Licochalcone A- induced human bladder cancer t24 cells apoptosis triggered by mito- chondria dysfunction and endoplasmic reticulum stress. Biomed Res.
Tumor Biol. DOI 10.1007/s13277-014-1897-x
RESEARCH ARTICLE
Dysfunction of mitochondria due to environmental carcinogens in nasopharyngeal carcinoma in the ethnic group of Northeast Indian population Sankar Kumar Ghosh & Anil Seram Singh & Rosy Mondal & Wetetsho Kapfo & V. Khamo & Y. Indibor Singh
Received: 9 January 2014 / Accepted: 26 March 2014 # International Society of Oncology and BioMarkers (ISOBM) 2014
Abstract Nasopharyngeal carcinoma (NPC) is a rare cancer worldwide, but in India, NPC is uncommon in its subcontinent except in the north-eastern part of the country. NPC is thought to be caused by the combined effects of environmental carcinogens, genetic susceptibility and Epstein-Barr virus (EBV). This is the first study that aimed to examine the selected risk factors, mostly dietary, viral environmental, metabolic gene polymorphisms, mitochondrial DNA (mtDNA) copy number variation and their risk, in subjects who are highly prone to NPC in the ethnic groups of Northeast India, which has included cases, first-degree relatives and controls. The cases and controls were selected from three ethnic groups (Manipuri, Naga and Mizo) of Northeast India with high prevalence of NPC. This case–control family study includes 64 NPC patients, 88 first-degree relatives and 100 controls
having no history of cancer. PCR-based detection was done for EBV–latent membrane protein 1 (LMP1) gene and glutathione S-transferase Mu 1 (GSTM1)–glutathione S-transferase theta 1 (GSTT1) polymorphism. A comparative ΔCt method was used for the determination of mtDNA content. An increased risk of 2.00–6.06-folds to NPC was observed with those who intake smoked meat and fish, salted fish and fermented fish; betel nut chewers; tobacco smokers; alcohol drinkers; and those who have kitchen inside the living room, glutathione S-transferase null genotype and EBV infection. The risk of NPC increased in cases with decreased mtDNA copy number (Ptrend =0.007). A significant difference between GST null genotypes and EBV infection with mtDNA content was found in the cases (P3 times a week Green salad/cooked vegetables intake Never Daily ≤3 times a week >3 times a week Betel nut chewing Current Former Never Occasionally Tobacco smoking Current Former Never
demonstrated a significant association of GSTM1 polymorphism and NPC risk [46, 47]. Moreover, the null genotypes of both GSTM1 and GSTT1 further increase the risk of NPC as observed in this study both in cases and FDRs as it is completely incapable of detoxification of the carcinogens generated from the different smoked foods, tobacco and betel quid consumption. A significant difference between GSTM1 and GSTT1 null genotypes with mtDNA content in cases,
