血小板源性生长因子-DD通过Akt信号通路促进膀胱癌T24细胞增殖

目的研究外源性血小板源性生长因子-DD(PDGF-DD)对膀胱癌T24细胞增殖及Akt信号转导通路的影响,阐述factor其诱导细胞增殖的机制。方法外源性PDGF-DD蛋白作用T24细胞,采用MTT法分析细胞的增殖;流失细胞仪检测细胞周期的变化;Western blot法观测膀胱癌T24细胞Akt、p-Akt、mTOR、p-mTOR以及核因子NF-κB蛋白表达的变化。结果 PDGF-DD促进T24细胞的增殖,并且具有浓度依赖性;DNA合成前期(G0/G1期)细胞比例下降,合成期(S期)细胞比例上升;Akt、mTOR表达变化不明显,而p-Akt、p-mTOR及NF-κB p65的表达均上调。LY294002抑制PI3K/Akt及其下游靶位蛋白磷酸化;雷帕霉素和PDTC分别抑制p-mTOR和NF-κBp65的表达。结论外源性PDGF-DD刺激T24细胞的增殖,其机制可能是通过Akt/mTOR和Akt/NF-κB两条独立的信号通路实现的。

PDGF-DD promotes bladder cancer cell T24 proliferation through Akt signal transduction pathway

Objective To investigate the effect of exogenous platelet-derived growth factor-DD(PDGF-DD) on proliferation of human cultured cells(T24)and Akt signal transduction pathway,and explain the mechanism of cell proliferation.Methods T24 cells were exposed to different concentration of PDGF-DD protein,and cell proliferation was detected by MTT assay.The effect of PDGF-DD on cell cycle was analyzed by flow cytometry.The expression levels of Akt,p-Akt,mTOR,p-mTOR,as well as nuclear factor NF-κB were measured by western blotting.Results PDGF-DD promoted proliferation of cells in a dose-dependent manner.Incubation of tumor cells with PDGF-DD decreased the G0/G1 event with the concomitant increase in the events in S phases of the cell cycle.The expression of Akt,mTOR were not significantly change,while p-Akt,p-mTOR and NF-κBp65 expression were up-regulated.LY294002 inhibited phosphorylation of PI3K/Akt and its downstream target protein and the p-mTOR and NF-κB p65 were inhibited by their inhibitor rapamycin and PDTC respectively.Conclusion These findings suggest that PDGF-DD may have a potent anti-proliferative effect on T24 cells,the mechanisms of which may be related to the mTOR and NF-κB pathways that independent downstream targets for Pl3K/Akt pathway.