中文摘要：

背景与目的人类棘皮动物微管相关蛋白样4（echinoderm microtubule-associated-protein-like 4,EML4）和人类间变性淋巴瘤激酶（anaplastic lymphoma kinase,ALK）融合基因EML4-ALK是新发现的非小细胞肺癌的驱动基因,患者具有独特的临床病理生理特征,ALK基因下游信号通路的异常持续激活是其重要的下游信号通路,而导致其下游基因持续激活的原因不明。细胞因子信号转导抑制因子（suppressor of cytokine signaling,SOCS）是一类在细胞信号转导过程中起重要作用的负调控因子,主要通过抑制JAK蛋白酪氨酸激酶（janus protein tyrosine kinase,JAK）信号传导和转录激活因子（signal transducer and activator of transcription,STAT）即JAK-STAT等信号通路来调控细胞的增殖、分化和凋亡。肿瘤中常存在SOCS基因的甲基化异常导致的失活,从而导致JAK2-STAT等信号通路持续异常活化。本研究的目的在于探讨EML4-ALK阳性H2228细胞和肺癌组织中SOCS3启动子区甲基化状态。方法甲基化特异性PCR检测EML4-ALK阳性H2228肺癌细胞及肺癌组织中SOCS3启动子区的甲基化状态,并通过测序验证。DNA甲基转移酶抑制剂5’-Aza-d C处理H2228细胞,并通过Real-time PCR和Western blot检测SOCS3的表达水平变化。结果 MSP及测序分析发现EML4-ALK阳性细胞株H2228中存在SOCS3启动子区甲基化;7例EML4-ALK阳性肺癌组织中的3例存在SOCS3启动子区甲基化,H2228细胞经过5’-Aza-d C去甲基化处理后SOCS3的表达明显增加。结论 EML4-ALK（＋）的H2228肺癌细胞及部分肺癌组织中存在SOCS3启动子区的异常甲基化,可能是EML4-ALK阳性肺癌的重要发病机制。

英文摘要：

Background and objective TheEML4-ALK fusion gene is a newly discovered driver gene of non-small cell lung cancer and exhibits special clinical and pathological features. hTe JAK-STAT signaling pathway, an important downstream signaling pathway of EML4-ALK, is aberrantly sustained and activated in EML4-ALK-positive lung cancer cells fusion gene, but the underlying reason remains unknown. hTe suppressor of cytokine signaling （SOCS） is a negative regula-tory factor that mainly inhibits the proliferation, differentiation, and induction of apoptotic cells by inhibiting the JAK-STAT signaling pathway. hTe aberrant methylation of theSOCS gene leads to inactivation of tumors and abnormal activation of the JAK2-STAT signaling pathway. hTe aim of this study is to investigate the methylation status of the SOCS3 promoter in EML4-ALK-positive H2228 cells and lung cancer tissues.Methods hTe methylation status of the SOCS3 promoter in EML4-ALK-positive H2228 lung cancer cells and lung cancer tissues was detected by methylation-speciifc PCR （MSP） analysis and veri-fied by DNA sequencing. hTe expression levels of SOCS3 in H2228 cells were detected by Western blot and Real-time PCR analyses atfer treatment with the DNA methyltransferase inhibitor 5＇-Aza-dC.Results MSP and DNA sequencing assay results indicated the presence of SOCS3 promoter methylation in H2228 cells as well as in three cases of seven EML4-ALK-positive lung cancer tissues. hTe expression level of SOCS3 signiifcantly increased in H2228 cells atfer 5′-Aza-dC treatment.Conclu-sion hTe aerrant methylation of the SOCS3 promoter region in EML4-ALK （＋） H2228 cells and lung cancer tissues may be signiifcantly involved in the pathogenesis of EML4-ALK-positive lung cancer.