Genetic variation of circHIBADH enhances prostate cancer risk through regulating HNRNPA1-related RNA splicing.

ABSTRACT

The current study aimed to investigate associations of circRNAs and related genetic variants with risk of prostate cancer (PCa) as well as to elucidate biological mechanisms underlying the associations. By using the MiOncoCirc database, we first compared expression levels of circRNAs between 25 paired PCa and adjacent normal tissues to identify risk-associated circRNAs. We then used logistic regression models to evaluate associations between genetic variants in candidate circRNAs and PCa risk among 4662 prostate cancer patients and 3114 healthy controls, and identified circHIBADH rs11973492 as a significant risk-associated variant (odds ratio = 1.20, 95% confidence interval 1.08-1.34, P = 7.06 × 10 -4) in a dominant genetic model, which altered the secondary structure of the corresponding RNA chain. In the in silico analysis, we found circHIBADH to sponge and silence 21 RNA-binding proteins (RPBs) enriched in the RNA splicing pathway, among which HNRNPA1 was identified and validated as a hub RBP using an external RNA-sequencing data as well as the in-house (four tissue samples) and publicly available single-cell transcriptomes. Additionally, we demonstrated that HNRNPA1 might influence hallmarks including MYC, DNA repair, and E2F target signaling pathways, thereby promoting carcinogenesis. In conclusion, genetic variants in circHIBADH may act as a sponge and inhibitor of RNA splicing-associated RBPs including HNRNPA1, playing an oncogenic role in PCa.