RCOR1 is targeted by miR-23b-3p to modulate growth, colony formation, migration, and invasion of prostate cancer cells.

OBJECTIVES: Prostate cancer holds the second-highest incidence rate among all male malignancies, with a noticeable scarcity of effective treatment approaches. The REST Corepressor 1 (RCOR1) protein exhibits elevated expression across various tumors, acting as an oncogene. Nevertheless, its functions and mechanisms in prostate cancer have yet to be documented. While miR-23 demonstrates reduced expression in prostate cancer, the downstream genes it regulates remain unclear. METHODS: RT-qPCR and Western blotting assays were utilized to elucidate the mRNA and protein levels of miR-23b-3p and RCOR1. The luciferase reporter assay was employed to unveil the targeting relationship between miR-23b-3p and RCOR1. Additionally, a CCK-8 assay demonstrated cell growth, while colony formation and Transwell assays were performed to observe clone formation, cell migration, and invasion. RESULTS: In this study, we observed substantial mRNA and protein levels of RCOR1 in prostate cancer cells such as DU145, PC3, and LNCap. RCOR1 overexpression enhanced the growth, colony formation, migration, and invasion of prostate cancer cells, whereas genetic silencing of RCOR1 suppressed these processes. Bioinformatics analysis identified miR-23b-3p as a potential regulator of RCOR1, and luciferase assays validated RCOR1 as a downstream target of miR-23b-3p. Increasing miR-23b-3p mimics diminished RCOR1's mRNA and protein levels, while raising miR-23b-3p levels boosted RCOR1's expression. Moreover, the stimulatory impact of RCOR1 on prostate cancer cell development could be countered by elevating miR-23b-3p mimics. CONCLUSION: In summary, our findings confirm that RCOR1 is indeed under the influence of miR-23, shedding light on the miR-23/RCOR1 pathway's role in prostate cancer development. This offers novel theoretical and experimental support for comprehending the underlying mechanisms of prostate cancer and for targeted therapeutic avenues.

Silencing HOXC13 exerts anti-prostate cancer effects by inducing DNA damage and activating cGAS/STING/IRF3 pathway.

BACKGROUND: Advanced prostate cancer (PCa) will develop into castration-resistant prostate cancer (CRPC) and lead to poor prognosis. As the primary subtype of CRPC, CRPC-AR accounts for the major induction of PCa heterogeneity. CRPC-AR is mainly driven by 25 transcription factors (TFs), which we speculate may be the key factors driving PCa toward CRPC. Therefore, it is necessary to clarify the key regulator and its molecular mechanism mediating PCa progression. METHODS: Firstly, we downloaded transcriptomic data and clinical information from TCGA-PRAD. The characteristic gene cluster was identified by PPI clustering, GO enrichment, co-expression correlation and clinical feature analyses for 25 TFs. Then, the effects of 25 TFs expression on prognosis of PCa patients was analyzed using univariate Cox regression, and the target gene was identified. The expression properties of the target gene in PCa tissues were verified using tissue microarray. Meanwhile, the related mechanistic pathway of the target gene was mined based on its function. Next, the target gene was silenced by small interfering RNAs (siRNAs) for cellular function and mechanistic pathway validation. Finally, CIBERSORT algorithm was used to analyze the infiltration levels of 22 immune cells in PCa patients with low and high expression of target gene, and validated by assaying the expression of related immunomodulatory factor. RESULTS: We found that HOX family existed independently in 25 TFs, among which HOXC10, HOXC12 and HOXC13 had unique clinical features and the PCa patients with high HOXC13 expression had the worst prognosis. In addition, HOXC13 was highly expressed in tumor tissues and correlated with Gleason score and pathological grade. In vitro experiments demonstrated that silencing HOXC13 inhibited 22RV1 and DU145 cell function by inducing cellular DNA damage and activating cGAS/STING/IRF3 pathway. Immune infiltration analysis revealed that high HOXC13 expression suppressed infiltration of γδ T cells and plasma cells and recruited M2 macrophages. Consistent with these results, silencing HOXC13 up-regulated the transcriptional expression of IFN-ß, CCL2, CCL5 and CXCL10. CONCLUSION: HOXC13 regulates PCa progression by mediating the DNA damage-induced cGAS/STING/IRF3 pathway and remodels TIME through regulation of the transcription of the immune factors IFN-ß, CCL2, CCL5 and CXCL10.

Integrated high-throughput analysis identifies super enhancers in metastatic castration-resistant prostate cancer.

Background: Metastatic castration-resistant prostate cancer (mCRPC) is a highly aggressive stage of prostate cancer, and non-mutational epigenetic reprogramming plays a critical role in its progression. Super enhancers (SE), epigenetic elements, are involved in multiple tumor-promoting signaling pathways. However, the SE-mediated mechanism in mCRPC remains unclear. Methods: SE-associated genes and transcription factors were identified from a cell line (C4-2B) of mCRPC by the CUT&Tag assay. Differentially expressed genes (DEGs) between mCRPC and primary prostate cancer (PCa) samples in the GSE35988 dataset were identified. What's more, a recurrence risk prediction model was constructed based on the overlapping genes (termed SE-associated DEGs). To confirm the key SE-associated DEGs, BET inhibitor JQ1 was applied to cells to block SE-mediated transcription. Finally, single-cell analysis was performed to visualize cell subpopulations expressing the key SE-associated DEGs. Results: Nine human TFs, 867 SE-associated genes and 5417 DEGs were identified. 142 overlapping SE-associated DEGs showed excellent performance in recurrence prediction. Time-dependent receiver operating characteristic (ROC) curve analysis showed strong predictive power at 1 year (0.80), 3 years (0.85), and 5 years (0.88). The efficacy of his performance has also been validated in external datasets. In addition, FKBP5 activity was significantly inhibited by JQ1. Conclusion: We present a landscape of SE and their associated genes in mCPRC, and discuss the potential clinical implications of these findings in terms of their translation to the clinic.

CircPDHX promotes prostate cancer cell progression in vitro and tumor growth in vivo via miR-497-5p/ACSL1 axis.

BACKGROUND: Circular RNAs (circRNAs) have been proved could regulate many cancers, including prostate cancer (PCa). In this paper, we reconnoitered the roles of circRNA pyruvate dehydrogenase complex component X (circPDHX) in PCa. METHODS: The circPDHX, microRNA (miR)-497-5p and acyl-CoA synthetase long chain family member 1 (ACSL1) contents were detected by quantitative real-time PCR and Western blot analysis. Cell proliferation was measured by cell counting kit-8 assay, 5-Ethynyl-2'-deoxyuridine assay, and colony formation assay. Cell migration was examined by wound healing assay. The apoptosis was detected by flow cytometry assay. The ELISA kits were applied to quantify the fatty acid metabolites. Furthermore, the interplay between miR-497-5p and circPDHX or ACSL1 was detected by dual-luciferase reporter assay and RIP assay. The role of circPDHX in PCa was supplementary substantiated in vivo. RESULTS: CircPDHX and ACSL1 contents were upregulated, and the miR-497-5p level was downregulated in PCa. CircPDHX deficiency attenuated PCa cell proliferation, migration, and fatty acid metabolites, while intensified cell apoptosis. CircPDHX bound to miR-497-5p to adjust ACSL1. Moreover, miR-497-5p inhibited the PCa progression by regulating ACSL1. In the meantime, circPDHX deficiency repressed PCa tumor growth in vivo. CONCLUSION: CircPDHX stimulated PCa development via miR-497-5p/ACSL1, which presented a new thought for PCa treatment.

KIF4A: A potential biomarker for prediction and prognostic of prostate cancer.

PURPOSE: To investigate the clinical relevance and biological function of the kinesin super-family protein 4A (KIF4A) expression in prostate cancer (PCa). METHODS: We examined 1) the relationship between the expression of KIF4A and clinico-pathological characteristics of PCa patients using a tissue microarray and the Cancer Genome Atlas database, 2) the prognostic value of KIF4A expression in patients using Kaplan-Meier plots and 3) the functions of KIF4A in LNCaP and DU145 cells, such as cell proliferation, cell cycle and cell apoptosis. RESULTS: Compared with normal prostate, the mRNA and protein expressions of KIF4A were up-regulated in PCa. The up-regulation expression rates of KIF4A in PCa were significantly related to the Gleason score (P.

Genome-Scale CRISPR-Cas9 Transcriptional Activation Screening in Metformin Resistance Related Gene of Prostate Cancer.

Metformin is a classic type II diabetes drug which possesses anti-tumor properties for various cancers. However, different cancers do not respond to metformin with the same effectiveness or acquire resistance. Thus, searching for vulnerabilities of metformin-resistant prostate cancer is a promising strategy to improve the therapeutic efficiency of the drug. A genome-scale CRISPR-Cas9 activation library search targeting 23,430 genes was conducted to identify the genes that confer resistance to metformin in prostate cancer cells. Candidate genes were selected by total reads of sgRNA and sgRNA diversity, and then a CCK8 assay was used to verify their resistance to metformin. Interestingly, we discovered that the activation of ECE1, ABCA12, BPY2, EEF1A1, RAD9A, and NIPSNAP1 contributed to in vitro resistance to metformin in DU145 and PC3 cell lines. Notably, a high level of RAD9A, with poor prognosis in PCa, was the most significant gene in the CCK8 assay. Furthermore, we discerned the tumor immune microenvironment with RAD9A expression by CIBERSORT. These results suggested that a high level of RAD9A may upregulate regulatory T cells to counterbalance metformin in the tumor immune microenvironment.