Role Of Ubiquitin B In 17-AAG-Induced Cell Cycle Arrest In HeLa Cells

Background and Objective Selectively inhibites Hsp90 function in many cancer models resultes in a selective degradation of significance signaling proteins, which are involved in cell proliferation, cell cycle regulation, and apoptosis. This study is to explore the function and mechanism of Ubiquitin B in 17-AAG-induced cell cycle arrest.Methods Human cervical cancer cell lines Hela were cultured and then treated with different concentrations of 17-allylamino-17-demethoxy-geldanamycin (17-AAG). Use flow cytometry to detect the cell cycle and use fluorospectrophotometry to test the chymotrypsin-like proteasome activity. Ubb was knocked down by Ubb siRNA and was assayed by ABI Real Time PCR System. Use Western Blot to test the expression of Hec1 and Cdk1.Results 24 hours after 17-AAG treated, the proportion of cells in G2/M phase was upregulated from (14.38±4.93)% in control which was not treated by 17-AAG to (52.38±5.67)% which was treated by 1umol/L 17-AAG, and the difference was statistically significant (P < 0.05), the chymotrypsin-like proteasome activity upregulated simultaneously, Western Blot detected the downstream of Cdk1 and Hec1, but the expression of Mad2 had no change; When Ubb expression was interferenced by Ubb siRNA, 17-AAG-induced cell cycle arrest was suppressed, the proportion of cells in G2/M phase of 500nmol/L and 1umol/L 17-AAG decreased respectively from (32.68±3.79)% and(43.98±1.99)% before siRNA interference to (17.07±2.22)% and(25.95±6.69)% after interference.Conclusion Ubb play an important role in process of 17-AAG-induced HeLa cell cycle arrest, Ubb and 17-AAG are functionally interrelated, indicating Ubb as a possible target for 17-AAG-induced cell-cycle arrest and a new target for clinical therapy of cervical cancers.