Association of SMAD7 genetic markers and haplotypes with colorectal cancer risk

• Published in: BMC medical genomics Vol. 15; no. 1; p. 8
• Main Authors: Alidoust, Maryam, Hamzehzadeh, Leila, Khorshid Shamshiri, Asma, Afzaljavan, Fahimeh, Kerachian, Mohammad Amin, Fanipakdel, Azar, Aledavood, Seyed Amir, Allahyari, Abolghasem, Bari, Alireza, Moosanen Mozaffari, Hooman, Goshayeshi, Ladan, Pasdar, Alireza
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 11.01.2022; BioMed Central; BMC
• Subjects: Age; Analysis; Association study; Cancer; Care and treatment; Case-Control Studies; Colonoscopy; Colorectal cancer; Colorectal carcinoma; Colorectal Neoplasms - epidemiology; Colorectal Neoplasms - genetics; Developing countries; Diagnosis; Disease; Etiology; Genetic diversity; Genetic factors; Genetic Markers; Genetic polymorphisms; Genetic Predisposition to Disease; Genomes; Genotype; GWAS; Haplotypes; Humans; Identification and classification; LDCs; Polymorphism, Single Nucleotide; Polymorphisms; Population genetics; Precision medicine; Risk Factors; Single-nucleotide polymorphism; SMAD7; Smad7 protein; Smad7 Protein - genetics; Smad7 Protein - metabolism; Transforming growth factors; Iran; United States > US; Association study; GWAS; Polymorphisms; Colorectal cancer; SMAD7
• ISSN: 1755-8794; 1755-8794
• DOI: 10.1186/s12920-021-01150-3

Colorectal cancer (CRC) is one of the common cancers with a high mortality rate worldwide. In Iran, there has been a trend of increased incidence of colorectal cancer in the last three decades that necessitates the early diagnosis. Genetic factors have an influential role in its etiology along with the conventional risk factors such as age, diet, and lifestyle. Results from GWAS have shown significant associations between SMAD7 gene variants and risk of CRC. This study aimed to assess the association of certain polymorphisms as well as haplotypes of this gene and risk of colorectal cancer. This study was designed as a case-control association study. After obtaining ethical approval and informed consent, blood samples from 209 patients with colorectal cancer were collected and DNA was extracted. Four variants: rs4939827, rs34007497, rs8085824 and rs8088297 were genotyped using ARMS-PCR method. SMAD7 rs4939827 in the recessive and co-dominant models was associated with colorectal cancer risk [TT/CT + CC: OR = 2.90, 95%CI (1.38-6.09), p = 0.005; CC + TT/CT: OR = 1.66, 95%CI (1.00-2.75), p = 0.01]. Haplotype analysis indicated that some SNP combinations including two for-SNPs haplotypes of T-T-C-C and T-C-C-A were significantly associated with CRC risk. Based on the identified association of SMAD7 gene variations and haplotypes with colorectal cancer risk in our population, genetic variations in this gene region may have a role in CRC development. This data may shed light on the genetic predisposition of CRC which involves different pathways including TGF-β.