OBJECTIVE: RAS proteins control signaling pathways which are the main regulators of the normal cell growth and malignant transformation cells. The point mutations in the KRAS gene are current event in numerous human cancers including pancreatic, lung, colon, and breast cancer. BRAF protein is located in the downstream of KRAS and it is revealed to be somatically mutated in various human cancers. KRAS and BRAF mutated genes have a vital role in the establishment and development of tumors. Since there is a little information about BRAF and KRAS mutations in gastric cancer, the present study has been designed.

MATERIALS AND METHODS: We assessed 31 cases that experienced gastrectomy for diffuse gastric cancer, according to the histopathological criteria confirmed by pathologist. The patients were hospitalized in the Al-Zahra hospital in the Isfahan province (central Iran) and in the Alaa Cancer Control Center from 2011 to 2016. The DNA sequencing was completed by amplification exon 2 of KRAS and exon 15 of BRAF genes.

RESULTS: According to the electropherogram of DNA sequencing we did not find any alterations in the codon 12 and 13 of KRAS and codon 600 of BRAF genes.

CONCLUSIONS: Our results demonstrated that there was not association between codon 12, 13 of KRAS gene, and codon 600 of the BRAF gene in patients with diffuse gastric cancer in the Iranian population. The results of this study reveal that MAP kinas signaling pathway does not play any role in diffuse gastric cancer in the Iranian patients. Furthermore, the study suggested that other genes are probably involved in this cancer. More evidence is needed in a larger sample size to confirm these results.