Primary Prostate Cancer Tissues Research Articles

Quantifying Y chromosome loss in primary and metastatic prostate cancer by chromosome painting.

Somatic Y chromosome loss in hematopoietic cells is associated with higher mortality in men. However, the status of the Y chromosome in cancer tissue is not fully known due to technical limitations, such as difficulties in labelling and sequencing DNA from the Y chromosome. We have developed a system to quantify Y chromosome gain or loss in patient-derived prostate cancer organoids. Using our system, we observed Y chromosome loss in 4 of the 13 (31%) patient-derived metastatic castration-resistant prostate cancer (mCRPC) organoids; interestingly, loss of Yq (long arm of the Y chromosome) was seen in 38% of patient-derived organoids. Additionally, potential associations were observed between mCRPC and Y chromosome nullisomy. The prevalence of Y chromosome loss was similar in primary and metastatic tissue, suggesting that Y chromosome loss is an early event in prostate cancer evolution and may not a result of drug resistance or organoid derivation. This study reports quantification of Y chromosome loss and gain in primary and metastatic prostate cancer tissue and lays the groundwork for further studies investigating the clinical relevance of Y chromosome loss or gain in mCRPC.

Abstract 5199: Protease-activated CDCP1 as a marker for aggressive primary prostate cancer and castration resistance

Abstract CUB domain-containing protein 1 (CDCP1) is a type 1 transmembrane protein overexpressed in many cancers, including prostate cancer. CDCP1 has been associated with tumor progression, metastasis, drug resistance and poor prognosis in prostate cancer, making it a potential prognostic biomarker and therapeutic target. It has been shown to be overexpressed in a subset of castration resistant prostate cancers (CRPC) and cooperate with the loss of tumor suppressor PTEN to promote metastatic dissemination. Extracellular serine proteases activate CDCP1 by cleaving it into an N-terminal and C-terminal fragments. Proteolytic cleavage has been associated with the tumor-promoting functions of CDCP1. We studied the expression of full-length and cleaved form of CDCP1 in grade group 2-4 primary prostate cancer tissues and CRPCs using immunohistochemistry. Total CDCP1 staining was observed in 60% of primary prostate cancer samples, while the staining of cleaved CDCP1 was somewhat less frequently observed (45%). The results will be further analyzed regarding the PTEN status and for association with survival of the patients. In conclusion, so far, our results have indicated that cleaved CDCP1, which likely represents activated CDCP1, is detectable in GG 2-4 prostate cancers. Citation Format: Ruusu-Maaria Merivirta, Timo-Pekka Lehto, Antti Rannikko, Tuomas Mirtti, Hannu Koistinen. Protease-activated CDCP1 as a marker for aggressive primary prostate cancer and castration resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5199.

Identification of Genetic Alterations in Prostate Cancer Using Gene Expression Profiling

Aim: In this study, an open-access dataset of mRNAs from primary prostate cancer samples and matched normal tissue samples was used to identify genetic alterations that play a role in the development of prostate cancer, the most common malignant tumor in men with increasing incidence. Material and Methods: The dataset used in the study consists of 10 primary prostate cancer samples and a sample of normal tissue. 20024 genes were sequenced from these tissues. Gene expression analysis was performed with the data set using the limma package in the R programming language. Enrichment analysis was performed with the clusterProfiler package. Results: 1028 of 20024 genes showed different up- or down-regulation in primary prostate cancer tissues compared to normal tissues. According to the results of the enrichment analysis with these genes, the processes that play a role in primary prostate cancer are protein binding, binding, cellular process, biological process, and response to stimulus. Conclusion: As a result, it can be said that the genetic structure of primary prostate cancer tissues changes compared to normal tissues, with the information obtained from gene expression analysis and enrichment analysis. It can be said that it is possible to increase the therapeutic effectiveness of the disease by analyzing the biomarkers with comprehensive and various methods.

MiR-410 Is a Key Regulator of Epithelial-to-Mesenchymal Transition with Biphasic Role in Prostate Cancer.

The molecular basis of prostate cancer (PCa) progression from the primary disease to metastatic castration-resistant prostate cancer (CRPC) followed by therapy-induced neuroendocrine prostate cancer is not fully understood. In this study, we elucidate the role of miR-410, a little-studied microRNA located on chromosome 14q32.31 within the DLK1-DIO3 cluster, in PCa. miR-410 expression analyses in primary and metastatic PCa tissues and cell lines show that its levels are decreased in initial stages and increased in advanced PCa. Functional studies were performed in a series of PCa cell lines. In LNCaP cells, miR-410 overexpression led to decreases in cellular viability, proliferation, invasiveness, and migration. On the other hand, miR-410 overexpression in PC3 and C42B cells led to increased viability, proliferation, and invasiveness. Our data suggest that miR-410 represses epithelial-to-mesenchymal transition (EMT) in LNCaP cells by directly repressing SNAIL. However, it promotes EMT and upregulates PI3K/Akt signaling in PC3 and C42B cells. In vivo studies with PC3 xenografts support an oncogenic role of miR-410. These data suggest that miR-410 acts as a tumor suppressor in the initial stages of PCa and play an oncogenic role in advanced PCa. Our findings have important implications in understanding the molecular basis of PCa progression with potential translational implications.

TGF-β induces matrisome pathological alterations and EMT in patient-derived prostate cancer tumoroids

Extracellular matrix (ECM) tumorigenic alterations resulting in high matrix deposition and stiffening are hallmarks of adenocarcinomas and are collectively defined as desmoplasia. Here, we thoroughly analysed primary prostate cancer tissues obtained from numerous patients undergoing radical prostatectomy to highlight reproducible structural changes in the ECM leading to the loss of the glandular architecture. Starting from patient cells, we established prostate cancer tumoroids (PCTs) and demonstrated they require TGF-β signalling pathway activity to preserve phenotypical and structural similarities with the tissue of origin. By modulating TGF-β signalling pathway in PCTs, we unveiled its role in ECM accumulation and remodelling in prostate cancer. We also found that TGF-β-induced ECM remodelling is responsible for the initiation of prostate cell epithelial-to-mesenchymal transition (EMT) and the acquisition of a migratory, invasive phenotype. Our findings highlight the cooperative role of TGF-β signalling and ECM desmoplasia in prompting prostate cell EMT and promoting tumour progression and dissemination.

Correlation between E-cadherin/β-catenin, Vimentin expression, clinicopathologic features and drug resistance prediction in naïve prostate cancer: A molecular and clinical study.

Although epithelial-mesenchymal markers play an important role in prostate cancer (PC), further research is needed to better understand their utility in diagnosis, cancer progression prevention, and treatment resistance prediction. Our study included 111 PC patients who underwent transurethral resection, as well as 16 healthy controls. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to examine the expression of E-cadherin, β-catenin, and Vimentin. We found that E-cadherin and β-catenin were underexpressed in primary PC tissues. E-cadherin expression was found to be inversely associated with prostate-specific antigen progression (PSA-P; serum marker of progression; p = 0.01; |r| = 0.262). Furthermore, the underexpression of two markers, E-cadherin and β-catenin, was found to be associated with advanced tumor stage and grade (p < 0.05). On the other hand, Vimentin was overexpressed in PC patients with a fold change of 2.141, and it was associated with the diagnosis, prognosis, and prediction of treatment resistance to androgen deprivation therapy (p = 0.002), abiraterone-acid (p = 0.001), and taxanes (p = 0.029). Moreover, the current study highlighted that poor survival could be significantly found in patients who progressed after primary surgery, did not use drugs, and expressed these genes aberrantly. In Cox regression multivariate analysis (p < 0.05), a positive correlation between the Vimentin marker and coronary heart disease in PC patients was identified (p = 0.034). In summary, the present study highlights the diagnostic (p < 0.001), prognostic (p < 0.001), and therapeutic potential of Vimentin in primary PC (p < 0.05), as well as its implications for cardiovascular disease. Furthermore, we confirm the potential prognostic value of E-cadherin and β-catenin.

Depth of PSA nadir and subsequent PSA progression-free survival in patients (pts) with high-risk biochemically relapsed prostate cancer: Results from the phase 3 PRESTO study (AFT-19).

5077 Background: In the phase 3 PRESTO study, intensified androgen deprivation therapy (ADT) with apalutamide (Apa) with or without abiraterone acetate plus prednisone (AAP), administered for a finite treatment period of 52 weeks, prolonged prostate-specific antigen progression-free survival (PSA PFS) in pts with high-risk biochemically relapsed prostate cancer (BRPC). We evaluated the association between PSA nadir within 3 months of treatment initiation with subsequent PSA PFS in this study. Methods: PRESTO is a randomized phase 3, open-label trial in pts with BRPC following radical prostatectomy (RP) and PSA doubling time (PSADT) ≤ 9 months, without distant metastases on conventional imaging (NCT03009981). Pts were randomized 1:1:1 to receive a finite 52-week treatment course with ADT, ADT + Apa, or ADT + Apa + AAP, stratified by PSADT (&lt; 3 vs 3–9 months), with post-treatment follow-up. The association between PSA nadir within the first three months on treatment with subsequent PSA PFS was analyzed in a post hoc fashion. Results: 504 pts were randomized to ADT alone (N = 167), ADT + Apa (N = 168) or ADT + Apa + AAP (N = 169). 463 pts were evaluable for PSA nadir at 3 months. Across the three treatment arms, a PSA nadir of less than 0.1, between 0.1 – 0.2, and ≥ 0.2 ng/mL within the first three months of treatment was observed in 86.3%, 4.4%, and 9.3% of patients, respectively. A PSA nadir of &lt; 0.2 ng/mL was reached within 3 months of treatment initiation in 79.8%, 96.9%, and 95.0% of pts randomized to the ADT, ADT + Apa, and ADT + Apa + AAP arms, respectively. The association between time to PSA nadir and subsequent PSA PFS was -0.30 (standard error = 0.03, Kendall’s tau modified for bivariate censoring), and median time to PSA nadir was 2.0 months (interquartile range 1.12 – 4.76 months). Failure to reach a PSA nadir &lt; 0.2 ng/mL within the first three months of treatment was associated with a significantly shorter PSA PFS compared to pts with a PSA nadir ≤ 0.1 ng/mL (median PSA PFS of 13.9 vs. 22.8 months from 3 months post-treatment initiation; hazard ratio = 5.60, 95% CI: 3.58 – 8.75, p &lt; 0.0001). There was also a significant difference in PSA PFS in those with a three-month PSA nadir between 0.1 – 0.2 vs ≤ 0.1 ng/mL (median PSA PFS 17.4 vs 22.8 months, HR = 2.63, 95:CI: 1.49 – 4.63, p = 0.0008). Conclusions: Using a landmark analysis at 3 months, a failure to reach PSA nadir less than 0.1 ng/mL within three months following initiation of ADT in BRPC is associated with shorter time to subsequent progression following treatment discontinuation. Follow-up is ongoing to integrate genomic profiling of primary prostate cancer tissues and whole blood RNA in pts with suboptimal PSA nadir to identify potential markers of relative androgen pathway inhibitor resistance. Clinical trial information: NCT03009981 .

Abstract 1157: Uncovering a novel role of peroxisomal β-oxidation in advanced, treatment-resistant prostate cancer

Abstract Background and Aims: Prostate cancer (PCa) is highly reliant on lipids for energy, hence targeting fatty acid oxidation (FAO) is a highly promising approach to the treatment of PCa. Recent work by our group and others have shown that FAO is critical for cell viability and survival, and is one of the key drivers of treatment resistance. Although FAO occurs in both the mitochondria and peroxisomes, the functional relevance and therapeutic exploitability of peroxisomal FAO (perFAO) in PCa has not been extensively explored compared to the mitochondria. Herein, we aim to investigate the therapeutic efficacy of targeting perFAO in clinical prostate tumors and PCa cells, and explore its role in PCa progression. Methods and Results: Pharmacological inhibition of perFAO using the clinical agent, thioridazine, significantly suppressed proliferation, migration, and colony formation of a range of advanced and treatment-resistant PCa cells. Further, we evaluated the therapeutic efficacy of thioridazine in a more clinically relevant setting using patient-derived tissues and showed a significant inhibition of cell proliferation (n = 11, p &amp;lt; 0.05). Next, we performed a bioinformatics analysis of clinical RNAseq datasets composed of primary and metastatic PCa tissues and identified DECR2, the auxiliary enzyme of perFAO, as a key target of perFAO in PCa. DECR2 is overexpressed in metastatic castrate-resistant PCa (CRPC) tissues compared to primary PCa and benign tissues, and is significantly associated with shorter relapse-free survival (p &amp;lt; 0.01). DECR2 knockdown significantly suppressed proliferation and migration of CRPC and enzalutamide-resistant PCa cells, and markedly reduced LNCaP tumor growth in vivo. In contrast, overexpression of DECR2 in LNCaP cells significantly increased tumor growth in vivo. Interestingly, analysis of a published proteomics dataset of PCa cells that are either androgen-dependent or resistant to androgen receptor (AR) inhibitors revealed a significant correlation of peroxisomal genes (MSigDB) with acquired resistance to AR inhibition. Notably, DECR2 overexpression was significantly associated with shorter overall survival (p &amp;lt; 0.05) in a metastatic CRPC cohort treated with AR inhibitors. We further showed that DECR2 overexpression in LNCaP cells significantly reduced sensitivity to AR inhibitor treatments and androgen-deprivation, suggesting a role for perFAO in promoting survival and treatment resistance. Conclusion: Our study has revealed a novel role for perFAO in PCa progression and treatment resistance. Importantly, this study also identified DECR2 as a key regulator of tumor cell proliferation and lipid metabolism, representing a potential novel therapeutic target for advanced, treatment-resistant PCa that currently lacks effective targeted therapies. Citation Format: Chui Yan Mah, An D. Nguyen, Takuto Niijima, Madison Helm, Jonas Dehairs, Feargal J. Ryan, Natalie Ryan, Ian G. Mills, Johannes V. Swinnen, David J. Lynn, Zeyad D. Nassar, Lisa M. Butler. Uncovering a novel role of peroxisomal β-oxidation in advanced, treatment-resistant prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1157.

Rewiring of miRNA-mRNA bipartite co-expression network as a novel way to understand the prostate cancer related players

The differential expression and direct targeting of mRNA by miRNA are two main logics of the traditional approach to constructing the miRNA-mRNA network. This approach, could be led to the loss of considerable information and some challenges of direct targeting. To avoid these problems, we analyzed the rewiring network and constructed two miRNA-mRNA expression bipartite networks for both normal and primary prostate cancer tissue obtained from PRAD-TCGA. We then calculated beta-coefficient of the regression-model when miR was dependent and mRNA independent for each miR and mRNA and separately in both networks. We defined the rewired edges as a significant change in the regression coefficient between normal and cancer states. The rewired nodes through multinomial distribution were defined and network from rewired edges and nodes was analyzed and enriched. Of the 306 rewired edges, 112(37%) were new, 123(40%) were lost, 44(14%) were strengthened, and 27(9%) weakened connections were discovered. The highest centrality of 106 rewired mRNAs belonged to PGM5, BOD1L1, C1S, SEPG, TMEFF2, and CSNK2A1. The highest centrality of 68 rewired miRs belonged to miR-181d, miR-4677, miR-4662a, miR-9.3, and miR-1301. SMAD and beta-catenin binding were enriched as molecular functions. The regulation was a frequently repeated concept in the biological process. Our rewiring analysis highlighted the impact of β-catenin and SMAD signaling as also some transcript factors like TGFB1I1 in prostate cancer progression. Altogether, we developed a miRNA-mRNA co-expression bipartite network to identify the hidden aspects of the prostate cancer mechanism, which traditional analysis -like differential expression- was not detect it.

TEAD3 inhibits the proliferation and metastasis of prostate cancer via suppressing ADRBK2

TEAD3 acts as a transcription factor in many tumors to promote tumor occurrence and development. But in prostate cancer (PCa), it appears as a tumor suppressor gene. Recent studies have shown that this may be related to subcellular localization and posttranslational modification.We found that TEAD3 was down-expressed in PCa. Immunohistochemistry of clinical PCa specimens confirmed that TEAD3 expression was the highest in benign prostatic hyperplasia (BPH) tissues, followed by primary PCa tissues, and the lowest in metastatic PCa tissues, and its expression level was positively correlated with overall survival. MTT assay, clone formation assay, and scratch assay confirmed that overexpression of TEAD3 could significantly inhibit the proliferation and migration of PCa cells. Next-generation sequencing results indicated that Hedgehog (Hh) signaling pathway was significantly inhibited after overexpression of TEAD3. Rescue assays suggested that ADRBK2 could reverse the proliferation and migration ability caused by overexpression of TEAD3.TEAD3 is downregulated in PCa and associated with poor patient prognosis. Overexpression of TEAD3 inhibits the proliferation and migration ability of PCa cells via restraining the mRNA level of ADRBK2.These results indicate that TEAD3 was down-expressed in PCa patients and was positively correlated with a high Gleason score and poor prognosis. Mechanistically, we found that the upregulation of TEAD3 inhibits the proliferation and metastasis of prostate cancer by inhibiting the expression of ADRBK2.

Baseline characteristics associated with PSA progression-free survival in patients (pts) with high-risk biochemically relapsed prostate cancer: Results from the phase 3 PRESTO study (AFT-19).

208 Background: In the Phase 3 PRESTO study, intensified androgen deprivation therapy (ADT) with apalutamide (APA) with or without abiraterone acetate plus prednisone (AAP), administered for a finite treatment period of 52 weeks, prolonged prostate-specific antigen progression-free survival (PSA PFS) in pts with high-risk biochemically relapsed prostate cancer (BRPC). We evaluated baseline factors associated with PSA PFS in this study. Methods: PRESTO is a randomized phase 3, open-label trial in pts with BRPC following radical prostatectomy (RP) and PSA doubling time (PSADT) ≤ 9 months (mo), without distant metastases on conventional imaging (NCT03009981). Pts were randomized 1:1:1 to receive a finite 52-week treatment course with ADT, ADT + APA, or ADT + APA + AAP, stratified by PSADT (&lt; 3 vs 3–9 mo), with post-treatment follow-up. Baseline factors associated with PSA PFS including Gleason sum at RP (6-7, 8, ≥ 9) were analyzed in a post hoc fashion. Results: 504 pts were randomized to ADT alone (N = 167), ADT + APA (N = 168) or ADT + APA + AAP (N = 169). Baseline patient characteristics including Gleason sum at diagnosis, serum PSA and PSADT at study entry, time interval from radical prostatectomy, and receipt of prior radiation (none, adjuvant, salvage) were well balanced across the three treatment arms. At the first planned interim analysis, both experimental arms significantly prolonged PSA PFS compared to the control arm (median 24.9 mo for ADT + APA vs 20.3 mo for ADT, HR = 0.52 (95% CI: 0.35–0.77); median 26.0 mo for ADT + APA + AAP vs 20.0 mo for ADT, HR = 0.48 (95% CI: 0.32–0.71)). Across the study cohort, Gleason sum ≥ 9 at diagnosis was associated with shorter PSA PFS (median 21.9 mo for Gleason ≥ 9 vs. 31.1 mo for Gleason 8 vs. 25.2 mo for Gleason 6-7, log-rank p-value = 0.0409). In addition, within each treatment arm, a shorter observed median PSA PFS was detected for patients with Gleason ≥ 9 prostate cancer. Serum PSA and PSADT at study entry, time from prior radical prostatectomy, and prior radiation were not associated with PSA PFS in the overall study cohort or in individual study arms. Conclusions: Gleason sum ≥ 9 prostate cancer at diagnosis was associated with shorter time to PSA progression following subsequent intensified ADT administered for a finite treatment interval in BRPC. Follow-up is ongoing to integrate genomic profiling of primary prostate cancer tissue with these results and validate with longer term endpoints including metastasis-free survival. Clinical trial information: NCT03009981 .

Inhibition of CXCR4 Enhances the Efficacy of Radiotherapy in Metastatic Prostate Cancer Models.

Radiotherapy (RT) is a standard treatment for patients with advanced prostate cancer (PCa). Previous preclinical studies showed that SDF1α/CXCR4 axis could mediate PCa metastasis (most often to the bones) and cancer resistance to RT. We found high levels of expression for both SDF1α and its receptor CXCR4 in primary and metastatic PCa tissue samples. In vitro analyses using PCa cells revealed an important role of CXCR4 in cell invasion but not radiotolerance. Pharmacologic inhibition of CXCR4 using AMD3100 showed no efficacy in orthotopic primary and bone metastatic PCa models. However, when combined with RT, AMD3100 potentiated the effect of local single-dose RT (12 Gy) in both models. Moreover, CXCR4 inhibition also reduced lymph node metastasis from primary PCa. Notably, CXCR4 inhibition promoted the normalization of bone metastatic PCa vasculature and reduced tissue hypoxia. In conclusion, the SDF1α/CXCR4 axis is a potential therapeutic target in metastatic PCa patients treated with RT.

Scaffold protein MAPK8IP2 expression is a robust prognostic factor in prostate cancer associated with AR signaling activity.

Mitogen-activated protein kinase-8-interacting protein 2 (MAPK8IP2) is a scaffold protein that modulates MAPK signal cascades. Although MAPK pathways were heavily implicated in prostate cancer progression, the regulation of MAPK8IP2 expression in prostate cancer is not yet reported. We assessed MAPK8IP2 gene expression in prostate cancer related to disease progression and patient survival outcomes. MAPK8IP2 expression was analyzed using multiple genome-wide gene expression datasets derived from The Cancer Genome Atlas (TCGA) RNA-sequence project and complementary DNA (cDNA) microarrays. Multivariable Cox regressions and log-rank tests were used to analyze the overall survival outcome and progression-free interval. MAPK8IP2 protein expression was evaluated using the immunohistochemistry approach. The quantitative PCR and Western blot methods analyzed androgen-stimulated MAPK8IP2 expression in LNCaP cells. In primary prostate cancer tissues, MAPK8IP2 mRNA expression levels were significantly higher than those in the case-matched benign prostatic tissues. Increased MAPK8IP2 expression was strongly correlated with late tumor stages, lymph node invasion, residual tumors after surgery, higher Gleason scores, and preoperational serum prostate-specific antigen (PSA) levels. MAPK8IP2 upregulation was significantly associated with worse overall survival outcomes and progression-free intervals. In castration-resistant prostate cancers, MAPK8IP2 expression strongly correlated with androgen receptor (AR) signaling activity. In cell culture-based experiments, MAPK8IP2 expression was stimulated by androgens in AR-positive prostate cancer cells. However, MAPK8IP2 expression was blocked by AR antagonists only in androgen-sensitive LNCaP but not castration-resistant C4-2B and 22RV1 cells. These results indicate that MAPK8IP2 is a robust prognostic factor and therapeutic biomarker for prostate cancer. The potential role of MAPK8IP2 in the castration-resistant progression is under further investigation.

The ERα-NRF2 signalling axis promotes bicalutamide resistance in prostate cancer

BackgroundBicalutamide is a nonsteroidal antiandrogen widely used as a first-line clinical treatment for advanced prostate cancer (PCa). Although patients initially show effective responses to bicalutamide treatment, resistance to bicalutamide frequently occurs and leads to the development of castration-resistant PCa (CRPC). This research investigated the roles of the oestrogen receptor α (ERα)-nuclear factor E2-related factor 2 (NRF2) signalling pathway in bicalutamide resistance in PCa cells.MethodsWe performed bioinformatic analysis and immunohistochemical staining on normal and cancerous prostate tissue to evaluate ERα and NRF2 expression and their correlation. Gene expression and localization in PCa cell lines were further investigated using real-time reverse transcription PCR/Western blotting and immunofluorescence staining. We treated PCa cells with the ER inhibitor tamoxifen and performed luciferase reporter assays and chromatin immunoprecipitation (ChIP) assays to understand ERα-dependent NRF2 expression. Overexpression and knockdown of ERα and NRF2 were used to explore the potential role of the ERα-NRF2 signalling axis in bicalutamide resistance in PCa cells.ResultsWe found that the expression of ERα and NRF2 was positively correlated and was higher in human CRPC tissues than in primary PCa tissues. Treatment with oestrogen or bicalutamide increased the expression of ERα and NRF2 as well as NRF2 target genes in PCa cell lines. These effects were blocked by pretreatment with tamoxifen. ChIP assays demonstrated that ERα directly binds to the oestrogen response element (ERE) in the NRF2 promoter. This binding led to increased transcriptional activity of NRF2 in a luciferase reporter assay. Activation of the ERα-NRF2 signalling axis increased the expression of bicalutamide resistance-related genes. Inhibition of this signalling axis by knockdown of ERα or NRF2 downregulated the expression of bicalutamide resistance-related genes and inhibited the proliferation and migration of PCa cells.ConclusionsWe demonstrated the transcriptional interaction between ERα and NRF2 in CRPC tissues and cell lines by showing the direct binding of ERα to the ERE in the NRF2 promoter under oestrogen treatment. Activation of the ERα-NRF2 signalling axis contributes to bicalutamide resistance in PCa cells, suggesting that the ERα-NRF2 signalling axis is a potential therapeutic target for CRPC.CxbrQyr1MPyN3X1_gKxrKxVideo

Inhibition of circ_0081234 reduces prostate cancer tumor growth and metastasis via the miR-1/MAP 3K1 axis.

Circular RNAs (circRNAs) are crucial regulators of tumor occurrence and progression, and circRNAs are enriched and stable in exosomes. The present study aimed to explore the role and potential mechanism of cancer-derived exosomal circ_0081234 in prostate cancer (PCa). Exosomes were extracted using the ExoQuick Precipitation Kit (System Biosciences, Mountain View, CA, USA). The levels of circ_0081234, miR-1 and mitogen-activated protein kinase kinase kinase 1 (MAP 3K1) were examined using a quantitative real-time polymerase chain reaction or western blotting. Cell migration and invasion were evaluated via a transwell assay. The protein levels of N-cadherin, vimentin and E-cadherin were detected by western blotting. The interaction between miR-1 and circ_0081234 or MAP 3K1 was verified via a dual-luciferase reporter assay and an RNA pull-down assay. The circ_0081234 level was increased in PCa tissues with spinal metastasis in comparison to primary PCa tissues without spinal metastasis. Exosomal circ_0081234 promoted the migration, invasion and epithelial-mesenchymal transition of PCa cells. Knockdown of circ_0081234 blocked PCa cell progression by regulating miR-1. In addition, miR-1 overexpression suppressed PCa cell progression by repressing MAP 3K1. Moreover, circ_0081234 increased MAP 3K1 level via sponging miR-1. Depletion of circ_0081234 inhibited tumor growth in vivo. Exosomal circ_0081234 promoted migration, invasion and epithelial-mesenchymal transition of PCa cells by regulating the miR-1/MAP 3K1 axis.

Influence of Androgen Deprivation Therapy on the PD-L1 Expression and Immune Activity in Prostate Cancer Tissue.

Immune checkpoint inhibitors have become a promising new therapy for cancer treatment. However, due to prostate cancer’s high heterogeneity and immune-suppressive tumour microenvironment, clinical trials with immune checkpoint inhibitors for prostate cancer resulted in low or no response. This descriptive and retrospective study investigates the influence of androgen deprivation therapy (ADT) on PD-L1 expression and CD8+ T-cell tumour infiltration and activity in primary prostate cancer tissue. Therefore, immunohistochemistry was used to assess PD-L1, CD8+ T-cell, and the immune activation marker Granzyme B (GrB) in PCa tissue before and under ADT. In line with previous studies, few prostate cancer tissues showed PD-L1 expression and CD8+ T-cell infiltration. However, PD-L1 expression levels on tumour cells or infiltrating immune cells above 5% generated an immune-suppressive tumour microenvironment harbouring hypofunctional CD8+ T-cells. Moreover, analysis of a longitudinal patient cohort before and under ADT revealed that ADT increased hypofunctional CD8+ T cells in the tumour area suggesting a tumour immune milieu optimal for targeting with immunotherapy.

A multidisciplinary approach to optimize primary prostate cancer biobanking.

Biobanking tissue of high quality and fidelity is imperative for cancer genomics research. Since it is a challenging process, we sought to develop a protocol that improves the fidelity and quantity of biobanked primary prostate cancer (CaP) tissue. We conducted a pilot study evaluating pathologic concordance of biobanked tissue and the radical prostatectomy specimen using either standard protocol (SP) vs. next-generation protocol (NGP). There were no significant differences in clinical and pathologic characteristics (age, BMI, preoperative PSA, prostate weight, race, final prostatectomy Gleason score, or pathologic tumor and nodal stages) between the two protocol arms. Utilization of the NGP compared to the standard protocol resulted in a significantly higher rate of pathologic concordance between the biobanked and RP specimens (61.8% vs. 37.9%, P = 0.0231) as well as a nearly two-fold increase in the amount of biobanked tumor tissue (330 mm3 vs. 174 mm3, P < 0.001). When looking at relevant clinical and pathologic characteristics, NGP was associated with pathologic concordance on both univariate [OR 2.65 (95% CI 1.13-6.21), P = 0.025] and multivariate analysis [OR 3.11 (95% CI 1.09-8.88), P = 0.034]. Our study validates the NGP as a multidisciplinary approach for improving the fidelity and amount of biobanked primary CaP tissue for future studies. Given the challenges to banking tissue from primary CaP as tumors are often difficult to visualize grossly and are frequently multifocal, optimizing the fidelity and volume of biobanked tissue is an important step forward to improve the generalizability of genomic data as we move towards precision medicine.

Downregulation of miR-485-3p promotes proliferation, migration and invasion in prostate cancer through activation of TGF-β signaling.

Prostate cancer (PC) is the second leading cause of cancer-related death among men worldwide. Downregulation of miR-485-3p has been revealed to participate in the tumorigenesis and progression of many types of cancer. However, the clinical and biological role of miR-485-3p in PC remains largely unknown. The expression of miR-485-3p was analyzed in the published databases and detected in our clinical samples and cell lines by RT-qPCR assay. CCK8, transwell invasion and migration, and colony formation assays were performed to investigate the biological function of miR-485-3p. Bioinformatical analysis, RIP, western blotting and luciferase reporter assays were carried out to explore the downstream mechanism of miR-485-3p. The level of miR-485-3p was downregulated in PC tissues, particularly in primary PC tissues with metastasis relative to normal prostate tissues. miR-485-3p downregulation was positively correlated with poor disease-free and overall survival in patients with PC. Functionally, miR-485-3p overexpression dramatically suppressed the proliferation, migration and invasion ability of PC cells in vitro. Mechanistically, miR-485-3p overexpression suppressed the activity of TGF-β signaling by targeting TGFBR2 to play tumor-suppressive roles in PC progression. Our study reports the miR-485-3p/TGFBR2/ TGF-β signaling axis in tumor development of PC, suggesting miR-485-3p may be a potential target to develop therapeutic strategies against PC.

Identification of novel prostate cancer genes in patients stratified by Gleason classification: Role of antitumoral genes.

Prostate cancer (PCa) is a tumor with a great heterogeneity, both at a molecular and clinical level. Despite its global good prognosis, cases can vary from indolent to lethal metastatic and scientific efforts are aimed to discern those with worse outcomes. Current prognostic markers, as Gleason score, fall short when it comes to distinguishing these cases. Identification of new early biomarkers to enable a better PCa distinction and classification remains a challenge. In order to identify new genes implicated in PCa progression we conducted several differential gene expression analyses over paired samples comparing primary PCa tissue against healthy prostatic tissue of PCa patients. The results obtained show that this approach is a serious alternative to overcome patient heterogeneity. We were able to identify 250 genes whose expression varies along with tissue differentiation—healthy to tumor tissue, 161 of these genes are described here for the first time to be related to PCa. The further manual curation of these genes allowed to annotate 39 genes with antitumoral activity, 22 of them described for the first time to be related to PCa proliferation and metastasis. These findings could be replicated in different cohorts for most genes. Results obtained considering paired differential expression, functional annotation and replication results point to: CGREF1, UNC5A, C16orf74, LGR6, IGSF1, QPRT and CA14 as possible new early markers in PCa. These genes may prevent the progression of the disease and their expression should be studied in patients with different outcomes.

Implementation of a prostate cancer-specific targeted sequencing panel for credentialing of patient-derived cell lines and genomic characterization of patient samples.

Primary and metastatic prostate cancers have low mutation rates and recurrent alterations in a small set of genes, enabling targeted sequencing of prostate cancer-associated genes as an efficient approach to characterizing patient samples (compared to whole-exome and whole-genome sequencing). For example, targeted sequencing provides a flexible, rapid, and cost-effective method for genomic assessment of patient-derived cell lines to evaluate fidelity to initial patient tumor samples. We developed a prostate cancer-specific targeted next-generation sequencing (NGS) panel to detect alterations in 62 prostate cancer-associated genes as well as recurring gene fusions with ETS family members, representing the majority of common alterations in prostate cancer. We tested this panel on primary prostate cancer tissues and blood biopsies from patients with metastatic prostate cancer. We generated patient-derived cell lines from primary prostate cancers using conditional reprogramming methods and applied targeted sequencing to evaluate the fidelity of these cell lines to the original patient tumors. The prostate cancer-specific panel identified biologically and clinically relevant alterations, including point mutations in driver oncogenes and ETS family fusion genes, in tumor tissues from 29 radical prostatectomy samples. The targeted panel also identified genomic alterations in cell-free DNA and circulating tumor cells (CTCs) from patients with metastatic prostate cancer, and in standard prostate cancer cell lines. We used the targeted panel to sequence our set of patient-derived cell lines; however, no prostate cancer-specific mutations were identified in the tumor-derived cell lines, suggesting preferential outgrowth of normal prostate epithelial cells. We evaluated a prostate cancer-specific targeted NGS panel to detect common and clinically relevant alterations (including ETS family gene fusions) in prostate cancer. The panel detected driver mutations in a diverse set of clinical samples of prostate cancer, including fresh-frozen tumors, cell-free DNA, CTCs, and cell lines. Targeted sequencing of patient-derived cell lines highlights the challenge of deriving cell lines from primary prostate cancers and the importance of genomic characterization to credential candidate cell lines. Our study supports that a prostate cancer-specific targeted sequencing panel provides an efficient, clinically feasible approach to identify genetic alterations across a spectrum of prostate cancer samples and cell lines.