Identification of BBC3 as a novel indicator for predicting prostate cancer development and olaparib resistance

Prostate cancer (PCa) is a commonly occurring malignancy in elderly men. Olaparib, a poly ADP-ribose polymerase inhibitor, is utilized in PCa treatment. However, patients often develop resistance to olaparib after a period of treatment. Genetic alterations may play a significant role in this resistance, but the specific genes involved remain unclear. This study collected RNA-sequence data from the Gene Expression Omnibus database on both olaparib-sensitive and -resistant PCa cells to identify genes crucial for resistance. Subsequently, the enriched pathways of these genes were analyzed, and a protein-protein interaction (PPI) network was constructed to identify hub genes. The effect of these hub genes on PCa occurrence, progression, and prognosis was assessed using data from The Cancer Genome Atlas and Chinese Prostate Cancer Genome and Epigenome Atlas databases. Finally, this study validated our findings in clinical PCa samples and cells. From the GSE189186 dataset, 50 upregulated genes and 2 downregulated genes were identified in olaparib-resistant C4-2B and LNCaP cells. Utilizing the PPI network, eight upregulated genes (BBC3, TP53I3, FDXR, DDB2, CDKN1A, GADD45A, ZMAT3, and SESN1) were identified as hub genes for olaparib-resistant PCa cells. Furthermore, some of these genes were central to PCa occurrence, with BBC3 also influencing progression and prognosis. Importantly, BBC3 expression was upregulated in clinical PCa samples and affected PCa cells sensitive to olaparib, suggesting its potential as a predictive marker for PCa development and olaparib resistance.