Evaluation of P53 and MICAL-2 Gene Expression and Mutations in Gastric Cancer Patients in Kerman

  Stomach cancer is one of the most common cancers after lung cancer and the second cause of cancer deaths worldwide. Changes in the expression level of genes are one of the most important factors in cancers. Among them p53 and MICAL-2 were found have changes in their expression levels. P53 gene plays an important role as a tumor suppressor which is also regulates the cell cycle. MICAL-2 encodes monooxygenase which raises F-actin depolymerization. Increased expression of this gene involves the conversion of mesenchymal cells to epithelial which has been associated with metastasis. Considering that the MICAL-2 gene had not been studied with P53 gene at the same time in gastric cancer, this study was conducted to evaluate the expression level of P53 and MICAL-2 genes in stomach cancer patients in Kerman.

A case-control study was designed to determine the changes in the expression level of P53 and MICAL-2 genes. 30 tumor tissues and marginal non-tumor control tissues were obtained from patients. Total mRNA of the samples was extracted, then after cDNA synthesis, Real-Time RT-qPCR, PCR-SSCP as well as sequencing was performed to measure the gene expressions. T-test and ANOVA were used for data analysis.

According to the results, the expression levels of p53 gene were 0.38, 0.47 in cancerous tissues whereas they were 2.04 and 3.11 in normal tissues for exon 6 and 7 respectively. But the results indicated that exons 4 and 5 did not statistically different in normal and cancerous tissues. For MICAL-2 the expression level in the tumor was 2.2 fold increased in comparison to normal tissues. Therefore, it was found that the expression levels of p53 and MICAL-2 genes were significantly higher in tumor tissues compared to those from normal tissues (P<0.05). On the other hand, sequencing results demonstrated missense and deletion mutations in exon 4.

Regarding to the changes in the expression of P53 and MICAL2 genes in gastric cancer, determination of the expression level in individuals who have family history of this problem, these genes can be used as biomarkers. Because the diagnosis of cancer in the early stages definitely have a better response to therapies.