Expression Of P14ARF And MDM2 In Human Gastric Tumor

Gastric tumor is one of malignant tumors happened in human tissue with a very high incidence. It was considered a genetic disease for gastric tumor would happen if there were defects in genes that could control cell differentiation. P53 is a cancer suppressor gene. It could transduct stimulating information from outside of cell into gene, which could prevent cell from Gl into S phase and induce apoptosis. MDM2 is an oncogene. MDM2 protein encoded by MDM2 gene could inhibit the role of P53 by binding with each other. That will lead to control of P53 on cell lost and cell proliferation uncontrolled to be a cancer. P14ARF is encoded from INK4a - ARF, a cancer suppressor gene. P14ARF could arrest MDM2 inhibition on P53, which could postpone the degradation of P53. The P53 is regulated by both MDM2 and P14 in cell cycle regulation. The gastric tumor samples we collected were different in their pathological levels. In our research, the expression of MDM2 and P14 mRNA was identified by RT - PCR and the expression of MDM2 and P14 was investigated by Western - blot. We expected our research could redound to the clinical treatment in gastric tumor by analyzing the relationship of between the expression of P14, MDM2 and occurrence, progressing and prognosis.MethodsThe expression of MDM2 and P14 mRNA was identified by RT -PCR and the expression of MDM2 and P14 was investigated by Western - blot in clinical gastric tumor samples with different pathological levels. 1. Western - blotting; All the amount of samples were identified by Coomassie brilliant blue method. The samples resolved by SDS - PAGE and transblotted to nitrocellulose membrane. The blots were incubated with either MDM2 or P14 antibodies. The immune complex bands were visualized with ECL.2. RT -PCR: Total mRNA was extracted from the gastric tumor samples using TRIzol reagent. That cDNA synthesized from the mRNA was followed. PCR reactions were performed using corresponding primers. The final PCR products were stained with ethidium bromide after electrophoresis. The expression amount of mRNA for MDM2 and P14 was determined as a ratio to (3 - actin3. Statistics: Statistical analysis was performed with Chi Square Test. P<0.05 was considered significant.Results1. Western - blotting:1. 1 The band of immunoreactive MDM2 was seen by Western blot in both control and gastric tumor samples. The Western blot analysis results showed that the expression of MDM2 in gastric tumor samples was higher than that in control. This difference is significant in statistics. The expression amount is related with gastric tumor differen-tiation. But there was not significant difference among tumor samples.1.2 The band of immunoreactive PI 4 was also seen by Western blot in both control and gastric tumor samples. But the expression of P14 is not any difference between control and gastric tumor samples.2. RT-PCR:The results of RT-PCR showed that the expression of MDM2 mRNA was found both in gastric tumor samples and control with a higher expression in gastric tumor samples. This difference is significant in statistics. At the meanwhile, the expression amount of MDM2 mRNA is related to differentiation levels of gastric tumor. A higher expression is found in high - grade differentiation.The expression of P14 mRNA was also found both in gastric tumor samples and control. But there is not any significant in expression between tumor and control.Conclusions1 . The results of RT - PCR and Western blot MDM2 showed that the expression of MDM2 in gastric tumor samples was higher than that in control. This difference is significant in statistics. These suggest that MDM2 may play a specific role in the occurrence of gastric tumor.2. The results of RT - PCR showed that the expression of MDM2 mRNA was found both in gastric tumor samples and control with a higher expression in gastric tumor samples. This difference is significant in statistics. At the meanwhile, the expression amount of MDM2 mRNA is related to differentiation levels of ga...