结直肠癌K-ras基因突变位点的检测及其临床意义

Detection of K-ras gene mutation in colorectal cancer and its clinical significance

摘要:

目的：探讨结直肠癌中K-ras基因突变状态及其与临床病理特征的关系。 方法：应用实时荧光定量PCR（RT-qPCR）和直接基因测序法检测200例结直肠癌患者癌组织K-ras基因突变状态。将两种检测结果进行对比，并结合临床病理资料分析其意义。 结果：200例结直肠癌患者中，RT-qPCR检测出突变63例，突变检出率31.5%；经直接基因测序，测序成功的样品169例，检出突变50例，突变检出率29.6%。其中第12密码子GGT→GAT最常见，占34.9%（22/63）；其次是第13密码子GGC→GAC，占28.6%（18/63）；第12密码子GGT→CGT最少，全组未见（0/63）。两种方法突变检测一致率为98%。K-ras基因突变与肿瘤分化程度有关（P<0.05），而与患者性别、年龄、肿瘤部位、淋巴结转移及TNM分期无明显关系（均P>0.05）。 结论：RT-qPCR能快速、敏感、准确地检测结直肠癌K-ras基因突变位点，为临床靶向治疗提供可靠的参考依据。

Abstract:

Objective: To investigate K-ras gene mutation status and its relations with the clinicopathological characteristics in patients with colorectal cancer. Methods: The K-ras gene mutation status in the tumor tissues from 200 colorectal cancer patients were detected by Real-time fluorescence quantitative PCR (RT-qPCR) and direct sequencing, respectively. The results obtained by the two methods were compared and their significance was analyzed in conjunction with the main clinicopathological variables. Results: Of the 200 colorectal cancer specimens, 63 mutation cases were detected by RT-qPCR, and the mutation detection rate was 31.5%; 50 mutation cases were detected from the 169 specimens that were successfully sequenced by direct sequencing technique, and the mutation detection rate was 29.6%. The GGT→GAT at codon 12 was the most prevalent mutation and accounted for 34.9% (22/63) of the total mutation cases, followed by GGC→GAC at codon 13 that accounted for 28.6% (18/63) of the total mutation cases, while GGT→GCT at codon 12 was the rarest mutation that was not found in any case of the entire group (0/63). The concordance rate between two methods was 98%. K-ras gene mutation was significantly associated with the differentiation of the tumor (P<0.05), but not related to the sex, age, tumor location, lymph node metastasis or TNM stage of patients (all P>0.05). Conclusion: RT-qPCR is a rapid, sensitive and accurate method for detection of the K-ras gene mutation, and therefore provides reliable information for clinical applications of targeted therapy.