基于微流控芯片的温度梯度毛细管电泳检测大肠癌石蜡标本中K-ras基因突变

K-ras基因突变检测可用于大肠癌的早期筛查与诊断，并有利于筛选出抗表皮生长因子受体靶向药物治疗有效的大肠癌患者，以实现肿瘤的个体化治疗．采用以倾斜式热辐射原理建立的微流控温度梯度毛细管电泳(temperature gradient capillary electrophoresis，TGCE)基因突变检测系统，实现了对98例石蜡包埋大肠癌组织中K-ras基因突变的高灵敏度筛查，突变阳性检出率为47.96%，显著高于PCR产物直接测序的23.47%．克隆测序显示该方法至少能检测到2.08%的K-ras基因突变体．K-ras基因突变与临床病理学参数的关系分析显示，直肠癌中K-ras基因突变率明显高于结肠癌(P < 0.05)，而与年龄、性别、组织学类型和肿瘤分期等无显著相关性．该检测方法为肿瘤早期诊断和指导临床用药提供了一种灵敏度高、检测速度快、便于大规模筛查的有效手段.

Mutation Detection of K-ras Gene in Paraffin-embedded Colorectal Cancer Tissues by Using Chip-based TGCE

K-ras gene mutation is generally regarded as a significant indicator for colorectal cancer screening and early diagnosis and in favor of filtering out colorectal cancer patients benefiting from epidermal growth factor receptor (EGFR)-targeted therapy. The chip-based temperature gradient capillary electrophoresis (TGCE) was successfully used to detect K-ras gene mutation in 98 cases of paraffin-embedded colorectal cancer tissues with high sensitivity. Mutation-positive detection rate from chip-based TGCE (47.96%) was significantly higher than that from the PCR product direct sequencing (23.47%). Clone sequencing showed that this detection system could detect at least 2.08% of the mutant K-ras gene. Analysis of the relationship between K-ras gene mutation and clinical pathological parameters revealed that K-ras gene mutation rate in rectum cancer was significantly higher than that of colon cancer (P < 0.05), but no remarkable correlation between K-ras gene mutation rate with age, gender, histological type and tumor stage was observed. Therefore chip-based TGCE is very sensitive and rapid method for mutation detection, and it can be applied for large-scale screening, early diagnosis and guiding clinical treatment.