Hepatocellular carcinoma (HCC) affects more than 500,000 new patients each year and is characterized by fast growing, heterogeneous tumors and low five-year survival rates. Despite the identification of HCC risk factors, including alcohol consumption and chronic hepatitis B (HBV) infection, early diagnosis of HCC and molecular understanding of how these risk factors promote HCC both individually and in combination remain elusive. microRNAs (miRNAs), non-coding transcripts ~22 nt in length, have emerged as central mediators of post-transcriptional and translational gene regulation, and have been increasingly implicated in the initiation and progression of many cancers, including HCC. However, the dysregulation profile of miRNAs in HCCs of varying etiologies remains largely unexplored. To identify dysregulated miRNAs specifically associated with alcohol use or with HBV in HCC patients, we analyzed next-generation RNA-sequencing data from 234 HCCs in The Cancer Genome Atlas (TCGA). Through differential expression analyses on cohorts stratified by alcohol consumption and HBV status, we discovered 10 miRNAs specifically dysregulated in alcohol-associated HCCs and 251 miRNAs specifically dysregulated in HBV-associated HCCs (FDR < 0.05). Among these, two miRNAs, miR-944 and miR-223-3p, significantly overexpressed in HCC alcohol consumers, exhibited additional correlations with patient survival, tumor stage, and mutations in CTNNB1, MUC16 and TNN (p < 0.05). We subsequently validated the upregulation of miR-944 and miR-223-3p in vitro following treatment of both normal liver and HCC cell lines with biologically relevant doses of alcohol and acetaldehyde, the first breakdown metabolite of ethanol. Knockdown of miR-944 and miR-223-3p significantly reduced cellular proliferation in both acetaldehyde-treated and untreated normal and HCC cell lines, and resulted in increased sensitivity to cisplatin. Inhibition of both miRNAs in HCC cell lines also restored the expression of several tumor suppressor genes targeted by miR-944 and miR-223-3p. Taken together, our findings enhance knowledge of the respective roles of miRNAs in alcohol- and HBV-mediated HCC, and highlight the increased transcriptomic resolution afforded by etiology-specific studies of cancer pathogenesis and progression.

Note: This abstract was not presented at the meeting.

Citation Format: Pin Xue Li, Hao Zheng, Maarouf A. Saad, Angela E. Zou, Xiaoqi Wang, James G. Kwok, Avinaash Korrapati, Yuanhao Qu, Thomas K. Honda, Jessica Wang-Rodriguez, Weg M. Ongkeko. Alcohol consumption and hepatitis B-associated microRNAs in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4426. doi:10.1158/1538-7445.AM2017-4426