Axin通过激活p53的表达抑制结肠癌细胞的生长

目的： 观察过表达Axin对结肠癌SW480细胞生长的影响，并探讨其作用机制。方法：将pCMV5-HA-Axin质粒瞬时转染至结肠癌SW480细胞中，并设置转染空载体pCMV5-HA及未转染空白对照组，采用噻唑蓝(MTT)比色法及克隆形成实验检测细胞增殖状态的变化，流式细胞仪检测细胞周期变化；RT-PCR检测Axin及p53 mRNA的表达；Western blot检测Axin及P53蛋白的表达。结果：与转染空载体及空白对照组比较，过表达Axin显著抑制结肠癌SW480细胞的增殖。MTT实验显示转染Axin后细胞生长明显受到抑制，存活的瘤细胞明显减少(P<0.05)；克隆形成实验结果显示瞬时转染Axin质粒组细胞集落形成能力明显下降(P<0.05)；流式细胞仪分析检测结果显示转染Axin质粒后结肠癌SW480细胞周期G1前期比例升高，G1期明显被阻滞，S期比例下降(P均<0.05)。RT-PCR结果显示转染Axin的SW480细胞中p53 mRNA的表达较转染空载体组升高约1倍(P＜0.05)；同时，Western blot结果显示转染质粒Axin后结肠癌SW480细胞中P53的蛋白表达量明显增加，较转染空载体组几近升高1倍(P＜0.05)。结论：过表达Axin抑制结肠癌SW480细胞增殖，其作用机制是通过激活癌基因p53的表达而发挥效应的。

Axin inhibited the growth of colon cancer cells by activating p53

OBJECTIVE： To investigate the effect of Axin on the biological behavior of SW480 colon cancer cells and to elucidate its molecular mechanism.METHODS：SW480 colon cancer cells were transfered with pCMV5-HA-Axin and pCMV5-HA and blank control group was desigined. Cell proliferation was detected by MTT assay and colony formation assay,and the cell cycle was analyzed by flow-cytometry. At the same time,Real-time PCR and Western blot were used to assess the expressions of Axin and p53 oncogene in SW480 cells.RESULTS：Over-expression of Axin significantly inhibited the growth of SW480 colon cancer cells. MTT assay revealed over-expression of Axin inhibited the proliferation of SW480 cells（P〈0.05）. Transfection of Axin increased colon cancer SW480 cell cycle pre G1 ratio,inhibited G1 phase and decreased S ratio（P〈0.05）. p53 mRNA doubled in SW480 cells with transfered pCMV5-HA-Axin（P〈0.05）. P53 protein was also doubled in SW480 cells with transfered pCMV5-HA-Axin compared with empty vector groups（P〈0.05）.CONCLUSION：Over-expression of Axin could significantly inhibit the growth of colon cancer cells,and its mechanism might be related to the activation of the p53 oncogene.