喉鳞状细胞癌中 TIMP3基因启动子区甲基化状态的研究

摘要

Objective It is to observe the methylation status in promoter region of Tissue inhab‐itor of metalloproteinases 3(TIMP3) gene and the expression of TIMP3 protein in laryngeal squamous cell carcinoma (LSCC) .Methods A modified methylation specific PCR (MSP) was used to examine the methylation status in the 5'CpG island of TIMP3 and immunohistochemical SP method was performed to detect TIMP3 protein expression in tumors and corresponding normal adjacent tissues .Results TIMP3 gene in tumor specimens ,which was significantly higher than that in corresponding normal tis‐sues ( P <0 0.1);Methylation frequencies of LSCC in lymph node metastasis group were higher than that in no lymph node metastasis group ( P <0 .05);Methylation frequencies of poor differentiation group were higher than those in moderately and well differentiation groups( P <0 0.5);Positive im‐munostaining of TIMP3 in tumor tissues was significantly lower than that in matched normal tissues ( P <0 0.1) .TIMP3 protein expression of LSCC in lymph node metastasis group was remarkably lower than that in no lymph node metastasis group( P <0 0.5) .Conclusion Hypermethylation status in the 5'CpG island of TIMP3 gene-induced gene silencing may be one of the mechanisms underlying the de‐velopment of LSCC .Hypermethylation of TIMP3 gene can be used as an index reflecting the biological behaviors of LSCC .%①目的研究喉鳞状细胞癌（LSCC）中基质金属蛋白酶抑制因子3（TIMP3）基因启动子CpG岛甲基化及其蛋白表达情况。②方法采用改进的甲基化特异性PCR（MSP）和免疫组化SP法检测LSCC组织及相应癌旁正常组织中TIMP3基因的DNA甲基化和蛋白表达情况。③结果 LSCC组织中TIMP3基因启动子区CpG岛甲基化发生率显著高于癌旁正常组织（ P ＜00．1）；有淋巴结转移的LSCC组织中甲基化率高于无淋巴结转移的LSCC组织（ P ＜00．5）；低分化LSCC组织中甲基化发生率高于高、中分化LSCC组织（ P均＜00．5）；52例LSCC组织中TIMP3蛋白的表达率与相应癌旁正常组织的TIMP3蛋白表达率比较有统计学意义（ P ＜00．1）；有淋巴结转移的LSCC组织中蛋白表达率低于无淋巴结转移的LSCC组织（ P ＜00．5）。④结论 TIMP3基因启动子区CpG岛的异常甲基化导致基因沉默可能是LSCC的发生机制之一，可作为反映LSCC生物学行为的检测指标。