领导这一研究的是生化与细胞所季红斌研究员,其早年毕业于吉林大学,主要研究方向是肺癌发病的分子机理,希望能通过寻找与肺癌发生、发展以及转移相关的基因,并在体外肺癌细胞株模型和体内小鼠模型中验证这些基因的功能,阐明其作用机理。
在我国,每年约有40万人死于肺癌,在各类癌症引起的死亡中高居榜首。肺腺癌是肺癌的各种亚类中*常见的类型,在每年全球确诊的新增肺癌病患中约占40%。研究肺癌中基因突变对肺癌的临床诊断和预后有着重要的意义。LKB1又名STK11 (serine threonine kinase11),是丝氨酸苏氨酸激酶家族的成员,并且是家族性黑斑息肉综合症的致病基因。季红斌研究组此前的工作发现抑癌基因LKB1对肿瘤的转移有着重要的影响,其蛋白缺失可显著提高肿瘤细胞的转移。表皮生长因子EGFR是介导细胞生长信号的重要分子,并且在临床上携带该基因突的肺癌患者对抑制酪氨酸激酶的小分子化合物抑制剂(TyrosineKinaseinhibitors,TKIs)有着很高的响应。KRAS是EGFR通路下游的重要信号分子,对MAPK通路有着直接的调节作用。
上述三个基因在西方肺癌人群中有着相当比例的突变率,在亚洲包括韩国和日本肺癌人群中也有一定研究。我国的肺癌人群中LKB1,EGFR和KRAS突变的总体特征尚缺乏较为**的认识。季红斌课题组联合复旦大学肿瘤医院陈海泉主任领导的胸外科研究室对中国肺腺癌人群中重要的基因突变进行了筛查。他们筛查的结果发现LKB1在中国肺腺癌人群中的突变率为6.9%,而且LKB1突变主要来自吸烟患者。LKB1的F354L变异在肺腺癌人群中的比例约为10.5%且均为种系遗传(即从父母遗传而来),其中两例患者的肿瘤组织内F354L变异发生了杂合性缺失,提示该位点在肺癌的发生或发展中可能有着尚待探明的作用。
与此同时,在中国肺腺癌人群中发现的EGFR突变率为66.3%,KRAS突变仅为2.3%。在EGFR突变中,较为引人注意的是女性非吸烟患者的突变率高达83.8%,提示该类肺腺癌人群具有高度的EGFR突变倾向,并且可能作为TKIs小分子****的重点人群。这些工作为**而深入地揭示中国肺癌人群的基因突变谱奠定了一个良好的基础。
原文摘要:
Spectrum of LKB1, EGFR, and KRAS Mutations in Chinese LungAdenocarcinomas.Somatic LKB1 mutations are found in lung adenocarcinomas atdifferent frequencies in Caucasian and East Asian (Japanese andKorean) populations. This study was designed to characterize thefrequency of LKB1 mutations, their relationship to EGFR and KRASmutations, and their associated clinicopathologic characteristicsin Chinese patients. METHODS:: Two hundred thirty-nine lungadenocarcinomas consecutively collected from October 2007 to July2009 were dissected into 3 to 4 small (3 mm) pieces forhistopathological analyses of tumor content. Genomic DNA and/orcDNA from 86 samples with more than 70% tumor content were used forsequencing of LKB1 (exons 1-9), EGFR (exons 18-21), and KRAS (exon2). LKB1 germline mutation status was determined by sequencing ofgenomic DNA from matched histologically distant lung tissues thatare histologically normal. RESULTS:: 6.9% of lung adenocarcinomasharbored LKB1 somatic mutations. A total of 10.5% of patients hadan LKB1 germline polymorphism, F354L. Interestingly, in two ofthese patients, tumors displayed loss of heterozygosity at thisallele. EGFR kinase domain and KRAS mutations were found in 66.3%and 2.3% of Chinese lung adenocarcinomas, respectively. ConcurrentLKB1 and EGFR somatic mutations were observed in one patient. BothKRAS-mutant tumors harbored LKB1 mutations. CONCLUSIONS:: Thesedata provide important clinical and molecular characteristics oflung adenocarcinomas from Chinese patients.