Case Control Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Jul 15, 2015; 7(7): 87-94
Published online Jul 15, 2015. doi: 10.4251/wjgo.v7.i7.87
Association of endothelial nitric oxide synthase gene T-786C promoter polymorphism with gastric cancer
Devulapalli Krishnaveni, Bhayal Amar Chand, Porika Shravan Kumar, Malladi Uma Devi, Macherla Ramanna, Akka Jyothy, Nallari Pratibha, N Balakrishna, Ananthapur Venkateshwari
Devulapalli Krishnaveni, Bhayal Amar Chand, Akka Jyothy, Ananthapur Venkateshwari, Department of Cell Biology, Institute of Genetics and Hospital for Genetic Diseases, Osmania University, Begumpet, Hyderabad 500016, Telangana, India
Porika Shravan Kumar, Malladi Uma Devi, Macherla Ramanna, Department of Gastroenterology, Gandhi Hospital, Secunderabad 500003, Telangana, India
Nallari Pratibha, Department of Genetics, Osmania University, Hyderabad 500007, Telangana, India
N Balakrishna, Department of Biostatistics, National Institute of Nutrition, Hyderabad 500007, Telangana, India
Author contributions: Krishnaveni D had searched the literature and isolated genomic DNA from peripheral blood leucocytes; Krishnaveni D, Shravan Kumar P, Uma Devi M and Ramanna M collected blood samples from patients; Krishnaveni D performed the genotyping of genomic DNA; Amar Chand B, Jyothy A and Pratibha N gave suggestions in writing the article; Balakrishna N performed biostatistical review; Venkateshwari A directed and coordinated the study.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board of Institute of Genetics and Hospital for Genetic Diseases.
Informed consent statement: All the study subjects involved in the present study gave their informed written consent prior to study inclusion.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
Data sharing statement: The corresponding author states that Technical appendix, statistical code and dataset in the present research article entitled “Association of endothelial nitric oxide synthase gene T-786C promoter polymorphism with gastric cancer” has been submitted to Dryad repository to be made available and provide a permanent, citable and open-access home for the dataset.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Ananthapur Venkateshwari, Assistant Professor, Department of Cell Biology, Institute of Genetics and Hospital for Genetic Diseases, Osmania University, Begumpet, Hyderabad 500016, Telangana, India. venkateshwari@yahoo.com
Telephone: +91-40-23403681
Received: March 17, 2015
Peer-review started: March 21, 2015
First decision: April 10, 2015
Revised: May 14, 2015
Accepted: June 1, 2015
Article in press: June 2, 2015
Published online: July 15, 2015
Abstract

AIM: To investigate the role of endothelial nitric oxide synthase -786T > C promoter polymorphism in the etiology of gastric cancer (GC).

METHODS: A total of 150 GC patients and 150 control subjects were included in the study. The information on demographic features was elicited with an informed consent from all the patients and control subjects using a structured questionnaire. Helicobacter pylori (H. pylori) infectivity status was tested in antral biopsies from all the subjects by rapid urease test following the method of Vaira et al. Genomic DNA was isolated from whole blood samples following the salting out method of Lahiri et al. Genotype analysis of the rs2070744 polymorphism was carried out by allele-specific polymerase chain reaction method. The genotypes were determined based on the appearance of bands on an agarose gel stained with ethidium bromide under ultraviolet gel documentation with the help of 100 bp ladder. Odds ratios and corresponding 95%CIs were determined using java stat online software.

RESULTS: There was a significant difference in the distribution of C allele (C vs T; P = 0.000, OR = 5.038) in patient group compared to the control subjects exhibiting a fivefold increased risk for GC. When the T/T and C/C genotypes were compared, there was an enhanced GC risk for individuals with C/C genotype (T/T vs C/C; P = 0.000). Among the demographic factors, smoking and alcoholism were the common risk factors in patients compared to the control subjects (P < 0.05). Patients with smoking and alcoholism developed cancer even in heterozygous T/C condition (smoking: P = 0.020 and alcoholism: P = 0.005). Individuals with H. pylori infection showed seven fold increased risk for cancer. All the patients with C/C genotype revealed a significant association between H. pylori infection and GC. Among the patients 2.4% of them revealed familial incidence of GC. No significant difference was noticed between cases and controls with regard to consanguinity (P = 0.473).

CONCLUSION: The Present data suggest that eNOS-786 C/C genotype and C allele may be considered as potential risk factors in patients with GC.

Keywords: Genetics, Helicobacter pylori, Nutrition, Oncology, Endoscopy, Gastro duodenal, Nitric oxide, Single nucleotide polymorphism rs2070744, Agarose gel electrophoresis, Allele specific polymerase chain reaction

Core tip: The present study reveals first molecular epidemiological evidence from south Indian cohort for the association of endothelial nitric oxide synthase -786T > C promoter polymorphism with a risk to develop gastric cancer (GC). The CC genotype and C allele of the -786T > C polymorphism were significantly associated with an elevated risk to GC, probably due to the lowered nitric oxide levels in case of C/C genotype which result in tumour proliferation, angiogenesis and metastasis.