Prostate Cancer Liver Metastases Research Articles

High-fat diet promotes prostate cancer metastasis via RPS27

BackgroundMetastasis is the leading cause of death among prostate cancer (PCa) patients. Obesity is associated with both PCa-specific and all-cause mortality. High-fat diet (HFD) is a risk factor contributing to obesity. However, the association of HFD with PCa metastasis and its underlying mechanisms are unclear.MethodsTumor xenografts were conducted by intrasplenic injections. The ability of migration or invasion was detected by transwell assay. The expression levels of RPS27 were detected by QRT-PCR and western blot.ResultsThe present study verified the increase in PCa metastasis caused by HFD in mice. Bioinformatics analysis demonstrated increased RPS27 in the experimentally induced PCa in HFD mice, indicating that it is an unfavorable prognostic factor. Intrasplenic injections were used to demonstrate that RPS27 overexpression promotes, while RPS27 knockdown significantly reduces, PCa liver metastasis. Moreover, RPS27 inhibition suppresses the effects of HFD on PCa metastasis. Further mRNA sequencing analysis revealed that RPS27 promotes PCa metastasis by selectively enhancing the expression of various genes.ConclusionOur findings indicate that HFD increases the risk of PCa metastasis by elevating RPS27 expression and, subsequently, the expression of genes involved in PRAD progression. Therefore, RPS27 may serve as a novel target for the diagnosis and treatment of metastatic PCa.

Prostate Cancer Liver Metastasis: An Ominous Metastatic Site in Need of Distinct Management Strategies

Prostate cancer liver metastasis (PCLM), seen in upwards of 25% of metastatic castration-resistant PC (mCRPC) patients, is the most lethal site of mCRPC with a median overall survival of 10–14 months. Despite its ominous prognosis and anticipated rise in incidence due to longer survival with contemporary therapy, PCLM is understudied. This review aims to summarize the existing literature regarding the risk factors associated with the development of PCLM, and to identify areas warranting further research. A literature search was conducted through Ovid MEDLINE from 2000 to March 2023. Relevant subject headings and text words were used to capture the following concepts: “Prostatic Neoplasms”, “Liver Neoplasms”, and “Neoplasm Metastasis”. Citation searching identified additional manuscripts. Forty-one studies were retained for detailed analysis. The clinical risk factors for visceral/liver metastasis included <70 years, ≥T3 tumor, N1 nodal stage, de novo metastasis, PSA >20 ng/mL, and a Gleason score >8. Additional risk factors comprised elevated serum AST, LDH or ALP, decreased Hb, genetic markers like RB1 and PTEN loss, PIK3CB and MYC amplification, as well as numerous PC treatments either acting directly or indirectly through inducing liver injury. Further research regarding predictive factors, early detection strategies, and targeted therapies for PCLM are critical for improving patient outcomes.

Docetaxel enhances the therapeutic efficacy of PSMA-specific CAR-T cells against prostate cancer models by suppressing MDSCs.

Prostate cancer can undergo curative effects by radical prostatectomy or radical radiotherapy. However, the best treatment for more aggressive high-risk prostate cancer remains controversial. Insufficient infiltration capacity and dysfunction are commonly occurrences in engineered T lymphocytes expressing chimeric antigen receptor (CAR-T), characterizing cancer immunotherapy failure. We conducted this study to investigate whether the combinative application of docetaxel and PSMA-CAR-T cells could be a more effective treatment to prostate cancer. Expressions of prostate specific membrane antigen (PSMA) on prostate cancer cells were examined by Flow cytometry. The efficaciousness of PSMA-CAR-T was evaluated in vitro using ELISA and RTCA. The effect of intermixed therapy was assessed in vivo utilizing a human prostate cancer liver metastasis mouse model and a human prostate cancer cell xenograft mouse model. The outcome of cytokine discharge and cell killing assays demonstrated that PSMA-CAR-T cells have characteristic effector capacity against PSMA+ prostate cancer cells in vitro. Additionally, collaborative treatment of PSMA-CAR-T cells and docetaxel have cooperative efficacy in a mouse model of human prostate cancer. The merged strategy could be seen as an undeveloped avenue to augmenting adoptive CAR-T cell immunotherapy and mitigating the adverse side effects of chemotherapy. Cooperation of PSMA-specific CAR-T cells and the chemotherapy drug docetaxel can impressively ameliorate antitumor effectiveness against an installed metastatic human prostate cancer model in NPG mice.

Microparticle Encapsulation of a Prostate-targeted Biologic for the Treatment of Liver Metastases in a Preclinical Model of Castration-resistant Prostate Cancer

PRX302 is a highly potent, mutant bacterial pore-forming biologic protoxin engineered for selective activation by PSA, a serine protease expressed by benign and malignant prostate epithelial cells. Although being developed as a local therapy for benign prostatic hyperplasia and localized prostate cancer, PRX302 cannot be administered systemically as a treatment for metastatic disease due to binding to ubiquitously expressed glycosylphosphatidylinositol (GPI)-anchored proteins, which leads to poor accumulation within the tumor microenvironment. To overcome this limitation, poly-lactic-co-glycolic acid (PLGA) microparticles encapsulating the protoxin were developed, which are known to accumulate in the liver, a major site of metastasis for prostate cancer and other solid tumors. A highly sensitive and reproducible sandwich ELISA to quantify PRX302 released from microparticles was developed. Utilizing this assay, PRX302 release from different microparticle formulations was assessed over multiple days. Hemolysis assays documented PSA-dependent pore formation and lytic potential (i.e., function) of the released protoxin. MTT assays demonstrated that conditioned supernatant from PRX302-loaded, but not blank (i.e., unloaded), PLGA microparticles was highly cytotoxic to PC3 and DU145 human prostate cancer cells in the presence of exogenous PSA. Microparticle encapsulation prevented PRX302 from immediately interacting with GPI-anchored proteins as demonstrated in a competition assay, which resulted in an increased therapeutic index and significant antitumor efficacy following a single dose of PRX302-loaded microparticles in a preclinical model of prostate cancer liver metastasis with no obvious toxicity. These results document that PRX302 released from PLGA microparticles demonstrate in vivo antitumor efficacy in a clinically relevant preclinical model of metastatic prostate cancer.

Prostate cancer liver metastasis: Dormancy and resistance to therapy.

Liver metastasis causes nearly half of death from solid tumors. Metastatic lesions, to the liver in particular, can become detectable years or decades after primary tumor removal, leaving an uncertain long-term prognosis in patients. Prostate cancer (PCa), a prominent metastatic dormant cancer, has the worst prognosis when found in the liver compared to other metastatic sites. These metastatic nodules display a therapy resistance in the liver pro-metastatic microenvironment; the resistance appears to be conferred by both dormancy and independent of dormancy when the nodules emerge. Within the review, the molecular underpinnings of how the liver aids and protects PCa cells seeding, colonization and resistance will be discussed.

Abstract A26: Immune profiling and organoids generation of a rare case of prostate cancer liver metastasis

Abstract Introduction: Prostate cancer (PCa) is the second most frequent cancer in men and a leading cause of cancer-related mortality. Despite major advances in immunotherapy, PCa remains a poor responder. Metastatic PCa is responsible for the majority of PCa-associated mortality. Most PCa metastases are multifocal and display a strong bones tropism (91.1% of cases), but PCa metastases can also spread to the lymph nodes (8.7%), lungs (5.7%), liver (4.5%) and brain (1.8%). Liver metastases are associated with worse prognosis but due to their multifocal nature and frequent spreading to other sites, PCa metastases are rarely resected. Therefore, immunologic characterization of these lesions concomitant with generation of research tools derived from these lesions are urgently needed to understand how to intercept disease progression. Methods: A 62-year-old male who previously underwent radical prostatectomy in 2016 was diagnosed in July 2018 with a single liver metastasis (5.3 cm) by MRI. The tumor was surgically resected and tumor tissue along with peripheral blood was collected and processed for in-depth immunologic/molecular characterization and generation of tumor models. The study was done in accordance with the guidelines approved by MUHC IRB. Prior written informed consent was obtained from the subject to participate in the study (protocol: SDR-11-066). Results: The prostatic origin of the tumor mass was confirmed by positivity for PSMA and NKX3.1 expression. Patient-derived xenografts, 2D cell and organoid cultures were generated and immunophenotyping of the innate and adaptive peripheral and tumor-infiltrating immune cells subsets was performed. Genomic alterations are currently being characterized by multiplex ligation-dependent probe amplification (MLPA). Additionally, chromatin accessibility-based characterization of the gene regulatory network of tumor luminal cells (CD49-CD26+) using the assay for transposase-accessible chromatin using sequencing (ATAC-seq) together with RNA-seq is presently under way. Conclusions: Our collaborative effort will provide the much-needed research tools required to model and understand the processes leading to the rare, but lethal, progression from a localized PCa lesion to liver metastases. Combined with other ongoing research efforts, we believe this case will help us understand the molecular basis to the liver tropism of a subset of PCa metastases and ultimately provide biomarkers for early identification of patients with increased metastatic potential as well as a basis to determine the appropriate immunotherapy modality for metastatic patients. Citation Format: Aurélie Y. Le Page, Anna de Polo, K-P Guérard, A. Lazaris, S.K. Petrillo, W. Ebrahimizadeh, S. Tabariès, S. Shinde-Jadhav, A. Feldiorean, N. Boufaeid, W. Kassouf, C. Piccirillo, P.M. Siegel, A. Aprikian, A. Gregorieff, J. Lapointe, P. Metrakos, D.P. Labbé. Immune profiling and organoids generation of a rare case of prostate cancer liver metastasis [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr A26.

Abstract B21: Establishment of a novel spontaneous prostate cancer liver metastasis model

Abstract Objective: Prostate cancer (PCa) preferentially spreads to bone with additional metastasis to regional lymph nodes, lung and liver in a subset of patients. Understanding the determining factors of this metastatic pattern and to elucidate the involved pathways and interplay between epithelial and the stromal niche, we established a patient-derived xenograft (PDX) model showing spontaneous metastatic spread to all relevant organs and metastatic lesions in liver. Methods: PDX of PCa were obtained from NMRI tumor-bearing mice and 3D cell cultures were established by collagenase treatment o/n in prostate growth medium (PGM) containing 2% fetal calf serum. 3D cultures of PDX PC339 were established (PC339C) that could be passaged and stored in liquid nitrogen. PC339C was transfected with a lentiviral construct containing luc2-GFP fused protein (M21) and upon FACS-sorting the PC339C-M21 was retrieved. PC339C-M21 cells were inoculated subcutaneously in NSG mice and when tumors were established mice underwent tumorectomy (700-1000 mm3) to extend the life span of the animal and allow metastastic outgrowth. Mice were monitored weekly for metastatic outgrowth using IVIS, microCT and MRI. At sacrifice, M21-positive organs, including liver, lymph nodes, lung and bone, were sampled. Part of the tissue was used for culturing, part was fresh frozen for RNA and protein isolation to allow qPCR and western blot analyses, and part was formalin-fixed and paraffin-embedded for histology and immunohistochemistry. Results: PC339C-M21 tumors were established in NSG mice and after tumorectomy a spontaneous liver metastasis was established. Culturing of this tumor resulted in the PC339C-M21-L cell line. This cell line was inoculated subcutaneously in NSG mice to result in tumor formation and spontaneous liver metastasis in all mice. Tumorectomy was performed at 25-30 days after inoculation. Luciferase-positive signals in liver were detected by IVIS as early as 7 days after tumorectomy with MRI showing first visible lesions at 21 days and microCT at 28 days. 3D reconstructed microCT images and MRI-detected lesions confirmed the signals and location as seen by IVIS. When inoculated orthotopically, liver metastatic lesions became visible by IVIS at 40 days, which was not different from the subcutaneous tumors. However, these mice could not be followed longer due to the orthotopic tumor burden. On top of the PC339C-M21-L cell line, culturing of luciferase-positive organs resulted in cell lines from lymph node (PC339C-M21-L-LN), lung (PC339C-M21-L-LU), and bone (PC339C-M21-L-B) together constituting a cell line panel of metastatic PCa. This cell line panel is being further characterized in vitro and in vivo for their unique properties and metastatic potential. Conclusion: A new spontaneous PCa liver metastasis xenograft model, PCL339-M21-L, was generated. This model was extended to yield a panel of metastatic sublines from different organ origin. Together, this platform may serve as a tool to study the biology of spontaneous metastatic outgrowth in liver and other organs. Furthermore, we demonstrated the feasibility of non-invasive imaging techniques to follow metastatic spread and outgrowth allowing to monitor responses to anti-cancer therapies. Citation Format: Hanneke J.A.A. van Zoggel, Sigrun E. Erkens-Schulze, Corrina M.A. De Ridder, Wilma Teubel, Hamza Saleem, Stefan J. Roobol, Sander A.H. Hoeben, Yanto R. Ridwan, Joost C. Haeck, Wytske M. van Weerden{Authors}. Establishment of a novel spontaneous prostate cancer liver metastasis model. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr B21.

Abstract A5: Establishment of a novel spontaneous prostate cancer liver metastasis model

Abstract Introduction: It is well-documented that prostate cancer (PCa) preferentially spreads to bone, but the patterns of non-osseous metastases are less well-defined. With the increased options for treatment of late stage patients, metastatic spread to lung, lymph nodes and liver has become more prominent. Especially, men with visceral (especially hepatic) metastases have a particularly poor prognosis. To understand the determining factors of this metastatic pattern in PCa and to elucidate the mechanisms underlying metastatic outgrowth in the liver and other relevant organs, we set out to develop a patient-derived xenograft (PDX) model of metastasis. We used a multimodality imaging approach to identify and monitor metastatic outgrowth. Material & Methods: We established 3D cultures of the PC339 PDX model, originating from a TURP of a late stage patient. PCL339 3D cultures were transfected with M21 (firefly luciferase - GFP fused protein) and inoculated subcutaneously in NOD-SCID-gamma (NSG) mice. Mice with established PCL339-M21 tumors underwent tumorectomy (700-1000 mm3) to extent their life span and allow metastatic outgrowth. After tumorectomy, animals were imaged weekly using MRI, microCT and In Vivo Imaging System (IVIS) to monitor metastatic development. At sacrifice, liver and other luciferase-positive organs were stored for RNA isolation and qPCR and for immunohistochemistry. Additionally, the positive liver was cultured to retrieve the PCL339-M21-L subline. To investigate whether metastatic potential was improved, this subline was re-injected subcutaneously and the above described procedure was repeated. Positive organs, including lung, lymph node and bone, were cultured to retrieve the PCL339-M21-L-LN and PCL339-M21-ZL-LU sublines. Results: Subcutaneous PCL339-M21-L tumors spread more consistent (almost 100%) and faster to liver compared to PCL339-M21 tumors (30 days after tumorectomy). Luciferase-positive signals in liver were detected by IVIS as early as 7 days after tumorectomy. MRI showed the first visible lesions at 21 days while microCT imaging detected positive lesions only after 28 days. 3D reconstructed microCT images and MRI-detected lesions confirmed location of the signals as seen by IVIS. Similar to MRI images, macroscopic liver lesions could be clearly observed at 21 days. In all cases, additional (micro)metastatic spread to lymph nodes, lung and bone was seen by IVIS imaging. Positive signals from these micrometastases could be confirmed by qPCR and immunohistochemistry for androgen receptor, prostate specific antigen and luciferase or GFP. Conclusion: We have established a new reproducible and transplantable PCa liver metastasis model PCL339-M21-L that shows spontaneous spread to liver and other organs like lung and lymph nodes. We demonstrated the value of non-invasive multimodality imaging to localize and follow metastatic spread and outgrowth over time. This unique PCL339-M21-L model is a valuable asset to study the biological aspects of PCa liver metastasis and provide a new PDX model to test potential therapies aiming to block metastatic spread of PCa. Citation Format: Stefan J. Roobol, Johanneke A.A. van Zoggel, Corrina M.A. de Ridder, Sander A.H. Hoeben, Yin C.I.L. Versluis, Yanto R. Ridwan, Joost C. Haeck, Wytske M. van Weerden. Establishment of a novel spontaneous prostate cancer liver metastasis model. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A5.