ShRNA-mediated gene silencing of heat shock protein 70 inhibits human colon cancer growth.

Heat shock protein 70 (Hsp70), a chaperone involved in tumor progression, is overexpressed in various human tumors. However, its role in colon cancer progression is not completely understood. In the present study, two shRNA plasmid vectors against Hsp70 were constructed and stably transfected into the colon cancer cell line HT29 to determine the effect of Hsp70 on cell proliferation, cell cycle distribution and cell apoptosis in HT29 cells in vitro, and its effect on xenograft tumor growth and apoptosis in vivo. Cell proliferation was determined using MTT assay. The results revealed that Hsp70 silencing efficiently inhibited the growth of HT29 cells in culture, induced cell cycle arrest at the G1 phase, and significantly increased apoptosis. Moreover, stable clones from the Hsp70 shRNA-2 vector suppressed xenograft tumor growth and enhanced apoptosis in vivo compared with a mock and vector control group. In conclusion, specific Hsp70 shRNA silencing may inhibit colon cancer growth, indicating that Hsp70 silencing is a potential therapeutic strategy for the treatment of colon cancer.