Expression Of FHIT In Gastric Adenocarcinoma And Relationships With Cell Cycle Of Tumor Cell

The developments of tumor are linked with progressive disregulation of cell cycle. Mutations of Fragile histidine triad gene(FHIT) gene perhaps change the regulation of cell cycle and enhance proliferation of cell. Ki-67 protein is a kind of marked antibody, which represents cell cycle and tumor growth and is significantly related to cell proliferation. As one of the Cyclin-dependent kinases inhibitor (CKIs), p21^waf1 can inhibit cell proliferation by inhibiting the activity of Cyclin-dependent kinases (CDKs) complex. The objective of this study are to detect expression of FHIT gene and Ki-67 protein, p21^waf1 protein, cell cycle in gastric cancer and to investigate their biological significance by comparing to clinicopathological features of these tumors .Immunohistochemistry SP method was used to determine the expression of FHIT protein and Ki-67 protein and p21^Waf1 protein in 60 gastric cancer samples and the expression of FHIT protein in 60 corresponding paratumor tissues as control, while DNA ploidy patternsmeasurements by image cytometry(ICM) was used to determine the cell cycle of cancer cell. The expression of FHIT protein in gastric cancer samples and in control samples and the relationship between expression of FHIT protein and Ki-67 protein, p21^Waf1 protein, cell cycle and clinicopathologic feature(age gender location grade stage metastases) were analyzed statistically.Results: 1. The expression of level of FHIT gene was found to be significantly lower in gastric cancer tissues than in the normal gastric tissues (P<0.05). 2. The expression of FHIT gene in gastric cancer is related to grade, stage and invasion depth of tumor but not to lymph node metastases. 3. The reduction of FHIT gene expression might be related with the over-proliferation of gastric cancer cell(P<0.05). 4. The reduction of FHIT gene expression might be related with the reduction of amounts of G₀/G₁ phase cell in gastric cancer tissue (P<0.05). 5. The reduction of FHIT gene expression might be related with the reduction of p21^waf1 protein in gastric cancer tissue (P<0.05).Conclusion: As a kind of tumor suppressor gene, the expression of FHIT gene is significantly lower in gastric cancer and is related to the over-proliferation of tumor cell. The FHIT gene might be involved in the regulation of cell cycle control and might be mediated by p21^waf1 protein.