Effect Of Exogenous FHIT Gene Transfection Into Gastric Cancer Cell On Apoptasis,Cell Cycle And Adriamycin Sensitivity

[Background and Objective]Fragile histidine triad (FHIT) gene located in chromosomal region 3p14.2 has been cloned in 1996 by Ohta et al. It spans not only the t(3:8) (p14.2; q24) translocation breakpoint found in familial renal cell carcinoma but also the most common human fragile site, FRA3B. It is subordinated to histidine triad (HIT) protein superfamily. Abnormalities in the FHIT gene its expression have been identified in a variety of human cancer cell lines and tumors, especially in those which have close relation to carcinogenic agents. FHIT has been recently proposed as a tumor suppressor gene. Gastric carcinoma is one of the most common gastrointestinal malignant tumors. Inactivation of tumor suppressor gene is a main reason inducing cancerization. FHIT gene deletions or aberrant transcripts have been identified in a variety of human malignancies, including gastric carcinomas, suggesting that FHIT gene may play a key role in tumor development and treatment.In addition to surgery, chemotherapy is a very important means of gastric cancer treatment. But gastric cancer cells to a single chemotherapeutic drug treatment is less sensitive and easy-resistant. Meanwhile, chemotherapeutic drugs take destruction of tumor cells and also have a greater damage to normal cells. Therefore, the search for new and effective methods of treatment with the traditional treatment methods to improve the results have important clinical significance. With a deeper understanding of the mechanism of carcinogenesis, tumor suppressor gene therapy research has gone deeper and deeper. It has potential to become an effective tool for the treatment of tumors. In some research, with the transduction of FHIT gene into tumor cells, some of the malignant phenotype of tumor cells could be reversed, and it could also induce apoptosis in tumor cells. Another researcher transfected FHIT gene into lung cancer cell line NCI-H460 to study the sensitivity of some chemotherapeutic drugs. But there has not been domestic reports about the effect of FHIT gene expression in gastric cancer cell line on sensitivity of chemotherapeutic drugs. Wild type FHIT gene was transfected into human gastric cancer cell MGC-803 in which FHIT gene was lost totally, in order to investigate the effect of Adriamycin (ADM) on sensitivity in this study.[Methods]FHIT gene was transfected into gastric cancer cell line MGC-803 by liposome. Western bolt assay was employed to detected the expression of FHIT. Cancer cells which were transfected with empty vector pRcCMV and non-transfected gastric cancer cell line MGC-803 were viewed as control.and blank respectively. After treatment of adriamycin, MTT colormetric assay was applied to determine the inhibition ratio. The morphological changes of cancer cells were observed under inverted microscope. Apoptosis and cell cycle were analyzed by flow cytometry (FCM).[Results]1. Stable expression of FHIT protein in transfected MGC-803 cells was obtained.2. There was concentration dependent of adriamycin and time dependence on growth ratio.3. We found the apoptosis cells (19.59% vs 4.41%) and percentage of G₀/G₁ cells (74.43% vs 56.30%) were increased in the FHIT transfected cell line, compared with the control cell line carrying a plasmid devoid of FHIT.4. After treatment of Adriamycin, apoptosis cells were significantly higher in FHIT-transfected MGC-803 cells than those in control cells and in blank cells (40.66% vs 13.94%, 15.81%, P<0.01). Adriamycin-induced apoptosis can be enhanced by wild FHIT expression (P<0.05). The rates of G₀/G₁ phase were statistically higher in FHIT-transfected cells than those in control cells (99.27% vs 95.10%).[ Conclusions]1. FHIT gene might be involved in the apoptosis and might block the cell cycle of gastric cancer cell line MGC-803.2. The expression of wild FHIT gene can increase the sensitivity of gastric cancer cell line MGC-803 to Adriamycin.