Multivariate transcriptome analysis identifies networks and key drivers of metastatic castrationresistant prostate cancer

Abstract Prostate cancer (PCa) is the second most cancer-related cause of death in men. Most PCa are characterized as slow-growing or indolent, though some patients are at a high risk of for recurrent and eventually metastatic disease. The most lethal form of PCa is metastatic castration-resistant prostate cancer (mCRPC) that has progressed to the bone. The molecular mechanism underlying PCa progression to bone has not been fully elucidated. Here, we identify gene networks associated with CRPC bone metastasis and survival risk. Networks were investigated by using a novel weighted gene network co-expression analysis (WGCNA) method and examining overrepresentation of upstream regulators and signaling pathways within co-expressed transcriptome modules across clinically annotated transcriptomes from mCRPC patients (N=60). Functional Enrichment analysis was used, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and protein-protein interaction analysis, to identify biological functions of related hub genes overrepresented in our module of interest. WGCNA identified that cyan module was significantly associated with castration-resistant prostate cancer (CRPC) bone metastasis. KEGG and GO analysis results revealed genes in blue module were mainly related to collagen formation, cell signaling peptides, and bone regulation processes, including alkaline phosphatase, osteoblast formation, and endochondral ossification. Genes positively correlated with bone metastasis exhibited the following biological pathways: PI3K-Akt signaling, ECM-receptor interaction, and protein digestion and absorption pathways. This study provides novel insights into the biological pathways associated with CPRC metastasis to the bone. The module associated with bone metastasis and overall survival represent both known and novel pathways. Citation Format: Lawrence P. McKinney, Rajesh Singh, I. King Jordan, Sooryanarayana Varambally, Martin G. Sanda, Eric B. Dammer, James W. Lillard. Multivariate transcriptome analysis identifies networks and key drivers of metastatic castration-resistant prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2701.