A novel patient-derived intra-femoral xenograft model of bone metastatic prostate cancer that recapitulates mixed osteolytic and osteoblastic lesions

<p>Abstract</p> <p/> <p>Prostate cancer metastasizes to bone in the majority of patients with advanced disease leading 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. There are currently few models to elucidate mechanisms of interaction between the bone microenvironment and prostate cancer. It is, thus, essential to develop new patient-derived, orthotopic models. Here we report 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.</p> <p>Methods</p> <p>A femoral bone metastasis of prostate cancer was removed during hemiarthroplasty and transplanted into <it>Rag2^-/-;γ_c^-/-</it>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).</p> <p>Results</p> <p>PCSD1 cells isolated directly from the patient formed tumors in all mice that were transplanted intra-femorally or sub-cutaneously into <it>Rag2^-/-;γ_c^-/-</it>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.</p> <p>Conclusions</p> <p>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.</p

The role of E-selectin and P-selectin in T lymphocyte migration to inflammation using a novel quantitative mouse model

grantor: University of TorontoThe roles of E-selectin and P-selectin in T lymphocyte migration to cutaneous inflammatory reactions were investigated. Within 22 hours after i.v. injection, \sp{51}Cr-labelled splenic T lymphocytes migrated to cutaneous inflammatory reactions induced by IFN-$\gamma$ and TNF-$\alpha$ and even in greater numbers to inflammatory reaction induced by Con A or a combination of IFN-$\gamma$ and TNF-$\alpha.$ In anti-E-selectin mAb treated and in E-selectin deficient mice IFN-$\gamma,$ Con A and IFN-$\gamma$ plus TNF-$\alpha$ induced T cell accumulation was inhibited by approximately 55%, but not TNF-$\alpha$ induced T cell accumulation. In anti-P-selectin treated and in P-selectin deficient mice T cell accumulation in most of the lesions was unaffected. Combined, anti-E-selectin and anti-P-selectin inhibited T cell accumulation in all four types of lesions. Furthermore, T cell migration to Con A was inhibited by 80%, significantly more than by anti-E-selectin alone. Results from E-selectin and P-selectin deficient mice confirmed these observations.M.Sc

Osteosarcoma: a comprehensive review.

Osteosarcoma (OS) is a relatively rare tumor of bone with a worldwide incidence of 3.4 cases per million people per year. For most of the twentieth century, five-year survival rates for classic OS were very low. In the 1970s, the introduction of adjuvant chemotherapy in the treatment of OS increased survival rates dramatically. The current article reviews the various types of OS and analyzes the clinical and histological features. We also examine historical and current literature to present a succinct review of methods for diagnosis and staging, as well as treatment, and we also discuss some of the future directions of treatment

Management of soft tissue tumors of the upper extremity: a review

Introduction: Management of malignant tumors of the hand and wrist is challenging and is generally approached by limb salvage or amputation. With advances in care, amputation has been superseded by limb salvage as the treatment of choice. Methods: A narrative literature review was performed to identify articles on the topic of management of soft tissue tumors of the upper extremity, including surgical management, adjuvant radiation therapy, and chemotherapy. Results: A total of 29 articles were selected. Earlier reports favored radical tumor resection, which often led to amputation, whereas later articles demonstrated limb salvage as the preferential treatment modality. Conclusions: Given the detrimental effects on function and psychologic outcomes, amputation has been superseded by limb salvage in most cases, although it can occasionally be the only option. A variety of adjuvant therapies have been described, including radiation or brachytherapy, chemotherapy, and regional hyperthermia. Radiation treatment, and specifically brachytherapy, is beneficial to select patients. Controversy surrounds chemotherapy in certain subtypes, and regional hyperthermia requires further investigation

Management of soft tissue tumors of the upper extremity: a review.

IntroductionManagement of malignant tumors of the hand and wrist is challenging and is generally approached by limb salvage or amputation. With advances in care, amputation has been superseded by limb salvage as the treatment of choice.MethodsA narrative literature review was performed to identify articles on the topic of management of soft tissue tumors of the upper extremity, including surgical management, adjuvant radiation therapy, and chemotherapy.ResultsA total of 29 articles were selected. Earlier reports favored radical tumor resection, which often led to amputation, whereas later articles demonstrated limb salvage as the preferential treatment modality.ConclusionsGiven the detrimental effects on function and psychologic outcomes, amputation has been superseded by limb salvage in most cases, although it can occasionally be the only option. A variety of adjuvant therapies have been described, including radiation or brachytherapy, chemotherapy, and regional hyperthermia. Radiation treatment, and specifically brachytherapy, is beneficial to select patients. Controversy surrounds chemotherapy in certain subtypes, and regional hyperthermia requires further investigation

Detection and Prevention of ADAR1p150-Induced Hematopoietic Stem and Progenitor Cell Aging

Introduction: Over the last decade, ADAR1p150 has been linked by our research team and others to malignant progenitor reprogramming and therapeutic resistance in a broad array of malignancies. However, ADAR1p150's role in accelerated hematopoietic stem and progenitor cell (HSPC) aging in response to inflammatory cytokines had not been clearly elucidated. Here, we investigate ADAR1 splice isoform switching and the ADAR1p150 inhibitory effects of Rebecsinib on human HSPC function in normal humanized aged normal bone marrow (aNBM) HSPC mouse models. Methods: Whole transcriptome RNA sequencing (RNA-seq) was utilized with splice isoform and editome analysis to detect ADAR1 splice isoform switching and adenosine to inosine RNA editing. Rebecsinib (17S-FD-895), a pre-IND drug candidate, has shown promising potential as an inhibitor of ADAR1p150-mediated RNA editing ( Crews, Ma...Jamieson. Cell Stem Cell 2023), which is an important therapeutic target in patients with myelofibrosis or acute myeloid leukemia that overexpress ADAR1p150 compared with ADAR1p110. Human CD34 + cells, isolated from aged normal bone marrow (aNBM) from patients undergoing elective hip replacement surgery, were transduced with a lentiviral ADAR1-nano-luciferase reporter and transplanted into NSG-SGM3 adult mice that secrete human SCF, IL-3, and GM-CSF cytokines that support normal hematopoiesis. After engraftment confirmation peripheral blood human CD45 flow cytometric assessment and IVIS 200 system imaging of ADAR1-nano-luc-GFP reporter expressing HSPC engraftment, the mice were randomly divided into vehicle-treated and Rebecsinib-treated groups (15mg/kg, twice a week for two weeks). Peripheral blood, bone marrow, and spleen were collected upon treatment completion for analysis. Results: By HSPC RNA-seq, we detected an imbalance between ADAR1p150 and ADAR1p110 expression together with increased RNA editing and splicing alterations using whole transcriptome RNA sequencing (RNA-seq) of aged compared with young bone marrow hematopoietic stem and progenitor cells (HSPCs). However, the functional relevance of ADAR1 splice isoform switching had not been evaluated in human-aged normal bone marrow HSPC xenograft (PDX) mouse models nor had this cytokine-induced HSPC aging been reversed. Flow cytometric analysis and immunohistochemistry staining revealed that Rebecsinib treatment at a dose of 10mg/kg, twice a week for two weeks, effectively spared normal human immune cells (CD3+, CD14+, and CD19+ cells). Remarkably, Rebecsinib treatment not only preserved Hematopoietic Stem (CD34+CD38-) cells and Progenitor (CD34+CD38+) cells in peripheral blood, bone marrow, and spleen but also promoted their expansion. These findings demonstrate the potential of Rebecsinib to enhance the retention of HSPC populations in the bone marrow niche. Conclusions: Our pre-clinical experiments utilizing RNA-seq, a novel ADAR1-nano-luciferase-GFP reporter, and aNBM PDX mouse models provide compelling evidence supporting the potential of Rebecsinib to restore the balance of ADAR1p150:p110 ratios and engraftment in humanized aNBM HSPC mouse models. These findings highlight Rebecsinib as a promising therapeutic candidate for targeting leukemia and myelofibrosis while preserving essential HSPC populations

Specific bone region localization of osteolytic versus osteoblastic lesions in a patient-derived xenograft model of bone metastatic prostate cancer.

ObjectiveBone metastasis occurs in up to 90% of men with advanced prostate cancer and leads to fractures, severe pain and therapy-resistance. Bone metastases induce a spectrum of types of bone lesions which can respond differently to therapy even within individual prostate cancer patients. Thus, the special environment of the bone makes the disease more complicated and incurable. A model in which bone lesions are reproducibly induced that mirrors the complexity seen in patients would be invaluable for pre-clinical testing of novel treatments. The microstructural changes in the femurs of mice implanted with PCSD1, a new patient-derived xenograft from a surgical prostate cancer bone metastasis specimen, were determined.MethodsQuantitative micro-computed tomography (micro-CT) and histological analyses were performed to evaluate the effects of direct injection of PCSD1 cells or media alone (Control) into the right femurs of Rag2-/-γc-/- male mice.ResultsBone lesions formed only in femurs of mice injected with PCSD1 cells. Bone volume (BV) was significantly decreased at the proximal and distal ends of the femurs (p&nbsp;&lt;&nbsp;0.01) whereas BV (p&nbsp;&lt;&nbsp;0.05) and bone shaft diameter (p&nbsp;&lt;&nbsp;0.01) were significantly increased along the femur shaft.ConclusionPCSD1 cells reproducibly induced bone loss leading to osteolytic lesions at the ends of the femur, and, in contrast, induced aberrant bone formation leading to osteoblastic lesions along the femur shaft. Therefore, the interaction of PCSD1 cells with different bone region-specific microenvironments specified the type of bone lesion. Our approach can be used to determine if different bone regions support more therapy resistant tumor growth, thus, requiring novel treatments

Specific bone region localization of osteolytic versus osteoblastic lesions in a patient-derived xenograft model of bone metastatic prostate cancer

Objective: Bone metastasis occurs in up to 90% of men with advanced prostate cancer and leads to fractures, severe pain and therapy-resistance. Bone metastases induce a spectrum of types of bone lesions which can respond differently to therapy even within individual prostate cancer patients. Thus, the special environment of the bone makes the disease more complicated and incurable. A model in which bone lesions are reproducibly induced that mirrors the complexity seen in patients would be invaluable for pre-clinical testing of novel treatments. The microstructural changes in the femurs of mice implanted with PCSD1, a new patient-derived xenograft from a surgical prostate cancer bone metastasis specimen, were determined. Methods: Quantitative micro-computed tomography (micro-CT) and histological analyses were performed to evaluate the effects of direct injection of PCSD1 cells or media alone (Control) into the right femurs of Rag2−/−γc−/− male mice. Results: Bone lesions formed only in femurs of mice injected with PCSD1 cells. Bone volume (BV) was significantly decreased at the proximal and distal ends of the femurs (p < 0.01) whereas BV (p < 0.05) and bone shaft diameter (p < 0.01) were significantly increased along the femur shaft. Conclusion: PCSD1 cells reproducibly induced bone loss leading to osteolytic lesions at the ends of the femur, and, in contrast, induced aberrant bone formation leading to osteoblastic lesions along the femur shaft. Therefore, the interaction of PCSD1 cells with different bone region-specific microenvironments specified the type of bone lesion. Our approach can be used to determine if different bone regions support more therapy resistant tumor growth, thus, requiring novel treatments. Keywords: Bone metastatic prostate cancer, Patient-derived xenograft, Bone microenvironment, Microstructural CT, Osteolytic lesions, Osteoblastic lesion

RNA Splicing Modulation Selectively Impairs Leukemia Stem Cell Maintenance in Secondary Human AML.

Age-related human hematopoietic stem cell (HSC) exhaustion and myeloid-lineage skewing promote oncogenic transformation of hematopoietic progenitor cells into therapy-resistant leukemia stem cells (LSCs) in secondary acute myeloid leukemia (AML). While acquisition of clonal DNA mutations has been linked to increased rates of secondary AML for individuals older than 60 years, the contribution of RNA processing alterations to human hematopoietic stem and progenitor aging and LSC generation remains unclear. Comprehensive RNA sequencing and splice-isoform-specific PCR uncovered characteristic RNA splice isoform expression patterns that distinguished normal young and aged human stem and progenitor cells (HSPCs) from malignant myelodysplastic syndrome (MDS) and AML progenitors. In&nbsp;splicing reporter assays and pre-clinical patient-derived AML&nbsp;models, treatment with a pharmacologic splicing modulator, 17S-FD-895, reversed pro-survival splice isoform switching and significantly impaired LSC maintenance. Therapeutic splicing modulation, together with monitoring splice isoform biomarkers of healthy HSPC aging versus LSC generation, may be employed safely and effectively to prevent relapse, the leading cause of leukemia-related mortality