Syk基因启动子去甲基化对鼻咽癌细胞侵袭转移能力的影响

Effect of Syk gene promoter demethylation on invasion and metastasis of nasopharyngeal carcinoma cell line

目的:探讨去甲基化药物5-杂氮-2-脱氧胞苷(5-aza-2-deoxycytidine,5-aza-CdR)对鼻咽癌5-8F细胞Syk基因启动子去甲基化作用及其侵袭转移的影响。方法:利用5-aza-CdR处理体外培养的5-8F细胞,采用BS-PCR、Q-RT-PCR、Western Blot及Transwell方法分别检测药物干预前后5-8F细胞中Syk甲基化、Syk mRNA、Syk蛋白及穿膜细胞数的情况。结果:经5-aza-CdR处理后5-8F细胞株的甲基化水平降低(P<0.01),Syk mRNA及蛋白表达升高(P<0.05),其侵袭及转移能力降低(P<0.05),且呈剂量依赖性。结论:鼻咽癌细胞Syk基因启动子甲基化导致其基因沉默,Syk基因失表达,从而引起鼻咽癌细胞的侵袭转移能力增加,5-aza-CdR可以使鼻咽癌细胞Syk基因启动子去甲基化,使因甲基化沉默的Syk基因重新表达,恢复其抑制肿瘤细胞侵袭转移的能力。

Objective ： To investigate the effect of demethylation agent （ 5 - aza - 2 - deoxycytidine, 5 - aza - CdR） on the demethylation of Syk gene promoter and the invasion and metastasis of nasopharyngeal carcinoma cell line 5 -8F. Methods： Nasopharyngeal carcinoma cell line 5 -8F was treated with 5 -aza -CdR in vitro. BS - PCR, Q - RT - PCR, Western Blot and Transwell were used to detect Syk methylation, Syk mRNA, Syk protein of 5 - 8F cell line, as well as the cell number line that pricked mere -brane before and after treatment of 5 - aza - CdR. Results： The promoter methylation level of Syk gene was significantly decreased（ P 〈 0.01 ）. The expression of Syk mRNA and protein were up - regulated （P 〈 0.05 ）. The invasion ability and metastasis were concentration - depend- ently decreased（ P 〈0.05） in 5 -8F cell line after treatment of 5 -aza- CdR. Conclusion： Methylation around gene promoter region can lead to Syk silencing in nasopharyngeal carcinoma cell. The inactivation of Syk gene may result in enthancing vasion ability and metastasis. Moreover,5 - aza - CdR can induce the demethylation of the Syk promoter in nasopharyngeal carcinoma cell, rresulting in reexpression of Syk gene, and inhibiting the invasion and metastasis of tumour cells.