LncRNA FUNDC2P4 down-regulation promotes epithelial-mesenchymal transition by reducing E-cadherin expression in residual hepatocellular carcinoma after insufficient radiofrequency ablation

Purpose: Hepatocellular carcinoma (HCC) after insufficient radiofrequency ablation (RFA) could induce epithelial-mesenchymal transition (EMT) in residual tumours, resulting in rapid and aggressive recurrence. However, the role of EMT-related Long noncoding RNAs (lncRNAs) in residual tumour progression remains unclear.Methods: Insufficient RFA was simulated in vitro by heating Huh7 cells in water bath at 47 degrees C, named as Huh7-H. Cell invasion, migration assays and wound healing assay were conducted for functional analysis. Cell proliferation was determined by CCK8 assay. Differential expression profile of EMT-related lncRNAs between Huh7-H and Huh7 was analysed by LncPath human EMT array, and validated by qRT-PCR. Gain/loss-of-function assays of selected lncRNA were conducted by over-expressing or silencing its expression.Results: Huh7-H presented characteristic EMT morphological changes. WB analysis showed significantly decreased E-cadherin in Huh7-H cells. Transwell assays indicated the abilities of Huh7-H cells in migration and invasion were evidently strengthened. A new lncRNA, FUNDC2P4, was identified by LncPath human EMT array to be significantly down-regulated in Huh7-H cells. In vitro studies showed overexpression of FUNDC2P4 inhibited proliferation, invasion and migration potential and up-regulated E-cadherin expression in SMMC-7721 cells, whereas silencing FUNDC2P4 promoted these potentials and down-regulated E-cadherin expression in Huh7 cells.Conclusions: We explored that lncRNA FUNDC2P4 down-regulation promoted EMT leading to tumour proliferation, invasion and migration by reducing E-cadherin expression in residual HCC after insufficient RFA in vitro. These results suggest that FUNDC2P4 may have potentially therapeutic value for prevention and treatment of HCC recurrence after RFA in the future.