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

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

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。

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 path- way, 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, roTOR, p - roTOR, as well as nuclear factor NF - KB 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, roTOR were not significantly change, while p - Akt, p - roTOR and NF - KBp65 expression were up - regulated. LY294002 inhibited phosphorylation of PI3K/Akt and its downstream target protein and the p - mTOR and NF - KB p65 were inhibited by their inhibitor rapamyein 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 roTOR and NF - KB pathways that independent downstream targets for PI3K/Akt pathway.