Zhongguo aizheng zazhi (Oct 2022)
Effect of long non-coding RNA LINC00671 on biological behavior of hepatocellular carcinoma and its mechanism
Abstract
Background and purpose: Hepatocellular carcinoma (HCC) is one of the most common tumors in the world. Long non-coding RNA (lncRNA) is determined to be involved in the occurrence and development of HCC. Recent reports suggest that a novel lncRNA-LINC00671 may be a new tumor suppressor, however, its role and molecular mechanism in HCC remain uncertain. Current research aimed to discover the role of LINC00671 in HCC and its potential molecular mechanism. Methods: The expression and prognosis of LINC000671 in hepatocellular carcinoma tissues were analyzed by GEPIA and starBase database. The expression of LINC00671 in normal and hepatoma cell lines was detected by real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR). The subcellular localization of LINC00671 was observed by RNA fluorescence in situ hybridization (FISH). After knockdown or overexpression of LINC00671 in vitro, the effects of LINC00671 on the proliferation, apoptosis, migration and invasion of hepatoma cells were investigated by cell counting kit-8 (CCK-8), flow cytometry, wound healing and transwell assays. Subsequently, online bioinformatics prediction was conducted to identify the target gene of LINC00671. The correlation between LINC00671 and target molecule c-myc was analyzed by starBase and GEPIA database. And the regulation of LINC00671 on c-myc was verified by RTFQ-PCR and Western blot. The effect of LINC00671 on the methylation level of target gene promoter was tested by methylated DNA immunoprecipitation-PCR (MeDIP-PCR). Results: The results of online database analysis showed that LINC00671 was significantly downregulated in hepatocellular carcinoma, and its high expression predicted a better prognosis (P<0.05). LINC00671 was down regulated and differentially expressed in different hepatoma cell lines, and it was mainly located in the nucleus of hepatoma cells. The results of tumor behavior experiment in vitro indicated that LINC00671 could significantly inhibit the proliferation, migration and invasion of hepatoma cells (P<0.05), and remarkably enhanced the apoptotic rate (P<0.05). Bioinformatics results showed that LINC00671 might bind to c-myc promoter by Hoogsteen pairing in nucleus. The results from database revealed that LINC00671 was significantly negatively correlated with c-myc expression in HCC (P<0.05). LINC00671 could significantly suppress the expression of c-myc (P<0.05). The results of MeDIP-PCR suggested that LINC00671 could increase the methylation level of c-myc promoter (P<0.05). Conclusion: LINC00671 may downregulate the expression of c-myc by inducing the hypermethylation of c-myc promoter, so as to inhibit the progression of HCC.
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