LASS2 interacts with V-ATPase and inhibits cell growth of hepatocellular carcinoma.
- Author:
Ning TANG
1
;
Jie JIN
;
Yun DENG
;
Rong-Hu KE
;
Qiu-Jin SHEN
;
Shao-Hua FAN
;
Wen-Xin QIN
Author Information
1. Shanghai Medical College, Fudan University, Shanghai, China.
- Publication Type:Journal Article
- MeSH:
Apoptosis;
Carcinoma, Hepatocellular;
pathology;
Caspase 3;
metabolism;
Cell Line, Tumor;
Cell Proliferation;
Humans;
Liver Neoplasms;
pathology;
Membrane Proteins;
metabolism;
RNA, Small Interfering;
Sphingosine N-Acyltransferase;
metabolism;
Transfection;
Tumor Suppressor Proteins;
metabolism;
Vacuolar Proton-Translocating ATPases;
metabolism
- From:
Acta Physiologica Sinica
2010;62(3):196-202
- CountryChina
- Language:Chinese
-
Abstract:
Homo sapiens longevity assurance homologue 2 (LASS2) is a novel gene isolated from a human liver cDNA library by our laboratory, and it is a human homologue of the yeast longevity assurance gene LAG1 (Saccharomyces cerevisiae longevity assurance gene). According to our previous results, LASS2 could interact with subunit c of vacuolar type H(+)-ATPase (V-ATPase), and the overexpression of LASS2 could inhibit the cell growth of a human hepatocellular carcinoma (HCC) cell line, SMMC-7721. In order to understand the role of the interaction between LASS2 and V-ATPase in HCC cell growth, we transiently transfected plasmid pCMV-HA2-LASS2 into HCCLM3, a HCC cell line without the significant expression of endogenous LASS2. The pH-sensitive fluorescence probes, BCECF and BCECF-AM, were used to measure the intracellular and extracellular H(+) concentrations of HCCLM3 cells respectively. The effect of LASS2 gene on apoptosis was evaluated with Annexin-V/FITC and propidium iodide (PI) by flow cytometry. Western blot was used to detect cytochrome c (Cyt c) in the cytosol and mitochondria, as well as pro-caspase-3 in cytosol. The results showed that the cell growth of LASS2-transfected HCCLM3 cells was significantly inhibited compared with that of the mock control. LASS2 transfection increased intracellular H(+) concentration of HCCLM3 cells, while decreased extracellular H(+) concentration. Moreover, LASS2 transfection significantly enhanced the apoptosis of HCCLM3 cells. In LASS2-transfected cells, the amounts of Cyt c increased in the cytosol, while decreased in the mitochondria. Meanwhile, the expression of pro-caspase-3 in the cytosolic extracts was decreased. These results implicate that LASS2 gene might increase intracellular H(+) of HCC cells via the interaction with V-ATPase, thereby inducing cell apoptosis through mitochondrial pathway.
