the controls indicating that elevated plasma OPN levels precede scoliosis formation. There were no significant differences in mean plasma sCD44 levels and HA levels between all groups. In respect to pathophysiology of scoliosis, the bipedal C57Bl/6j mouse model demonstrated that the development of scoliosis requires OPN interactions with CD44 receptors since none of the genetically modified bipedal mice developed a scoliosis. Cut-off values for OPN disclosed herein were calculated using the commercial Elisa kit specific to human OPN from IBL. They may vary when a OPN expression (mRNA or protein) is measured differently (e.g. measuring OPN expression in a different biological sample through OPN RNA or OPN protein but using a different antibody).
OPN (also called secreted phosphoprotein-1, minopontin, or Eta-1) is a phosphorylated glycoprotein containing an arginine-glycine-aspartate (RGD) sequence present in mineralized tissues such as extracellular matrices. This multifunctional cytokine is involved in many pathological conditions.9,10 The presence of OPN transcripts and proteins in postural control centers such as the cerebellum, skeletal muscle proprioceptive sensory organs, and inner ear structures that control of equilibrium(11) is of interest, since AIS patients also exhibit defects in postural control, proprioception and equilibrium.(12; 13) High plasma OPN levels have been found in different adult cancers and inflammatory conditions30-33.
OPN Signaling Action:
The OPN signaling pathways are not well understood, although it is known that aside from interacting with integrins, OPN can interact with CD44 receptor at the cell surface.14,15 Although CD44 is a major receptor for hyaluronan (HA), it also acts as a receptor for OPN and has multiple RGD binding sites. All human isoforms of the CD44 family of adhesion molecules are encoded by a single gene. Alternate splicing of 12 of the 19 exons in the human CD44 gene leads to the production of multiple variant isoforms16,17 and such structural heterogeneity is responsible of the ligand repertoire of CD44, which includes fibronectin18, chondroitin sulphate19, osteopontin20, at least two heparin binding growth hormones and hyaluronan.21,22 Soluble variant isoforms of sCD44 (sCD44var) have been associated with several pathological conditions.16,18,23,24 It has been proposed that sCD44 isoforms are either generated through proteolytic cleavage of cell surface CD44 or by de novo synthesis due to alternative splicing. Functional diversity among CD44 molecules, unrelated to variant exon usage, is demonstrated by observations that CD44H, or any particular splice-variant, can be active for hyaluronan (HA) binding when expressed in some cell types but inactive in others. Many CD44 isoforms are tissue specific, but the full range of soluble variant isoform(s) of sCD44 has been associated with some pathological conditions. Indeed, circulating levels of total sCD44 and specific soluble CD44 isoforms have been shown to correlate with tumor metastasis in some malignancies, including non-Hodgkin's lymphoma and breast, gastric, and colon carcinomas. The level of soluble CD44 is also known to be higher in the body fluids of subjects with particular inflammatory conditions, such as rheumatoid arthritis, pouchitis and colitis, and bronchitis. Hyaluronan (HA), also called hyaluronate or hyaluronic acid, is a mucopolysaccharide widely distributed throughout the body and produced by a variety of cells including fibroblasts and other specialized connective tissue cells.
As used herein the term “subject” is meant to refer to any mammal including human, mice, rat, dog, cat, pig, monkey, horse, etc. In a particular embodiment, it refers to a human.
As used herein the term “brace” is meant to include dental and orthopedic brace and “bracing” thus refers to the action of placing the braces on the subject. In a specific embodiment, it is meant to refer to braces for scoliotic subjects.
As used herein the terminology “spinal disorders and disorders causing scoliosis” refers to disorders that may involve development of a scoliosis. Without so limited, it includes AIS, congenital scoliosis, congenital cyphose scoliosis, neurological scoliosis, dysplasic scoliosis, neurofibromatosis, cerebral palsy, muscular dystrophies, neuromuscular scoliosis, spondylolesthesis and Noonan syndrome. Scoliosis that may be stratified or predicted excludes those caused by an accident and certain congenital malformations.
As used herein the terms “likely candidate for developing adolescent idiopathic scoliosis” include children of which a least one parent has adolescent idiopathic scoliosis. Among other factors, age (adolescence), gender and heredity (i.e. born from a mother or father having a scoliosis) are factors that are known to contribute to the risk of developing a scoliosis and are used to a certain degree to assess the risk of developing AIS. In certain subjects, scoliosis develops rapidly over a short period of time to the point of requiring a corrective surgery. Current courses of action available from the moment AIS is diagnosed (when scoliosis is apparent) include observation (when Cobb's angle is around 10-25°), orthopaedic devices (when Cobb's angle is around 25-30°), and surgery (over 45°). The more reliable methods of determining the risk of progression and of monitoring treatment efficiency in accordance of the present invention may assist in 1) selecting an appropriate diet to remove certain food products identified as contributors to scoliosis; 2) selecting the best therapeutic agent; 3) selecting the least invasive preventive action and/or available treatment such as postural exercises, orthopaedic device, and/or less invasive surgeries or surgeries without fusions (a surgery that does not fuse vertebra and preserves column mobility).
As used herein, the terms “severe AIS” refers to a scoliosis characterized by Cobb's angle of 45° or more.
As used herein the terms “risk of developing scoliosis” refer to a genetic or metabolic predisposition of a subject to develop a scoliosis (i.e. spinal deformity) and/or to develop a more severe scoliosis at a future time. For instance, an increase of the Cobb's angle of a subject (e.g. from 40° to 50°, or from 18° to 25°) is a “development” of scoliosis.
As used herein the terminology “biological sample” refers to any solid or liquid sample isolated from a living being. In a particular embodiment, it refers to any solid or liquid sample isolated from a human. Without being so limited it includes a biopsy material, blood, tears (48), saliva, maternal milk, synovial fluid, urine, ear fluid, amniotic fluid and cerebrospinal fluid. In a specific embodiment it refers to a blood sample.
As used herein the terminology “blood sample” is meant to refer to blood, plasma or serum. In a preferred embodiment, plasma is used. In a more specific embodiment it refers to a plasma sample.
As used herein the terminology “control sample” is meant to refer to a sample that does not come from a subject known to have scoliosis or known to be a likely candidate for developing a scoliosis. In methods for determining the risk of developing scoliosis in a subject that is pre-diagnosed with scoliosis, the sample may however also come from the subject under scrutiny at an earlier stage of the disease or disorder.
As used herein the term “treating” or “treatment” in reference to scoliosis is meant to refer to at least one of a reduction of Cobb's angle in a preexisting spinal deformity, improvement of column mobility, preservation/maintenance of column mobility, improvement of equilibrium and balance in a specific plan; maintenance/preservation of equilibrium and balance in a specific plan; improvement of functionality in a specific plan, preservation/maintenance of functionality in a specific plan, cosmetic improvement, and combination of any of the above.
As used herein the term “preventing” or “prevention” in reference to scoliosis is meant to refer to a at least one of a reduction in the progression of a Cobb's angle in a patient having a scoliosis or in an asymptomatic patient, a complete prevention of apparition of a spinal deformity, including changes affecting the rib cage and pelvis in 3D, and a combination of any of the above.
As used herein the term “osteopontin inhibitor” refers to an agent able to reduce or block expression (transcription or translation) of OPN (gene called sspi1), an agent able to reduce or block OPN secretion or an agent able to reduce or block OPN binding to its receptor CD44. Without being so limited, the agent can be natural or synthetic and can be a protein such as but not limited to an antibody that specifically binds to OPN, a peptide, a small molecule, a nucleotide such as but not limited to an antisense or a siRNA specific to OPN.
As used herein the term “CD44 inhibitor” refers to an agent able to reduce expression (transcription or translation) of CD44, or an agent able to reduce CD44 localization at the cellular membrane. Without being so limited, the agent can be natural or synthetic and can be a protein such as but not limited to an antibody that specifically binds to CD44, a peptide, a small molecule, a nucleotide such as but not limited to an antisense or a siRNA specific to CD44.
As used herein the term “sCD44 stimulator” refers to an agent able to increase expression (transcription or translation) of sCD44, an agent able to increase sCD44 secretion or an agent able to increase sCD44 affinity toward OPN. Without being so limited, the agent can be a protein, a peptide, a small molecule or a nucleotide.
The articles “a,” an and “the” are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.
The term “including” and “comprising” are used herein to mean, and re used interchangeably with, the phrases “including but not limited to” and “comprising but not limited to”.
The terms “such as” are used herein to mean, and is used interchangeably with, the phrase “such as but not limited to”.
The present invention also relates to methods for the determination of the level of expression (i.e. transcript or translation product) of OPN, HA or sCD44. The present invention therefore encompasses any known method for such determination including Elisa (Enzyme Linked Immunosorbent Assay), RIA (Radioimmunoassay), real time PCR and competitive PCR, Northern blots, nuclease protection, plaque hybridization and slot blots.
The present invention also concerns isolated nucleic acid molecules including probes and primers to detect OPN, sCD44 or CD44. In specific embodiments, the isolated nucleic acid molecules have no more than 300, or no more than 200, or no more than 100, or no more than 90, or no more than 80, or no more than 70, or no more than 60, or no more than 50, or no more than 40 or no more than 30 nucleotides. In specific embodiments, the isolated nucleic acid molecules have at least 17, or at least 18, or at least 19, or at least 20, or at least 30, or at least 40 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 20 and no more than 300 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 20 and no more than 200 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 20 and no more than 100 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 20 and no more than 90 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 20 and no more than 80 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 20 and no more than 70 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 20 and no more than 60 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 20 and no more than 50 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 20 and no more than 40 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 17 and no more than 40 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 20 and no more than 30 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 17 and no more than 30 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 30 and no more than 300 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 30 and no more than 200 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 30 and no more than 100 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 30 and no more than 90 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 30 and no more than 80 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 30 and no more than 70 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 30 and no more than 60 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 30 and no more than 50 nucleotides. In other specific embodiments, the isolated nucleic acid molecules have at least 30 and no more than 40 nucleotides. It should be understood that in real-time PCR, primers also constitute probe without the traditional meaning of this term. Primers or probes appropriate to detect OPN sCD44 and CD44 in the methods of the present invention can be designed with known methods using sequences distributed across their respective nucleotide sequence (49).
Probes of the invention can be utilized with naturally occurring sugar-phosphate backbones as well as modified backbones including phosphorothioates, dithionates, alkyl phosphonates and α-nucleotides and the like. Modified sugar-phosphate backbones are generally known. Probes of the invention can be constructed of either ribonucleic acid (RNA) or deoxyribonucleic acid (DNA), and preferably of DNA.
The types of detection methods in which probes can be used include Southern blots (DNA detection), dot or slot blots (DNA, RNA), and Northern blots (RNA detection). Although less preferred, labeled proteins could also be used to detect a particular nucleic acid sequence to which it binds. Other detection methods include kits containing probes on a dipstick setup and the like.
As used herein the terms “detectably labeled” refer to a marking of a probe or an antibody in accordance with the presence invention that will allow the detection of OPN, HA and/or sCD44 in accordance with the present invention. Although the present invention is not specifically dependent on the use of a label for the detection of a particular nucleic acid sequence, such a label might be beneficial, by increasing the sensitivity of the detection. Furthermore, it enables automation. Probes can be labeled according to numerous well known methods. Non-limiting examples of labels include 3H, 14C, 32P, and 35S, Non-limiting examples of detectable markers include ligands, fluorophores, chemiluminescent agents, enzymes, and antibodies. Other detectable markers for use with probes, which can enable an increase in sensitivity of the method of the invention, include biotin and radionucleotides. It will become evident to the person of ordinary skill that the choice of a particular label dictates the manner in which it is bound to the probe.
As commonly known, radioactive nucleotides can be incorporated into probes of the invention by several methods. Non-limiting examples thereof include kinasing the 5′ ends of the probes using gamma 32P ATP and polynucleotide kinase, using the Klenow fragment of Pol I of E. coli in the presence of radioactive dNTP (e.g. uniformly labeled DNA probe using random oligonucleotide primers in low-melt gels), using the SP6/T7 system to transcribe a DNA segment in the presence of one or more radioactive NTP, and the like.
The present invention also relates to methods of selecting compounds. As used herein the term “compound” is meant to encompass natural, synthetic or semi-synthetic compounds, including without being so limited chemicals, macromolecules, cell or tissue extracts (from plants or animals), nucleic acid molecules, peptides, antibodies and proteins.
The present invention also relates to arrays. As used herein, an “array” is an intentionally created collection of molecules which can be prepared either synthetically or biosynthetically. The molecules in the array can be identical or different from each other. The array can assume a variety of formats, e.g., libraries of soluble molecules; libraries of compounds tethered to resin beads, silica chips, or other solid supports.
As used herein “array of nucleic acid molecules” is an intentionally created collection of nucleic acids which can be prepared either synthetically or biosynthetically in a variety of different formats (e.g., libraries of soluble molecules; and libraries of oligonucleotides tethered to resin beads, silica chips, or other solid supports). Additionally, the term “array” is meant to include those libraries of nucleic acids which can be prepared by spotting nucleic acids of essentially any length (e.g., from 1 to about 1000 nucleotide monomers in length) onto a substrate. The term “nucleic acid” as used herein refers to a polymeric form of nucleotides of any length, either ribonucleotides, deoxyribonucleotides or peptide nucleic acids (PNAs), that comprise purine and pyrimidine bases, or other natural, chemically or biochemically modified, non-natural, or derivatized nucleotide bases. The backbone of the polynucleotide can comprise sugars and phosphate groups, as may typically be found in RNA or DNA, or modified or substituted sugar or phosphate groups. A polynucleotide may comprise modified nucleotides, such as methylated nucleotides and nucleotide analogs. The sequence of nucleotides may be interrupted by non-nucleotide components. Thus the terms nucleoside, nucleotide, deoxynucleoside and deoxynucleotide generally include analogs such as those described herein. These analogs are those molecules having some structural features in common with a naturally occurring nucleoside or nucleotide such that when incorporated into a nucleic acid or oligonucleotide sequence, they allow hybridization with a naturally occurring nucleic acid sequence in solution. Typically, these analogs are derived from naturally occurring nucleosides and nucleotides by replacing and/or modifying the base, the ribose or the phosphodiester moiety. The changes can be tailor made to stabilize or destabilize hybrid formation or enhance the specificity of hybridization with a complementary nucleic acid sequence as desired.
As used herein “solid support”, “support”, and “substrate” are used interchangeably and refer to a material or group of materials having a rigid or semi-rigid surface or surfaces. In many embodiments, at least one surface of the solid support will be substantially flat, although in some embodiments it may be desirable to physically separate synthesis regions for different compounds with, for example, wells, raised regions, pins, etched trenches, or the like. According to other embodiments, the solid support(s) will take the form of beads, resins, gels, microspheres, or other geometric configurations.
Any known nucleic acid arrays can be used in accordance with the present invention. For instance, such arrays include those based on short or longer oligonucleotide probes as well as cDNAs or polymerase chain reaction (PCR) products. Other methods include serial analysis of gene expression (SAGE), differential display, as well as subtractive hybridization methods, differential screening (DS), RNA arbitrarily primer (RAP)-PCR, restriction endonucleolytic analysis of differentially expressed sequences (READS), amplified restriction fragment-length polymorphisms (AFLP).
The present invention encompasses using antibodies for detecting or determining OPN, sCD44 or CD44 levels for instance in the samples of a subject and for including in kits of the present invention. Antibodies that specifically bind to these biological markers can be produced routinely with methods further described below. The present invention also encompasses using antibodies commercially available. Without being so limited antibodies that specifically bind to OPN include those listed in Table 1 below.
Both monoclonal and polyclonal antibodies directed to OPN are included within the scope of this invention as they can be produced by well established procedures known to those of skill in the art. Additionally, any secondary antibodies, either monoclonal or polyclonal, directed to the first antibodies would also be included within the scope of this invention.
As used herein, the term “anti-OPN antibody” or “immunologically specific anti-OPN antibody” refers to an antibody that specifically binds to (interacts with) an OPN protein and displays no substantial binding to other naturally occurring proteins other than the ones sharing the same antigenic determinants as the OPN protein. The term antibody or immunoglobulin is used in the broadest sense, and covers monoclonal antibodies (including full length monoclonal antibodies), polyclonal antibodies, multispecific antibodies, and antibody fragments so long as they exhibit the desired biological activity. Antibody fragments comprise a portion of a full length antibody, generally an antigen binding or variable region thereof. Examples of antibody fragments include Fab, Fab′, F(ab′)2, and Fv fragments, diabodies, linear antibodies, single-chain antibody molecules, single domain antibodies (e.g., from camelids), shark NAR single domain antibodies, and multispecific antibodies formed from antibody fragments. Antibody fragments can also refer to binding moieties comprising CDRs or antigen binding domains including, but not limited to, VH regions (VH, VH-VH), anticalins, PepBodies™, antibody-T-cell epitope fusions (Troybodies) or Peptibodies. Additionally, any secondary antibodies, either monoclonal or polyclonal, directed to the first antibodies would also be included within the scope of this invention.
In general, techniques for preparing antibodies (including monoclonal antibodies and hybridomas) and for detecting antigens using antibodies are well known in the art (Campbell, 1984, In “Monoclonal Antibody Technology: Laboratory Techniques in Biochemistry and Molecular Biology”, Elsevier Science Publisher, Amsterdam, The Netherlands) and in Harlow et al., 1988 (in: Antibody A Laboratory Manual, CSH Laboratories). The term antibody encompasses herein polyclonal, monoclonal antibodies and antibody variants such as single-chain antibodies, humanized antibodies, chimeric antibodies and immunologically active fragments of antibodies (e.g. Fab and Fab′ fragments) which inhibit or neutralize their respective interaction domains in Hyphen and/or are specific thereto.
Polyclonal antibodies are preferably raised in animals by multiple subcutaneous (sc), intravenous (iv) or intraperitoneal (ip) injections of the relevant antigen with or without an adjuvant. It may be useful to conjugate the relevant antigen to a protein that is immunogenic in the species to be immunized, e.g., keyhole limpet hemocyanin, serum albumin, bovine thyroglobulin, or soybean trypsin inhibitor using a bifunctional or derivatizing agent, for example, maleimidobenzoyl sulfosuccinimide ester (conjugation through cysteine residues), N-hydroxysuccinimide (through lysine residues), glutaraldehyde, succinic anhydride, SOCl2, or R1N═C═NR, where R and R1 are different alkyl groups.
Animals may be immunized against the antigen, immunogenic conjugates, or derivatives by combining the antigen or conjugate (e.g., 100 μg for rabbits or 5 μg for mice) with 3 volumes of Freund's complete adjuvant and injecting the solution intradermally at multiple sites. One month later the animals are boosted with the antigen or conjugate (e.g., with ⅕ to 1/10 of the original amount used to immunize) in Freund's complete adjuvant by subcutaneous injection at multiple sites. Seven to 14 days later the animals are bled and the serum is assayed for antibody titer. Animals are boosted until the titer plateaus. Preferably, for conjugate immunizations, the animal is boosted with the conjugate of the same antigen, but conjugated to a different protein and/or through a different cross-linking reagent. Conjugates also can be made in recombinant cell culture as protein fusions. Also, aggregating agents such as alum are suitably used to enhance the immune response.
Monoclonal antibodies may be made using the hybridoma method first described by Kohler et al., Nature, 256: 495 (1975), or may be made by recombinant DNA methods (e.g., U.S. Pat. No. 6,204,023). Monoclonal antibodies may also be made using the techniques described in U.S. Pat. Nos. 6,025,155 and 6,077,677 as well as U.S. Patent Application Publication Nos. 2002/0160970 and 2003/0083293 (see also, e.g., Lindenbaum et al., 2004).
In the hybridoma method, a mouse or other appropriate host animal, such as a rat, hamster or monkey, is immunized (e.g., as hereinabove described) to elicit lymphocytes that produce or are capable of producing antibodies that will specifically bind to the antigen used for immunization. Alternatively, lymphocytes may be immunized in vitro. Lymphocytes then are fused with myeloma cells using a suitable fusing agent, such as polyethylene glycol, to form a hybridoma cell.
The hybridoma cells thus prepared are seeded and grown in a suitable culture medium that preferably contains one or more substances that inhibit the growth or survival of the unfused, parental myeloma cells. For example, if the parental myeloma cells lack the enzyme hypoxanthine guanine phosphoribosyl transferase (HGPRT or HPRT), the culture medium for the hybridomas typically will include hypoxanthine, aminopterin, and thymidine (HAT medium), which substances prevent the growth of HGPRT-deficient cells.
As used herein, the term “purified” in the expression “purified antibody” is simply meant to distinguish man-made antibody from an antibody that may naturally be produced by an animal against its own antigens. Hence, raw serum and hybridoma culture medium containing anti-OPN antibody are “purified antibodies” within the meaning of the present invention.
The present invention also encompasses arrays to detect and/or quantify the translation products of OPN, HA or sCD44. Such arrays include protein micro- or macroarrays, gel technologies including high-resolution 2D-gel methodologies, possibly coupled with mass spectrometry imaging system at the cellular level such as microscopy combined with a fluorescent labeling system.
The present invention also encompasses methods for identifying specific mutation(s) directly or indirectly affecting the transcription, translation, post-translational modification or activity of OPN. Without being so limited, mutations of interest include any mutation affecting the interactions between OPN and any soluble or non soluble isoform of CD44 or the binding of HA to any soluble or non soluble isoform of CD44.
The present invention also encompasses the monitoring of the biomarkers disclosed herein to assess the efficacy of numerous approaches to prevent scoliosis and curve progression such as any physical therapies (e.g. postural exercises, physiotherapies, biomechanical stimulations by manipulation or using specific devices e.g. vibrant plates); the monitoring of bracing efficacy or development of novel braces; the monitoring of new surgical devices with or without fusion of vertebras, and the monitoring of the efficacy of specific diet, nutraceutical and/or pharmacological treatments. Without being so limited, the first measure after the braces have been applied could be performed 1 month later to determine for instance whether the braces are well adjusted and determine whether the patient is compliant to the treatment. Thereafter, the monitoring could be performed every three to six months depending on whether high OPN levels are detected or not. This method of the present invention may advantageously reduces the requirement for x-rays. X-rays could be performed for instance only at visits where OPN levels detected are too high.
The present invention also encompasses the monitoring of the biomarkers disclosed herein to identify patients having a risk of progression for early bracing or for less-invasive surgeries with novel fusionless devices, for pharmacological treatments and to monitor responses to treatment in patients with AIS. Of note, fusionless devices are particularly useful for patients still possessing a growth potential so that identification of the risk of developing a scoliosis as early as possible in the life of the subject is beneficial. In a specific embodiment, monitoring begins when the subject is about 5 years old or less in subjects having a scoliosis family antecedent/history. The frequency of the testing could typically be every six months. In case where OPN values are above the cut-off value (i.e. >800 ng/ml when the OPN IBL ELISA kit code No. 27158 is used), the frequency would be advantageously significantly increased (e.g. every month, every two months, every three months . . . ).
The present invention also encompasses methods to screen/select for potential useful therapeutic agents using whole cells assays, the therapeutic compound being able to repress the transcription and/or synthesis of OPN (encoded by ssp1 gene), and/or able to increase the production of sCD44 which could sequester circulating OPN, and/or able to interfere with OPN liaison with the CD44 receptor, and/or able to block the CD44 receptor. Cells for use in such methods includes cells of any source (including in house or commercially available cell lines) and type (any tissue). In house cell lines could be made for instance by immortalizing cells from AIS subjects. In specific embodiments, methods of screening of the invention seek to identify agents that inhibit OPN expression (transcription and/or translation) and agents that increase sCD44 expression (transcription and/or translation). Useful cell lines for these embodiments include those producing high levels of OPN and/or low levels of sCD44. Such useful cell lines are described in references 43-56.
In a particular embodiment, it includes cells of any cell type derived from a scoliotic patient. In specific embodiments, it includes osteoblasts, chondrocytes, myoblasts or blood cells including lymphocytes. As used herein, the term “cell derived from a scoliotic patient” refers to cells isolated directly from scoliotic patients, or immortalized cell lines originating from cells isolated directly from scoliotic patients. In specific embodiments, the cells are paraspinal muscle cells. Such cells may be isolated by a subject through needle biopsies for instance.
Pharmaceutical compositions can also be administered by routes such as nasal, intravenous, intramuscular, subcutaneous, sublingual, intrathecal, or intradermal route. The route of administration can depend on a variety of factors, such as the environment and therapeutic goals.
Any amount of a pharmaceutical and/or nutraceutical and/or dietary supplement compositions can be administered to a subject. The dosages will depend on many factors including the mode of administration. Typically, the amount of anti-scoliosis composition (e.g. osteopontin inhibitor or selenium compound) contained within a single dose will be an amount that effectively prevents, delays or reduces scoliosis without inducing significant toxicity “therapeutically effective amount”.
In some embodiments, the therapeutically effective amount of the neutraceutical anti-scoliosis composition (e.g. selenium supplement) can be altered. Useful effective amount concentrations include amounts ranging from about 0.01% to about 10% of a total diet on a weight by weight basis, from about 1% to about 6% of a total diet on a weight by weight basis, or from about 02% to about 6% of a total diet on a weight by weight basis.
The effective amount of the osteopontin inhibitor or selenium compound may also be measured directly. The effective amount may be given daily or weekly or fractions thereof. Typically, a pharmaceutical and/or nutraceutical and/or dietary supplement composition of the invention can be administered in an amount from about 0.001 mg up to about 500 mg per kg of body weight per day (e.g., 10 mg, 50 mg, 100 mg, or 250 mg). Dosages may be provided in either a single or multiple dosage regimen. For example, in some embodiments the effective amount is a dose that ranges from about 1 mg to about 25 grams of the anti-scoliose preparation per day, about 50 mg to about 10 grams of the anti-scoliose preparation per day, from about 100 mg to about 5 grams of the anti-scoliose preparation per day, about 1 gram of the anti-scoliose preparation per day, about 1 mg to about 25 grams of the anti-scoliose preparation per week, about 50 mg to about 10 grams of the anti-scoliose preparation per week, about 100 mg to about 5 grams of the anti-scoliose preparation every other day, and about 1 gram of the anti-scoliose preparation once a week.
By way of example, a pharmaceutical (e.g. containing an osteopontin inhibitor) and/or nutraceutical (e.g. containing selenium) and/or dietary supplement (e.g. containing selenium) composition of the invention can be in the form of a liquid, solution, suspension, pill, capsule, tablet, gelcap, powder, gel, ointment, cream, nebulae, mist, atomized vapor, aerosol, or phytosome. For oral administration, tablets or capsules can be prepared by conventional means with at least one pharmaceutically acceptable excipient such as binding agents, fillers, lubricants, disintegrants, or wetting agents. The tablets can be coated by methods known in the art. Liquid preparations for oral administration can take the form of, for example, solutions, syrups, or suspension, or they can be presented as a dry product for constitution with saline or other suitable liquid vehicle before use. Dietary supplements of the invention also can contain pharmaceutically acceptable additives such as suspending agents, emulsifying agents, non-aqueous vehicles, preservatives, buffer salts, flavoring, coloring, and sweetening agents as appropriate. Preparations for oral administration also can be suitably formulated to give controlled release of the active ingredients.
In addition, a pharmaceutical (e.g. containing an osteopontin inhibitor) and/or nutraceutical (e.g. containing selenium) and/or dietary supplement (e.g. containing selenium) composition of the invention can contain a pharmaceutically acceptable carrier for administration to a mammal, including, without limitation, sterile aqueous or non-aqueous solutions, suspensions, and emulsions. Examples of non-aqueous solvents include, without limitation, propylene glycol, polyethylene glycol, vegetable oils, and injectable organic esters. Aqueous carriers include, without limitation, water, alcohol, saline, and buffered solutions. Pharmaceutically acceptable carriers also can include physiologically acceptable aqueous vehicles (e.g., physiological saline) or other known carriers appropriate to specific routes of administration.
An osteopontin inhibitor or selenium may be incorporated into dosage forms in conjunction with any of the vehicles which are commonly employed in pharmaceutical preparations, e.g. talc, gum arabic, lactose, starch, magnesium searate, cocoa butter, aqueous or non-aqueous solvents, oils, paraffin derivatives or glycols. Emulsions such as those described in U.S. Pat. No. 5,434,183, may also be used in which vegetable oil (e.g., soybean oil or safflower oil), emulsifying agent (e.g., egg yolk phospholipid) and water are combined with glycerol. Methods for preparing appropriate formulations are well known in the art (see e.g., Remington's Pharmaceutical Sciences, 16th Ed., 1980, A. Oslo Ed., Easton, Pa.).
In cases where parenteral administration is elected as the route of administration, preparations containing osteopontin inhibitor or selenium may be provided to patients in combination with pharmaceutically acceptable sterile aqueous or non-aqueous solvents, suspensions or emulsions. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oil, fish oil, and injectable organic esters. Aqueous carriers include water, water-alcohol solutions, emulsions or suspensions, including saline and buffered medical parenteral vehicles including sodium chloride solution, Ringer's dextrose solution, dextrose plus sodium chloride solution, Ringer's solution containing lactose, or fixed oils. Intravenous vehicles may include fluid and nutrient replenishers, electrolyte replenishers, such as those based upon Ringer's dextrose, and the like.
These are simply guidelines since the actual dose must be carefully selected and titrated by the attending physician based upon clinical factors unique to each patient or by a nutritionist. The optimal daily dose will be determined by methods known in the art and will be influenced by factors such as the age of the patient and other clinically relevant factors. In addition, patients may be taking medications for other diseases or conditions. The other medications may be continued during the time that the osteopontin inhibitor or selenium compound is given to the patient, but it is particularly advisable in such cases to begin with low doses to determine if adverse side effects are experienced.
The present invention also relates to kits. Without being so limited, it relates to kits for stratifying scoliotic subjects and/or predicting whether a subject is at risk of developing a scoliosis comprising an isolated nucleic acid, a protein or a ligand such as an antibody in accordance with the present invention as described above. For example, a compartmentalized kit in accordance with the present invention includes any kit in which reagents are contained in separate containers. Such containers include small glass containers, plastic containers or strips of plastic or paper. Such containers allow the efficient transfer of reagents from one compartment to another compartment such that the samples and reagents are not cross-contaminated and the agents or solutions of each container can be added in a quantitative fashion from one compartment to another. Such containers will include a container which will accept the subject sample (DNA genomic nucleic acid, cell sample or blood samples), a container which contains in some kits of the present invention, the probes used in the methods of the present invention, containers which contain enzymes, containers which contain wash reagents, and containers which contain the reagents used to detect the extension products. Kits of the present invention may also contain instructions to use these probes and or antibodies to stratify scoliotic subjects or predict whether a subject is at risk of developing a scoliosis.
The present invention is illustrated in further details by the following non-limiting examples.
Generation of Bipedal C57Bl/6J OPN-Null and CD44-Null Mice.
Experiments in mice were conducted according to protocols approved by The Ste-Justine Hospital's Animal Health Care Review Committee. Breeding pairs of C57Bl/6 devoid of either OPN(OPN-null mice) or CD44 receptor (CD44-null mice) backcrossed for more than 10 generations in C57Bl/6j mice were graciously obtained from Dr. Susan Rittling, (Rutger University, NJ, USA) and Dr. Tak Mak (University of Toronto, ON, Canada), respectively, to establish new colonies, while C57Bl/6j mice served as wild-type control mice (Charles-River, Wilmington, Mass., USA). The C57Bl6/6j mouse strain was used because it is naturally deficient in melatonin(28), exhibits high circulating OPN levels(27) and develops scoliosis when they are maintained in a bipedal state.(28) It is a well known scoliosis animal model. Bipedal surgeries were performed after weaning by amputation of the forelimbs and tail under anesthesia as reported previously.(28) All mice underwent complete radiographic examination under anesthesia using a Faxitron™ X-rays apparatus (Faxitron X-rays Corp. Wheeling, Ill., USA) every two weeks starting at the age of six weeks. Anteroposterior X-rays were taken and each digital image was evaluated subsequently for the presence of scoliosis. Cobb's angle threshold value of 10° or higher was retained as a significant scoliotic condition.
Immunodetection of Mouse OPN
Mouse serum was obtained from peripheral blood samples for the determination of serum levels of OPN and were collected in serum separator tubes containing silica gel (BD Microtainer, BD New Jersey, USA) and then centrifuged. Derived serum samples were aliquoted and kept frozen at −80° C. until thawed and analyzed. Serum concentrations of OPN were measured by capture enzyme-linked immunosorbent assays (ELISA) according to the protocol provided by the manufacturer (IBL, Hamburg, Germany). The OPN ELISA kit measured total concentration of both phosphorylated and non-phosphorylated of all isoforms of OPN in serum. ELISA tests were performed in duplicate and the optical density was measured at 450 nm using an AsysHiTech™ Expert-96 microplate reader (Biochrom, Cambridge, UK). Although serum was used in mice herein, the present invention also encompasses measuring OPN in mice plasma.
Generation of Pinealectomized Chickens.
A percentage of pinealectomized chickens develop a scoliosis and they are thus used as a scoliosis model. For this study, 145 newly hatched chickens (Mountain Hubbard) were purchased at a local hatchery and pinealectomy were performed as previously described(25).
Expression Analysis and Immunodetection of Chicken OPN.
Total cellular RNA was prepared from paraspinal muscles of pinealectomized chickens by phenol/chloroform extraction. For RT-PCR, 1 microgramme total RNA was reversed transcribed using ThermoScript™ reverse transcriptase (Invitrogen), and the equivalent of 0.1 microgramme of reverse-transcribed RNA used for PCR reactions. These were carried out in a final volume of 50 microliters containing 200 micromolars dNTPs, 1.5 millimolars MgCl2, 10 picomolars each primer, and 1 U Pfu DNA-polymerase (Stratagene, LaJolla, Calif., USA). PCR reactions were performed using the following primers and conditions: chicken OPN (420 by PCR product): 5′-ACACTTTCACTCCAATCGTCC-3′ (SEQ ID NO: 19) (forward), 5′-TGCCCTTTCCGTTGTTGTCC-3′ (SEQ ID NO: 20) (reverse) 35 cycles: 95° C./45 seconds, 66° C./45 seconds, 72° C./1 minute. For quantitative analysis, all amplifications were normalized against that of the housekeeping gene β-actin; chicken β-actin (460 bp PCR product) 5′-GGAAATCGTGCGTGACAT-3′ (SEQ ID NO: 21) (forward), 5′-TCATGATGGAGTTGAATGTAGTT-3′ (SEQ ID NO: 22) (reverse) 32 cycles: 94° C./45 seconds, 55° C./45 seconds, 72° C./1 minute. PCR amplified products were analyzed on 1.5% agarose gel containing ethidium bromide. Total protein extracts of paraspinal muscles were used to detect chicken OPN by Western blot using anti-human OPN antibodies cross-reacting with chicken OPN (clone 8E5, Kamiya Biomedial, WA, USA).
Human Populations
The institutional review boards of The Sainte-Justine Hospital, The Montreal Children's Hospital, The Shriners Hospital for Children in Montreal, McGill University and The Affluent School Board, approved the study. Parents or legal guardians of all participants gave written informed consent, and minors gave their assent.
All patients with AIS were examined by one of six orthopedic surgeons. A person was deemed to be affected if history and physical examination were consistent with the diagnosis of idiopathic scoliosis and a minimum of a ten degree curvature in the coronal plane with vertebral rotation was found on a standing radiograph of the spine. Healthy controls were recruited in elementary schools of Montreal. Each subject was examined by the same orthopedic surgeon using Adam's forward bending-test with a scoliometer.
Three populations were investigated: patients with AIS, healthy controls without any family antecedent/history for scoliosis and asymptomatic offspring, born from at least one scoliotic parent, who are considered as at risk of developing a scoliosis. A group of 252 consecutive patients with AIS, 35 healthy control subjects and 70 asymptomatic children at risk of developing a scoliosis were recruited. All subjects were Caucasians and demographic characteristics are shown in Table 2 below).
Osteopontin, sCD44 and Ha Enzyme-Linked Immunosorbent Assays
Peripheral blood samples for AIS patients, asymptomatic children and control groups were collected in EDTA-containing tubes and then centrifuged. Derived plasma samples were aliquoted and kept frozen at −80° C. until thawed and analyzed. Plasma concentrations of OPN and sCD44 were measured by capture enzyme-linked immunosorbent assays (ELISA) according to protocols provided by the manufacturer (IBL, Hamburg, Germany). The sCD44 Elisa kit (sCD44std) measured all circulating (soluble) CD44 isoforms comprising the standard protein sequences but not the rare isoforms associated with alternative splicing between exons V2 and V10 (50) (see also
Statistical Analysis
Age and gender differences among the different AIS and control groups were assessed using Pearson's Chi-square and Student's t tests, respectively. Multiple linear regression models were used to test for association between groups and levels of OPN, sCD44, and HA. Values were adjusted for age, gender, and age-gender interaction when these potential confounders were associated with the biomarker levels at p<0.1. Interactions between group and gender were also investigated. It was first tested for an overall group effect using a global F test comparing models with and without group effects. Were then tested specific differences between groups, applying a Bonferroni correction for multiple testing. Receiver-operating characteristics (ROC) curves were used to evaluate the diagnostic value of OPN, and to identify the optimal threshold values. The sensitivity (proportion of true-positive results when the assay was applied to patients known to have AIS) and specificity (proportion of true-negative results when the assay was applied to healthy controls) of OPN were profiled by curves. The area under ROC curve (AUC) and associated 95% confidence interval were calculated. The test of the hypothesis that the theoretical AUC is 0.5 was based on the confidence interval. Statistical analysis was performed with the SAS software, version 9.1, with the exception of the ROC curve analysis, which was performed with the ROCR package for R(51,52). In all analyses except when otherwise mentioned a p-value <0.05 was considered statistically significant.
Expression analysis and immunodetection analysis of OPN in pinealectomized chicken were performed as described in Example 1 above. OPN at the mRNA and protein levels occurring in pinealectomized chicken were measured.
Bipedal C57Bl/6j mice were generated and their OPN level was determined as described in Example 1 above. Bipedal ambulation for 8 weeks in C57Bl/6j mice induced scoliosis at a rate of 46 percent in females and 24 percent in males which correlated well with higher plasma OPN levels found in females (Table 3 below). The relevance of this animal model is strengthened by the fact that scoliosis are more frequently seen in number and severity in bipedal C57Bl/6j females (46%) when compared to bipedal males (24%) as is also observed in humans.
The contribution of OPN and CD44 receptor as an integral part of the pathophysiology cascade in scoliosis formation and curve progression was also examined by studying genetically modified bipedal C57Bl/6j mice by conducting experiments as described in Example 1 above. As shown in Table 3 above, it was found that none of the bipedal C57Bl/6j OPN-null (n=54) and C57Bl/6j CD44-null mice (n=60) respectively, developed a scoliosis even if their analysis was extended over 52 weeks. Scoliosis development is detected 8 weeks after the surgery. A longer follow-up was performed to demonstrate that scoliosis development was not simply delayed in OPN-null and CD44-null mice.
In parallel, melatonin circulating levels were measured in wild-type and OPN-KO mice to exclude the possibility that absence of scoliosis in bipedal C57Bl/6 OPN-KO mice was due to an increased production of melatonin.
As indicated above, C57Bl/6j mice are melatonin deficient and may develop a scoliosis (S) in contrast to the FVB strain, which produces high melatonin levels. OPN-knockout mice do not develop a scoliosis (NS) even if they are in the same genomic background (C57Bl6/j), although melatonin is markedly decreased, suggesting that melatonin negatively regulates OPN expression and synthesis in vivo. Without being bound by this hypothesis, it is also suggested that in absence of OPN in genetically modified mice, the melatonin level will be further decreased accordingly as an adaptive physiological response to enhance OPN expression and synthesis.
Two compounds suspected of having an effect on OPN transcription or synthesis were injected intraperitonealy at a dosage of 500 μg/kg of body weight/day to chicken 24-48 h prior pinealectomy.
As is apparent in
A group of 252 patients with AIS and 35 healthy control subjects were tested as described in Example 1 above. Patients with AIS were divided into two subgroups according to their spinal curve severity (10°-44° vs. ≧45°) In the most severely affected AIS subgroup, none of the patients had corrective surgery at the time of the tests. Consistent with literature reporting increased AIS prevalence in teenage girls when compared to boys for moderate curves (ratio 10:1 for curve with a Cobb's angle ≧30°), a greater proportion of girls in the AIS groups (86% and 84% in the 10°-44° and 45° subgroups, respectively were observed compared to the control groups (54% and 64% in healthy and at risk control groups, respectively, p≦0.0001 when comparing the control groups). There was no significant gender difference between the two AIS subgroups (p=0.76) or between the two control groups (p=0.32). Mean age was significantly higher in AIS patients with Cobb's angle ≧45° compared to those with 10-40° angle (15.2±1.8 vs. 13.8±2.1, p<0.0001). Both AIS groups had higher mean age compared to control groups (10.7±0.6 for the healthy and 9.9±3.4 for the at risk group, p<0.0001 when comparing to either AIS group).
The plasma OPN levels in patients with AIS exhibiting a severe deformity (Cobb's angle ≧45°), low to moderate curve (Cobb's angle between 10° and 44°) and healthy controls are summarized in Table 4 below according to various clinical parameters. The mean plasma OPN levels were significantly higher in both AIS groups when compared to healthy control group although plasma OPN levels were more elevated in patients with the most severe deformities (Cobb's angle ≧45°) (Bonferroni-corrected p<0.001 after adjustment for age, gender, and age-gender interaction). Plasma OPN levels in AIS patients were correlated with the severity of curve deformity (
Receiver-operating characteristics (ROC) curves analyzes of plasma OPN comparing the patients with AIS more severely affected (Cobb's angle ≧45°) with healthy controls showed an AUC of 0.94 with a standard error of 0.03 (95 percent confidence interval 0.88 to 0.99) (see
Although as indicated above, high levels of OPN are found in other adult diseases, high plasma OPN levels found in patients with scoliosis are unique in the pediatric population. The detection of OPN level can thus be used to identify within asymptomatic children those who are at risk of developing a scoliosis (AIS or other spinal disorders and disorders causing scoliosis) and identify among scoliotic subjects, those or are at risk of experiencing a progression of scoliosis. Moreover, plasma OPN levels found in AIS patients were often higher than those measured in adult diseases. OPN levels can also be used to predict the risk in adults (e.g. degenerative scoliosis and idiopathic scoliosis that progress through adulthood). Certain mutations have already been associated with other disorders that may lead to scoliosis. In a particular embodiment, the OPN levels could be used in combination with the detection of these mutations.
A group of 70 asymptomatic children at risk of developing a scoliosis and 35 healthy control subjects were tested as described in Example 1 above. The mean plasma OPN levels in the group at risk of developing a scoliosis (846.30±402 nanograms per milliliter) differed significantly (p=0.001) from the healthy controls (570±156 nanograms per milliliter) and both groups were age- and gender-matched. No significant gender difference was observed (see Table 4 above).
Using a cut-off value of 800 nanograms per milliliter, it was observed that 47.9 percent of asymptomatic children in that group were above this plasma OPN value while only 8.6 percent of healthy controls were above this value. These results are in agreement with previous reports showing that the offspring of at least one affected parent develops more often a scoliosis than ones born from unaffected parents (34, 35).
An enzyme-linked immunosorbent assay (ELISA) or RIA for OPN for instance can thus be used for early identification of subjects at risk of developing a scoliosis for purposes of prognosis and/or scoliotic patients stratification for early bracing and less-invasive surgeries with novel fusionless devices, for pharmacological treatments and to monitor responses to treatment in patients with AIS.
Experiments were conducted as described in Example 1 above. The plasma sCD44 and HA levels in healthy controls, both AIS groups and asymptomatic at risk children are displayed in Table 4 above. Comparison among all groups showed no significant change in mean plasma sCD44 and HA values. However, AIS patients exhibiting the most severe spinal deformities (≦45°) had also the lowest mean plasma sCD44 level when compared to the other three groups (p=0.066).
CD44 and sCD44 can act as a receptor and decoy receptor for OPN respectively. In spite that no significant changes were measured among all groups tested, the most severely affected AIS patients 45°) showed the lowest mean sCD44 value among all groups tested. Interestingly, decreased plasma sCD44 levels were found in immunodeficiency and autoimmune diseases(35-37), but none of these conditions normally lead to scoliosis in absence of high plasma OPN levels, suggesting that sCD44 could play a role in AIS as disease-modifying factor by interfering with the action of OPN (see
The progression of biomarkers (OPN and sCD44 levels) and Cobb's angle was measured over follow up time in AIS patients.
OPN level can be used to identify among pre-diagnosed patients those in which scoliosis will progress.
Tables 5 to 8 below present the clinical and biochemical profiles in detail for each of the healthy control subjects (Table 5), of the AIS patients with Cobb's angles of less than 45 degrees (Table 6), of the AIS patients with Cobb's angles 45° or more (Table 7), and of the asymptomatic at risk children (Table 8).
OPN levels were measured in non AIS scoliotic patients (NAIS patients). Results are summarized in Table 9 below. A comparison of OPN, sCD44 and HA levels in healthy, AIS and NAIS patients is also provided in
Table 10 below presents in detail biomarkers levels for non AIS scoliotic patients.
OPN levels were measured in AIS patients pre (n=79) and post (N=28) operations. Interestingly, comparison of AIS patients in pre-operation vs. post operation showed a reduction in circulating OPN levels, which further support the role of OPN at the cellular level as mechanosensor (
OPN were measured in AIS female patients pre (n=10) and post (N=10) treatment with braces. Similarly, sCD44 levels were measured in AIS female patients pre (n=15) and post (N=12) operations. Results are presented in
A distribution of 12 AIS patients was also performed across the predefined cut-off zones pre-operation and post-operation.
Panel B of
OPN levels were also measured in AIS patients prior to being treated with brace (n=79) and after brace (N=28). Table 11 below also shows the effect of braces on biomarkers.
A distribution of AIS patients across the predefined cut-off zones was also performed prior to being treated with bracing and after bracing. Eight patients were tested a certain number of months after bracing, namely for each of patients #1 to 8: 7, 7, 8, 22, 22, 22 and 26 months after bracing, respectively.
Selenium concentration was reported to be significantly decreased in plasma of AIS patients (42). Selenium and more specifically Se-methylselenocystein, an organoselenium naturally occurring in diet, are used to prevent metastasis in breast cancer as chemopreventive therapy by targeting OPN transcription (43-45).
Plasma selenium concentration was thus measured in pediatric populations (AIS vs. healthy controls) to determine whether or not low selenium levels correlate with higher OPN concentrations in AIS. Plasma selenium concentrations were determined by a fluorometric method using 2,3-diaminonaphthalene (DAN) (46, 47). Results presented in
Although the present invention has been described hereinabove by way of specific embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims.
This application is a continuation of U.S. application Ser. No. 12/594,181, filed Sep. 30, 2009, which is a National Entry Application of PCT application no. PCT/CA2008/000595 filed on Mar. 31, 2008 and published in English under PCT Article 21(2), which itself claims the benefit of U.S. provisional application Ser. No. 60/909,408, filed on Mar. 30, 2007 and on U.S. provisional application Ser. No. 61/025,571, filed on Feb. 1, 2008. All of these applications are incorporated herein in their entirety by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60909408 | Mar 2007 | US | |
| 61025571 | Feb 2008 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12594181 | Sep 2009 | US |
| Child | 13775069 | US |
