子宫内膜癌组织中dMMR蛋白和miRNA Let-7表达水平及临床价值的研究

Expression Level and Clinical Value of dMMR Proteins and miRNA Let-7 in Endometrial Carcinoma Tissue

目的探讨子宫内膜癌(endometrial carcinoma,EC)中微小RNA Let-7(miRNA Let-7)表达水平与DNA错配修复(DNA mismatch repair,dMMR)蛋白表达缺失的关系及意义。方法选取2016年5月~2022年12月在江苏省连云港市妇幼保健院行根治性手术切除的子宫内膜癌患者74例,分别用免疫组织化学法检测dMMR蛋白(包括MLH1,PMS2,MSH2,MSH6)的表达、实时荧光定量聚合酶链反应(qRT-PCR)检测miRNA Let-7的相对表达量,按照dMMR蛋白表达情况,将EC患者分为表达完整组(n=43)和表达缺失组(n=31),采用Logistic多因素回归分析与dMMR蛋白缺失相关的危险因素、绘制受试者工作特征(receiver operating characteristic,ROC)曲线评估相关因素的预测价值。结果74例EC病例中,miRNA Let-7的表达水平在肌层浸润<1/2组显著高于肌层浸润≥1/2组,差异具有统计学意义(t=1.79,P=0.04);dMMR蛋白表达的缺失率为41.89%,且年龄<55岁组和miRNA Let-7低表达组(<0.715)患者中的dMMR蛋白缺失率高于≥55岁组和miRNA Let-7高表达组(≥0.715),差异具有统计学意义(χ2=3.92,4.50,均P<0.05);Logistic多因素回归分析结果显示miRNA Let-7表达水平是发生dMMR表达缺失的独立危险因素(P=0.012);Spearman相关分析表明,miRNA Let-7的表达水平与dMMR蛋白缺失呈明显负相关(r=-0.247,P=0.034);ROC曲线分析结果显示,miRNA Let-7表达水平对于预测EC患者中发生dMMR蛋白的缺失具有一定的价值,其AUC为0.737,最佳临界值为0.77,敏感度和特异度分别为0.651,0.806。结论子宫内膜癌患者中miRNA Let-7的表达水平与dMMR蛋白缺失具有相关性,也是发生dMMR蛋白缺失的危险因素,有望为预测dMMR的表达缺失提供帮助。

Objective To investigate the relationship between the expression level of miRNA Let-7 and the deletion of DNA mismatch repair(dMMR)proteins in endometrial carcinoma(EC).Methods A total of 74 patients with EC who underwent radical surgery at Lianyungang Maternal and Child Health Hospital in Jiangsu Province from May 2016 to December 2022 were selected.Immunohistochemistry was used to detect the expression of dMMR proteins(including MLH1,PMS2,MSH2,and MSH6),while real-time fluorescence quantitative polymerase chain reaction(qRT-PCR)was performed to measure the relative expression levelof miRNA Let-7.According to the expression of dMMR proteins,EC patients were divided into the complete expression group(n=43)and the absent expression group(n=31).Logistic multivariate regression analysis was conducted to identify risk factors associated with dMMR protein deficiency,and receiver operating characteristic(ROC)curve was plotted to evaluate the predictive value of relevant factors.Results In 74 cases of EC,the expression level of miRNA Let-7 was higher in the myographic infiltration<1/2 group than in the myographic infiltration≥1/2 group,and the difference was significant(t=1.79,P=0.04).The deletion rate of dMMR protein expression was 41.89%,the deletion rate in patients aged<55 years and miRNA Let-7 low expression group(<0.715)were higher than those in≥55 years and miRNA Let-7 high expression group(≥0.715),with significant differences(χ2=3.92,4.50,all P<0.05).Logistic regression analysis revealed that miRNA Let-7 expression level was an independent risk factor for dMMR expression deletion(P=0.012).Spearman correlation analysis demonstrated a negative correlation between miRNA Let-7 expression level and dMMR protein deletion(r=-0.247,P=0.034).ROC curve analysis indicated that the expression level of miRNA Let-7 had a certain predictive value for dMMR protein deletion in EC patients,with an AUC of 0.737,an optimal critical value of 0.77,a sensitivity and a specificity of 0.651 and 0.806,respectively.Conclusion The expression level of miRNA Let-7 was correlated with the deletion of dMMR proteins in patients diagnosed with EC.Moreover,it served as a potential risk factor for dMMR protein deficiency.It may offer valuable insights into predicting dMMR expression deletion.