| Renal carcinoma cell is one of the most common malignant tumor in urinary system .It is the secondary maligment tumor in urinary system, just inferior to carcinoma of bladder .For the reasons of the extension of average longerity and the promotion of examination tecnique, the cases in clinic had been found on the rise. When renal cancer is diagnosed , surgical therapy must be carried into execution as soon as possible. However, during to the sensitivity of renal carcinoma cell to the radiotherapy and the chemotherapy, biologic therapy is becoming one of the focuses for the patients of postoperation or losing the opportunity of operation.Suicide gene therapy which was also named drug sensitivity gene therapy is a major method in biologic therapy, and it is one of the most methods being researched at present. p-Glucuronidase is a kind of acid hydrolase in lysosome, involved in the processes of physiology, pathyology and metabolism of the drugs. It can hydrolysis glucuronide glycoside bond, releasing the glucuronic acid and ligand. It was well established that the prodrug of pG can selectively kill the tumor cells in the research of ADEPT(antibody directed enzyme prodrug therapy). By combining the βG, prodrugs and the gene therapy, a new oriented molecular chemotherapy may be developed. The renal carcinoma cells with high expression of βG take the prodrug and will be killed selectively. In this study, .by thelipofectAMINE, a retrovirus eukaryotic expression vector pcDNA3.1(+) containing the whole length sequence of the |3G cDNA was transfected into the human renal carcinoma cell line GRC-1. After the G418 screening, a clone that get the stable transfection of the βG was obtained. It was confirmed that the (3G gene had been stably integrated into the genomic DNA of the GRC-1 cell and got a highly expression by the means of PCR test, Immunoflurescence, Immunohistochemistry, The stably transfected cell was named GRC-1/ βG. .The biological characteristics of the βG transfected cell were studied by the methods of microscopy and electron microscop. The series studies of the in vitro effects of the prodrug DOX-GA3 on GRC-1/ βG showed that the stably transfected cells are more sensitive to the DOX-GA3 than the parent. The DOX-GA3 with a concentration of 1 μ M sustaining for 4-5 days had little affection on the growth of the GRC-1 cells, but it will kill the transfected cells with high βG expression, showing the obvious "suicide effects". The GRC-1/βG cells were mixed with parental cells not transfected with various proportion and 60%-80% of the mixed cells were killed when the GRC-1/ βG cell accounting for 10%-20%. It showed the strong by stander effect. We inoculated the GRC-1/BG cells and the GRC-1 cells into the hypoderm of nude mice.It grew up into tumors after 2 weeks.we observed the regression of the tumor by the means of the abdomen-injection with the prodrug of DOX-GA3 for 2 weeks.It showed that the tumor volume of the control made continuously progess and arrived 600-700% compared with the volume of the commencement of the therapy. While the one of the GRC-1/βG minished significantly ,it was 56.7% compared of the volume of therapy start, and the restrain rate was 88.1%.We drew the conclusion that in vivo,the RCC transfected by the pcDNA3.1(+)-PG gene could be killed effectively by the prodrug DOX-GA3 .Thus a new suicide gene system was built up.The study showed that the βG gene and its prodrug could be introduced into the...
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