In the present study we investigate the effects of
small interfering RNA (
siRNA)-mediated silencing of
prohibitins (Phbs) gene expressions on gastric
carcinoma cell proliferation and apoptosis in vitro and in vivo. Firstly, Phbs
proteins in five human gastric
carcinoma cell lines were evaluated by Western blotting. Then three
siRNA sequences targeting Phbs were designed and transfected into the
cancer cell line with the highest Phbs
protein expressions. The cell proliferation and apoptosis were analyzed by MTT and flow cytometry methods. In vivo, the effects of siRNAs on the proliferation and apoptosis were assayed in xenografted
tumors of nude mice. Phbs
proteins were expressed highest in gastric
carcinoma cell line SGC7901. The cell proliferation significantly decreased upon Phbs silencing. The cell percentage in S phase was significantly lower in Phbs silenced groups, and the apoptotic cell ratio was significantly higher.
siRNA targeting Phbs significantly inhibited the growth of the xenografted
tumors. Further, Bcl-2 and Bax was respectively downregulated and upregulated after the Phbs silencing in the xenografted
tumors.
Caspase-3 and
caspase-9 activities were significantly enhanced in the Phbs-silenced
tumors. In summary,
siRNA-mediated silencings of Phbs inhibit proliferation and promotes apoptosis of gastric
carcinoma cells SGC7901 in vitro and in vivo, suggesting key roles of Phbs in the development of SGC7901 cell line.