Mutations in Exons 7 and 8 of P53 Gene in Colorectal Cancer and Their Association with Histopathologic Parameters and Anatomic Locations of the Tumor

Abstract

Background: Colorectal cancer (CRC) is a common and lethal malignancy worldwide. The incident rate of CRC is different in various geographica regions. CRC is a multifactorial disease; the factors involved included dietary and genetic factors. P53 gene is the most important tumor suppressor gene which involved in many cancers. The mutation rate in exons 7 and 8 of P53 gene in CRC was reported to be different in the world. The objective of this study was to detect the mutations in the exons 7 and 8 of P53 gene and to determine their correlationship with histopathologic parameters in CRC.

Materials and Methods: This study was performed on 80 specimens taken from patients with CRC referred to to Isfahan hospitals between 2003 and 2006. DNA was extracted by phenol chloroform isoamil alcohol after tissue processing and making the pathologic diagnosis in the Genetic Department of Isfahan Medical School. Exons 7 and 8 of P53 gene were amplified using specific primers in a PCR assay. After gel electrophoresis, the mutations were detected by SSCP method.

Results: From 80 specimens, 9 (11%) were found to have mutations; 4 (5%) had mutations in exon 7 and 5 (6%) in exon 8. The presence of mutations did not have any significant association with stage and level of cell differentiation of tumors and with anatomical region (p›0.05).

Conclusion: Although we could not observe any association between the presence of P53 gene mutations and some histopathologic and anatomic presentations of CRC, the pattern of mutations observed in exons 7 and 8 of P53 gene in CRC was different from that reported from many areas of the world.