ABSTRACT
Objective To explore the effects of cAMP response element binding protein ( CREB) on taxol-induced cell cycle arrest in HeLa cells .Methods MTT assay was used to determine the optimal concentration and treatment time . PCR method was used to construct the recombinant plasmid pCI neo /CREB( PN) and site-directed mutagenesis recombinant plasmid pCI neo/CREB-M(PM).Cell cycle was assayed by flow cytometry .Expressions of pCREB, CREB, cyclins and CDKs were assayed by Western blotting .Results The effective conditions of taxol treatment on HeLa cells were 0.1μmol/L for 24 hours.After cells were treated with 0.1μmol/L taxol, G2/M phase was arrested in a time-dependent manner , accomplished with the decrease of cyclin A , a significant increase of cyclin B1, D1 and phosphorylated CREB (pCREB) protein expression, whereas, no marked changes were observed in cyclin E , CDK1, CDK2, CDK4 and CREB expressions. However, combinantion of PM and taxol treatment significantly reduced taxol-induced G2/M phase arrest, and reversed the effect of taxol-decreased cyclin A, increased cyclin B1 and D1 expression.Conclusion Tanscription factor CREB-mediated specific cyclins play a pivotal role in taxol-induced G 2/M arrest in HeLa cells .