ABSTRACT
Objective:To investigate the effects of methyltransferase-like protein 14 (METTL14)-mediated long-chain non-coding RNA EIF3J antisense RNA1 (Inc EIF3J-AS1) on the migration and invasion of cholangiocarcinoma cells and its mechanism.Methods:From September 2017 to December 2018, 10 pairs of cholangiocarcinoma and adjacent normal tissues were collected from the First Affiliated Hospital of Naval Medical University, which were surgically resected and pathologically confirmed. The expression of METTL14 mRNA and Inc EIF3J-AS1 in cholangiocarcinoma tissues was detected by fluorescence quantitative PCR, and the protein expression of METTL14 was detected by Western blotting. Cholangiocarcinoma cell lines HUCCTI and RBE were divided into control group and METTL14 or Inc EIF3J-AS1 knockdown group. The corresponding normal lentivirus was transfected in the control group, and METTL14 or Inc EIF3J-AS1 knockdown group was transfected with lentivirus that interfered with the expression of METTL14 or Inc EIF3J-AS1, respectively. Transwell assay was used to detect the ability of cell migration and invasion, and Western blotting was used to detect the expression of epidermal growth factor receptor (EGFR) and AKT protein.Results:The expressions of METTL14 mRNA and lnc EIF3J-AS1 in cholangiocarcinoma tissues were significantly higher than those in adjacent normal tissues (0.075±0.012 vs 0.031±0.006, 0.140±0.032 vs 0.064±0.012), and there was a positive correlation between expression of METTL4 mRNA and expression of lnc EIF3J-AS1 ( r=0.883, P=0.0007). The expression of METTL14 protein in cholangiocarcinoma tissues was higher than that in adjacent normal tissues (0.354±0.131 vs 0.187±0.183). Compared with the control group, the expression of lnc EIF3J-AS1 was significantly lower in METTL14 or Inc EIF3J-AS1 knockdown group (0.217±0.020 vs 1.000±0.052, 0.149±0.066 vs 1.000±0.045). The migration and invasion ability of cell lines HUCCTI and RBE decreased significantly in lnc EIF3J-AS1 knockout group (5.00±0.58 vs 23.33±0.33, 20.33±0.67 vs 70.67±0.33; 12.00±0.58 vs 25.00±2.52, 22.33±0.89 vs 43.67±0.33). The expression of EGFR and p-AKT/AKT protein were also significantly decreased (0.109±0.015 vs 1.000±0.018, 0.226±0.036 vs 1.000±0.051; 0.118±0.052 vs 1.000±0.069, 0.132±0.098 vs 1.000±0.023). The above differences were statistically significant (all P<0.05). Conclusions:Abnormal expression of lnc EIF3J-AS1 in cholangiocarcinoma mediated by METTL14 can promote tumor cell migration and invasion.