N6-methyladenosine-modified long non-coding RNA KIF9-AS1 promotes stemness and sorafenib resistance in hepatocellular carcinoma by upregulating SHOX2 expression

Figure 3 Methyltransferase-like 3 stabilizes and upregulates long noncoding RNA KIF9-AS1 expression in an N6-methyladenosine-insulin-like growth factor 2 mRNA-binding protein 1-dependent manner. A: The N6-methyladenosine (m6A) content in hepatocellular carcinoma tissues and para-cancerous tissues was examined using a commercial kit (n = 20); B: m6A levels of KIF9-AS1 in Huh-7 and Huh-7/R cells were examined via methylated RNA immunoprecipitation-quantitative polymerase chain reaction; C: Methyltransferase-like 3 (METTL3) protein expression in Huh-7 and Huh-7/R cells was quantified via western blotting; D: METTL3 protein expression in Huh-7 and Huh-7/R cells transfected with sh-METTL3 or sh-NC was quantified via western blotting; E: The m6A level of KIF9-AS1 was calculated via methylated RNA immunoprecipitation-quantitative polymerase chain reaction; F: The insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) protein level was evaluated via western blotting; G: The interaction between IGF2BP1 and KIF9-AS1 was verified via an RNA immunoprecipitation assay; H: The protein expression of IGF2BP1 was assessed via western blotting; I: After blocking the synthesis of new RNA with actinomycin D (5 μg/mL) for 0, 3, and 6 hours, the expression of KIF9-AS1 was evaluated via quantitative reverse transcription polymerase chain reaction. The data are shown as the means ± SDs (n = 3). ^aP < 0.05, ^bP < 0.01, ^cP < 0.001. Each experiment was repeated three times. m6A: N6-methyladenosine; METTL3: Methyltransferase-like 3; IGF2BP1: Insulin-like growth factor 2 mRNA-binding protein 1.