Expression and biological role of the neutral cholesterol ester hydrolase 1 gene in liver cancer tissue and cell lines / 临床肝胆病杂志

ABSTRACT

ObjectiveTo investigate the expression of the neutral cholesterol ester hydrolase 1 (NCEH1) gene in liver cancer tissue and human hepatoma cell lines and the effect of NCEH1 gene knockdown on the proliferation, apoptosis, invasion, and metastasis abilities of human hepatoma SMMC-7721 cells. MethodsLiver cancer tissue samples and adjacent tissue samples were collected from 32 patients with liver cancer who underwent surgical treatment in Guangzhou Red Cross Hospital Affiliated to Jinan University from January 2013 to June 2019, and quantitative real-time PCR was used to measure the relative expression level of the NCEH1 gene. Gene expression data of liver cancer samples up to September 2020 were downloaded from the ICGC database, and R software was used to analyze the data and obtain the expression level of the NCEH1 gene in each sample. The paired Wilcoxon signed-rank test and the Wilcoxon rank-sum test were used to investigate the differences between liver cancer tissue and adjacent tissue. Quantitative real-time PCR was used to measure the expression level of the NCEH1 gene in human hepatoma SMMC-7721, Bel-7402, HepG2, and Hep3B cells and normal human HL7702 liver cells. The lentivirus-mediated small interfering RNA (siRNA) technique was used to establish a human hepatoma SMMC-7721 cell line with NCEH1 gene knockdown, and the cells were divided into NCEH1 knockdown group (KD group) and negative control group (NC group); quantitative real-time PCR was used to measure the knockdown efficiency of the NCEH1 gene, and then MTT assay, flow cytometry with Annexin V-APC single staining, wound healing assay, Transwell assay, and Transwell chamber invasion assay were used to measure the proliferation, apoptosis, metastasis, and invasion abilities of SMMC-7721 cells in both groups. The t-test was used for statistical analysis of data between the two groups. ResultsThe mean expression level of the NCEH1 gene in liver cancer tissue was significantly higher than that in adjacent tissue (specimens from our hospital: Z=2.263, P=0.024; ICGC database: U=18 768, P＜0.001). SMMC-7721 cell line with moderate potential of invasion and metastasis had the highest expression level of the NCEH1 gene, followed by BEL-7402 and HepG2 cell lines with low potential of invasion and metastasis, and Hep3B cell line without the potential of invasion and metastasis had the lowest expression level. The KD group had a significantly lower expression level of the NCEH1 gene than the NC group (t=11.578, P=0000 3), and the knockdown efficiency of the NCEH1 gene was as high as 74.0%. Compared with the NC group, the KD group had a significant reduction in cell growth rate, a significant increase in apoptosis rate, and significant reductions in migration rate and the number of metastatic and invasive cells (t=32.100, 27.303, 9.51, 38.123, and 22.331, all P＜0.001). Conclusion There is a significant increase in the expression of the NCEH1 gene in liver cancer tissue and cell lines, and the NCEH1 gene can promote the growth, proliferation, invasion, and metastasis of hepatoma cells and inhibit their apoptosis, suggesting that it may be a potential therapeutic target for liver cancer.