Paclitaxel Inhibits Proliferation by Negatively Regulating Cdk1-Cell Cycle Axis in Rat Airway Smooth Muscle Cells.

OBJECTIVE: Paclitaxel exhibits outstanding biological activities in inhibiting cell proliferation and inducing cell apoptosis. But the effects of paclitaxel on airway smooth muscle cells (ASMCs) have not been reported yet. The purpose of this study is to determine the effects of paclitaxel on the proliferation and apoptosis of ASMCs.

METHODS: Rat primary ASMCs were isolated and used in all the experiments. Cell Counting Kit-8 (CCK-8) assay and Edu assay were used to analyse the cell viability and proliferation respectively. Flow cytometry was used to detect the cell cycle and apoptosis. Quantitative real-time PCR (qRT-PCR), western blotting, and immunostaining were used to detect the expression of Cyclin-dependent kinase 1 (Cdk1).

RESULTS: Our study showed that paclitaxel inhibits the proliferation of ASMCs in a dose and time gradient dependent manner. Further study displayed that cell cycle is arrested at G2/M phase. And Cdk1 was dramatically down-regulated by paclitaxel treatment. Cell morphological analysis showed that ASMCs are elliptical with a larger surface area after paclitaxel treatment. Nucleus morphological analysis showed that the nuclei are in a diffuse state after paclitaxel treatment. But paclitaxel did not induce the apoptosis of ASMCs.

CONCLUSIONS: Our study demonstrated that paclitaxel inhibits the proliferation of ASMCs at least partly by negatively regulating Cdk1-cell cycle axis.