Abstract: Objective To investigate the expression levels of acetaldehyde dehydrogenase 1A1 (ALDH1A1) and microRNA-140-5p (miR-140-5p) in hepatocellular carcinoma (HCC) tissues and their relationship with chemotherapy sensitivity.Methods Ualcan database was used to search the expression level of ALDH1A1 in HCC tissues and normal liver tissues. Ninety-one patients with stage III HCC who underwent transcatheter hepatic arterial chemoembolization (TACE) from April 2016 to January 2021 were selected as HCC group, and ninety-one with non-HCC who underwent HCC screening were selected as control group, and the tissues were collected during the biopsy. The expression of ALDH1A1 mRNA and miR-140-5p in tissues was determined by real-time fluorescent quantitative PCR (qRT-PCR); the correlation between the expression level of ALDH1A1 mRNA in HCC tissue and miR-140-5p was analyzed; according to TACE treatment effect, HCC patients were divided into chemotherapy resistance group (53 cases) and chemotherapy sensitive group (38 cases), the relationship between the clinical characteristics of HCC, the expression levels of ALDH1A1 and miR-140-5p in HCC tissues and chemotherapy sensitivity were analyzed; the influencing factors of HCC chemotherapy sensitivity were analyzed.Results The Ualcan database showed that the expression level of ALDH1A1 mRNA (559.76±138.67) in normal liver tissues was lower than that in HCC tissues (851.70±245.89) (P<0.05). The qRT-PCR method showed that the expression level of ALDH1A1 mRNA (1.01±0.34) in the control group was lower than that in the HCC group (1.97±0.65) (P<0.05), and the expression level of miR-140-5p (1.06±0.35) was higher than that in the HCC group (0.50±0.17) (P<0.05); the level of ALDH1A1 mRNA in HCC tissues was negatively correlated with miR-140-5p (P<0.05); the proportions of HCC patients with multiple occurrences, serum AFP level ≤ 20 μg/L, relative expression of ALDH1A1 mRNA in HCC tissue ≤ 1.97, and relative expression of miR-140-5p in HCC tissue > 0.50 in the chemotherapy sensitive group were higher than those in the chemotherapy resistance group (P<0.05); ALDH1A was an independent risk factor that affected chemotherapy sensitivity of HCC patients (P<0.05), and miR-140-5p was an independent protective factor that affected chemotherapy sensitivity of HCC patients (P<0.05).Conclusion The expression of ALDH1A1 is up-regulated and the expression of miR-140-5p is down-regulated in HCC tissues. Both ALDH1A1 and miR-140-5p are related to chemotherapy sensitivity, and both are expected to be indicators for evaluating the chemotherapy sensitivity of HCC patients.

Key words: Acetaldehyde dehydrogenase 1A1, Hepatocellular carcinoma, MicroRNA-140-5p, Chemotherapy sensitivity