中国人结直肠癌454例K-ras基因突变状态分析  

K-ras gene mutation status in 454 Chinese patients with colorectal cancer

作　　者：范少安[1] 袁轶伟[1] 赵新泰[1] 

机构地区：[1]上海赛安生物医药科技有限公司,卫生部医药卫生科技发展研究中心肿瘤个体化用药分子诊断技术研究基地,上海200436

出　　处：《肿瘤》2013年第4期355-360,共6页Tumor

基　　金：卫生部医药卫生科技发展研究中心基金项目(编号:W2012FZ139)

摘　　要：目的:分析结直肠癌(colorectal cancer,CRC)患者肿瘤组织或血浆样本中K-ras基因突变状态,以促进针对表皮生长因子受体(epidermal growth factor receptor,EGFR)的靶向药物(如西妥昔单抗和帕尼单抗等)应用于CRC个体化治疗。方法:采用低变性温度下复合扩增聚合酶链反应(coamplication at lower denaturation temperature PCR,COLD-PCR)再结合测序的方法,定点分析431例中国CRC患者的肿瘤组织和另外23例CRC患者的血浆中K-ras基因序列结构,计算K-ras基因突变率。对不同CRC样本及不同年龄患者群的K-ras基因突变频率,采用χ2检验进行统计学分析,以P<0.05为差异有统计学意义。结果:在431例CRC患者的肿瘤组织中,K-ras基因发生突变的总体频率为25.29%;其中2种主要形式的突变为G12D(第12密码子由甘氨酸突变为天冬氨酸)和G13D(第13密码子由甘氨酸突变为天冬氨酸),它们发生的频率分别是12.99%和6.26%。而在23例CRC患者血浆中检出K-ras基因突变的发生频率为21.74%,其与肿瘤组织中的总突变率无明显差异(P>0.05)。在60岁及以上的CRC患者中,检测出任一种K-ras基因突变的可能频率为37.94%,显著高于60岁以下CRC患者的检出率(7.30%,P<0.01)。结论:采用COLD-PCR扩增再结合测序的方法检测K-ras基因突变状态时,在缺乏CRC肿瘤组织的情况下可以采用血浆样本来代替。另外,鉴于60岁及以上的CRC患者更易发生K-ras基因突变,建议对这些老年患者在治疗前须先常规检测K-ras基因突变状态。Objective： To analyze the mutation status of K-ras gene in CRC （colorectal cancer） tissues and plasma samples of CRC patients, ultimately to promote the targeted agents against EGFR （epidermal growth factor receptor） （such as cetuximab and panitumumab, etc.） used in personalized treatment for CRC patients. Methods： The sequence of K-ras gene at specific sites was investigated in 431 CRC tissues and 23 plasma samples collected from 454 CRC patients, respectively. To improve the detection sensitivity, a combinatory approach was chosen which included the COLD-PCR （coamplification at lower denaturation temperature PCR） method, followed by DNA sequencing. Chi-square test was employed to analyze K-ras mutation frequencies in various sample types or subgroups of CRC patients according to age, and the difference was considered statistically significant if P value was less than 0.05. Results： The overall K-ras mutation rate was 25.29% in 431 CRC tissue samples. The two major forms of K-ras mutation were G12D （mutation of glycine to an aspartate residue at codon 12） and G13D （mutation of glycine to an aspartate residue at codon 13）, and their occurrence frequencies were 12.99% and 6.26%, respectively. Interestingly, the overall K-ras mutation rate was 21.74% in blood samples from additional 23 CRC patients, without a significant difference from the mutation rate in the tumor samples （P 〉 0.05）.Moreover, the occurrence frequency of anyone form of K-ras mutation was 37.94% in CRC patients aged 60 and over, which was significantly higher than the detection rate （7.30%） of the patients under the age of 60 （P 〈 0.01）. Conclusion： COLD-PCR amplification combined with DNA sequencing method can be used to detect the mutation status of K-ras gene, and plasma samples can be used insteadly if CRC tumor tissues are unavailable. In addition, for elderly patients aged of 60 and over, it is suggested that K-ras mutation status should be routinely detected before treatment.

关 键 词：结直肠肿瘤 基因 ras DNA突变分析 血浆 低变性温度下复合扩增聚合酶链反应 

分 类 号：R735.34[医药卫生—肿瘤]