激光显微切割技术富集肿瘤细胞在基因突变检测中的意义

目的 探讨激光显微切割技术富集肿瘤细胞对检测非小细胞肺癌（non-small cell lung cancer,NSCLC）表皮生长因子受体（epidermal growth factor receptor,EGFR）基因突变检测的影响以及其临床病理学意义.方法 采用激光显微切割技术富集49例NSCLC患者的石蜡包埋样本的肿瘤细胞,采用PCR技术对EGFR基因第18、19、20、21号外显子片段进行扩增后直接测序,分析其结果并比较其与常规肿瘤组织筛选后进行EGFR基因突变检测结果的异同.结果 49例NSCLC样本中21例（42.9％）存在EGFR基因突变,包括第19号外显子13例,第21号外显子8例,没有发现两者同时突变的样本.分析外显子突变情况发现,利用激光显微切割技术富集的样本检测突变率42.9％（21/49）,高于利用常规筛选后的突变率34.7％（17/49）,两种方法的差异有统计学意义（P=0.045 5＜0.05）.且比较两种方法,可以发现前者检测得到的突变峰峰高明显高于后者.结论 利用激光显微切割技术富集肿瘤细胞能有效去除间质细胞对肿瘤细胞的基因组干扰,更能体现肿瘤细胞基因组状态,有效提高EGFR基因突变检测检出率,有利于患者靶向治疗的临床筛选.

Significance of laser microdissection-enriched tumor cells in detection of gene mutation

Objective To study the effect of laser microdissection-enriched tumor cells on detection of epidermal growth factor receptor （EGFR） gene mutation in non-small cell lung cancer （NSCLC） and its clinicopathological significance.Methods Paraffinembedded tumor cells from 49 NSCLC patients were enriched by laser microdissection.EGFR gene fragments from exon 18 to 21 were amplified by PCR and sequenced.The EGFR gene mutations in NSCLC were compared with those in other cancers.Results Of the 49 NSCLC samples,21 （42.9%） had EGFR gene mutations including exon 19 mutation in 13 and exon 21 mutation in 8.However,both exon 19 and exon 21 mutations were not detected.The analysis of exon mutations showed that the mutation rate was higher in laser microdissection-enriched samples than in conventional tumor tissue samples （42.9% vs 34.7%,P 〈 0.05）.The mutation peak was significantly higher in the former than in the latter.Conclusion Laser microdissection-enriched tumor cells can effectively prevent the intervention of tumor cell genome against interstitial cells,reflect the status of tumor cells genome,effectively improve the detection rate of EGFR gene mutations,thus contributing to the clinical screening of target therapy for NSCLC patients.