Progression Of Prostatic Adenocarcinoma Research Articles

Neuroendocrine Differentiation in Prostate Cancer Requires ASCL1.

Most patients with prostate adenocarcinoma develop resistance to therapies targeting the androgen receptor (AR). Consequently, a portion of these patients develop AR-independent neuroendocrine prostate cancer (NEPC), a rapidly progressing cancer with limited therapies and poor survival outcomes. Current research to understand the progression to NEPC suggests a model of lineage plasticity whereby AR-dependent luminal-like tumors progress towards an AR-independent NEPC state. Genetic analysis of human NEPC identified frequent loss of RB1 and TP53, and the loss of both genes in experimental models mediates the transition to a neuroendocrine lineage. Transcriptomics studies have shown that lineage transcription factors ASCL1 and NEUROD1 are present in NEPC. In this study, we modeled the progression of prostate adenocarcinoma to NEPC by establishing prostate organoids and subsequently generating subcutaneous allograft tumors from genetically-engineered mouse models harboring Cre-induced loss of Rb1 and Trp53 with Myc overexpression (RPM). These tumors were heterogeneous and displayed adenocarcinoma, squamous, and neuroendocrine features. ASCL1 and NEUROD1 were expressed within neuroendocrine-defined regions, with ASCL1 being predominant. Genetic loss of Ascl1 in this model did not decrease tumor incidence, growth, or metastasis; however, there was a notable decrease in neuroendocrine identity and an increase in basal-like identity. This study provides an in vivo model to study progression to NEPC and establishes the requirement for ASCL1 in driving neuroendocrine differentiation in prostate cancer.

Targeting GLI1 and BAX by nanonoscapine could impede prostate adenocarcinoma progression

Prostate cancer as a critical global health issue, requires the exploration of a novel therapeutic approach. Noscapine, an opium-derived phthalide isoquinoline alkaloid, has shown promise in cancer treatment thanks to its anti-tumorigenic properties. However, limitations such as low bioavailability and potential side effects have hindered its clinical application. This study introduces nanonoscapine as a novel medication to overcome these challenges, leveraging the advantages of improved drug delivery and efficacy achieved in nanotechnology. We monitored the effects of nanonoscapine on the androgen-sensitive human prostate adenocarcinoma cell line, LNCaP, investigating its impact on GLI1 and BAX genes’ expressions, crucial regulators of cell cycle and apoptosis. Our findings, from MTT assays, flow cytometry, and gene expression analyses, have demonstrated that nanonoscapine effectively inhibits prostate cancer cell proliferation by inducing G2/M phase arrest and apoptosis. Furthermore, through bioinformatics and computational analyses, we have revealed the underlying molecular mechanisms, underscoring the therapeutic potential of nanonoscapine in enhancing patient outcomes. This study highlights the significance of nanonoscapine as an alternative or adjunct treatment to conventional chemotherapy, warranting further investigation in clinical settings.

An androgen receptor-based signature to predict prognosis and identification of ORC1 as a therapeutical target for prostate adenocarcinoma.

Aberrant activation of androgen receptor (AR) signaling plays a crucial role in the progression of prostate adenocarcinoma (PRAD) and contributes significantly to the development of enzalutamide resistance. In this study, we aimed to identify a novel AR-driven signature that can predict prognosis and endows potentially reveal novel therapeutic targets for PRAD. The Seurat package was used to preprocess the single-cell RNA sequencing (scRNA-seq). Differentially expressed genes were visualized using limma and pheamap packages. LASSO and multi-variate Cox regression models were established using glmnet package. The package "Consensus Cluster Plus" was utilized to perform the consensus clustering analysis. The biological roles of origin recognition complex subunit 1 (ORC1) in PRAD were determined by gain- and loss-of-function studies in vitro and in vivo. We characterized the scRNA-seq data from GSE99795 and identified 10 AR-associated genes (ARGs). The ARGs model was trained and validated in internal and external cohorts. The ARGs were identified as an independent hazard factor in PRAD and correlated with clinical risk characteristics. In addition, the ARGs were found to be correlated with somatic tumor mutation burden (TMB) levels. Two groups that have distinct prognostic and molecular features were identified through consensus clustering analysis. ORC1 was identified as a critical target among these ARGs, and it ORC1 promoted proliferation and stem-like properties of PRAD cells. Chromatin immunoprecipitation (ChIP)-qPCR assay confirmed that AR could directly bind the promoter of ORC1. Activated AR/ORC1 axis contributed to enzalutamide resistance, and targeting ORC1 rendered PRAD cells more susceptible to enzalutamide. This study defines an AR-driven signature that AR activates ORC1 expressions to promote PRAD progression and enzalutamide resistance, which may provide novel targets for PRAD treatment.

Differential tempol effects in prostatic cancer: angiogenesis and short- and long-term treatments.

Prostate cancer (PCa) is the second cause of cancer death among men worldwide. Several processes are involved in the development and progression of PCa such as angiogenesis, inflammation and oxidative stress. The present study investigated the effect of short- or long-term Tempol treatment at different stages of prostate adenocarcinoma progression, focusing on angiogenic, proliferative, and stromal remodeling processes in TRAMP mice. The dorsolateral lobe of the prostate of TRAMP mice were evaluated at two different stages of PCa progression; early and late stages. Early stage was again divided into, short- or long-term. 50mg/kg Tempol dose was administered orally. The results demonstrated that Tempol mitigated the prostate histopathological lesion progressions in the TRAMP mice in all treated groups. However, Tempol increased molecules involved in the angiogenic process such as CD31 and VEGFR2 relative frequencies, particularly in long-term treatment. In addition, Tempol upregulated molecule levels involved in angiogenesis and stromal remodeling process VEGF, TGF-β1, VE-cadherin and vimentin, particularly, in T8-16 group. Thus, it was concluded that Tempol treatment delayed prostatic lesion progression in the dorsolateral lobe of the TRAMP mice. However, Tempol also led to pro-angiogenic effects and glandular stromal microenvironment imbalance, especially, in the long-term treatment.

Immunohistochemical Expression Status of HER2/neu and E-cadherin in Prostate Adenocarcinoma: A Cross-sectional Study

Introduction: Prostate cancer is a common tumour, accounting for 92% of malignancies in the male genital tract. Due to the high recurrence rate, it is important to identify prognostic markers in prostate cancer. Human Epidermal Growth Factor Receptor 2 (HER2) and Epithelial cadherin (E-cadherin) are speculated to be associated with carcinogenesis, but the literature has provided controversial results. Aim: To investigate the expression of HER2/neu and E-cadherin in prostatic adenocarcinoma and its correlation with clinicopathological parameters. Materials and Methods: A retrospective cross-sectional study was conducted at the Department of Pathology, SDM University, Dharwad, Karnataka, India. The study duration was one year and five months, from October 2020 to March 2022. A total of 45 cases diagnosed as prostatic adenocarcinoma between October 2016 and September 2019 were included. Clinicopathological parameters such as age, Prostate- Specific Antigen (PSA) levels, metastasis, perineural invasion, Gleason score, Gleason grade, and two-year survival were retrieved from hospital records and through telephone interviews. Immunohistochemistry (IHC) staining for HER2 and E-cadherin was performed and assessed by pathologists. Statistical analysis was conducted using Statistical Package for Social Sciences (SPSS) version 20.0, and the Chi-square test was applied. Results: The mean age of the study participants was 69.6 years, ranging from 52 to 95 years. The rates of HER2/neu overexpression/positivity and reduced E-cadherin expression were 25 (55.5%) and 14 (31.1%), respectively. No statistically significant associations were found between HER2 and E-cadherin expression and age, PSA levels, perineural invasion, Gleason score, Gleason grade, and two-year survival (p>0.05). However, a statistically significant association was observed between HER2 expression and distant metastasis (p-value=0.006), whereas no significant association was found with E-cadherin (p-value=0.81). Conclusion: The study demonstrated a significant association between HER2/neu overexpression and tumour metastasis, suggesting that HER2/neu could serve as a prognostic parameter to assist surgeons. In contrast, E-cadherin showed no association with clinicopathological parameters, raising questions about its involvement in the progression of prostatic adenocarcinoma.

USF1-mediated ALKBH5 stabilizes FLII mRNA in an m6A-YTHDF2-dependent manner to repress glycolytic activity in prostate adenocarcinoma.

Upstream-stimulating factor 1 (USF1) is a ubiquitously expressed transcription factor implicated in multiple cellular processes, including metabolism and proliferation. This study focused on the function of USF1 in glycolysis and the malignant development of prostate adenocarcinoma (PRAD). Bioinformatics predictions suggested that USF1 is poorly expressed in PRAD. The clinical PRAD samples revealed a low level of USF1, which was correlated with an unfavorable prognosis. Artificial upregulation of USF1 significantly repressed glycolytic activity in PRAD cells and reduced cell growth and metastasis in vitro and in vivo. Potential downstream genes of USF1 were probed by integrated bioinformatics analyses. The chromatin immunoprecipitation and luciferase assays indicated that USF1 bound to the α-ketoglutarate-dependent dioxygenase alkB homolog 5 (ALKBH5) promoter for transcription activation. Flightless I (FLII) was identified as the gene showing the highest degree of correlation with ALKBH5. As an m6A demethylase, ALKBH5 enhanced FLII mRNA stability by inducing m6A demethylation in an m6A-YTH N6-methyladenosine RNA-binding protein F2 (YTHDF2)-dependent manner. Either silencing of ALKBH5 or FLII blocked the role of USF1 in PARD cells and restored glycolysis, cell proliferation, and invasion. This study demonstrates that USF1 activates ALKBH5 to stabilize FLII mRNA in an m6A-YTHDF2-dependent manner, thereby repressing glycolysis processes and the progression of PRAD.

The effect of ubiquitin-specific peptidase 21 on proliferation, migration, and invasion in DU145 cells

Abstract Objectives Although ubiquitin-specific peptidase 21 (USP21) has been shown to promote the development of various cancers, its role in prostate cancer has been poorly reported. Therefore, this study attempted to investigate the involvement of USP21 in prostate adenocarcinoma (PRAD) progression. Methods Information from public databases was used to evaluate the pattern of USP21 expression in PRAD tissues and its effect on patient prognosis. Subsequently, we either upregulated or knocked down USP21 expression in the human PRAD cell line DU145 to assess cell growth, migration, invasiveness, and apoptosis. Results The transcript levels of USP21 in PRAD tissues were low, indicating a poor prognosis. In DU145 cells, USP21 silencing impaired cell proliferation, colony formation, cell cycle progression, migratory capacity, and invasiveness, while it increased rates of apoptosis. Furthermore, cell proliferation, migration, and invasion were all induced by upregulating USP21. In addition, gene enrichment analysis revealed that USP21 had the potential to regulate cell adhesion and the cell cycle. This observation was further validated by the detection of expression of related genes in cells with either knockdown or increased USP21 expression levels. The expression and copy numbers of USP21 were significantly correlated with the infiltration levels of immune cells. Conclusions Expression level of USP21 is associated with PRAD progression and poor prognosis, and may have a role in potential therapeutic strategies for patients with PRAD.

Long noncoding RNA MIAT regulates TP53 ubiquitination and expedites prostate adenocarcinoma progression by recruiting TBL1X

Despite recent advances in cancer immunotherapy, their efficacy for treating patients with prostate adenocarcinoma (PRAD) is low due to complex immune evasion mechanisms. However, the function of long non-coding RNA (lncRNAs) in immune evasion has not been fully clarified. This study aimed to expound the role of myocardial infarction-associated transcript (MIAT), a lncRNA significantly upregulated in three PRAD-associated datasets, in immune evasion and try to reveal the potential mechanism. MIAT was highly expressed in PRAD tissues and predicted poor prognosis, and suppression of MIAT inhibited the malignant biological behavior of PRAD cells. Moreover, the depletion of MIAT promoted the immune response of CD8+ T cells and hampered the immune evasion of PRAD cells. In addition, MIAT downregulated TP53 protein expression by recruiting transducin beta-like protein 1X (TBL1X) for ubiquitination modification. Silencing of TP53 or overexpression of TBL1X was enough to abate the tumor suppressive effects of MIAT knockdown in vitro and in vivo. Our results provide evidence for a novel regulation mechanism of CD8+ T cells in PRAD and MIAT may serve as a potential therapeutic target in PRAD.

Abstract A023: RNF185 modulates prostate cancer metastatic potential through regulation of epithelial-mesenchymal transition

Abstract RNF185 is a RING finger domain-containing ubiquitin ligase which is anchored to the ER and resemble RNF5, a ubiquitin ligase implicated in ER associated degradation. In prostate cancer, deregulation of the expression or activity of several ubiquitin ligases has been shown to contribute to disease progression (e.g., Siah2, SPOP, RNF6). Analysis of prostate tumor patient data revealed a negative correlation between RNF185 expression and prostate adenocarcinoma progression and metastasis. Supporting these observations, several prostate cancer cell lines exhibited greater migration and invasion capabilities upon RNF185 depletion, in vitro. Subcutaneous inoculation of mouse prostate cancer MPC3 cells, stably expressing shRNA against RNF185, resulted in larger tumors and more frequent lung metastases in NSG mice. These results suggest that the increased metastatic potential associated with lower RNF185 levels may depend on molecular changes intrinsic to the tumors cells. RNA-sequencing and Ingenuity Pathway Analysis of RNF185-depleted compared to control MPC3 cells identified wound healing and cellular movement among the most significantly upregulated pathways in RNF185-depleted cells. Transcription regulators of Epithelial-Mesenchymal Transition (EMT) Snai2 and Zeb1 were among the most upregulated genes that were predicted to be activated based on the expression of their target genes. Comparison between differentially expressed genes in patients with low RNF185 expression, and RNF185-depleted cell lines (from mouse and human prostate tumors) confirmed deregulation of genes implicated in EMT. Taken together, our results identify RNF185 as gatekeeper of prostate cancer metastasis, via its control of EMT genes implicated in cell motility and metastasis. Citation Format: Benjamin Van Espen, Ladan Fazli, Htoo Z. Oo, Rabi Murad, Martin Gleave, Ze'ev A. Ronai. RNF185 modulates prostate cancer metastatic potential through regulation of epithelial-mesenchymal transition [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr A023.

Gleason Score-related MT1L as biomarker for prognosis in prostate adenocarcinoma and contribute to tumor progression in vitro.

The Gleason Score is well correlated with biological behavior and prognosis in prostate adenocarcinoma (PRAD). This study was derived to determine the clinical significance and function of Gleason-Score-related genes in PRAD. RNA-sequencing profiles and clinical data were extracted from the The Cancer Genome Atlas PRAD database. The Gleason-Score-related genes were screened out by the Jonckheere-Terpstra rank-based test. The "limma" R package was performed for differentially expressed genes. Next, a Kaplan-Meier survival analysis was performed. Correlation MT1L expression levels with tumor stage, non-tumor tissue stage, radiation therapy, and residual tumor were analyzed. Further, MT1L expression was detected in PRAD cell lines by reverse transcription-quantitative polymerase chain reaction assay. Overexpression of MT1L was constructed and used for cell count kit-8, flow cytometric assay, transwell assay, and wound-healing assay. Survival analysis showed 15 Gleason-Score-related genes as prognostic biomarkers in PRAD. The high-frequency deletion of MT1L was verified in PRAD. Furthermore, MT1L expression was decreased in PRAD cell lines than RWPE-1 cells, and overexpression of MT1L repressed cell proliferation and migration, and induced apoptosis in PC-3 cells. Gleason-Score-related MT1L may serve as a biomarker of poor prognostic biomarker in PRAD. In addition, MT1L plays a tumor suppressor in PRAD progression, which is beneficial for PRAD diagnosis and treatment research.

SOX9 and HMGB3 co-operatively transactivate NANOG and promote prostate cancer progression.

The homeodomain-containing transcription factor NANOG is overexpressed in prostate adenocarcinoma (PCa) and predicts poor prognosis. The SOX family transcription factor SOX9, as well as the transcription co-activator HMGB3 of the HMGB family, are also overexpressed and may play pivotal roles in PCa. However, it is unknown whether SOX9 and HMGB3 interact with each other, or if they regulate NANOG gene transcription. We identified potential SOX9 responsive elements in NANOG promoter, and investigated if SOX9 regulated NANOG transcription in co-operation with HMGB3 by experimental analysis of potential SOX9 binding sites in NANOG promoter, reporter gene transcription assays with or without interference or artificial overexpression of SOX9 and/or HMGB3, and protein-binding assays of SOX9-HMGB3 interaction. Clinicopathologic and prognostic significance of SOX9-HMGB3 overexpression in PCa was analyzed. SOX9 activated NANOG gene transcription by preferentially binding to a highly conserved consensus cis-regulatory element (-573 to -568) in NANOG promoter, and promoted the expression of NANOG downstream oncogenic genes. Importantly, HMGB3 functioned as a partner of SOX9 to co-operatively enhance transactivation of NANOG by interacting with SOX9, predominantly via the HMG Box A domain of HMGB3. Overexpression of SOX9 and/or HMGB3 enhanced PCa cell survival and cell migration and were significantly associated with PCa progression. Notably, Cox proportional regression analysis showed that co-overexpression of both SOX9 and HMGB3 was an independent unfavorable prognosticator for both CRPC-free survival (relative risk [RR] = 3.779，95% confidence interval [CI]: 1.159-12.322, p = 0.028) and overall survival (RR = 3.615，95% CI: 1.101-11.876, p = 0.034). These findings showed a novel SOX9/HMGB3/NANOG regulatory mechanism, deregulation of which played important roles in PCa progression.

Cutaneous Scrotal Metastasis Secondary to Primary Prostate Adenocarcinoma Responding to Immunotherapy

This case demonstrates the aggressive progression of prostate adenocarcinoma, failing 3 treatment regimens. Although the patient initially responded to treatments, he developed cutaneous metastasis. Genomic tumor analysis of scrotal tissue confirmed targetable molecular mutations. Treatment with systemic immunotherapy was initiated with complete resolution of disease. This case reveals the rare metastasis of prostate adenocarcinoma to the scrotum with advanced refractory cancer and the successful response to immunotherapy. It illustrates the importance of tumor genomic testing in advanced refractory prostate cancer.

Interferon signalling contributes to therapy‐resistant prostate cancer progression

Interferon signalling contributes to therapy‐resistant prostate cancer progression

The novel transcriptomic signature of angiogenesis predicts clinical outcome, tumor microenvironment and treatment response for prostate adenocarcinoma

Angiogenesis plays the critical roles in promoting tumor progression, aggressiveness, and metastasis. Although few studies have revealed some angiogenesis-related genes (ARGs) could serve as prognosis-related biomarkers for the prostate cancer (PCa), the integrated role of ARGs has not been systematically studied. The RNA-sequencing data and clinical information of prostate adenocarcinoma (PRAD) were downloaded from The Cancer Genome Atlas (TCGA) as discovery dataset. Twenty-three ARGs in total were identified to be correlated with prognosis of PRAD by the univariate Cox regression analysis, and a 19-ARG signature was further developed with significant correlation with the disease-free survival (DFS) of PRAD by the least absolute shrinkage and selection operator (LASSO) Cox regression with tenfold cross-validation. The signature stratified PRAD patients into high- and low-ARGs signature score groups, and those with high ARGs signature score were associated with significantly poorer outcomes (median DFS: 62.71 months vs unreached, p < 0.0001). The predicting ability of ARGs signature was subsequently validated in two independent cohorts of GSE40272 & PRAD_MSKCC. Notably, the 19-ARG signature outperformed the typical clinical features or each involved ARG in predicting the DFS of PRAD. Furthermore, a prognostic nomogram was constructed with three independent prognostic factors, including the ARGs signature, T stage and Gleason score. The predicted results from the nomogram (C-index = 0.799, 95%CI = 0.744–0.854) matched well with the observed outcomes, which was verified by the calibration curves. The values of area under receiver operating characteristic curve (AUC) for DFS at 1-, 3-, 5-year for the nomogram were 0.82, 0.83, and 0.83, respectively, indicating the performance of nomogram model is of reasonably high accuracy and robustness. Moreover, functional enrichment analysis demonstrated the potential targets of E2F targets, G2M checkpoint pathways, and cell cycle pathways to suppress the PRAD progression. Of note, the high-risk PRAD patients were more sensitive to immune therapies, but Treg might hinder benefits from immunotherapies. Additionally, this established tool also could predict response to neoadjuvant androgen deprivation therapy (ADT) and some chemotherapy drugs, such as cisplatin, paclitaxel, and docetaxel, etc. The novel ARGs signature, with prognostic significance, can further promote the application of targeted therapies in different stratifications of PCa patients.

Pyruvate Kinase M1 Suppresses Development and Progression of Prostate Adenocarcinoma.

Differential expression of PKM1 and PKM2 impacts prostate tumorigenesis and suggests a potential therapeutic vulnerability in prostate cancer.

Lysine demethylase 5A promotes prostate adenocarcinoma progression by suppressing microRNA-330-3p expression and activating the COPB2/PI3K/AKT axis in an ETS1-dependent manner.

Lysine demethylase 5A (KDM5A) is a histone demethylase frequently involved in cancer progression. This research aimed to explore the function of KDM5A in prostate adenocarcinoma (PRAD) and the molecular mechanism. KDM5A was highly expressed in collected PRAD tissues and acquired PRAD cells. High KDM5A expression was correlated with reduced survival and poor prognosis of patients with PRAD. Knockdown of KDM5A suppressed the proliferation, colony formation, migration, and invasiveness of PRAD cells and reduced angiogenesis ability of endothelial cells. Downstream molecules implicated in KDM5A mediation were predicted using integrated bioinformatic analyses. KDM5A enhanced ETS proto-oncogene 1 (ETS1) expression through demethylation of H3K4me2 at its promoter. ETS1 suppressed the transcription activity of miR-330-3p, and either further ETS1 overexpression or miR-330-3p inhibition blocked the functions of KDM5A knockdown in PRAD. miR-330-3p targeted coatomer protein complex subunit β2 (COPB2) mRNA. Downregulation of miR-330-3p restored the expression of COPB2 and activated the PI3K/AKT pathway in PRAD. The results in vitro were reproduced in vivo where KDM5A downregulation suppressed the growth and metastasis of xenograft tumors in nude mice. In conclusion, this study demonstrated that KDM5A promoted PRAD by suppressing miR-330-3p and activating the COPB2/PI3K/AKT axis in an ETS1-dependent manner.

CORRELATION OF EXPRESSION OF TGF- β AND MMP2 BETWEEN PROSTATIC ADENOCARCINOMA AND ADJACENT UNAFFECTED PARENCHYMA.

In prostate adenocarcinoma, both tumorous stroma and epithelium have important role in tumor progression. Transforming growth factor beta (TGF- β) is a promotor in advanced stages of prostate cancer. Matrix Metalloproteinase 2 (MMP2), the endopeptidase that degrades extracellular matrix is considered to be overexpressed in prostatic carcinoma related to its growth and aggressiveness. Therefore, the aim was to analyze the expression of proteins TGF- β and MMP2 between both epithelium and stroma of prostatic adenocarcinoma and adjacent unaffected parenchyma. The intensity of TGF- β and MMP2 expression in epithelium, tumorous stroma and adjacent unaffected parenchyma was analyzed in 62 specimens of prostatic adenocarcinoma by microarray-based immunohistochemistry. TGF- β was more expressed in tumorous than in prostate stroma (p =0.000), while no statistical significance in case of MMP2 (p = 0.097) was found. MMP2 was more expressed in tumorous than in prostate epithelium (p =0.000), while no statistical significance in case of TGF- β (p = 0.096) was observed. The study results indicate that both tumorous stroma and epithelium have a role in tumor progression and support potential role of TGF- β and MMP2 in prostatic adenocarcinoma progression.

Lipid-loaded tumor-associated macrophages sustain tumor growth and invasiveness in prostate cancer.

Tumor-associated macrophages (TAMs) are correlated with the progression of prostatic adenocarcinoma (PCa). The mechanistic basis of this correlation and therapeutic strategies to target TAMs in PCa remain poorly defined. Here, single-cell RNA sequencing was used to profile the transcriptional landscape of TAMs in human PCa, leading to identification of a subset of macrophages characterized by dysregulation in transcriptional pathways associated with lipid metabolism. This subset of TAMs correlates positively with PCa progression and shorter disease-free survival and is characterized by an accumulation of lipids that is dependent on Marco. Mechanistically, cancer cell-derived IL-1β enhances Marco expression on macrophages, and reciprocally, cancer cell migration is promoted by CCL6 released by lipid-loaded TAMs. Moreover, administration of a high-fat diet to tumor-bearing mice raises the abundance of lipid-loaded TAMs. Finally, targeting lipid accumulation by Marco blockade hinders tumor growth and invasiveness and improves the efficacy of chemotherapy in models of PCa, pointing to combinatorial strategies that may influence patient outcomes.

Abstract 1760: Role of Batf-dependant Th17 immune response in PTEN-null mouse model

Abstract Basic leucine zipper transcription factor ATF-like (BATF) belongs to the activator protein 1 (AP-1) family of transcription factors and has been shown to be predominantly expressed in cells of hematopoietic origin, especially in T cells. Mice deficient for BATF were first described to lack T helper cell type 17 (Th17). Th17 cells are a distinct lineage of CD4+ T helper cells that provide protective immunity to infections but are also involved in chronic inflammation and autoimmunity. However, the role of Th17 response in prostate cancer remains controversial. In this study, we took a genetic approach to explore the role of BATF-dependent Th17 cells in prostate cancers by interbreeding BATF-deficient (Batf-/-) mice with mice that are conditionally mutant for PTEN, an established preclinical model for prostate cancer. Batf+/+;Pten-/- and Batf+/-;Pten-/- mice presented similar prostate phenotypes thus were put into one group (named Batf+), which were compared to the Batf-/-;Pten-/- group (named Batf-). We found that Batf- prostates were clearly smaller than Batf+ prostates at 30 weeks. The genitourinary bloc weight was significantly heavier in Batf+ mice than in Batf- mice at 12 and 30 weeks. Batf+ mice developed significantly higher percent of invasive adenocarcinomas in different prostate lobes at 9, 12, and 30 weeks, respectively compared to Batf- mice. Tumors in Batf- mice exhibited lower rates of cellular proliferation and higher apoptosis, as well as reduced inflammatory cell infiltration and angiogenesis in the prostatic stroma. Moreover, Batf- mice exhibited significantly reduced mRNA and protein levels of Th17 cytokines, AP-1 family members and IL-23R, and reduced NF-kB pathway activity in both spleen and prostate tissues. CD4+ T cells from Batf- mice cultured under Th17 conditions for 4 days, expressed reduced AP-1 family-regulated genes compared to Batf+ mice. Prostate cancer cells (LNCaP) with overexpression of BATF in vitro exhibited increased IL-23R expression. Prostate tissues from Batf- mice cultured under IL-6 or Th17 conditions for 4 days had reduced IL-23R expression compared to that from Batf+ mice. Taken together, our results suggest that Batf promotes the initiation and progression of prostate adenocarcinoma via Th17-mediated inflammatory immune responses and that the Batf-IL-23-IL-17 axis is a critical pathway that is needed for prostate adenocarcinoma development and progression. This work was supported by the NIH-National Institute of General Medical Sciences COBRE on Aging and Regenerative Medicine (P20GM103629, PD: S. Michal Jazwinski; PI: Q.Z.) and the Carol Lavin Bernick Faculty Grant from Tulane University (PI: Q.Z.). Citation Format: Qiuyang Zhang, Sen Liu, Bing Zhang. Role of Batf-dependant Th17 immune response in PTEN-null mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1760.

Identification of microenvironment related potential biomarkers of biochemical recurrence at 3 years after prostatectomy in prostate adenocarcinoma.

Prostate adenocarcinoma is one of the leading adult malignancies. Identification of multiple causative biomarkers is necessary and helpful for determining the occurrence and prognosis of prostate adenocarcinoma. We aimed to identify the potential prognostic genes in the prostate adenocarcinoma microenvironment and to estimate the causal effects simultaneously. We obtained the gene expression data of prostate adenocarcinoma from TCGA project and identified the differentially expressed genes based on immune-stromal components. Among these genes, 68 were associated with biochemical recurrence at 3 years after prostatectomy in prostate adenocarcinoma. After adjusting for the minimal sets of confounding covariates, 14 genes (TNFRSF4, ZAP70, ERMN, CXCL5, SPINK6, SLC6A18, CHRM2, TG, CLLU1OS, POSTN, CTSG, NETO1, CEACAM7, and IGLV3-22) related to the microenvironment were identified as prognostic biomarkers using the targeted maximum likelihood estimation. Both the average and individual causal effects were obtained to measure the magnitude of the effect. CIBERSORT and gene set enrichment analyses showed that these prognostic genes were mainly associated with immune responses. POSTN and NETO1 were correlated with androgen receptor expression, a main driver of prostate adenocarcinoma progression. Finally, five genes were validated in another prostate adenocarcinoma cohort (GEO: GSE70770). These findings might lead to the improved prognosis of prostate adenocarcinoma.