Mutation screening of exon 9 of DR5 receptor in patients with breast cancer using PCR-SSCP

Breast cancer is the most common malignant tumor and the first leading cause of cancer-related deaths in women worldwide. Cancer is the disease that spreads on the basis of uncontrolled division rate of cells. It is now clear that some oncogenic mutations disrupt apoptosis, leading to tumor initiation, progression, or metastasis. The p53-induced apoptosis is an important biological process to prevent the development of cancer. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a cytokine that preferentially induces apoptosis in tumor cells compared with normal cells through two receptors (DR4 and DR5). In the present study, we investigated genetic alterations of exon 9 of the DR5 gene as a p53-responsive gene in 30 breast cancer cases in Iran. The synthesized complementary DNA (cDNA) from extracted RNAs was determined by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP). PCR reaction and the results were analyzed using acrylamide gel and subsequently sequenced. PCR-SSCP showed significant different migration patterns in exon 9 of the DR5 in seven of the samples. Sequencing results of the seven samples and control sequence of exon 9 (National Center for Biotechnology Information, NCBI) were aligned using CLC Genomics Workbench. Five samples had same alternations in the two positions including G60 and C122. Alternations including substitution, duplication, and deletion of both G60 and C122 positions of the five samples were detected. We found same alterations in the five samples (16.6 %) in positions G60 and C122. In conclusion, these results suggest that the commonly found mutations in exon 9 of the DR5 gene may be one of the sensitive positions for tumorigenesis of the cancer.