Identification of key enzalutamide-resistance-related genes in castration-resistant prostate cancer and verification of RAD51 functions
Wen Xu , Li Liu , Zhongqi Cui ， Mingyang Li , Jinliang Ni , Nan Huang , Yue Zhang , Jie Luo , Limei Sun , Fenyong Sun
Abstract
Patients with castration-resistant prostate cancer (CRPC) often develop drug resistance after treatment with enzalutamide. The goal of our study was to identify the key genes related to enzalutamide resistance in CRPC and to provide new gene targets for future research on improving the efficacy of enzalutamide. Differential expression genes (DEGs) associated with enzalutamide were obtained from the GSE151083 and GSE150807 datasets. We used R software, the DAVID database, protein-protein interaction networks, the Cytoscape program, and Gene Set Cancer Analysis for data analysis. The effect of RAD51 knockdown on prostate cancer (PCa) cell lines was demonstrated using Cell Counting Kit-8, clone formation, and transwell migration experiments. Six hub genes with prognostic values were screened (RAD51, BLM, DTL, RFC2, APOE, and EXO1), which were significantly associated with immune cell infiltration in PCa. High RAD51, BLM, EXO1, and RFC2 expression was associated with androgen receptor signaling pathway activation. Except for APOE, high expression of hub genes showed a significant negative correlation with the IC50 of Navitoclax and NPK76-II-72-1. RAD51 knockdown inhibited the proliferation and migration of PC3 and DU145 cell lines and promoted apoptosis. Additionally, 22Rv1 cell proliferation was more significantly inhibited with RAD51 knockdown than without RAD51 knockdown under enzalutamide treatment. Overall, six key genes associated with enzalutamide resistance were screened (RAD51, BLM, DTL, RFC2, APOE, and EXO1), which are potential therapeutic targets for enzalutamide-resistant PCa in the future.
Figure 11: Effect of RAD51 on the proliferation, migration, and apoptosis of PCa cell lines. (a) 22Rv1 cells were transfected with siRAD51 to verify the knockdown efficiency of RAD51 at the mRNA and protein expression levels (one-way analysis of variance). (b) Effect of RAD51 knockdown on the viability of 22Rv1 cells treated with different concentrations of enzalutamide for 48 h as detected using a CCK-8 assay. *P-value < 0.05, **P-value < 0.01, ***P-value < 0.001, ****P-value < 0.0001.
