Jornal de Genômica Clínica e Médica

Mutation Profiling in Mitochondrial D-Loop Associated with Stomach Cancer and Tobacco Consumers

Abstract

Rebecca Lalmuanpuii, Souvik Ghatak, Jeremy L Pautu, Doris Lallawmzuali, Rajendra Bose Muthukumaran and Nachimuthu Senthil Kumar

Within North East India, the people of Mizoram are mongoloid in origin and Cancer is a major disease condition among this tribal populace. A peculiar habit of consuming ‘‘tuibur’’ (tobacco smoke–infused aqueous solution) has been practiced in Mizoram. Blood and oral swab samples were collected from stomach cancer patients, tuibur consumers and healthy people. DNA was extracted followed by PCR amplification of the D-loop region of mtDNA. Restriction enzyme digestion of 1050 bp of the hyper variable control region of mtDNA was performed in order to gain an insight into the phylogenetic relationship of populace of Mizoram besides the genetic variations among tuibur consumers. The phylogram based on restriction enzyme analysis (AluI, HaeIII, MspI and KpnI) of the D-loop region subsumed within same mtDNA haplogroups and the markers resulted in a similar clustering of the population. The polymorphic samples were sequenced, analyzed and compared with the MITOMAP database. In the hypervariable control region, 292A>AA and 316C>CC are novel microsatellites instability as they have been reported for the first time as it has not been found in the mitochondrial database. 292A>AA position of MT-HV II region is a locus for the mtTF1 binding site Y. Due to the microsatellite instability of this position, the binding of mtTF1 may be altered. 316C>CC is present at the conserved sequence block II in MT-HV II region of human mitochondrial control region. The present study revealed a variety of mtDNA D-loop region mutations and polymorphisms among tuibur consumer besides stomach cancer patients of Mizoram, some of which might be involved in the development of carcinogenesis in stomach for the tuibur consumer.