The disclosure herein relates to oncology, cellular and developmental biology and drug discovery. In alternative embodiments, the disclosure herein provides a bone metastasis-derived prostate cancer xenograft model. In alternative embodiments, the disclosure provides methods for making a bone metastasis-derived prostate cancer xenograft model. In alternative embodiments, the disclosure provides compositions and methods for testing whether a drug, compound, diet, therapy or treatment is effective or efficacious for preventing, ameliorating, slowing the progress of, stopping or slowing the metastasis of, or for causing a full or partial remission of, a cancer, or a prostate cancer, or a human prostate cancer. In alternative embodiments, the disclosure provides compositions and methods whether a drug, compound, diet, therapy or treatment is effective or efficacious for modifying or effecting the structure or organization or vascularization of a tumor microenvironment; or effects the growth, survival, phenotype or histology (tissue or organ structure or microenvironments) of connective tissue, bone cells, osteoblasts, osteocytes, osteoclasts, bone marrow cells, fibroblasts or angiogenic cells.
Bone metastases are detected in 80 to 100% of men who die of prostate cancer; such metastases lead to painfully debilitating fractures, spinal compression and rapid decline. In addition, prostate cancer bone metastases often become resistant to standard therapies including androgen deprivation, radiation and chemotherapy. A major limitation in understanding prostate cancer bone metastatic disease is that primary human prostate cancer bone metastasis tissues are rarely available for direct analysis and there are few models to elucidate mechanisms of interaction between the bone microenvironment and prostate cancer.
Research on prostate cancer bone metastasis has been limited because there are currently few models to elucidate mechanisms of interaction between the bone microenvironment and prostate cancer or in which to test therapies. Currently, there are three prostate cancer bone metastasis-derived orthotopic bone xenograft models: PC3, LAPC9 and VCaP. Xenograft transplantation of these cell lines into bone demonstrated the range of bone lesions produced by prostate cancer bone metastases: PC3 formed purely osteolytic lesions in intra-tibial xenografts, VCaP produced mixed osteoblastic/osteolytic lesions, while LAPC9 formed purely osteoblastic lesions.
In alternative embodiments, the disclosure provides compositions and methods for making a bone metastasis-derived prostate cancer xenograft model, comprising:
and optionally unpassaged or uncultured cells, or the passaged or cultured cells, are cryopreserved, lyophilized, freeze-dried or otherwise stored before placement (insertion) into the non-human animal,
and optionally the cells or cells are initially derived from a biopsy; and
(c) placing, injecting or inserting the human prostate cancer cell or cells into the non-human animal;
wherein optionally the cell or cells are injected, placed or inserted by injection subcutaneously (SQ), intravenously (IV), or directly into bone, or intra-femorally (IF), and/or intradermally.
In alternative embodiments, the non-human animal is murine animal or a mouse lacking all or part of a functional immune system or humoral immune system, and wherein the animal can be reconstituted fully or partly with a human immune system, or human humoral immune system (the ability to make human or human-like antibodies in the mouse), wherein optionally the murine animal is a XENOMOUSE™ (Abgenix Inc., Amgen, Fremont, Calif.), or a HuMAb-Mouse™ system (Medarex, Bristol Myers Squibb, Princeton, N.J.).
In alternative embodiments, the mammalian or human prostate cancer cell or cells are an advanced luminal prostate cancer bone metastatic cancer cell or cells, or have a prostate cancer phenotype or genotype or a human prostate cancer phenotype or genotype comprising one or more or all of the following: PSA+, AR+, K5−, K14−, K8+, K18+, AMACR+, N10(3.1+, and TMPRSS2:ERG−.
In alternative embodiments, the mammalian or human cell or cells, or the biopsy, is or are derived from a mixed osteoblastic and/or an osteolytic lesion.
In alternative embodiments, the invention provides bone metastasis-derived prostate cancer xenograft non-human animal or animal models made by a protocol or method comprising or consisting of a method disclosed herein.
In alternative embodiments, the disclosure provides compositions (e.g., the bone metastasis-derived prostate cancer xenograft non-human animal or animal models disclosed herein) and methods for testing whether a drug, compound, diet, therapy or treatment is effective or efficacious for: preventing, ameliorating, slowing the progress of, stopping or slowing the metastasis of, or for causing a full or partial remission of, a cancer, or a prostate cancer, or a human prostate cancer; or, modifies or effects the structure or organization or vascularization of a tumor microenvironment; or effects the growth, survival, phenotype or histology (tissue or organ structure or microenvironments) of connective tissue, bone cells, osteoblasts, osteocytes, osteoclasts, bone marrow cells, fibroblasts or angiogenic cells, comprising:
administering or applying the drug, compound, diet, therapy or treatment to the bone metastasis-derived prostate cancer xenograft model disclosed herein, or a bone metastasis-derived prostate cancer xenograft non-human animal or animal model made by a method comprising or consisting of a method disclosed herein, and
after administering or applying the drug, compound, diet, therapy or treatment to the bone metastasis-derived prostate cancer xenograft model, determining or measuring the effect of the drug, compound, diet, therapy or treatment on the cancer cells, or the effect of the drug, compound, diet, therapy or treatment on cells or composition or structure or organization or vascularization of a tumor microenvironment, or on connective tissue, bone cells, osteoblasts, osteocytes, osteoclasts, bone marrow cells, fibroblasts or angiogenic cells,
wherein optionally it is measured and/or determined whether the drug, compound, diet, therapy or treatment is effective or efficacious for preventing, ameliorating, slowing the progress of, stopping or slowing the metastasis of, or for causing a full or partial remission of, a cancer, or a prostate cancer, or a human prostate cancer,
and optionally it is measured and/or determined whether the drug, compound, diet, therapy or treatment is effective or efficacious for preventing, ameliorating, slowing the progress of, stopping or slowing a bone lesion formation, or effects bone or effects osteolysis, osteoschlerosis, osteoporosis, or osteopetrosis caused by a cancer, a prostate cancer or a human prostate cancer or cells,
and optionally a drug, compound, diet, therapy or treatment known to be effective or efficacious is co-administered, or administered to the same or similar animal, as a positive control.
In alternative embodiments, disclosed herein are immunocompromised mouse models in which PCSD1 cells are transplanted subcutaneously (SQ), intravenously (IV), or directly into bone, or intra-femorally (IF), and/or intradermally and a cancer forms. In an aspect of this embodiment, the cancer expresses AR, NKX3.1, Keratins 8 and 18 and AMACR. In other aspects of this embodiment, the PCSD1 cells are transplanted intrafemorally and the cancer that forms is bone cancer. In alternative embodiments, the bone cancer has osteolytic and osteoblastic lesions. In alternative embodiments, the transplanted cells are from a prostate metastatic bone cancer that is both osteolytic and osteoblastic and expresses AR, NKX3.1, Keratins 8 and 18 and AMACR. In alternative embodiments, the immunocompromised mouse is NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ. In still other aspects of this embodiment, the mouse model is used as a screening method of therapeutic agents for prostate cancer that has metastasized to bone, which comprises administering a test substance to the PCSD-1 mouse model or mouse model derived from transplanted cells from a prostate metastatic bone cancer that is both osteolytic and osteoblastic and expresses AR, NKX3.1, Keratins 8 and 18 and AMACR.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure herein will be apparent from the description and drawings, and from the claims.
All publications, patents, patent applications cited herein are hereby expressly incorporated by reference for all purposes.
In alternative embodiments, the disclosure herein provides a patient-derived model of bone metastatic prostate cancer. In alternative embodiments, the disclosure herein provides an animal model, e.g., a murine model, as a xenograft model of human bone metastatic prostate cancer, and methods for making and using these animals or models.
In other embodiments, the disclosure provides a bone metastasis-derived prostate cancer xenograft model. In alternative embodiments, the disclosure provides methods for making a bone metastasis-derived prostate cancer xenograft model. In alternative embodiments, described herein are compositions and methods for testing whether a drug, compound, drug combination, diet, therapy or treatment is effective or efficacious for preventing, ameliorating, slowing the progress of, stopping or slowing the metastasis of, or for causing a full or partial remission of, a cancer, or a prostate cancer, or a human prostate cancer. In alternative embodiments, described herein are compositions and methods to determine if a drug, compound, drug combination, diet, therapy or treatment is effective or efficacious for modifying or effecting the structure or organization or vascularization of a tumor microenvironment; or effects the growth, survival, phenotype or histology (tissue or organ structure or microenvironments) of connective tissue, bone cells, osteoblasts, osteocytes, osteoclasts, bone marrow cells, fibroblasts or angiogenic cells.
In still other embodiments, the disclosure provides methods of making these animals or models by injecting a specimen (e.g., an isolated, cultured and/or harvested cell or cells from a patient, or a biopsy sample from a patient) of patient-derived prostate cancer bone metastasis into the femurs of immunodeficient mice, wherein serially transplantable tumors were formed in the bone niche.
In alternative embodiments, described herein are animals or models (designated as the so-called “PCDS1 model”, where PCDS1 represents Prostate Cancer San Diego 1, as discussed in Example 1, below), and/or methods used to develop, validate or optimize new or improved compounds, treatments, diets or therapies, or to develop, validate or optimize new or improved test compounds, treatments, diets or therapies for the ability to prevent, reverse, ameliorate and/or inhibit prostate cancer growth in a bone-niche.
In alternative embodiments, described herein are animals or models (designated as a “PCDS 1 model”), and/or methods used to characterize, analyze and/or dissect the complex interactions between prostate cancer and the bone.
In still other embodiments disclosed herein are animals or models (designated as a “PCDS1 model”), and/or methods used to understand mechanisms of failure of standard-of-care therapy, or proposed new therapies for prostate metastatic bone cancer.
In alternative embodiments, described herein are animals or models (designated as a “PCDS 1 model”), and/or methods used to gain an understanding of the unexpected, discordant effects that are being reported for some new prostate (or other) cancer therapies.
In alternative embodiments, the disclosure herein includes use of a novel, patient-derived xenograft (PDX) model of bone metastatic prostate cancer (so called “PCDS1 model”), that is unique and, in alternative embodiments, can expand on and improve currently used therapies and treatments, e.g., in the following ways:
As described in Example 1, below, PCSD1 xenografts tumors were characterized as advanced, luminal epithelial prostate cancer from a bone metastasis by RT-PCR and immunohistochemical biomarker analyses. MicroCT scanning showed that PCSD1 intra-femoral xenografts formed mixed osteoblastic/osteolytic lesions that closely resembled the bone lesions in the patient. Models disclosed herein are ready for use in pre-clinical drug testing as well as basic research, e.g., on castration-resistant prostate.
Bone metastasis models disclosed herein, including the so-called PCSD1 model, can be used to understand the complex mechanisms of interaction of prostate cancer with the bone microenvironment and the variation in response to therapies in different patients, types of bone lesions or stages of bone metastatic prostate cancer progression.
Current therapies such as bisphosphonates, radiation, anti-androgens, chemotherapy (docetaxel) often eventually fail in patients with castrate-resistant prostate cancer. In alternative embodiments, the so-called “PCSD1 model” disclosed herein is used not only to understand mechanisms of failure standard-of-care therapy but more importantly to develop new therapies alone or in combination with current therapies. In alternative embodiments, the so-called “PCSD1 model” can be used to gain an understanding of the unexpected, discordant effects of some new prostate cancer therapies that are being reported for bone metastatic prostate cancer. For example, in a Phase II Study of the new anti-androgen: abiraterone, it was found that approximately one third of patients with chemotherapy-naive metastatic castration-resistant prostate cancer displayed bone scan flare discordant with PSA serologic response. In other words, many patients with significantly lowered PSA levels after treatment with abiraterone still showed positive bone scans. Conversely, some patients treated with the new c-Met tyrosine kinase inhibitor cabozantinib (c-Met TKI, XL184) showed dramatic reductions in positive bone scans but, paradoxically, no decrease in their PSA levels. Accordingly, the bone metastasis models disclosed herein, including the so-called PCSD1 model, are effective for understanding the complex mechanisms of interaction of prostate cancer with the bone microenvironment and the variation in response to therapies in different patients, types of bone lesions or stages of bone metastatic prostate cancer progression. In alternative embodiments, the bone metastasis models disclosed herein, including the so-called PCSD1 model, comprise new primary prostate cancer bone metastasis-derived xenograft models to study metastatic diseases in the bone and to develop novel therapies for inhibiting prostate cancer growths in a bone-niche.
In other embodiments, the PCSD1 model when developed in sites other than bone, e.g., subcutaneously can be used to study and determine how tumors established at sites other than bone respond to different drugs and their characteristics as compared to the same tumor type in the bone environment.
The disclosure herein provides kits comprising compositions and/or instructions for practicing methods described herein. As such, kits, cells, vectors and the like can also be provided. In alternative embodiments, the disclosure herein provides kits comprising: a composition used to practice methods described herein, or a composition, a pharmaceutical composition or a formulation disclosed herein, and optionally comprising instructions for use thereof.
The embodiments disclosed herein will be further described with reference to the following examples; however, it is to be understood that the embodiments disclosed herein are not limited to such examples.
This example provides data demonstrating that the methods and compositions described are, in alternative embodiments, effective as a prostate cancer bone metastasis model and methods. The so-called PCSD1 model disclosed herein is a validated patient-derived xenograft tumor model ready for use in pre-clinical drug testing as well as basic research on prostate cancer and tumor growth in the bone microenvironment/niche, e.g., a murine castration-resistant prostate cancer and tumor growth model in the bone.
Described herein is a patient-derived prostate cancer bone metastasis specimen that when injected into the femurs of immunodeficient mice formed serially transplantable tumors in the bone niche, the so-called “PCSD1 model”. The tumors were characterized by RT-PCR and immunohistochemistry as: PSA+, AR+, K5−, K14−, K8+, K18+, AMACR+, NKX3.1+, TMPRSS2;ERG−, advanced, luminal epithelial prostate cancer. MicroCT scanning showed that PCSD1 induced mixed osteoblastic/osteolytic lesions that closely recapitulated bone metastatic prostate cancer lesions in patients.
Described herein is the development and characterization of PCSD1 (Prostate Cancer San Diego 1), a novel patient-derived intra-femoral xenograft model of prostate bone metastatic cancer that recapitulates mixed osteolytic and osteoblastic lesions.
A femoral bone metastasis of prostate cancer was removed during hemiarthroplasty and transplanted into Rag2−/−;γc−/− mice either intra-femorally or sub-cutaneously. Xenograft tumors that developed were analyzed for prostate cancer biomarker expression using RT-PCR and immunohistochemistry. Osteoblastic, osteolytic and mixed lesion formation was measured using micro-computed tomography (microCT).
PCSD1 cells isolated directly from the patient formed tumors in all mice that were transplanted intra-femorally or sub-cutaneously into Rag2−/−;γc−/− mice. Xenograft tumors expressed human prostate specific antigen (PSA) in RT-PCR and immunohistochemical analyses. PCSD1 tumors also expressed AR, NKX3.1, Keratins 8 and 18, and AMACR. Histologic and MicroCT analyses revealed that intra-femoral PCSD1 xenograft tumors formed mixed osteolytic and osteoblastic lesions. PCSD1 tumors have been serially passaged in mice as xenografts intra-femorally or sub-cutaneously as well as grown in culture.
PCSD1 xenografts tumors were characterized as advanced, luminal epithelial prostate cancer from a bone metastasis using RT-PCR and immunohistochemical biomarker analyses. PCSD1 intra-femoral xenografts formed mixed osteoblastic/osteolytic lesions that closely resembled the bone lesions in the patient. PCSD1 is a new primary prostate cancer bone metastasis-derived xenograft model to study metastatic disease in the bone and to develop novel therapies for inhibiting prostate cancer growth in the bone-niche.
Tumor xenograft preparation: A primary prostate cancer bone metastasis sample was obtained from a lytic lesion in the proximal femur from a patient with castrate-resistant prostate cancer with mixed osteoblastic and osteolytic bone metastases and a Gleason score of 9 (5+4). Tumor specimen was prepared aseptically in biohazard safety cabinet according to standard protocols with minor modifications [28, 43-47]. Specimen was first minced with sterile razor blades to 1-3 mm3 sized pieces. Some of the minced tumor was snap frozen for genomic DNA and RNA extraction, cryopreserved in 10% DMSO/90% FBS, or fixed for immunohistochemistry. For sub-cutaneous transplantation the minced tumor was mixed 1:1 with High Concentration Matrigel (BD: Matrigel-Catalog Number: 354248). For intra-femoral injection, the minced tumor sample was disaggregated by digestion filtered through sterile, mesh filter (Falcon). Dissociated cells were centrifuged at 1200 RPM, 5 minutes, 4° C., washed three times and resuspended in Iscove's modified DMEM media, 10% FBS at 6.7×106 cells/ml. Cells were mixed 1:1 with high concentration Matrigel for intra-femoral injection of 50,000 cells in 15 μl using UCSD animal welfare IACUC approved protocol. Remainder of the dissociated tumor cells were cryopreserved or used for DNA and RNA purification. All studies with human subjects were conducted with the approval of the University of California, San Diego School of Medicine Institutional Review Board. All patients provided written informed consent.
Sub-cutaneous injections were performed with UCSD animal welfare IACUC approval using standard protocols [26, 28, 33]. Briefly, male Rag2−/−;γc−/− mice 6-8 weeks old were anesthetized with ketamine/xylamine, skin sterilized with 70% ethanol, 2-3 mm incision with autoclaved dissection scissors, trochar (10 ml *LDEV-Free, 14-gauge catheter (SC injections) Terumo 14G IV Catheter), 100 μl of tumor/matrigel mix below skin right flank, skin flaps brought together and sealed with VetBond, mice revived post-surgery with Antisedan injected sub-cutaneously at base of neck ruff. For Intra-femoral injections mice were anesthesized by intra-peritoneal injection of a mix of 100 mg/kg ketamine and 10 mg/kg Xylazine and injections performed in a BL2 biosafety cabinet. Right hind limb was prepared under standard sterile conditions with 70% ethanol. Knee was held in flexed position and 25G needle (Monoject 200 25×5/8A) was used to make a port in the femoral plateau until there was no resistance that was used as a guide-hole for injection of 15 ul of the tumor cell/Matrigel suspension using a 0.3 ml syringe and 27G needle. Injection of sample was performed slowly with minimal resistance. Needle was withdrawn and leg immediately straightened, dabbed with antibiotic ointment (RX Neomycin, Polymyxin, Bacitracin Ophthalmic Ointment USP Sterile NDC 13985-017-55), on a sterile cotton tipped applicator (Q-Tips) and held for straight for approximately 1 minute. Mice were injected with Antisedan and placed on a warm Deltaphase Isothermal Pad, Ref 25-806 2 pc, Pur-Wraps, and carefully watched during recovery until ambulatory and active.
Prostate cancer cell lines: LAPC4, was a gift from Dr. Lily Wu, UCLA, and VCaP, purchased from ATCC, were maintained in Iscove's media, 10% FBS, penicillin-streptomycin and K562, a chronic myelogenous leukemia cell line in 10% heat-inactivated FBS, RPMI, Pen-strep.
Genomic DNA and RNA were extracted using mortar and pestle pulverization of flash frozen tumor pieces in liquid nitrogen and the Qiagen All-prep kit [47]. RNA was re-purified with RNeasy and treated with RNAse-free, DNase to remove contaminating genomic DNA. For cell lines and purified, dissociated xenograft tumor cells, RNA was extracted using Qiagen RNeasy mini-prep kit. cDNA synthesis was performed with Superscript III (Invitrogen, Inc.) according to manufacturer's protocol, and used for PCR (Taq polymerase, Monserate Biotechnology Group LLC, San Diego, Calif.). RT-PCR products were resolved on 1% agarose gels. All RT-PCR products of the correct size were verified by sequencing (Retrogen, Inc., San Diego, Calif.).
PSA immunostaining was carried out using rabbit anti-human PSA antibody (DAKO A0562) using standard protocols [55] performed by the Moores Cancer Center Histology Core, UCSD, La Jolla, Calif. Paraformaldehyde-fixed and paraffin embedded sections from sub-cutaneous PCSD1 xenografts were mounted and 6-μm sections were stained with H&E, anti-PSA, or rabbit IgG isotype control (DAKO N1699) using HRP goat anti-Rabbit as secondary antibody (Jackson 111-035-144) and AEC (Vector SK4200). For intra-femoral tumors, the tumor plus femur and tibia were dissected out as one, formalin-fixed and EDTA de-calcified according to Lavoie et al. [56]. Tissues were mounted in OCT, 6 μm cryosections were fixed in acetone, blocked in 1% BSA/PBS, incubated with anti-PSA or IgG isotype control antibody then processed as above.
Femurs of mice injected intra-femorally with PCSD1 were scanned by micro-computed tomography (μCT) SkyScan 1076 (Skyscan, Belgium) at the maximal potential 60 kV and 167 μA with 0.5 mm thick aluminum filter and at the voxel resolution of 9 μm. The μCT scans were performed over 360° of total rotation with each angular rotation step of 0.7°. The reconstructions, performed using the NRecon™ software package (Skyscan), are based on the Feldkamp algorithm and resulted in axial glayscale images. The 2D images were created using CTAn software package (Skyscan) [57]. The 3D μCT models of each femur were created using a 3D reconstruction software package (Mimics 14.0, Materialise, Belgium) [57, 58].
Patient derived-prostate cancer bone metastasis tumor specimen generated tumors in immunodeficient mice: Prostate tumor specimen was obtained from a castrate-resistant patient-derived femoral bone prostate metastasis and transplanted sub-cutaneously or intra-femorally into immunodeficient, male Rag2−/−;γc−/− mice [59]. Minced tumor sample that was injected sub-cutaneously (SQ) produced xenograft tumors in all ten male Rag2−/−;γc−/− mice. Disaggregated primary tumor cells that were injected intra-femorally (IF) generated tumors in all eight Rag2−/−;γc−/− mice. As shown in
To demonstrate whether the xenograft tumors originated from prostate cancer in the patient bone metastasis specimen, the expression of prostate specific antigen (PSA) was measured. As shown in
PSA protein expression was determined using immunohistochemical staining of PCSD1 xenograft tumor sections. Cytoplasmic PSA staining was detected in cells in sub-cutaneous PCSD1 xenografts (
Further molecular analysis to characterize PCSD1 tumors was performed using RT-PCR on additional human prostate biomarkers. Expression of keratins 5 (K5) and 14 (K14) are characteristic of basal prostate epithelial cells whereas keratins 8 (K8) and 18 (K18) are expressed in luminal prostate epithelial cells [44-46, 50]. PCSD1 xenograft tumors expressed human K8 and K18 and very low levels of K5 and K14 (
The TMPRSS2-ERG fusion gene is a frequent genomic rearrangement in prostate cancers that results in placing the ERG ETS-family transcription factor under the androgen-regulated expression of the TMPRSS2 gene [54]. RT-PCR was performed to determine whether this gene fusion event was present in PCSD1. While the fusion transcript was detected in VCaP cells as shown previously [54], the TMPRSS2-ERG gene fusion was not detected in PCSD1 (
Micro computed tomography small animal scanning (microCT) was performed on mice injected intra-femorally with PCSD1 to determine the effect of the growth of the tumors [31]. MicroCT scans from mice injected intra-femorally with the primary patient bone metastasis sample are shown in
Prostate cancer progression is marked by metastasis to bone, resistance to androgen deprivation therapy, radiotherapy and chemotherapy as well as the emergence of an apoptosis-resistant, tumor-initiating population for which there is no effective therapy [34, 60-66]. There is a pressing need for new models to investigate prostate cancer interaction with the bone microenvironment and to develop therapies but they have been difficult to establish due to poor take-rates of xenograft transplantation of primary prostate tumors [17-19]. Described herein is a bone metastasis-derived prostate cancer intra-femoral xenograft model (the “PCSD model”) for studying prostate metastatic bone disease. PCSD1 generated serially-transplantable sub-cutaneous and intra-femoral tumors when transplanted into immunodeficient Rag2−/−;γc−/− male mice. PCSD1 xenograft tumors were characterized as PSA+, AR+, K5−, K14−, K8+, K18+, AMACR+, NKX3.1+, and TMPRSS2:ERG− human prostate cancer. These biomarkers identified PCSD1 as an advanced luminal prostate cancer bone metastatic cancer [43-47, 51, 63, 64]. MicroCT analyses revealed PCSD1 formed mixed osteoblastic and osteolytic lesions in a murine femoral injection model which closely resembled the bone lesions in the patient [28, 31, 60].
In alternative embodiments, the PCSD1 xenograft model is used to understand the development of prostate cancer in the bone microenvironment, e.g., a castrate-resistant prostate cancer in the bone microenvironment. Tumor growth of PCSD1 xenografts in intact versus surgically castrated mice can be measured. In culture, PCSD1 cells demonstrated androgen-independence as they can survive and proliferate without the addition on androgens.
Current standard-of-care therapies such as bisphosphonates, radiation, anti-androgens, chemotherapy, such as docetaxel, often eventually fail in patients who develop castrate-resistant prostate cancer [1, 5, 15, 67-70]. The PCSD1 model will be used not only to elucidate mechanisms of failure of standard-of-care therapy but also to develop new therapies alone or in combination with current therapies.
The PCSD1 model will also be used to gain understanding of the unexpected, discordant effects of some new prostate cancer therapies that are being reported for bone metastatic prostate cancer. For example, in a Phase II Study of the new anti-androgen, Abiraterone, it was found that approximately one third patients with chemotherapy-naive metastatic castration-resistant prostate cancer displayed bone scan flare discordant with PSA serologic response [71]. In other words, many patients with significantly lowered PSA levels after treatment with abiraterone still showed positive bone scans [71]. Conversely, some patients treated with the new c-Met tyrosine kinase inhibitor, Cabozantinib (c-Met TKI, XL184), showed dramatic reductions in positive bone scans but, paradoxically, no decrease in their PSA levels [72]. New bone metastasis models such as PCSD1 are, therefore, essential to understand the complex mechanisms of interaction of prostate cancer with the bone microenvironment and the variation in response to therapies in different patients, types of bone lesions or stages of bone metastatic prostate cancer progression.
PCSD1 xenografts tumors were characterized as advanced, luminal epithelial prostate cancer from a bone metastasis using RT-PCR and immunohistochemical biomarker analyses. PCSD1 intra-femoral xenografts formed mixed osteoblastic/osteolytic lesions that closely resembled the bone lesions in the patient. PCSD1 is a new primary prostate cancer bone metastasis-derived xenograft model to study metastatic disease in the bone and to develop novel therapies for inhibiting prostate cancer growth in the bone-niche.
AR—androgen receptor, IHC—Immunohistochemistry, FACS—fluorescence activated cell scanning or sorting, IF—intra-femoral injection or transplantation, K562—Chronic myelogenous leukemia derived human cell line, LAPC4—Los Angeles Prostate Cancer cell line 4, LAPC9—Los Angeles Prostate Cancer cell line 9, Micro-CT—X-ray micro-computed tomography, P0—primagraft: primary patient sample injected, P1—first serial passage of tumor cells, that is, tumor cells harvested from P0 tumors are re-implanted into new mice and tumors allowed to develop, P2—second serial passage of xenograft tumors, PCSD1—Prostate Cancer San Diego 1 patient-derived xenograft or tumor cells, PSA—prostate specific antigen, Rag2−/−;γc−/−—immunodeficient mouse strain with homozygous targeted deletions of Recombinase activated gene-2 and Interleukin 2 receptor common gamma chain, RT-PCR—Reverse transcription and polymerase chain reaction, SC—sub-cutaneous injection or transplantation, VCaP—vertebral metastasis of cancer of the prostate cell line.
Tumor passage number: P0=primagraft: primary patient sample injected; P1=first serial passage of tumor cells, that is, tumor cells harvested from P0 tumors are re-implanted into new mice and tumors allowed to develop; P2=second serial passage of xenograft tumors; SC=sub-cutaneously transplanted tumors; IF=intra-femorally transplanted tumors.
A number of embodiments have been described herein. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the embodiments disclosed. Accordingly, other embodiments are within the scope of the following claims.
This application claims the benefit of priority to U.S. Provisional Application Ser. No. 61/546,996 entitled, “XENOGRAFT MODEL OF HUMAN BONE METASTATIC PROSTATE CANCER,” filed Oct. 13, 2011, which is incorporated by reference herein in its entirety, including all figures.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2012/060128 | 10/12/2012 | WO | 00 | 4/11/2014 |
Number | Date | Country | |
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61546996 | Oct 2011 | US |