Targeting SOX4/PCK2 signaling suppresses neuroendocrine trans-differentiation of castration-resistant prostate cancer.

BACKGROUND: Neuroendocrine prostate cancer (NEPC), a lethal subset of prostate cancer (PCa), is characterized by loss of AR signaling and resistance to AR-targeted therapy. While it is well reported that second-generation AR blockers induce neuroendocrine (NE) trans-differentiation of castration-resistant prostate cancer (CRPC) to promote the occurrence of NEPC, and pluripotent transcription factors might be potential regulators, the underlying molecular mechanisms remain unclear. METHODS: We analyzed the data from public databsets to screen candidate genes and then focused on SOX4, a regulator of NE trans-differentiation. The expression changes of SOX4 and its relationship with tumor progression were validated in clinical tumor tissues. We evaluated malignant characteristics related to NEPC in prostate cancer cell lines with stable overexpression or knockdown of SOX4 in vitro. Tumor xenografts were analyzed after inoculating the relevant cell lines into nude mice. RNA-seq, ATAC-seq, non-targeted metabolomics analysis, as well as molecular and biochemical assays were carried out to determine the mechanism. RESULTS: We screened public datasets and identified that expression of SOX4 was significantly elevated in NEPC. Overexpressing SOX4 in C4-2B cells increased cell proliferation and migration, upregulated the expression of NE marker genes, and inhibited AR expression. Consistently, inhibition of SOX4 expression in DU-145 and PC-3 cells reduced the above malignant phenotypes and repressed the expression of NE marker genes. For the in vivo assay, we found that knockdown of SOX4 inhibited tumor growth of subcutaneous xenografts in castrated nude mice which were concomitantly treated with enzalutamide (ENZ). Mechanically, we identified that one of the key enzymes in gluconeogenesis, PCK2, was a novel target of SOX4. The activation of carbohydrate metabolism reprogramming by SOX4 could promote NE trans-differentiation via the SOX4/PCK2 pathway. CONCLUSIONS: Our findings reveal that SOX4 promotes NE trans-differentiation both in vitro and in vivo via directly enhancing PCK2 activity to activate carbohydrate metabolism reprogramming. The SOX4/PCK2 pathway and its downstream changes might be novel targets for blocking NE trans-differentiation.

Mendelian randomization evidence based on European ancestry for the causal effects of leukocyte telomere length on prostate cancer.

BACKGROUND: Several lines of evidence suggest that leukocyte telomere length (LTL) can affect the development of prostate cancer (PC). METHODS: Here, we employed single nucleoside polymorphisms (SNPs) as instrumental variables (IVs) for LTL (n = 472,174) and conducted Mendelian randomization analysis to estimate their causal impact on PCs (79,148 patients/61,106 controls and 6311 patients/88,902 controls). RESULTS: Every 1-s.d extension of LTL increased the risk of PCs by 34%. Additionally, the analysis of candidate mediators between LTL and PCs via two-step Mendelian randomization revealed that among the 23 candidates, Alzheimer's disease, liver iron content, sex hormone binding global levels, naive CD4-CD8-T cell% T cell, and circulating leptin levels played substantial mediating roles. There is no robust evidence to support the reverse causal relationship between LTL and the selected mediators of PCs. Adjusting for the former four mediators, rather than adjusting for circulating leptin levels, decreased the impact of LTL on PCs. CONCLUSION: This study provides potential intervention measures for preventing LTL-induced PCs.

PAX6 promotes neuroendocrine phenotypes of prostate cancer via enhancing MET/STAT5A-mediated chromatin accessibility.

BACKGROUND: Neuroendocrine prostate cancer (NEPC) is a lethal subset of prostate cancer which is characterized by neuroendocrine differentiation and loss of androgen receptor (AR) signaling. Growing evidence reveals that cell lineage plasticity is crucial in the failure of NEPC therapies. Although studies suggest the involvement of the neural transcription factor PAX6 in drug resistance, its specific role in NEPC remains unclear. METHODS: The expression of PAX6 in NEPC was identified via bioinformatics and immunohistochemistry. CCK8 assay, colony formation assay, tumorsphere formation assay and apoptosis assay were used to illustrate the key role of PAX6 in the progression of in vitro. ChIP and Dual-luciferase reporter assays were conducted to confirm the binding sequences of AR in the promoter region of PAX6, as well as the binding sequences of PAX6 in the promoter regions of STAT5A and MET. For in vivo validation, the xenograft model representing NEPC subtype underwent pathological analysis to verify the significant role of PAX6 in disease progression. Complementary diagnoses were established through public clinical datasets and transcriptome sequencing of specific cell lines. ATAC-seq was used to detect the chromatin accessibility of specific cell lines. RESULTS: PAX6 expression was significantly elevated in NEPC and negatively regulated by AR signaling. Activation of PAX6 in non-NEPC cells led to NE trans-differentiation, while knock-down of PAX6 in NEPC cells inhibited the development and progression of NEPC. Importantly, loss of AR resulted in an enhanced expression of PAX6, which reprogramed the lineage plasticity of prostate cancer cells to develop NE phenotypes through the MET/STAT5A signaling pathway. Through ATAC-seq, we found that a high expression level of PAX6 elicited enhanced chromatin accessibility, mainly through attenuation of H4K20me3, which typically causes chromatin silence in cancer cells. CONCLUSION: This study reveals a novel neural transcription factor PAX6 could drive NEPC progression and suggest that it might serve as a potential therapeutic target for the management of NEPC.

The Role of Extracellular Vesicles in the Treatment of Prostate Cancer.

Prostate cancer (PCa) has become a public health concern in elderly men due to an ever-increasing number of estimated cases. Unfortunately, the available treatments are unsatisfactory because of a lack of a durable response, especially in advanced disease states. Extracellular vesicles (EVs) are lipid-bilayer encircled nanoscale vesicles that carry numerous biomolecules (e.g., nucleic acids, proteins, and lipids), mediating the transfer of information. The past decade has witnessed a wide range of EV applications in both diagnostics and therapeutics. First, EV-based non-invasive liquid biopsies provide biomarkers in various clinical scenarios to guide treatment; EVs can facilitate the grading and staging of patients for appropriate treatment selection. Second, EVs play a pivotal role in pathophysiological processes via intercellular communication. Targeting key molecules involved in EV-mediated tumor progression (e.g., proliferation, angiogenesis, metastasis, immune escape, and drug resistance) is a potential approach for curbing PCa. Third, EVs are promising drug carriers. Naïve EVs from various sources and engineered EV-based drug delivery systems have paved the way for the development of new treatment modalities. This review discusses the recent advancements in the application of EV therapies and highlights EV-based functional materials as novel interventions for PCa.

Extracellular vesicles related gene HSPH1 exerts anti-tumor effects in prostate cancer via promoting the stress response of CD8 + T cells.

BACKGROUND: T cell stress response state (TSTR), as a novel immune concept previous studies have proposed, has not yet been explored in prostate cancer (PC). As a type of cellular efflux, exosomes play important roles in the occurrence and development of PC. METHOD: Here, we conducted a combined analysis on extracellular vesicle related genes (EVRGs) in PC using data from single-cell RNA (scRNA), spatial transcriptome (ST), and bulk RNA sequencing. RESULT: Preliminary findings have revealed that heat shock protein family H (Hsp110) member 1 (HSPH1) possesses two identities, one being EVRGs and the other being a member of the heat shock protein family involved in TSTR, which may promote the differentiation of conventional T cells towards Th1 or Th2 cells through the pathway of IL2-MYC-IL2RA, thereby promoting the increase of CD8 + T cells in the tumor area, especially in the invasive zone, and inhibiting the invasion of PCs. We also notice the negative response of HSPH1 + CD8 + T cell related genes in immune checkpoint blockade (ICB). Western blot (WB) and droplet digital Polymerase Chain Reaction (ddPCR) demonstrated that the mRNA and protein levels of HSPH1 in EVs of PCs were significantly higher than those in adjacent tissues. CONCLUSION: Results above indicate the potential of HSPH1 as a critical therapeutic target in PC.

Precise diagnosis and risk stratification of prostate cancer by comprehensive serum metabolic fingerprints: a prediction model study.

OBJECTIVES: Prostate cancer (PCa) is one of the most common malignancies in men worldwide and has caused increasing clinical morbidity and mortality, making timely diagnosis and accurate staging crucial. The authors introduced a novel approach based on mass spectrometry for precise diagnosis and stratification of PCa to facilitate clinical decision-making. METHODS: Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry analysis of trace blood samples was combined with machine learning algorithms to construct diagnostic and stratification models. A total of 367 subjects, comprising 181 with PCa and 186 with non-PCa were enrolled. Additional 60 subjects, comprising 30 with PCa and 30 with non-PCa were enrolled as an external cohort for validation. Subsequent metabolomic analysis was carried out using Autoflex MALDI-TOF, and the mass spectra were introduced into various algorithms to construct different models. RESULTS: Serum metabolic fingerprints were successfully obtained from 181 patients with PCa and 186 patients with non-PCa. The diagnostic model based on the eight signals demonstrated a remarkable area under curve of 100% and was validated in the external cohort with the area under curve of 87.3%. Fifteen signals were selected for enrichment analysis, revealing the potential metabolic pathways that facilitate tumorigenesis. Furthermore, the stage prediction model with an overall accuracy of 85.9% precisely classified subjects with localized disease and those with metastasis. The risk stratification model, with an overall accuracy of 89.6%, precisely classified the subjects as low-risk and high-risk. CONCLUSIONS: Our study facilitated the timely diagnosis and risk stratification of PCa and provided new insights into the underlying mechanisms of metabolic alterations in PCa.

Identifying High Gleason Score Prostate Cancer by Prostate Fluid Metabolic Fingerprint-Based Multi-Modal Recognition.

Prostate cancer (PCa) is the second most common cancer in males worldwide. The Gleason scoring system, which classifies the pathological growth pattern of cancer, is considered one of the most important prognostic factors for PCa. Compared to indolent PCa, PCa with high Gleason score (h-GS PCa, GS ≥ 8) has greater clinical significance due to its high aggressiveness and poor prognosis. It is crucial to establish a rapid, non-invasive diagnostic modality to decipher patients with h-GS PCa as early as possible. In this study, ferric nanoparticle-assisted laser desorption/ionization mass spectrometry (FeNPALDI-MS) to extract prostate fluid metabolic fingerprint (PSF-MF) is employed and combined with the clinical features of patients, such as prostate-specific antigen (PSA), to establish a multi-modal diagnosis assisted by machine learning. This approach yields an impressive area under the curve (AUC) of 0.87 to diagnose patients with h-GS, surpassing the results of single-modal diagnosis using only PSF-MF or PSA, respectively. Additionally, using various screening methods, six key metabolites that exhibit greater diagnostic efficacy (AUC = 0.96) are identified. These findings also provide insights into related metabolic pathways, which may provide valuable information for further elucidation of the pathological mechanisms underlying h-GS PCa.

Taurine Inhibits Ferroptosis Mediated by the Crosstalk between Tumor Cells and Tumor-Associated Macrophages in Prostate Cancer.

Tumor-associated macrophages (TAMs) play an essential role in tumor therapeutic resistance. Although the lethal effect of ferroptosis on tumor cells is well reported, how TAMs inhibit the effect of ferroptosis in tumors has not been clearly defined. In this study, it is demonstrated that TAM-secreted taurine suppresses ferroptosis in prostate cancer (PCa) by activating the Liver X receptor alpha/Stearoyl-Coenzyme A desaturase 1 (LXRα/SCD1) pathway. Blocking taurine intake via inhibition of taurine transporter TauT restores the sensitivity to ferroptosis in tumors. Furthermore, LXRα activates the transcription of both miR-181a-5p and its binding protein FUS to increase the recruitment of miR-181a-5p in tumor-derived extracellular vesicles (EVs). It is observed that macrophages appear to be recipient cells of the miR-181a-5p-enriched EVs. Intake of miR-181a-5p in macrophages promotes their M2 polarization and enhances the taurine export by inhibiting expression of its target gene lats1, which in turn inactivates the hippo pathway and results in a Yes-associated protein (YAP) nuclear translocation for transcriptional activation of both M2 polarization-related genes such as ARG1 and CD163 and the taurine transport gene TauT. Taken together, the findings indicate a reciprocal interaction between PCa cells and TAMs as a positive feedback-loop to repress ferroptosis in PCa, mediated by TAM-secreted taurine and tumor EV-delivered miR-181a-5p.

Early serial circulating tumor DNA sequencing predicts the efficacy of chemohormonal therapy in patients with metastatic hormone-sensitive prostate cancer.

Chemohormonal therapy is a standard treatment for metastatic hormone-sensitive prostate cancer (mHSPC); however, there are no biomarkers to guide clinical decisions regarding therapeutic options. We aimed to evaluate the clinical utility of serial circulating tumor DNA (ctDNA) sequencing in early prediction of the efficacy of chemohormonal therapy in patients with mHSPC. We conducted a retrospective observational study of 66 patients with mHSPC receiving chemohormonal therapy who underwent serial targeted gene-panel ctDNA sequencing. Peripheral blood samples were collected before treatment and after one cycle of chemotherapy. Kaplan-Meier and log-rank analyses were used to analyze the association between ctDNA status and disease progression-free survival. Serial changes in the ctDNA fraction and genetic alterations were also observed. After one cycle of chemotherapy, 23 (34.8%) patients displayed elevated ctDNA levels, whereas the other patients (65.2%, n = 43) did not. The median time to castration resistance in the group with reduced ctDNA levels was significantly longer than that in the group with increased ctDNA levels (17.70 vs. 8.43 months [mo], p < 0.001). Interestingly, patients with de novo alterations in homologous recombination pathway genes after treatment experienced a shorter time to castration resistance than that experienced by the remaining patients (8.02 vs. 13.20 mo, p = 0.011). The increased ctDNA levels or de novo alterations detected in homologous recombination pathway genes are a harbinger of disease progression. Early serial ctDNA sequencing could aid clinicians in making accurate treatment decisions.

Baseline PSMA-PET/CT as a predictor of PSA persistence following radical prostatectomy in high-risk nonmetastatic prostate cancer patients receiving neoadjuvant therapy.

BACKGROUND: The precise staging and proper management of high-risk prostate cancer (PCa) continues to be a challenge. We aimed to demonstrate the prognostic value of baseline prostate-specific membrane antigen-ligand positron emission tomography/computed tomography (PSMA-PET/CT) in high-risk, nonmetastatic PCa patients who received neoadjuvant hormonal or chemohormonal treatment followed by radical prostatectomy (RP). METHODS: We performed retrospective analyses of 70 patients with high-risk, nonmetastatic PCa confirmed by biopsy between 2018 and 2021. All patients underwent neoadjuvant therapy followed by RP and pelvic lymph node dissection (PLND); PSMA-PET/CT was performed before initiation of neoadjuvant therapy. Acquired image information and clinical characteristics/outcomes were examined for possible associations. RESULTS: Among 70 high-risk PCa patients, median age was 69 years old and median prostate specific antigen (PSA) at presentation was 58.5 ng/mL. Thirty (42.9%) patients had uptake of the PSMA tracer only in the primary PCa lesions and 40 (57.1%) patients had PSMA-positive lesions in regional or distant sites. Sixteen (32%) localized PCa patients defined by pre-PET magnetic resonance imaging were found to have locally advanced PCa based on PSMA-PET/CT. Fifteen (30%) localized PCa patients and 7 (35%) locally advanced PCa patients were upstaged to metastatic PCa. The sensitivity and specificity of PSMA-PET/CT for the detection of lymph node involvement were 90.9% and 69.5%, respectively, with a positive prediction value of 35.7% and negative prediction value of 97.6%. The diagnostic accuracy was 72.9%. Univariate analysis showed upstaging, tumor stage, and metastasis location based on PSMA-PET/CT are predictors to PSA persistence after surgery, while multivariate logistic regression analysis showed only the tumor stage based on PSMA-PET/CT remained an independent predictor of the outcome. CONCLUSIONS: This study further highlights the accuracy and necessity of PSMA-PET/CT in newly diagnosed, high-risk, nonmetastatic PCa patients.

IL-1ß Is an Androgen-Responsive Target in Macrophages for Immunotherapy of Prostate Cancer.

Great attention is paid to the role of androgen receptor (AR) as a central transcriptional factor in driving the growth of prostate cancer (PCa) epithelial cells. However, the understanding of the role of androgen in PCa-infiltrated immune cells and the impact of androgen deprivation therapy (ADT), the first-line treatment for advanced PCa, on the PCa immune microenvironment remains limited. On the other hand, immune checkpoint blockade has revolutionized the treatment of certain cancer types, but fails to achieve any benefit in advanced PCa, due to an immune suppressive environment. In this study, it is reported that AR signaling pathway is evidently activated in tumor-associated macrophages (TAMs) of PCa both in mice and humans. AR acts as a transcriptional repressor for IL1B in TAMs. ADT releases the restraint of AR on IL1B and therefore leads to an excessive expression and secretion of IL-1ß in TAMs. IL-1ß induces myeloid-derived suppressor cells (MDSCs) accumulation that inhibits the activation of cytotoxic T cells, leading to the immune suppressive microenvironment. Critically, anti-IL-1ß antibody coupled with ADT and the immune checkpoint inhibitor anti-PD-1 antibody exerts a stronger anticancer effect on PCa following castration. Together, IL-1ß is an important androgen-responsive immunotherapeutic target for advanced PCa.

Early Plasma Circulating Tumor DNA as a Potential Biomarker of Disease Recurrence in Non-metastatic Prostate Cancer.

PURPOSE: In non-metastatic prostate cancer (nmPCa) setting, it is important to early identify the patients at risk of biochemical recurrence (BCR) for immediate postoperative intervention. Our study aimed to evaluate the potential clinical utility of circulating tumor DNA (ctDNA) for predicting disease recurrence. Materials and Methods: This real-world observational study evaluated 161 cases of nmPCa undergoing next-generation sequencing at our institution. A total of 139 ctDNA samples and 31 biopsied tumor tissue underwent genomic profiling. The study endpoint was BCR after radical prostatectomy. Relationships between the ctDNA status and the biochemical progression-free survival (bPFS) were analyzed by log-rank test and multivariate Cox regression. RESULTS: Of 161 enrolled patients, 19 (11.8%) harbored deleterious alterations in NCOR2, followed by BRCA2 (3.7%), ATR (2.5%), and CDK12 (2.5%). Of available pre-operative blood samples (n=139), ctDNA was detectable in 91 (65.5%). Until last follow-up, 56 of 68 patients (85.3%) with detectable ctDNA had achieved BCR, whereas only eight of 39 patients (20.5%) with undetectable ctDNA had achieved BCR. Patients who had undetectable ctDNA experienced significantly longer bPFS compared with those who had detectable ctDNA (not available vs. 8.2 months; hazard ratio, 0.14; p < 0.01). Pre-operative ctDNA status was a significant prognostic factor of disease recurrence. CONCLUSION: Pre-operative ctDNA detection could identify patients at high risk of recurrence and has the potential to inform immediate postoperative interventions, but these approaches remain to be validated in prospective studies. ctDNA studies can provide insights into accurate monitoring and precise treatment rather than simply following routine clinical care.

Engineering the MoS2 /MXene Heterostructure for Precise and Noninvasive Diagnosis of Prostate Cancer with Clinical Specimens.

High-throughput metabolic fingerprinting has been deemed one of the most promising strategies for addressing the high false positive rate of prostate cancer (PCa) diagnosis in the prostate-specific antigen (PSA) gray zone. However, the current metabolic fingerprinting remains challenging in achieving high-precision metabolite detection in complex biological samples (e.g., serum and urine). Herein, a novel self-assembly MoS2 /MXene heterostructure nanocomposite with a tailored doping ratio of 10% is presented as a matrix for laser desorption ionization mass spectrometry analysis in clinical biosamples. Notably, owing to the two-dimensional architecture and doping effect, MoS2 /MXene demonstrates favorable laser desorption ionization performance with low adsorption energy, which is evidenced by efficient urinary metabolic fingerprinting with an enhanced area under curve (AUC) diagnosis capability of 0.959 relative to that of serum metabolic fingerprinting (AUC = 0.902) for the diagnosis of PCa in the PSA gray zone. Thus, this MoS2 /MXene heterostructure is anticipated to offer a novel strategy to precisely and noninvasively diagnose PCa in the PSA gray zone.

PD-1 inhibitor plus anlotinib for metastatic castration-resistant prostate cancer: a real-world study.

Management and treatment of terminal metastatic castration-resistant prostate cancer (mCRPC) remains heavily debated. We sought to investigate the efficacy of programmed cell death 1 (PD-1) inhibitor plus anlotinib as a potential solution for terminal mCRPC and further evaluate the association of genomic characteristics with efficacy outcomes. We conducted a retrospective real-world study of 25 mCRPC patients who received PD-1 inhibitor plus anlotinib after the progression to standard treatments. The clinical information was extracted from the electronic medical records and 22 patients had targeted circulating tumor DNA (ctDNA) next-generation sequencing. Statistical analysis showed that 6 (24.0%) patients experienced prostate-specific antigen (PSA) response and 11 (44.0%) patients experienced PSA reduction. The relationship between ctDNA findings and outcomes was also analyzed. DNA-damage repair (DDR) pathways and homologous recombination repair (HRR) pathway defects indicated a comparatively longer PSA-progression-free survival (PSA-PFS; 2.5 months vs 1.2 months, P = 0.027; 3.3 months vs 1.2 months, P = 0.017; respectively). This study introduces the PD-1 inhibitor plus anlotinib as a late-line therapeutic strategy for terminal mCRPC. PD-1 inhibitor plus anlotinib may be a new treatment choice for terminal mCRPC patients with DDR or HRR pathway defects and requires further investigation.

RNA profiling of circulating tumor cells systemically captured from diagnostic leukapheresis products in prostate cancer patients.

The application of circulating tumor cells (CTCs) in both clinical practice and research has been continuously limited by the rare number of targets that can be found in a tube of peripheral blood. Diagnostic leukapheresis (DLA) was used to increase the sampling volume. AdnaTest was used to process the whole leukopak, and the RNAs of captured CTCs was then profiled by NanoString nCounter platform. Spike-in experiments and leukopaks from patients with metastatic prostate cancer were used to validate this new strategy. The whole leukopak was further concentrated five times to reduce the total volume from 150 â€‹mL to 30 â€‹mL, which enabled it to be processed by 3 separate AdnaTest kits. The spike-in experiment demonstrated a reliable capture when there were more than 100 cancer cells/10 â€‹mL of concentrated leukopak. In 1 out of 5 real patient samples, CTCs were only detected in the leukopak, but not in peripheral blood. The RNA profiling of DLA CTCs indicated a more aggressive phenotype of CTCs occurred when the patient was experiencing a disease relapse, even when the serum prostate specific antigen (PSA) level was still relatively low and CTCs in peripheral blood were not detectable. We established a new protocol, integrating DLA, AdnaTest and NanoString nCounter technology, to profile RNAs from CTCs captured from a large blood screening volume. The new protocol can process the whole leukopak with sensitive CTC capture. The RNA profiling of CTCs can provide valuable information for disease monitoring.

Olaparib for Chinese metastatic castration-resistant prostate cancer: A real-world study of efficacy and gene predictive analysis.

To evaluate the real-world effectiveness and gene predictive analysis of olaparib in Chinese patients with metastatic castration-resistant prostate cancer (mCRPC), a multicenter, retrospective, real-world study was conducted by involving Chinese patients with mCRPC from December 2017 to June 2021. Homologous Recombination repair (HRR)gene mutation (HRRm) status was identified using targeted next-generation sequencing (NGS). The primary end point includes prostate-specific antigen (PSA) response rate (PSA50). Secondary end points include PSA progression-free survival (PSA-PFS), exploratory endpoints include PSA50, and PSA-PFS in HRRm-negative patients with variants of unknown significance (VUS). Survival rates were analyzed using Kaplan-Meier (KM) plot. A total of 39 eligible patients with a median age of 65 (interquartile range [IQR]: 59.5-69.5) years were included in the study. Overall, 40% (12/30) of the patients with mCRPC achieved PSA50 and the median PSA-PFS was 3.1 months (95% Confidence interval [CI]: 2.4-7). Furthermore, higher PSA50 rate and longer PSA-PFS were observed in HRRm-positive patients (PSA50: 50% [7/14]; median PSA-PFS: 5.3 months, 95% CI: 3.73-10). Among the HRRm-positive patients, those harboring the BRCA2 aberrations experienced best clinical efficacy (PSA50: 55.5% [5/9] and median PSA-PFS [95% CI]: 9.5 months [4.3, NA]). Clinical benefit was also observed in HRRm-negative patients (PSA50: 31.3% [5/16]; median PSA-PFS [95% CI]:2.05 months [1.5,8]), wherein most patients with a PSA50 response were carrying VUS (PSA50: 50% [4/8]; median PSA-PFS [95% CI]: 2.75 months [1.27, NA]). In one patients with mutation in the ATR gene, the PSA level decreased by 62%. Olaparib improved PSA response and prolonged PSA-PFS in Chinese mCRPC patients especially in those carrying HRR mutation. Among the HRR genes, patients with BRCA2 mutation showed the best clinical benefit. Besides, some patients carrying VUS on HRR gene and other DNA damage response (DDR) gene mutations also showed response to olaparib treatment, indicating that the clinical benefits observed in HRR-negative group were driven by VUS and other DDR gene mutation. However, this should be further explored in the future, and more molecular functional studies are needed to reclassify VUS for better clinical treatment decision-making and management of mCRPC.

Tumor-derived miR-378a-3p-containing extracellular vesicles promote osteolysis by activating the Dyrk1a/Nfatc1/Angptl2 axis for bone metastasis.

Most prostate cancer (PCa)-related deaths are caused by progression to bone metastasis. Recently, the importance of extracellular vesicles (EVs) in pre-metastatic niche formation has been reported. However, whether and how tumor-derived EVs interact with bone marrow macrophages (BMMs) to release EV-delivered microRNAs to promote osteolysis and induce pre-metastatic niche formation for PCa bone metastasis remain unclear. Our in vitro and in vivo functional and mechanistic assays revealed that EV-mediated release of miR-378a-3p from tumor cells was upregulated in bone-metastatic PCa, maintaining low intracellular miR-378a-3p concentration to promote proliferation and MAOA-mediated epithelial-to-mesenchymal transition. Moreover, miR-378a-3p enrichment in tumor-derived EVs was induced by hnRNPA2B1 (a transfer chaperone) overexpression. After tumor-derived EVs were taken in by BMMs, enriched miR-378a-3p promoted osteolytic progression by inhibiting Dyrk1a to improve Nfatc1 (an osteolysis-related transcription factor) nuclear translocation, to activate the expression of downstream target gene Angptl2. As a feedback, increased Angptl2 secretion into the tumor environment promoted PCa progression. In conclusion, tumor-derived miR-378a-3p-containing EVs play a significant role in PCa bone metastasis by activating the Dyrk1a/Nfatc1/Angptl2 axis in BMMs to induce osteolytic progression, making miR-378a-3p a potential predictor of metastatic PCa. Reducing the release of miR-378a-3p-containing EVs or inhibiting the recruitment of miR-378a-3p into EVs can be a therapeutic strategy against PCa metastasis.

Distinct Response to Platinum-Based Chemotherapy among Patients with Metastatic Castration-Resistant Prostate Cancer Harboring Alterations in Genes Involved in Homologous Recombination.

PURPOSE: We aimed to explore the association between genomic status and clinical outcome of platinum-based chemotherapy among patients with metastatic castration-resistant prostate cancer (mCRPC). MATERIALS AND METHODS: We conducted a retrospective study of 55 patients with mCRPC who received platinum-based chemotherapy after the progression to docetaxel chemotherapy and underwent genomic profiling of 14 homologous recombination (HR) pathway genes. Progression-free survival (PFS) was analyzed using the Kaplan-Meier method. RESULTS: Of 55 patients, 23 harbored genomic defects in HR pathway genes. Median prostate specific antigen (PSA)-PFS for the HR defect group was 6.7 months compared with 2.6 months for the no HR defect group (p=0.001). The patients harboring somatic HR defect displayed shorter PSA-PFS than those harboring germline HR defect (4.5 months vs not available; p=0.066). The PSA50 (patients who survived for 12 weeks and had a PSA decline over 50% from baseline) response rate displayed higher in patients harboring BRCA2 or ATM defect (6/8, 75.0%) than in those harboring CDK12 defect (2/9, 22.2%; p=0.06). Patients harboring BRCA2 or ATM defect displayed prolonged PSA-PFS, compared with those harboring CDK12 defect and those harboring other HR defect (p=0.038). In multivariate Cox regression analysis, HR defect and BRCA2 or ATM defect were independent significant factors associated with superior PAS-PFS to platinum-based chemotherapy. CONCLUSIONS: The patients with mCRPC harboring alterations in different HR genes displayed distinct response to platinum-based chemotherapy. Patients with mCRPC harboring genomic defects in crucial HR genes either in the germline or somatic, especially BRCA2 and ATM, might experience superior outcomes to platinum-based chemotherapy, compared with those harboring CDK12 defect.