新基因CT120在肺癌组织中的表达及其对细胞生长的影响

Expression of Human Novel Gene CT120 in Lung Cancer and Its Effects on Cell Growth

背景与目的:基因CT120是我们实验室从染色体17p13.3位点获得的一个细胞膜相关新基因,mRNA水平检测结果表明该基因在人正常肺组织中不表达,但在人肺癌细胞系SPC-A-1中高表达。本研究进一步从蛋白水平研究CT120在肺癌及癌旁组织中的差异表达及CT120异位表达(ectopicexpression)与过表达(overexpression)对细胞生长的影响。方法:用生物信息学方法设计15肽,合成并偶联到大分子载体KLH上制成人工免疫原,制备鸡抗CT120多肽抗体;通过Westernblotting方法检测CT120在不同肿瘤细胞系中的表达;通过免疫组织化学技术比较CT120在肺癌及癌旁组织中的差异表达;通过集落形成试验研究CT120异位表达对NIH/3T3细胞生长的影响;通过生长曲线及裸鼠成瘤试验研究CT120过表达对A549细胞生长的影响。结果:获得有效的鸡抗CT120抗体(IgY);CT120蛋白在不同肿瘤细胞系中表达程度不同,并在不同类型的肺癌组织中高表达;CT120基因异位表达显著促进NIH/3T3细胞的生长;同时CT120过表达对A549细胞在体内体外的生长有促进作用。结论:基因CT120与肺癌的发生发展有关,是一个人肺癌相关新基因。

BACKGROUND & OBJECTIVE:A novel membrane associated gene CT120 was isolated from chromosome 17p13.3 locus in our laboratory. Its mRNA was not expressed in human normal lung tissues, but was abundant in human lung cancer cell line SPC A 1. This study was designed to investigate the differential expression patterns of CT120 in different lung cancer and noncancerous tissues using immunohistochemistry and to explore the effects of ectopic expression and overexpression of CT120 on cell growth in vitro and in vivo. METHODS:A polypeptide at the C terminus of CT120 was selected by bioinformatics, then was synthesized and conjugated to KLH (a high molecular carrier). The chicken anti CT120 antibody IgY was prepared with the synthesized antigen and was used to determine the different expression patterns of CT120 in various tumor cell lines and in lung cancer and noncancerous tissues. The effects of ectopic expression of CT120 on NIH/3T3 cell growth were investigated through colony formation analysis. The effect of overexpression of CT120 on the cell growth of A549 was analyzed using growth curve assay and tumor formation assay of transfected cells in nude mice. RESULTS:The novel gene CT120 expressed in various tumor cell lines and expressed remarkably higher in lung cancers than in noncancerous tissues as well as normal lung tissues. Also, it promoted the proliferation of NIH/3T3 and A549 cells in vitro and in vivo. CONCLUSION:CT120 gene may be a novel candidate gene closely related to lung carcinogenesis.