A Unique Profile of Adenomatous Polyposis Coli Gene Mutations in Iranian Patients Suffering Sporadic Colorectal Cancer

OBJECTIVE: Colorectal cancer (CRC) is one of the most common and aggressive cancers worldwide. The majority of CRC cases are sporadic that caused by somatic mutations. The Adenomatous Polyposis Coli (APC; OMIM 611731) is a tumor suppressor gene of Wnt pathway and is frequently mutated in CRC cases. This study was designed to investigate the spectrum of APC gene mutations in Iranian patients with sporadic colorectal cancer. MATERIALS AND METHODS: In this descriptive study, Tumor and normal tissue samples were obtained from thirty randomly selected and unrelated sporadic CRC patients. We examined the hotspot region of the APC gene in all patients. Our mutation detection method was direct DNA sequencing. RESULTS: We found a total of 8 different APC mutations, including two nonsense mutations (c.4099C>T and c.4348C>T), two missense mutations (c.3236C>G and c.3527C>T) and four frame shift mutations (c.2804dupA, c.4317delT, c.4464_4471delATTACATT and c.4468_4469dupCA). The c.3236C>G and c.4468_4469dupCA are novel mutations. The overall frequency of APC mutation was 26.7% (8 of 30 patients). CONCLUSION: This mutation rate is lower in comparison with previous studies from other countries. The findings of present study demonstrate a different APC mutation spectrum in CRC patients of Iranian origin compared with other populations.