Analysis of mitochondrial ND1 gene in human colorectal cancer

• Main Authors: Mansoureh Akouchekian, Massoud Houshmand, Mohammad Hassan Hosseini Akbari, Behnam Kamalidehghan, Masoumeh Dehghan
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2011-01-01
• Series: Journal of Research in Medical Sciences
• Subjects: DNA; Mitochondrial; Colorectal Neoplasms; Electron Transport Complex I; MT-ND1 Protein; Human; Oxidative Phosphorylation; Reactive Oxygen Species
• Online Access: http://www.jmsjournal.net/article.asp?issn=1735-1995;year=2011;volume=16;issue=1;spage=50;epage=55;aulast=Akouchekian
• ISSN: 1735-1995; 1735-7136

Background: Colorectal cancer as a mortal disease affected both sexes of all ethnic and racial human groups. Former studies have indicated some mutations in the mitochondrial DNA (mtDNA) in different human cancers. Complex I NADH has the most subunits encoded by mtDNA. For a better understanding of the mtDNA abnormality in colorectal cancer some genes of this complex is screened for existence of mutations. Methods: One of the main regions of the mtDNA encoding protein was screened by PCR-RFLP followed by DNA sequencing. The obtained sequences were aligned with the revised Cambridge Reference Sequence (rCRS). Each altera-tion recorded as single nucleotide polymorphisms (SNPs), deletions or insertions. Results: Eight mutations were found in 15 samples out of 30 studied populations and no mutation detected in other 15 samples. Among these 15 mutated samples, 7 different mutations were found in 7 patients, that means one mutation per patient and the 8th mutation (T4216C) was common in the rest of 8 samples; in other words T4216C mutation in 27% of tested samples was identified (8 patients out of 30 patients). The existence of T4216C mutation was found to be sig-nificantly different (p ≤ 0.05) between tumoral patient′s tissue and adjacent normal tissue. Conclusions: Results showed that a high frequency of somatic alterations of mtDNA occurs during the carcinogenesis and/or the progression of colorectal cancer. Based on the mtDNA mutation pattern observed in this study and other pre-viously studies it is believed that looking for somatic mutations in mtDNA would be one of the diagnostic values in early detection of cancer.