非小细胞肺癌的肿瘤干细胞与非肿瘤干细胞中表皮生长因子受体基因异质性的研究

Genetic heterogeneity of EGFR in cancer and non-cancer stem cells from non-small cell lung cancer

目的研究非小细胞肺癌(non-small cell lung cancer,NSCLC)的肿瘤干细胞和非肿瘤干细胞中表皮生长因子受体(epidermal growth factor receptor,EGFR)基因状态。方法收集2010年6月至2011年8月四川省肿瘤医院及四川大学华西医院胸外科NSCLC新鲜手术标本35例,流式细胞术分选出CD133+细胞和CD133-细胞,采用扩增阻滞突变系统(amplification refractory mutation system,ARMS)分别检测EGFR基因突变,观察其有无差异。结果 35例NSCLC样本中均检测到CD133的表达。35例CD133+细胞中EGFR基因突变检出率为28.6%,腺癌突变率高于鳞癌(P<0.05),而在不同性别、年龄、有无吸烟史中无统计学差异(P>0.05);CD133-细胞中EGFR基因突变检出率为42.9%,腺癌、无或少吸烟史者突变率高(P<0.05),而不同性别、年龄的突变率无统计学差异(P>0.05)。11例患者标本的CD133+/-细胞存在EGFR基因异质性,占31.4%(11/35)。24例患者标本CD133+/-细胞的EGFR基因状态相同(18例患者中CD133+和CD133-细胞EGFR基因均为野生型,6例患者中CD133+和CD133-细胞EGFR基因为相同的敏感性突变)。结论NSCLC患者中CD133+细胞和CD133-细胞中存在EGFR基因异质性。

Objective To investigate the genetic status of epidermal growth factor receptor（EGFR） in cancer stem cells（CSCs） and non-cancer stem cells from non-small cell lung cancer（NSCLC）.Methods Thirty-five NSCLC surgical fresh specimens were collected in our department and the Second Peoples’Hospital of Sichuan Province from June 2010 to August 2011.CD133-positive cells and CD133-negative cells were sorted by flow cytometry after CD133 staining.Amplification refractory mutation system（ARMS） was employed to detect the presence of EGFR mutations in the 2 types of cells.The correlation of the EGFR mutations in different cells was analyzed.Results CD133-positive cells were detected in all collected specimens.The EGFR mutation rate was 28.6% in CD133-positive cells,which was higher in adenocarcinomas than in squamous cell carcinomas（P〈0.05）.But there was no significant difference among different gender,age or smoking history（P〈0.05）.The EGFR mutation rate was 42.9% in CD133-negative cells,which was higher in adenocarcinomas,and non-or slight-smokers（P〈0.05）.There was no significant difference between different gender,or age（P〉0.05）.There were 11 specimens out of 35 which had EGFR gene heterogeneity in both CD133-positive cells and CD133-negative cells（11 /35,31.4%）.The remaining 24 specimens had the same EGFR gene status in both CD133-positive cells and CD133-negative cells（18 cases exhibited EGFR wild type in both CD133-positive and-negative cells,and 6 cases displayed activating EGFR mutations regardless of CD133 expression）.Conclusion There are EGFR genetic heterogeneity existing between CD133-positive cells and CD133-negative cells in NSCLC.