胃癌和癌旁组织中hMSH2和p27蛋白的表达及其意义

背景:错配修复(MMR)基因是保证DNA复制高保真度的重要基因,与消化道肿瘤的发生密切相关。抑癌基因p27可阻止细胞周期G1/S期转换,p27表达下调在肿瘤的进展、转移过程中起有一定作用。目的:探讨MMR基因hMSH2和p27在胃癌和癌旁组织中的表达及其意义。方法:以免疫组化方法检测93例胃癌患者癌组织和癌旁组织中hMSH2和p27蛋白的表达。结果:胃癌组织中hMSH2蛋白的阳性表达率为65.6%,显著高于癌旁组织的38.7%(P<0.01);p27蛋白的阳性表达率为46.2%,显著低于癌旁组织的80.6%(P<0.01)。胃癌组织中hMSH2蛋白的表达与肿瘤临床病理特征无相关性;p27蛋白的表达与肿瘤分化程度、浸润深度、淋巴结转移和TNM分期相关。hMSH2和p27蛋白在胃癌组织中的表达呈负相关。结论:MMR基因hMSH2表达异常和抑癌基因p27表达下调可能与胃癌的发生有关。

Expression of hMSH2 and p27 Proteins in Gastric Cancerous and Paracancerous Tissues and their Significances

Background:Mismatch repair(MMR) genes are important genes in keeping the accuracy of DNA replication,and have close relationship with the genesis of gastrointestinal tumors.Tumor suppressor gene p27 arrests G1/S transition of cell cycle.Downregulation of p27 expression has an effect on the progression and metastasis of cancer.Aims:To investigate the expression of hMSH2,a MMR gene and p27 in gastric cancerous and paracancerous tissues and their significances.Methods:Immunohistochemical method was used to determine the protein expression of hMSH2 and p27 in cancerous and paracancerous tissues of 93 gastric cancer patients.Results:The positivity rate of hMSH2 protein in gastric cancerous tissue was 65.6%,significantly higher than that in the paracancerous tissue(38.7%,P<0.01),and the positivity rate of p27 protein in gastric cancerous tissue was 46.2%,significantly lower than that in the paracancerous tissue(80.6%,P<0.01).Expression of hMSH2 protein in gastric cancerous tissue was not relevant with the clinicopathological parameters of gastric cancer,whereas expression of p27 protein was related with differentiation,infiltration,lymph node metastasis and TNM staging of gastric cancer.Negative correlation was found between hMSH2 and p27 protein expression in gastric cancerous tissue.Conclusions:Abnormal expression of hMSH2 and downregulation of p27 expression may have close relationship with the genesis of gastric cancer.