Involvement of p27KIP1 in G1 arrest mediated by an anti-epidermal growth factor receptor monoclonal antibody.

摘要: Activation of the cyclin dependent kinases (CDK4/CDK6 and CDK2) is required for G1 phase progression entry into S-phase. The activation these regulated by checkpoints that monitor environmental intracellular conditions. Progression S-phase controlled, in part, availability growth factors, we have investigated relationship between factor CDK kinases. Blocking epidermal (EGF) receptor tyrosine kinase with anti-EGF monoclonal antibody (mAb) 225 induces cell cycle arrest DiFi human colon adenocarcinoma cells. When cells are treated mAb 24 h, observe marked decreases activities CDK2 E-associated which not accompanied reduced levels E proteins. However, amount cyclin/CDK inhibitor p27KIP1 increases mAb-treated bound to increasing amounts. Immunodepletion removes an inhibitory activity from lysates cells: immunodepleted heated lose capacity inhibit E/CDK2 vitro assay. results suggest induced EGF blockade involves p27KIP1.