CPGL的基因结构及其与肝癌相关性的研究

目的 克隆carboxypeptidase of glutamate like(CPGL)全长cDNA，初步探讨它在肝癌发生发展中的作用。方法 通过5’-RACE方法和RT-PCR验证，确定(CPGL)全长序列，根据其全长与人类基因组的比较进而确定基因的染色体定位和其外显子、内含子；应用Western Blot方法检测CPGL在肝癌组织和癌旁组织中的表达；细胞克隆形成及生长曲线检测CPGL对肝癌细胞生长的影响。结果 CPGL全长2616bp，编码475个氨基酸的蛋白，染色体定位于18q22.3，蛋白产物定位于细胞质中，Western Blot结果发现CPGL在肝癌组织中的表达明显低于癌旁组织。将CPGL转染肝癌细胞系SMMC7721发现其具有抑制生长的作用。同源比较发现CPGL含有M20蛋白酶家族的保守功能域。结论 上述发现表明CPGL是具有潜在抑癌作用的基因。

Genomic structure of CPGL and its interrelation with liver cancer

Objective The gene CPGL (carboxypeptidase of glutamate like) was firstly screened out from the cDNA library of human placenta. This report is mainly concentrated on the identification and characteristics of CPGL. Methods By the 5'-RACE, the complete sequence of CPGL was acquired. Computational analysis showed the genomic localization of CPGL and the structure of the gene. Western Blot was used to detect the different expression of the cancerous and the noncancerous liver tissues. Experiments of cell colony formation and cell growth curve were done to observe the effect that CPGL put on the cancer cells. Results The complete length of CPGL is 2616bp, encoding a protein with 475 amino acids. CPGL expressed highly in the human liver, kidney and brain. Western Blot revealed significantly higher expression of CPGL gene in noncancerous liver tissues than that in the HCC (hepatocellular carcinoma) samples. Stable transfection of the gene to the SMMC7721 liver cancer cell line demonstrated a growth inhibitory effect. Through homologous comparison, the CPGL possessed the conservative function of M20 proteinase family. Conclusion In all, the findings suggest a potential role of CPGL as a hepatocellular carcinoma suppressor gene.