Investigation Of The Effect Of C2 Gene Transduction On Human Gastric Cancer Cell SGC7901

C2 gene is a new cloned human eukaryotic translation factor during the study of hepatic carcinoma. The primary study of the gene found that it has functions similar to the antioncogene p53. It can inhibit the growth of cells, make sure the accuracy of protein translation and keep not only the balance of the frame of ribosome but also the efficiency of frameshifting. So, the gene is presumed as an inhibitor during the course of protein translation. In this study, we are going to enlarge and purify the eukaryotic vector carrying the full length of C2 gene, transfect it into human gastric cancer cells SGC7901 and investigate C2 gene's effects to gastric cancer cell's biological characteristics. The main content and results are as follows.Immunohistochemical staining showed that the rate of high C2 protein expression in the tissues of gastric cancer and colonic cancer, which is 42.9% and 35.0%, is lower than that in the para-cancer normal tissues, which is 82.4% and 68.4%. C2 protein is not or low expressed in SGC7901 cells.The eukaryotic vector carrying C2 gene was enlarged and purified and the product is pure without the mixture of RNA and protein, which can be hydrolyzed by enzyme Hindlll and BamH I in one system into a 1.3kb segment of aimed gene and another 5.4kb one of vector.C2 gene and the vector pcDNA3 were transfected separately into SGC7901 cells conducted by lipofectamine. After G418 selecting, the cells were transfected steadily. Immunohistochemical staining showed that C2 gene transducted cells express C2 protein markedly. The results of Western Blot and FACS showed the same conclusion.The growth graph was protracted by the methods of cell counting and MTT, which showed that the growth of C2 gene transducted cells is slower than that of vector transducted cells.The clone formation rate in plate was tested to investigate the oncogenesis character of C2 gene transducted cells in vitro. Theaverage clone formation rate of C2 gene transducted cells is 43.8%, which is lower than that of vector transducted cells' 76.9%. In vivo, the time of oncogenesis of C2 gene transducted cells in nude mouse is prolonged and the volume of tumor node is smaller.The results showed that C2 gene inhibits the human gastric cancer cells' malignancy.FACS detected the cell cycle of C2 gene transducted cells. An apoptosis peak is observed in both transient and steady C2 gene transducted cells and the duration of DNA block is prolonged. Furthermore, in electric transmission microscopy, apoptosis cells of C2 gene transducted cells can be observed.MTT cytoxicity assay indicated C2 transducted cells are more sensitive to ADR and VCR. The cells' sensitivity to MMC do not change.In a word, C2 gene is low expressed in human gastric cancer cells. The transduction of C2 gene makes the cells express C2 protein steadily and highly, inhibits the cells' malignancy, induces the cells into apoptosis and maybe changes the cells' drug-resistance.