The invention relates to a class of engineered polypeptides that are derived from the ADAM (A Disintegrin and Metalloproteinase) mammalian family of multirole proteases and methods of making same. The invention also relates to the use of these engineered polypeptides for anti-angiogenesis and anti-tumor growth activity. The invention also relates to administering the engineered polypeptides for endothelial cell dysfunction and for diagnosis of integrin-related conditions.
The invention is related to U.S. Publication no. 20060246541 by Minea et al., and titled “Method of expressing proteins with disulfide bridges” and to PCT Patent Application No. PCT/US09/64256, filed Nov. 12, 2009, and titled “Method of expressing proteins with disulfide bridges with enhanced yields and activity.” The contents of both are incorporated herein by reference thereto including all figures.
The ADAMs are class of multidomain mammalian transmembrane or secreted proteins that are involved in every step of embryonic development (where they control cell proliferation, cell migration, cell specification, axon elongation and organ morphogenesis) as well as in multiple physiological and pathological processes in the adult life (from wound healing to various inflammatory processes and from angiogenesis and metastasis to organ repair and regeneration) [1-5]. Numerous reports show that many proteolytic members of ADAM family appear to be overexpressed in human malignancies which indicates that these proteases may play important roles in tumor progression [6-15]. Interestingly, while the overexpression of catalytically active ADAMs appears to be generally linked to poor outcomes in cancers, the non-proteolytic ones seem to play a role as tumor inhibitors. For instance, the overexpression of ADAM22 in human gliomas has been shown to correlate with tumor growth inhibition [16].
The structure of ADAM proteins closely resembles that of their orthologues, the PIII-class snake venom metalloproteinases. Like the PIII-class of snake venom metalloproteinases (SVMPs), the ADAMs are multidomain proteins that possess metalloprotease, disintegrin and cysteine-rich domains [17, 28]. The ADAM scaffold contains several inter- and intra-domain cysteine residues, among which is a very important one located in the disintegrin domain at the tip of a structural element called the disintegrin loop. The inter-domain cysteine residues are located in the spacer regions between the metalloprotease and disintegrin domains and between the disintegrin and cysteine-rich domains [20]. These cysteine residues, which are found in ADAMs and PIII-SVMPs but generally not in snake venom disintegrins, form the disulfide bridges that link the inter-domain (spacer) regions with the metalloprotease, disintegrin and cysteine-rich domains in ADAMs and PIII-SVMPs [20]. These spacer-domain disulfide bridges in the ADAM scaffold represent the structural elements that lock the three domains together in a tightly folded structure allowing these multidomain proteins to better survive in the extracellular environment (i.e., more resistant to a proteolytic attack etc). This stabilized ADAM scaffold naturally evolved through disulfide bond engineering into a newer fold, the PII-class SVMPs, that gives rise to free disintegrins through a mechanism that involves a proteolytic attack. As a result of molecular evolution, several of the cysteine residues characteristic of the ADAM scaffold (i.e., the ones that participate in spacer-domain disulfide bridges) were either mutated to a different residue or deleted. The consequence of these mutations was that disulfide bridges could no longer form between the spacer region and both the metalloprotease and disintegrin domains in these newer proteins (the PIIclass SVMPs) which renders their inter-domain regions susceptible to proteolysis and makes possible the release of the individual domains as free domains of snake venom disintegrins [20]. Therefore, the PII snake venom disintegrins emerged as a class of free disintegrin domain polypeptides that have become the most potent natural platelet aggregation inhibitors through their high-affinity interaction with the platelet specific integrin alphaIIbbeta3. In contrast to the ADAM scaffold disintegrin domains, these later evolving PII class SVMPs are released as free polypeptides in the venom of hematotoxic snakes and possess a novel 11-amino acid disintegrin loop, the unique structural element characteristic to this class of molecules and naturally engineered to act as a potent soluble integrin ligand by mimicking the action of extracellular matrix protein motifs (ECM-mimetic) [19]. This loop freely protrudes from the disulfide stabilized polypeptide core and interacts with integrin receptors via a tripeptide motif (usually an Arg-Gly-Asp motif) that is displayed at the tip of the loop [21].
There are 24 members in the human integrin family of which 23 have a complex expression pattern, tissue distribution and physiological functions whereas the alphaIIbbeta3 integrin is a platelet specific receptor instrumental to blood clot formation. When deregulated in different tissues or organs, by being either abnormally expressed, or mislocalized at the plasma membrane or inappropriately activated or a combination of these mechanisms, the abnormal functioning of many of these receptors is linked to a diverse pathology ranging from neoplasia to inflammatory diseases and to complex physiological responses such as wound healing and tissue regeneration [22-25].
Snake venom disintegrins have therapeutic potential as anticancer agents when delivered in a liposomal formulation [21, 26, 27]. Aside from their natural biological activity (i.e., the inhibition of platelet aggregation through a high affinity interaction with integrin alphaIIbbeta3), it has been shown that snake venom disintegrins disrupt tumor-associated processes such as metastasis and angiogenesis by their ability to engage a defined set of integrins (e.g., alphavbeta3, alphavbeta5, and alpha5beta1) that are mechanistically involved in the pathogenesis of these processes [21]. Despite these favorable attributes, these polypeptides still possess potentially negative immunological characteristics due to their derivation from snake venom. Free disintegrins are not known to be present in humans or any other mammals—the only human disintegrins identified so far exist as subdomains buried within the larger sequence of the ADAM family protein members [17]. There are over 30 ADAM proteins indentified in the mammalian kingdom (of which humans possess 20 genes and 3 pseudogenes) and all of them possess disintegrin domains [1]. Of 23 ADAM transcripts identified in humans, 3 are from pseudogenes (ADAM 1, 3 and 6) which do not translate into functional proteins.
Provided herein compositions, and methods related thereto, of Modified ADAM-derived Polypeptides (MAPs), having an ADAM-derived Polypeptide (AP) that is modified at the following amino acid residues:
The MAP can be derived from an ADAM (A Disintegrin and Metalloproteinase) which includes ADAM15, ADAM28, ADAM1, ADAM2, ADAM3, ADAM6, ADAM7, ADAM8, ADAM9, ADAM10, ADAM 11, ADAM12, ADAM18, ADAM19, ADAM20, ADAM21, ADAM22, ADAM23, ADAM29, ADAM30, ADAM32, ADAM33. These corresponding MAPs can be MAP15, MAP28, MAP1, MAP2, MAP3, MAP6, MAP7, MAP8, MAP9, MAP10, MAP11, MAP12, MAP18, MAP19, MAP20, MAP21, MAP22, MAP23, MAP29, MAP30, MAP32, MAP33.
Also provided herein are fusion proteins of MAPs with an N-terminal segment of thioredoxin and nucleic acids that code these fusions.
The MAPs can have the properties of inhibiting the movement of HUVEC or MDA-MB-435 cells through a reconstituted basement membrane, increasing the level of phosphorylation of FAK in MDA-MB-435 cells or inhibiting tube formation of HUVECs in culture.
Also provided herein are expression vectors that express MAPs and prokaryotic host cells transformed with these expression vectors. The expression vector can be under inducible control, such as where the host also carries stable mutations in thioredoxin reductase B (trxB) gene and/or the glutathione reductase (gor) gene.
Also provided herein are methods of treating an individual suffering from cancer by administering an effective amount of at least one MAP. The cancer can be an integrin expressing cancer. The cancer can be breast cancer, colorectal cancer, basal cell carcinoma, adenocarcinoma, gastrointestinal cancer, colon cancer, liver cancer, bladder cancer, pancreatic cancer, ovarian cancer, cervical cancer, lung cancer, skin cancer, prostate cancer, renal cell carcinoma, central nervous system (CNS) cancer, and leukemia. The gastrointestinal cancer can be lip cancer, mouth cancer, esophageal cancer, small bowel cancer or stomach cancer. The skin cancer can be squamous cell or basal cell cancer.
Also provided herein are methods of inhibiting the binding of an integrin to a ligand by contacting a cell that expresses the integrin with an effective amount of a MAP or fusion thereof.
Also provided herein are methods of determining the presence of cancer cells in an individual by contacting the cancer cells with at least one MAP and detecting the at least one MAP. The MAP can be labeled and the label can be a Positron Emmission Tomography (PET) probe or a fluorescent probe.
Also provided herein are methods of preparing an artificial ECM scaffold by coating an artificial ECM scaffold with a MAP. The artificial ECM scaffold can further include stem cell precursors. The artificial ECM scaffold can be a urinary bladder scaffold, an esophageal scaffold or an anal scaffold.
Also provided are stents coated with a composition that includes at least one MAP.
Also provided are MAPs that are an AP having a distintegrin-like domain from an ADAM having (i) the Cys-Asp-Cys (CD) motif, (ii) the tripeptide motif as indicated in
Provided herein are a class of uniquely designed polypeptides, designated MAPs (Modified ADAM-derived Polypeptides), and encoding nucleic acids. As used herein, MAPs refer to a modified form of the native disintegrin domain of an ADAM protein. See Appendix for listing of ADAM encoding nucleic acid and amino acid sequences. As used herein, a “disintegrin domain of an ADAM protein” which may be referred to herein as “AP” (“ADAM derived Polypeptide”) is a disintegrin domain of the ADAM lacking all or substantially all of its metalloprotease and cysteine-rich domains and interdomain segments. Lacking substantially all means that the remaining amino acid sequence no longer retains the function of that domain. Examples of APs are shown in
A “MAP” is a “modified” form of an AP, the modifications involving an alteration(s) in the amino acid sequence of the AP to achieve the beneficial properties described herein. MAPs, therefore, have sequences which are modified relative to the sequence normally present in the AP and corresponding sequence of the ADAM polypeptide. As used herein, “modified” means that the amino acid is deleted, substituted or chemically modified and, in an embodiment, the modification results in disruption of interdomain disulfide linkage. Exemplary MAPs are shown in
MAPs can be expressed and further purified as stand alone biologically active molecules in a bacterial system that supports both the generation of active soluble disulfide-rich polypeptides and high expression yields for these products. While not wishing to be bound by theory, the MAPs were designed from the native APs so that they could adopt a snake venom disintegrin fold rather than their native ADAM conformations. The MAPs can be expressed with high yields in the Origami B (DE3) E. coli strain and further purified as stable and active free polypeptides that can interact with a class of mammalian cell surface receptors, the integrins, in a manner that is similar to that of native snake venom disintegrins. The MAPs can also retain some of the signaling properties that are characteristic of the APs or disintegrin domain activities from the ADAM polypeptide from which the MAP was derived. For instance, retained characteristics may include signaling attributes related to the putative ability of the ADAM disintegrin domains to engage integrin receptors by utilizing amino acid residues located outside the classical disintegrin loop. Cellular functions of ADAMs are well known [1-5, 34].
Although not wishing to be bound by theory, it is believed that the PII-class SVMPs that give rise to the prototypical medium-sized snake venom disintegrins (e.g., Trimestatin, Kistrin, Flavoridin etc) fail to form a critical disulfide bridge between the upstream spacer region and the disintegrin domain and thus the proteolytic attack happens in the residues located immediately N-terminal to where the disintegrin domain starts, the consequence of this being that the released medium-sized disintegrins are complete disintegrin domains containing no portion of the upstream spacer region. In contrast, it is believed that the PII-class SVMPs that give rise to the long-sized snake venom disintegrins (e.g., Bitistatin, Salmosin3 etc) fail to form a critical disulfide bridge between the metalloprotease domain and the downstream spacer region and consequently a proteolytic attack happens further N-terminal in the spacer region with the release of a longer disintegrin having a portion of the spacer region attached N-terminally to the freed disintegrin domain (see the sequence alignment of various disintegrin and disintegrin domains in
The 23 different ADAM transcripts that have been identified in the human genome (3 of them being pseudogenes that are not normally translated into a protein product) have been used as the basis for creating the encoded MAPs as described herein that adopt the snake venom disintegrin fold.
Several ADAM transcripts encode a number of isoforms. Nonetheless, inside the isoforms of different ADAMs the disintegrin domain's sequence is conserved and therefore there are only 23 different disintegrin domains in the human family of ADAM proteins. When produced recombinantly, the MAPs of the invention can interact in a high affinity manner with a defined integrin set. This property makes these mutant polypeptides broad spectrum integrin ligands for clinical and therapeutic use.
Similar to the other human ADAM member transcripts, the non-functional transcripts do contain complete disintegrin sequences that, if artificially translated in a recombinant system, can generate active polypeptides with novel biological functions. The disintegrin domains of human ADAMs have between 76 to 86 amino acids (the disintegrin domain of ADAM1 is the shortest, whereas that of ADAM10 is the longest), and, with 2 exceptions (ADAMs 1 and 17), they all contain 14 canonical cysteine residues of the ADAM scaffold (see the aligned sequences of human ADAMs below). See
The disintegrin domain of human ADAM15 contains a RGD tripeptide motif in its disintegrin loop which supports the hypothesis that human ADAM15 plays important regulatory roles in the cardiovascular system. This RGD tripeptide motif in ADAM 15 is shown in AP15 in
MAPs for each AP portion of all 23 known human ADAM members were generated. The human ADAM disintegrin domain sequences were modified according to the rationale presented above, which includes removing the residues (among which include 2 cysteine residues) in the ADAM disintegrin domain that normally participate in interdomain-disintegrin domain disulfide bridge formation in the native ADAM proteins. Not wishing to be bound by theory, the apparent function of these disulfide bridges is to keep the disintegrin loops in ADAMs tightly packed and unavailable to integrin receptors. By modifying the residues that participate in the formation of these disulfide bridges, such as by deletion, these MAPs acquire the mobility of the canonical 11-amino acid loop and the disintegrin-fold characteristic of snake venom disintegrins. Among the 23 members of the human ADAMs, 6 members perfectly fit the above-mentioned scheme (ADAMs 7, 8, 12, 19, 28 and 33) when aligned with long- and medium-sized snake venom disintegrins as well as with PIII-class SVMPs (see
As used herein, “interdomain regions” or “spacer regions” means the polypeptide portion of an ADAM between the metalloprotease and disintegrin domain (the “MD interdomain region”) and between the disintegrin domain and the cysteine-rich domain (the “DC interdomain region”), respectively, wherein the MD interdomain region starts at least 10 amino acid residues N-terminal to the AP and the DC interdomain region starts at least 10 amino acid residues C-terminal to the AP. Each interdomain is 5 to 15 amino acids in length.
The DNA sequences of all 23 MAPs were de novo synthesized and cloned into the pET32a expression vector [30] downstream of bacterial thioredoxin A (TrxA). The MAPs were produced in the Origami B (DE3) bacterial strain as described in PCT Patent Application No. PCT/US09/64256, filed Nov. 12, 2009, and titled “Method of expressing proteins with disulfide bridges with enhanced yields and activity.” This application describes an improvement upon the expression system disclosed in U.S. Publication no. 20060246541, which includes, as an embodiment, expression of a chimeric snake venom disintegrin Vicrostatin (VCN) in the Origami B (DE3)/pET32a system. The improved method was used to generate increased amounts of correctly-folded active MAPs. This is achieved by growing the Origami B cells in a less selective environment and thus allowing for the generation and expansion of VCN-transformants that display a more optimal redox environment during the induction of the heterologous recombinant protein production. Unlike other E. coli strains, the Origami B is unique in that, by carrying mutations in two key genes, thioredoxin reductase (trxB) and glutathione reductase (gor), that are critically involved in the control of the two major oxido-reductive pathways in E. coli, this bacterium's cytoplasmic microenvironment is artificially shifted to a more oxidative redox state, which is the catalyst state for disulfide bridge formation in proteins [18, 29].
The Origami B strain has growth rates and biomass yields similar to those obtained with wild-type E. coli strains, which makes it an attractive and scalable production alternative for difficult-to-express recombinant proteins like VCN. This strain is also derived from a lacZY mutant of BL21. The lacY1 deletion mutants of BL21 (the original Tuner strains) enable adjustable levels of protein expression by all cells in culture. The lac permease (lacY1) mutation allows uniform entry of IPTG (a lactose derivative) into all cells in the population, which produces a controlled, more homogenous induction. By adjusting the concentration of IPTG, the expression of target proteins can be optimized and theoretically maximal levels could be achieved at significantly lower levels of IPTG. Thus the Origami B combines the desirable characteristics of BL21 (deficient in ompT and lon proteases), Tuner (lacZY mutant) and Origami (trxB/gor mutant) hosts in one strain. As mentioned above, the mutations in both the thioredoxin reductase (trxB) and glutathione reductase (gor) greatly promote disulfide bond formation in the cytoplasm [29].
Although the Origami B strain offers a clear advantage over E. coli strains with reducing cytoplasmic environments like BL21 (
Furthermore, after purifying expressed disintegrin domains (APs) of ADAM 9 and 15, in a process that involves TEV protease treatment and RP-HPLC purification, the collected free polypeptides appeared to be unstable and to precipitate out of solution after reconstitution from lyophilized powder. In contrast, the corresponding MAP polypeptides, generated by employing the same purification steps, appear to be more soluble and stable when reconstituted in water after lyophilization.
MAPs of the invention are prepared so as to be substantially isolated or substantially purified. As used herein, the term “substantially purified” (or isolated) in reference to a MAP does not require absolute purity. Instead, it represents an indication that the MAP is preferably greater than 50% pure, more preferably at least 75% pure, and most preferably at least 95% pure, at least 99% pure and most preferably 100% pure. MAPs can be prepared synthetically or prepared by recombinant expression as described herein.
The term “substantially” as used herein means plus or minus 10% unless otherwise indicated.
Pharmaceutical compositions containing MAPs should comprise at a minimum an amount of the MAP effective to achieve the desired effect (e g inhibit cancer growth or prevent or inhibit cancer metastasis) and include a buffer, salt, and/or suitable carrier or excipient. Generally, in these compositions, MAPs are present in an amount sufficient to provide about 0.01 mg/kg to about 50 mg/kg per day, preferably about 0.1 mg/kg to about 5.0 mg/kg per day, and most preferably about 0.1 mg/kg to about 0.5 mg/kg per day.
MAPs may be administered by a variety of heretofore known means suitable for delivery thereof into the body of a subject (e.g. the blood stream) in substantial amounts. Intravenous administration of MAPs in a suitable liquid vehicle or excipient is presently contemplated as the preferred route of administration. MAPs are soluble in water, and may therefore be effectively administered in a suitable aqueous solution (e.g., phosphate buffered saline). Alternatively, MAPs may be administered orally (in the form of tablets or capsules formulated with a suitable binder or excipient material, or in the form of aqueous or oily suspensions, solutions, emulsions, syrups or elixirs) or as a parenteral suspension. MAPs can also be delivered intraarterially or intraductally, or may be introduced locally at the intended site of action. As is well known in the art, adjuvants or excipients such as local anesthetics, preservatives, buffering agents, lubricants, wetting agents, colorants, flavorings, fillers and diluents may suitably be included in any of these formulations.
MAPs may be delivered by way of liposomes. Liposomal delivery is well known in the art and has been described for delivery of disintegrins. For example, Swenson et al. describes use of intravenous delivery of contortrostatin in liposomes for therapy of breast cancer [26].
MAPs, such as MAP9, display pro-angiogenic effects (see below). Not wishing to be bound by theory, this could represent a more general characteristic of the members of the meltrin class of ADAM family (ADAMs 9, 12, and 19). The meltrins are mesenchymal ADAMs that were originally described to be expressed in the course of differentiation induction of muscle cells where they are involved in cell fusion and other processes and may play an important role in the stabilization of neovessels [33]. Consequently, recombinant polypeptides derived from the meltrin class of ADAM proteins can be used therapeutically to stimulate the formation of new capillary networks and maintain the collateral capillary growth in diseases such as coronary artery disease (CAD) or other ischemic conditions. Therefore, for example, MAPs may be coated on or chemically coupled to stents for use in therapy of CAD and related diseases that utilize stents.
MAPs can also be directly or indirectly conjugated to drugs, toxins, radionuclides and the like, and these conjugates used for diagnostic or therapeutic applications. For instance, a MAP can be used to identify or treat tissues or organs that express a cognate integrin. MAPs or bioactive fragments or portions thereof, can be coupled to detectable or cytotoxic molecules and delivered to a mammal having cells, tissues or organs that express the cognate integrin or integrins.
Suitable detectable molecules may be directly or indirectly attached to a MAP, and include radionuclides, enzymes, substrates, cofactors, inhibitors, fluorescent markers, chemiluminescent markers, magnetic particles and the like. Suitable cytotoxic molecules may be directly or indirectly attached to the polypeptide or antibody, and include bacterial or plant toxins (for instance, diphtheria toxin, Pseudomonas exotoxin, ricin, abrin and the like), as well as therapeutic radionuclides, such as iodine-131, rhenium-188 or yttrium-90 (either directly attached to the polypeptide or antibody, or indirectly attached through means of a chelating moiety, for instance). MAPs may also be conjugated to cytotoxic drugs, such as adriamycin. For indirect attachment of a detectable or cytotoxic molecule, the detectable or cytotoxic molecule can be conjugated with a member of a complementary/anticomplementary pair, where the other member is bound to the polypeptide or antibody portion, such as biotin/streptavidin.
The disclosed compositions can be used either singly or in combination for the treatment of diseases related to endothelial cell dysfunction. In an embodiment, the disclosed compositions are useful for cancer treatment. The cancer can be of epithelial origin. The cancer can be breast cancer, colorectal cancer, basal cell carcinoma, adenocarcinoma, gastrointestinal cancer, such as, for example, lip cancer, mouth cancer, esophageal cancer, small bowel cancer and stomach cancer, colon cancer, liver cancer, bladder cancer, pancreatic cancer, ovarian cancer, cervical cancer, lung cancer, and skin cancer, such as squamous cell and basal cell cancers, prostate cancer, renal cell carcinoma, central nervous system (CNS) cancer, leukemia and other known cancers that effect epithelial cells throughout the body. Not wishing to be bound by theory, in many forms of cancer a pathogenic cross-talk exists between ADAMs (membrane-tethered and/or secreted forms) and their integrin counter-receptors, a process that is mechanistically important for cancer progression. These pathological interactions serve in cancer for the recruitment of ADAM metalloproteinases via integrins into multiprotein complexes (i.e., invadosomes) that are assembled by highly migratory cells (cancer, inflammatory or endothelial cells) in the process of executing some critical integrin-driven steps in tumor progression: the infiltration of tumor stroma by inflammatory cells where they are shown to play important supportive roles, the migratory steps associated with tumor angiogenesis where endothelial cells from preexisting vessels are recruited to assemble neovessels, and, finally, the migratory and invasive events associated with metastasis. The disruption of these pathological processes by MAPs reduce malignancies. In addition to their potential antiangiogenic, antiinflammatory and antimetastatic effects, the broad spectrum anti-integrin MAPs can also impact tumor differentiation. The ability to send the right differentiation signals to cancer stem cells, by forcing them to acquire a more stable and differentiated phenotype during the course of therapy, remains one of the main goals of cancer therapy. For instance, Yuan et al. showed that a cell population with stem characteristics that was isolated from human glioblastoma multiforme (a highly-aggressive form of brain cancer) could be manipulated to differentiate in vitro and adopt more benign features [32]. Differentiation signals coming from soluble integrin ligands (e.g., either single or combinations of MAPs), cancer stem cells from various human malignancies may be induced to fully commit along their differentiation lineages and stay differentiated.
Composition of the invention can also be used for screening a candidate compounds for MAP-specific binding by comparing the relative binding of said candidate compound to an integrin in the presence and in the absence of a MAP, wherein a decrease of integrin binding in the presence of said MAP indicates that said MAP-specific integrin binding molecule is MAP-specific.
Compositions of the invention can be used for early detection of cancer by taking advantage of specific “integrin signatures” displayed by cancer cells. An “integrin signature” or “integrin profile” is the one or more integrins expressed on the surface of a cell. For example, carcinomas and sarcomas can display specific ‘integrin signatures’ based on a tumors' state of differentiation and organ localization. MAP-specific binding can be employed to identify and diagnose various cancer types based on integrin signatures either as in vivo cancer imaging agents (diagnostic imaging) and/or ex vivo molecular tools for tumor specimen staining (diagnostic pathology). In the latter case, staining cancer specimens with different MAPs can lead to characteristic staining patterns depending on various tumors' origin and grading. Compositions of the invention can be used for cancer staging, monitoring cancer cancer progression or therapy. The cancer can be of epithelial origin. The cancer can be breast cancer, colorectal cancer, basal cell carcinoma, adenocarcinoma, gastrointestinal cancer, such as, for example, lip cancer, mouth cancer, esophageal cancer, small bowel cancer and stomach cancer, colon cancer, liver cancer, bladder cancer, pancreatic cancer, ovarian cancer, cervical cancer, lung cancer, and skin cancer, such as squamous cell and basal cell cancers, prostate cancer, renal cell carcinoma, and other known cancers that effect epithelial cells throughout the body. MAPs can be used with PET (Positron Emission Tomography) probes to take advantage of the unique ability of MAPs with known integrin affinities to differentially bind to primary tumors, metastatic foci, as well as the tumor neovasculature based on the specific integrin expression of each particular solid tumor. For example, MAPs can be labeled with 18F through the amino group using N-succinimidyl-4-18F-fluorobenzoate (18F-SFB) under optimized fluorination reaction conditions or by conjugation with the metal chelator DOTA/NOTA for 64Cu/68Ga-labeling. Furthermore, fluorescently-labeled MAPs may be used in vivo and ex vivo (on biopsy specimens) for tumor integrin expression profile analysis.
Compositions of the invention may be also utilized as molecular tools in regenerative medicine. For example, by coating artificial ECM scaffolds (organ molds) with a MAP or combinations of MAPs, stem cell precursors can be induced into populating these scaffolds and differentiate into desirable epithelial and mesenchymal layers. For example, a urinary bladder scaffold coated with such a composition containing one or more MAPs can be used to direct stem cell progenitors to commit into both urothelium and muscular layers. Other examples include esophageal and rectal scaffolds coated with such a composition containing one or more MAPs can be used to direct stem cell progenitors to commit into the relevant tissue layers. Compositions of the invention can also be used to create defined tissue culture plate coatings that could either support the growth and maintain the stemness of embryonic stem cells in vitro or guide the commitment of these totipotent cells along their differentiation lineages in the same system.
Compositions of the invention may be used as novel drugs for supporting the collateral growth of capillaries in various ischemic conditions, such as drug-eluting stents. For example, MAPs can be conjugated with a radionuclide, such as with a beta-emitting radionuclide, to reduce restenosis. Such therapeutic approach poses less danger to clinicians who administer the radioactive therapy.
Bacterial cells and reagents. The Origami B (DE3) E. coli strain and pET32a expression vector carrying the bacterial thioredoxin A gene (trxA) were purchased from Novagen (San Diego, Calif.). All 23 MAP DNA sequences were de novo synthesized and inserted into a plasmid by Epoch Biolabs, Inc. (Sugar Land, Tex.). The AP DNA sequences were PCR amplified from cDNA libraries built from several mammalian cell lines including HUVEC (PromoCell GmbH, Heidelberg, Germany), MDA-MB-435 (ATCC, Manassas, Va.), MDA-MB-231 (ATCC, Manassas, Va.), and Jurkat (ATCC, Manassas, Va.). The oligonucleotide primers used for further cloning the APs and MAPs DNA sequences into pET32a expression vector were synthesized by Operon Biotechnologies, Inc. (Huntsville, Ala.). All restriction enzymes and ligases used for cloning the APs and MAPs DNA sequences into pET32a expression vector were purchased from New England Biolabs, Inc. (Ipswich, Mass.). The recombinant TEV protease was purchased from Invitrogen (Carlsbad, Calif.).
Construction of MAP expression vectors and recombinant production. The synthetic MAPs DNA sequences that were cloned into pET32a expression vector downstream of TrxA are listed in
The APs were cloned into pET32a, transformed into Origami B, and expressed using the same procedures described above for MAPs.
Purification of recombinant MAPs. The MAPs were purified from filtrated lysates by employing a high-performance liquid chromatography (HPLC) procedure according to a protocol previously established for snake venom disintegrins [2]. Purification was performed by C18-reverse phase HPLC using the standard elution conditions previously employed for the purification of native CN [2]. Individual filtrated lysates processed as described above were loaded onto a Vydac C18 column (218TP54, Temecula, Calif.). A ten-minute rinse (at 5 ml/min) of the column with an aqueous solution containing 0.1% TFA was followed by a linear gradient (0-100%) elution over 150 min in a mobile phase containing 80% acetonitrile and 0.1% TFA. The MAPs start eluting in 35-40% acetonitrile.
Expression analysis of MAPs. E. coli transformants were grown overnight at 37° C. in shaker flasks were induced in 1 mM IPTG for 5 hours at 37° C. and 250 rpm. At the end of the induction period, the cells were pelleted at 4,000×g, lysed by multiple freeze-thaw cycles, and further centrifuged at 40,000×g to remove the insoluble cell debris. 5 μl of soluble cell lysates from various E. coli hosts were loaded under reducing conditions on a precast 4-20% NuSep iGel (NuSep Inc., Lawrenceville, Ga.) and then Coomassie stained.
The resultant expression yield of AP9 and AP15 was lower than that compared to their corresponding MAPs (MAP9 and MAP15) (
The Trx-MAPs produced in Origami B (DE3) using the method described above were analyzed by flow cytometry for differential binding to multiple cell lines (
MAPs were then tested for angiogenic activity using the in vitro HUVEC tube formation assay. HUVEC cells were plated on ‘Endothelial Cell Tube Formation’ plates (BD Biosciences) in the presence of 10 nM of either MAP9 or MAP15. A known tube formation inhibitor (Suramin) was used as a negative control. See
To assess the antiangiogenic effect of LMAP15, administered either alone or in combination, tumors from each group in the MDA-MB-231 study were dissected and extracted from dead or sacrificed animals and subsequently analyzed for microvessel density by immunohistochemistry. The extracted tumors were embedded in Tissue-Tek O.C.T (‘Optimal Cutting Temperature’ compound, Sakura Finetek USA) then frozen in dry ice, cut into 5 micron sections, fixed in acetone and stored at 4° C. until stained. For CD31 staining, the acetone-fixed slides were washed in PBS and blocked in PBS containing 5% goat serum then incubated overnight at room temperature with 200 μl of a rat polyclonal anti-CD31 antibody (BD Biosciences, San Diego, Calif.) diluted 1:50 in PBS and applied to the slides according to the manufacturer's protocol. This was followed by multiple washings in PBS (7 minutes/wash) and addition of 200 μl of a biotinylated secondary goat anti-rat antibody diluted 1:100 and applied for 45 minutes at room temperature. After 3 more washings in PBS, 200 μl of Avidin Binding Complex (Vector Laboratories, Burlingame, Calif.) diluted 1 drop in 2 ml PBS was applied to each slide for 30 minutes at room temperature after which the 3-amino-9-ethylcarbazole chromogen was added to visualize the antibody-stained microvessels. After three more washings in PBS, the slides were counterstained with Myers Hematoxylin and then mounted. To quantitate the CD31-stained microvessels, the slides were subjected to ‘random field’ analysis [35, 36]. Images were captured blindly from random fields on each slide at 200× using an Olympus E20N digital camera (Olympus America, Melville, N.Y.) attached to a microscope. For each group, 4 tumors were stained and 40 random fields analyzed. The CD31-positive areas were computed for each random field as % of total stained area using the ‘SimplePCI’ advanced imaging software (C-Imaging Systems, Cranberry Township, Pa.) and then averaged for each group. To eliminate bias, the random field image capture and the subsequent processing and analysis of the captured images were carried out in a blind fashion. LMAP15 was shown to significantly reduce microvessel density in this xenograft model (
To evaluate the MAPs therapeutic efficacy as anti-invasive/anti-metastatic agents the optical luciferase imaging approach (in vivo bioluminescence) is employed in several animal models of spontaneous metastatic breast cancer. The following cell lines are stably infected with an adenoviral transduction system: a human breast cancer cell line (the MDA-MB-231, a triple-negative cell line), and two murine breast cancer lines (the 4T1, a HER2-negative line, and the D2F2, a HER2-positive line) with both luciferase and green fluorescence protein (GFP) reporter genes. In the human xenograft MDA-MB-231 model, an inoculum of 2×106 cells suspended in complete Matrigel is injected in the mammary fat pads of nude mice and allowed to grow until the formed tumors are palpable (approx. 2 weeks after implantation). The following treatment groups (5 animals per group) are formed: group 1 control (animals receiving no treatments or manipulations), group 2 control (animals receiving empty liposomes intravenously), group 3 control (animals receiving PBS intravenously), group 1 treated (animals receiving Avastin intravenously), group 2 treated (animals receiving Docetaxel intraperitoneally), group 3 treated (animals receiving a combination of Avastin intravenously and Docetaxel intraperitoneally), group 4 treated (animals receiving MAP15 intravenously), group 5 treated (animals receiving a liposomal formulation of MAP15 intravenously), group 6 treated (animals receiving a combination of MAP15 intravenously, Avastin intravenously and Docetaxel intraperitoneally), and group 7 treated (animals receiving a combination of a liposomal formulation of MAP15 intravenously, Avastin intravenously and Docetaxel intraperitoneally). The treatments are administered as follows: Avastin and Docetaxel are administered weekly using the maximum dosages previously reported in the literature as efficacious against primary tumors and metastatic foci in this model, MAP15 is administered at the dose of 100 μg polypeptide/injection every other day, and liposomal MAP15 is administered at the dose equivalent of 100 μg polypeptide/injection twice weekly.
Similar to the MDA-MB-231 model, the MAP15 efficacy as an anti-invasive/anti-metastatic agent is also determined in two murine breast cancer models (the 4T1 and the D2F2 models). In these models an inoculum of 5×105 cells (either 4T1 or D2F2) in PBS is injected in the mammary fat pads of immunocompetent BALB/c mice and allowed to grow tumors that become palpable (approx. 1 to 1.5 weeks after implantation). Once tumors become palpable, the following treatment groups (5 animals per group) are started: group 1 control (animals receiving no treatments or manipulations), group 2 control (animals receiving empty liposomes intravenously), group 3 control (animals receiving PBS intravenously), group 1 treated (animals receiving Avastin intravenously), group 2 treated (animals receiving Lapatinib intravenously), group 3 treated (animals receiving Herceptin intravenously), group 4 treated (animals receiving a combination of Avastin, Lapatinib and Herceptin intravenously), group 5 treated (animals receiving MAP15 intravenously), group 6 treated (animals receiving a liposomal formulation of MAP15 intravenously), group 7 treated (animals receiving a combination of MAP15, Avastin, Lapatinib, and Herceptin intravenously), and group 8 treated (animals receiving a combination of a liposomal formulation of MAP15, Avastin, Lapatinib, and Herceptin intravenously). The treatments are administered as following: Avastin, Lapatinib and Herceptin are administered weekly using the maximum dosages previously reported in the literature as efficacious against primary tumors and metastatic foci in these models, MAP15 is administered at the dose of 100 μg polypeptide/injection every other day, and liposomal MAP15 is administered at the dose equivalent of 100 μg polypeptide/injection twice weekly.
The tumor growth before and after initiating the treatments in mammary fat pads and at distant sites is monitored in all models by weekly Xenogen bioluminescence imaging. Primary tumor size is also measured by caliper and volumes calculated on the basis of the formula: 1×w2×0.5. For the weekly bioluminescence (luciferase) imaging, mice are injected via an intraperitoneal route with a Luciferin solution (15 mg/mL or 30 mg/kg, in PBS, dose of 5-50 mg/kg) which is allowed to distribute in non-anesthetized animals for about 5-15 minutes. The mice are then placed into a clear Plexiglas anesthesia box (2-4% isofluorane) which allows unimpeded visual inspection of the animals and monitoring of their breathing status. In this setting, the anesthesia delivery tube that supplies the anesthesia to the box is split so that the same concentration of anesthesia is delivered to the anesthesia manifold located inside the imaging chamber on the Xenogen IVIS 100 imaging instrument. After the mice are fully anesthetized, they are transferred from the anesthesia box to the anesthesia nose cones attached to the manifold in the imaging chamber, the door is closed, and images are acquired using Xenogen instrument. The imaging time is between one to five minutes per side (dorsal/ventral), depending on the experiment. When the animals are turned from dorsal to ventral (or vice versa) they are monitored for any signs of distress or changes in vitality. The acquired images are evaluated by comparing the level luciferase activity at the site of the control and treated tumors, and by comparing the distribution area under the curve associated with the luminescence from tumors in each treatment group. By employing the above approach the efficacy of MAP15 against primary tumors and bioluminescent metastatic foci is determined. Animal weights are also measured twice weekly and animals are observed visually for any signs of stress response or malaise. Animals that showed severe signs of impairment are excluded from the experiment.
At the conclusion of these studies (after 8 weeks of treatment in the MDA-MB-231 model, and after 3 weeks of treatment in the 4T1 and D2F2 models) a determination of whether MAP15 alone is as efficacious as or better than any of the monotherapies tested (either Avastin or Docetaxel or Lapatinib or Herceptin) at inhibiting primary tumor growth is made, reducing the number and size or both of metastatic foci, and prolonging animal survival in these tumor models. In addition, when administered in combination with either Avastin plus Docetaxel in the MDA-MB-231 model or in combination with Avastin plus Lapatinib in the 4T1 model or in combination with Avastin plus Lapatinib plus Herceptin in the D2F2 model, MAP15 proved to be more efficacious than any monotherapy or other combinations at inhibiting primary tumor growth, reducing the number and size or both of metastatic foci, and prolonging survival in these tumor models.
Nucleic acid sequences corresponding to ADAM RNA transcripts are provided in
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
The inventions illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising,” “including,” “containing,” etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.
Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification, improvement and variation of the inventions embodied therein herein disclosed may be resorted to by those skilled in the art, and that such modifications, improvements and variations are considered to be within the scope of this invention. The materials, methods, and examples provided here are representative of preferred embodiments, are exemplary, and are not intended as limitations on the scope of the invention.
The invention has been described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention. This includes the generic description of the invention with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein.
All publications, patent applications, patents, and other references mentioned herein are expressly incorporated by reference in their entirety, including all formulas and figures, to the same extent as if each were incorporated by reference individually. In case of conflict, the present specification, including definitions, will control.
Other embodiments are set forth within the following claims.
This application claims the benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/303,631, filed Feb. 11, 2010, which is incorporated by reference herein in its entirety including all figures and tables.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US11/24243 | 2/9/2011 | WO | 00 | 10/29/2012 |
Number | Date | Country | |
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61303631 | Feb 2010 | US |