PKB介导的bFGF在人类大肠癌细胞中的表达及其相关性

PKB-dependent pathway in colorectal cancer cell growth induction by bFGF

目的研究碱性成纤维细胞生长因子(bFGF)通过磷脂酰肌醇3激酶(PI3K)/蛋白激酶B (PKB)通路调控大肠癌细胞生长的信号转导机制。方法MTT法分析bFGF对大肠癌LoVo细胞增生程度的影响;(γ-^(32)P)ATP掺入法检测LoVo细胞株中PKB的活性;RT-PCR法检测LoVo细胞株中细胞周期素A(cyclinA)的表达;Western Blot检测PKB和cyclinA的表达。结果bFGF以不同时间作用于LoVo细胞时,通过(γ-^(32)P)ATP掺入法检测发现可提高细胞PKB活性。PKB的抑制剂LY294002预处理后再施加bFGF,可显著降低PKB的活性(P<0.05),bFGF刺激LoVo细胞cyclinA蛋白表达都高于其他各组,LY294002抑制组蛋白明显降低,而PKB在各组中的表达无明显变化。结论bFGF刺激大肠癌LoVo细胞后可通过依赖PI3K/PKB途径调节cyclin A的转录活性促进其表达,进而促进细胞增生。

Objective To investigate the signal transduction of bFGF to regulate the colorectal carci- noma cell growth via PI3K/PKB pathway.Methods MTT assay was used to determine the suppressive effect of bFGF on the growth rate of LoVo cell;(γ-^(32)P)ATP incorporation assay was used to detect the increased activity of PKB in LoVo cell;the RT-PCR technique was used to test the expression of cyclin A;Western Blot analysis was used to detect the expressions of PKB and cyclin A protein.Results When the bFGF worked on the LoVo cell at various times,it was found that the PKB activity of the LoVo cell was increased by the(γ-^(32)P) ATP incorporation assay.By preprocessing by the depressor-LY294002 and bFGF,the activity of PKB was sig- nificantly reduced(P<0.05);by stimulating the LoVo cell by bFGF the protein expressions of cyclin A were higher than by other groups,while the protein expression of the imposed group by LY294002 was decreased obviously,and the PKB expressions in all groups had no distinct changes.Conclusion After stimulating the colorectal LoVo cells,the bFGF could regulate the transcriptional activity of cyclin A and modulate its expres- sion via PI3K/PKB pathway,which accelerate the proliferation of LoVo cell.