辽宁省典型镉污染地区肺癌的分子亚型及相关异常信号通路鉴定

Epidemiological studies have shown that atmospheric cadmium pollution was significantly related with lung cancer. The mass concentration of cadmium elements in atmospheric PM2.5 of huludao city, a typical atmospheric cadmium pollution region in liaoning province, is as high as 470.86 ng/m3. In our previous study, we have: ①confirmed the exist of cadmium exposure related lung cancer in this area; ②continue to emply the "urine cadmium screening + tissue samples confirmation" strategy to collect this type of lung cancer samples, and looking for early warning value of the urine cadmium concentration to predict the risk of suffering from this type of lung cancer; Selection of adenocarcinoma, squamous cell carcinoma and adenosquamous cancer samples first, and then distinguishing the heterogeneity components of these cancer by immunohistochemical method; Screening the mutation samples, and obtain the heterogeneous components of cancer by Laser capture microdissection(LCM)technology, respectively, detecting the mutation of drive genes and important tumor-suppressor genes, and identificating the molecule type of cadmium exposure related lung cancer ultimately; ② Transforming and establishing one alveolar epithelial cell lines by cadmium contained medium, as the adenocarcinoma model, and detecting the driver gene mutations and related signal transduction network. This project based on the serious situation of high incidence of lung cancer in atmospheric cadmium pollution area in liaoning province, aimed to determine the molecular type of cadmium exposure related lung cancer and related signaling pathway, and provide the important reference information for the early diagnosis as well as formulate effective targeted therapy of cadmium exposure related lung cancer

流行病学研究表明大气镉污染与肺癌发生明显相关,作为大气镉污染的典型地区,辽宁省葫芦岛市大气PM2.5中镉元素的质量浓度达到470.86 ng/m3.我们已①证实该地区存在镉暴露相关肺癌;②用含镉培养液成功转化1株支气管上皮细胞,并揭示了一部分异常分子机制.本研究拟① 继续用“尿镉超标初筛+组织样本确定”的方式留取该类肺癌样本,寻找尿镉浓度预测罹患该类肺癌风险的预警值;选取腺癌、鳞癌和腺鳞癌样本,用免疫组化区分其中的异质性成分;初筛突变样本,用LCM分别获取样本中的异质成分后,探明驱动基因和重要抑癌基因的突变情况,最终确定分子类型② 再用含镉培养液建立1株肺泡上皮向腺癌转化的细胞模型，探明相关基因突变和信号调控网络。本课题立足于辽宁省内大气镉污染地区肺癌高发的严峻现实，旨在通过探明镉暴露相关肺癌的分子类型及相关信号通路变化,以期为该类肺癌的早期诊断、制定有效的靶向治疗方案提供重要参考依据。

项目背景： 镉是环境中常见的重金属毒物，被国际抗癌联盟（IARC）定为IA 级致癌物。然而，新近研究显示，低浓度镉暴露还具有抑癌作用。不过目前对于低浓度镉暴露的抑癌作用了解尚少，尤其缺乏长时间（超过1个月）镉暴露的研究。因此，探讨长期低浓度镉暴露对肺腺癌细胞增殖能力的影响，解析低浓度镉暴露下肺腺癌细胞外显子突变情况、转录组的变化和蛋白质的差异性表达情况，能够为进一步揭示长期低浓度镉暴露的抑癌机制提供重要的基础实验数据。.主要研究内容：长期低浓度镉暴露（1μM，8个月）对肺癌细胞全外显子、全转录组、差异蛋白及重要信号通路的影响；对肺癌细胞生物学行为及裸鼠成瘤能力的影响。.重要结果：1）A549-Cd组独有的SNP位点有4222个，其中非同义突变位点有382个；2）A549-Cd组差异表达基因共1250个，其中784个基因表达上调，466个基因表达下调；3）2-D电泳结果表明，有34个明显改变的蛋白质点，其中11个斑点表达减低，23个斑点表达增加。质谱分析成功鉴定出11个不同的蛋白质斑点；4) Erk、P38和JNK、c-met磷酸化水平升高， CIAP1表达升高，YAP表达下降；而cyclin D1和Survivin表达明显减弱；E-cadherin表达明显增强，而N-cadherin表达明显减弱，vimentin表达变化不大，ZO-1和p120ctn表达下降，RhoA表达略有下降； LC3B表达明显下降；IκB磷酸化水平下降。5) 体内外研究结果都表明细胞的增殖能力显著下降，A549-Cd组移植瘤瘤体重量和瘤体体积明显小于对照组。.科学意义：我们的研究表明，与短期的镉暴露不同，长期低浓度镉暴露其具有抑制肿瘤细胞生长的作用；在长期低浓度镉暴露过程中，细胞的外显子组、转录组和蛋白表达均出现了明显改变。