结直肠癌中KRAS基因突变与SETDB1表达的相关性及临床意义

  目的  探讨KRAS基因突变与SETDB1（set domain bifurcated 1）蛋白表达在结直肠癌中的临床意义及两者间的关系。  方法  收集2017年1月至2017年12月于西南医科大学附属医院住院接受诊治的122例结直肠癌患者的组织标本及病例资料，采用二代测序技术（NGS）检测KRAS基因突变情况，免疫组织化学染色检测SETDB1蛋白的表达情况。  结果  122例结直肠癌组织中KRAS基因突变率为41.8%，KRAS基因突变状态与肿瘤部位、术前血清CEA水平相关（P < 0.05），与年龄、性别、分化程度、肿瘤大小、pT?NM分期、淋巴结转移等无关（P>0.05）。KRAS基因突变状态与SETDB1蛋白表达呈正相关（r=0.232，P=0.008）。SETDB1蛋白水平与肿瘤分化程度、大小及术前血清CEA水平相关（P < 0.05），与年龄、性别、肿瘤部位、pTNM分期、淋巴结转移等无关（P>0.05）。  结论  SETDB1蛋白在KRAS突变型结直肠癌组织中呈现高表达，KRAS基因突变可能影响SETDB1蛋白表达。 

Correlation of KRAS mutation with SETDB1 expression in colorectal cancer and its clinical significance

  Objective  To explore the correlation of KRAS gene mutation with set domain bifurcated 1 (SETDB1) protein expression in colorectal cancer and its clinical significance.  Methods  Tissue samples and the case data of 122 patients with colorectal cancer hospitalized in the Affiliated Hospital of Southwest Medical University from January 2017 to December 2017 were collected. Next-generation sequencing (NGS) was used to detect KRAS gene mutations, and immunohistochemistry was used to detect SETDB1 protein expression.  Results  Mutation rate of KRAS gene in colorectal cancer tissues was 41.80%, and the mutation status of KRAS gene was correlated with tumor location and preoperative serum carcinoembryonic antigen (CEA) level (P < 0.05), but not with age, sex, differentiation degree, tumor size, pTNM stage, or lymph node metastasis (P>0.05). KRAS gene mutation status was positively correlated with SETDB1 protein expression (r=0.232, P=0.001). The level of SETDB1 protein expression was correlated with tumor differentiation, size, and initial serum CEA level (P < 0.05) but not with age, sex, tumor location, pTNM stage, or lymph node metastasis (P>0.05).  Conclusions  We observed high expression of SETDB1 protein in KRAS gene mutated colorectal cancer tissues, indicating that KRAS gene mutation might affect SETDB1 protein expression.