Mitochondrial D-loop and Cytochrome Oxidase C subunit I polymorphisms among the breast cancer patients of Mizoram, Northeast India

Abstract

Mitochondrial DNA (mtDNA) is known for its high frequencies of polymorphisms and mutations as it is prone to oxidative stress. The aim of the present study is to assess the novel mutations in mitochondrial genes from blood samples among the breast cancer patients from a less studied Northeast Indian population. D, B, L haplogroups were observed in the cancer samples and a total of 44 mtDNA D-loop sequence variations at 42 distinct nucleotide positions were found. All the sequence variations were transitional substitutions and 6 were heteroplasmic states, except for a cytosine copy number change (9C/8C) at np 303e309 in three samples examined. A total of 88 Cytochrome Oxidase C subunit I (COXI) sequence differences with respect to the Revised Cambridge Reference Sequence (rCRS) were identified including 20 missense variants with 100 % sample mutation frequency. All 20 missense mutations are highly conserved with a Cumulate Index of 100 %. Among 88 COXI mutations, 24 (13 were Non-Synonymous and 11 were Synonymous) were not previously reported (novel mutation) in the literature or the public mtDNA mutation databases. Analysis of three-dimensional structure of COXI open reading frame (ORF) predicted the effect of one single codon (96R > C, 217T > I, 224-225GG > EE and 227D > T) mutations located in the signal peptide binding position. Analysis of mitochondrial DNA mutations, as a viable alternative, has the advantage of being capable of detecting inherent risk factors for breast cancer development.

Novel APC gene mutations associated with protein alteration in diffuse type gastric cancer

“…The study design and data collection methods have been described in detail previously [24]. For this study, a total of 62 gastric cancer (GC) patients with or without a family history of cancer (median age 58 years; range 37–79) who received treatment between September 2012 and February 2014 at Agartala Govt.…”

Xenobiotic Pathway Gene Polymorphisms Associated with Gastric Cancer in High Risk Mizo‐Mongoloid Population, Northeast India

“…Patients with gastric neoplasms including adenocarcinoma (MALT lymphoma, stromal, or carcinoid tumors) were included. Patients with secondary or recurrent GC, previous history of other malignancies, or refusal to participate were excluded from the study . Medical charts were reviewed using a standard protocol to obtain information on cancer treatment, clinical stage, dietary habits, previous disease history, physical activity, tobacco, and alcohol use by an in‐person interview using a structured questionnaire .…”

Relevance of GSTM1, GSTT1 and GSTP1 Gene Polymorphism to Breast Cancer Susceptibility in Mizoram Population, Northeast India

“…Patients who were histopathologically confirmed as breast adenocarcinoma were selected for this study. Demographic data and family history for BC were collected by a structured questionnaire administered by trained personnel as previously described (Ghatak et al 2014). One ml of peripheral blood was collected from each patient including 10 control samples (HC) from healthy volunteers with no previous history of breast cancer and matched by gender, age (±5 years) and area of residence with the cancer patients.…”

“…Mizoram belonging to North Eastern state of India has a high agestandardised breast cancer rate of 14.1 per 1,00,000 population (NCRP 2013). Studies have shown that consumption of alcohol, tobacco and peculiar food habits, especially high fat intake, are important risk factors for breast cancer (Ghatak et al 2014;Sieri et al 2008).…”