Effect of NHE1 antisense gene transfection on the biological behavior of SGC-7901 human gastric carcinoma cells

Abstract

To study the effect of type 1 Na(+)/H(+) exchanger (NHE1) antisense human gene transfection on the biological behavior of gastric carcinoma cell line SGC-7901. Antisense NHE1 eukaryotic expression on vector pcDNA3.1 was constructed by recombinant DNA technique and transfected into gastric carcinoma cell line SGC-7901 with DOTAP liposome transfection method. Morphological changes of cells were observed with optic and electron microscopes. Changes in cell proliferative capacity, apoptosis, intracellular pH (pH(i)), cell cycle, clone formation in two-layer soft agar, and tumorigenicity in nude mice were examined. Antisense eukaryotic expressing vectors were successfully constructed and transfected into SGC-7901. The transfectant obtained named 7901-antisense (7901-AS) stablely produced antisense NHE1. There was a significant difference between the pH(i) of 7901-AS cells (6.77 +/- 0.05) and that of 7901-zeo cells and SGC-7901 cells (7.24 +/- 0.03 and 7.26 +/- 0.03, P < 0.01). Compared with SGC-7901 and 7901-zeo cells, 7901-AS cells mostly showed cell proliferation inhibition, G1/G0 phase arrest, increased cell apoptotic rate, recovery of contact inhibition, and density contact. The tumorigenicity in nude mice and cloning efficiency in the two-layer soft agar were clearly inhibited. NHE1 antisense gene significantly restrains the malignant behavior of human gastric carcinoma cells, suppresses cell growth and induces cell apoptosis, and partially reverses the malignant phenotypes of SGC-7901. These results suggest a potential role for human tumor gene therapy.