肺癌变基因表达差异cDNA微阵列的研究

Study of Gene Expression Difference in Lung Carcinogenesis by cDNA Microarray

背景与目的:肺癌发病率和死亡率均较高,其发病的分子机制尚不清楚。本实验旨在研究人肺癌组织、癌旁组织、正常肺组织及淋巴结转移癌组织的基因差异表达情况,寻找肺癌组织中相对高表达基因,为肺癌的早期诊断和治疗提供可能的理论依据。方法:将新鲜肺癌组织、癌旁组织、正常肺组织及淋巴结转移癌组织用液氮速冻,提取总的RNA后逆转录标记cDNA探针,与含588个基因的cDNA微阵列膜杂交,通过放射自显影、灰度扫描杂交信号强弱获得差异表达基因。结果:肺癌组织中差异表达的基因有40个,其中早期生长反应蛋白1(earlygrowthresponseprotein1,EGR1)、分泌性凋亡相关蛋白1(secretedapoptosisrelatedprotein1,SARP1)等36个基因表达上调,诱导骨髓白细胞分化蛋白1(myeloidcellleukemiaprotein1,MCL1)等4个基因表达下调,以癌基因/抑癌基因、细胞周期调节、生长因子及凋亡相关基因上调为主;癌旁组织有33个差异表达基因,基质金属蛋白酶-9(matrixmetalloproteinase-9,MMP-9)等20个基因上调,而下调的基因有MCL1、内皮素2(endothelin2,ET2)等13个;转移淋巴结组织有21个基因表达差异,CD40受体相关因子1(CD40receptor-associatedfactor1,CRAF1)等15个基因下调,而上调的基因仅有6个,主要以细胞粘附分子、基质金属蛋白酶。

BACKGROUND &OBJECTIVE: Lung cancer is a kind of disease with high incidence and mortality, however its molecular mechanism is not clear yet. This study was designed to investigate gene expression differences among lung cancer tissues, lung paracancerous tissues,matched peripheral normal lung tissues and the metastases of lymph nodes, and to seek the relatively high expressed genes in lung carcinoma tissues, providing possible theoretical basis for early diagnosis and treatment of pulmonary carcinoma. METHODS: Fresh lung cancer tissue, lung paracancerous tissue, matched normal lung tissue and metastases of lymph nodes were deep frozen in liquid nitrogen; their total RNA were extracted for reversed transcription cDNA probes, which were labeled and subsequently used to hybridize with cDNA microarray with 588 genes. Different gene expression profiles were obtained by analyzing the integrated density (ID) of spot images on the X ray. RESULTS: In lung cancer tissues, 40 genes were detected to be differentially expressed, 36 of which such as early growth response protein 1 (EGR1), secreted apoptosis related protein 1 (SARP1) were upregulated while the others such as myeloid cell leukemia protein 1 (MCL1) were downregulated. The upregulated genes were mainly oncogene/suppressor gene, cell cycle regulatory gene, growth factors and apoptosis related genes. In lung paracancerous tissues, 33 genes had different expression, 20 of which such as matrix metalloproteinase 9 (MMP 9) were upregulated, and the other 13 such as MCL1,endothelin 2 (ET2) were downregulated. In metastases of lymph nodes, there were 21 genes found to be differently expressed, 15 of which such as CD40 receptor associated factor 1 (CRAF1) were downregulated while the rest were upregulated, and the upregulated genes (6 in 15) were mainly the genes associated with adhesion molecules, matrix metalloproteinases and collagen. CONCLUSION: EGR1, SARP1, NDKA, etc. may be the key genes in pulmonary carcinogenesis course. At the same time, MMP9, thrombospondin 2 (TSP2), etc.may play an important role in pulmonary cancer metastasis and infiltration.