SOX11基因甲基化与宫颈癌的相关性研究
Relationship between methylation of SOX11 gene and cervical cancer

摘要：目的 检测正常宫颈组织、宫颈癌组织及宫颈癌细胞系中SOX11基因的甲基化状态并探讨甲基化状态与SOX11基因表达的关系。方法 亚硫酸氢盐测序法及TA克隆分析正常宫颈、宫颈癌组织及宫颈癌细胞系中SOX11基因启动子区DNA的甲基化状态。RT-PCR检测宫颈癌细胞系、宫颈癌组织及正常宫颈组织中SOX11基因mRNA表达。结果 宫颈癌组织中SOX11基因呈高甲基化状态，平均甲基化率为81.07%，远高于正常宫颈组织中SOX11甲基化率(12.86%)，差异具有统计学意义(P<0.001)。宫颈癌细胞系HeLa、SiHa、C33-A和CaSki中SOX11均呈高甲基化状态，其甲基化率分别为90.71%、97.14%、77.14%、99.64%。宫颈癌组织中SOX11基因mRNA的表达量远低于正常宫颈组织中的表达，差异有统计学意义(P<0.001)。SOX11基因的表达与其启动子区高甲基化呈负相关(P<0.001，r=－0.808)。经去甲基化剂5-氮杂胞苷处理后，在宫颈癌细胞系中SOX11 mRNA的表达水平明显升高。宫颈癌HPV感染可能增加SOX11启动子甲基化发生。结论 宫颈癌组织中SOX11基因启动子区的DNA高甲基化而使其表达沉默。
ABSTRACT: Objective To detect the methylation status of SOX11 gene in normal cervix, cervical cancer tissues and cervical cancer cell lines so as to explore the relationship between methylation status and expression of SOX11 gene. Methods DNA methylation status of SOX11 gene in normal cervical, cervical cancer tissues and cervical cancer cell lines was analyzed by bisulfite sequencing and TA cloning assay. The expression of SOX11 mRNA in cervical cancer tissues, cell lines and normal cervical was detected by RT-PCR. Results The average methylation rate of SOX11 in cervical cancer tissues (81.07%) was significantly higher than that in normal cervical tissues (12.86%) (P<0.001). The methylation status of SOX11 in HeLa, SiHa, C33-A and CaSki cells was all hypermethylated with the methylation of 90.71%, 97.14%, 77.14% and 99.64%, respectively. The expression of SOX11 mRNA in cervical cancer tissues was significantly lower than that in normal cervixes (P<0.001). The SOX11 gene expression was significantly negatively correlated with its promoter hypermethylation (P<0.001, r=－0.808). After demethylation agent 5-azacytidine treatment, SOX11 mRNA expression in cervical cancer cell lines was significantly increased. Further analysis showed that HPV infection in cervical cancer might increase SOX11 promotor methylation. Conclusion SOX11 gene in cervical cancer is silenced by the hypermethylation of DNA in the promoter region