Genome stability-related lncRNA ZFPM2-AS1 promotes tumor progression via miR-3065-5p/XRCC4 in hepatocellular carcinoma

Long noncoding RNAs (lncRNAs) have a certain link to genomic stability (GS). However, the regulatory relationship of lncRNAs and GS has not been thoroughly investigated in hepatocellular carcinoma (HCC). In the present study, samples were retrieved from The Cancer Genome Atlas with somatic mutations and lncRNA expression data. Cox regression analysis was used to identify independent prognostic factors. The RNA levels were determined by reverse transcription-quantitative PCR and protein levels were detected by western blot analysis. Cell Counting Kit-8 and colony-formation assays were used to assess cell viability. Cell migration was measured by wound-healing and Transwell assays. Cell apoptosis and cell-cycle progression were evaluated by flow cytometry. GS was detected by alkaline comet and chromosomal aberration assays. A xenograft model and lung metastasis model were used to assess the role of zinc finger protein, FOG family member 2 antisense 1 (ZFPM2-AS1) in tumor growth in vivo. The molecular mechanisms underlying the biological functions of ZFPM2-AS1 were investigated through bioinformatics prediction, RNA pull-down and luciferase reporter assays. A total of 85 genomic instability-related lncRNAs were identified and a prognostic model was developed. The prognostic model exhibited good predictive power (area under the receiver operating characteristic curve, 0.786). ZFPM2-AS1 was significantly upregulated in tumor tissues (P<0.001) and it promoted DNA damage repair (P<0.01) and tumor progression in vitro and in vivo. Luciferase reporter assays demonstrated that miR-3065-5p was able to bind directly with ZFPM2-AS1 and X-ray repair cross complementing 4 (XRCC4). ZFPM2-AS1 upregulated XRCC4 expression by acting as a sponge (P<0.001). In the present study, a prognostic model for HCC was developed and validated, and one lncRNA of its components was experimentally investigated. ZFPM2-AS1 regulates XRCC4 by sponging miR-3065-5p to promote GS and HCC progression.