Heterozygosity of stromelysin-1 (rs3025058) promoter polymorphism is associated with gastric cancer.

BACKGROUND: Gastric cancer (GC) is the third most common cancer in India and is mediated by multiple genetic, epigenetic and environmental risk factors. A single nucleotide polymorphism rs3025058 at -1171 of the stromelysin-1 (matrix metalloproteinase [MMP]-3) promoter is resulting due to insertion/deletion of adenine thought to have an impact on increasing the risk for tumor formation. AIM: This study is aimed to understand the role of stromelysin-1 rs3025058 (-1171, 5A/6A) promoter polymorphism in the etiology of GC in Indian population. MATERIALS AND METHODS: Genomic DNA was isolated from blood samples of the GC patients and controls. The genotyping of stromelysin-1 rs3025058 (-1171, 5A/6A) promoter polymorphism was carried out by amplification refractory mutation system-polymerase chain reaction method followed by agarose gel electrophoresis. RESULTS: The frequency of 5A/5A, 5A/6A, and 6A/6A genotypes in GC patients were 7.69%, 76.92%, and 15.38%, while in controls were 5.31%, 86.73%, and 7.96%, respectively. There was a significant difference in the distribution of 5A/6A genotype in patients compared to the controls (P < 0.05). CONCLUSION: This study showed an increased frequency of heterozygotes for stromelysin-1 rs3025058 and thought to be involved in the etiology of GC.

The complete genome sequence of a south Indian isolate of Rice tungro spherical virus reveals evidence of genetic recombination between distinct isolates.

In this study, complete genome of a south Indian isolate of Rice tungro spherical virus (RTSV) from Andhra Pradesh (AP) was sequenced, and the predicted amino acid sequence was analysed. The RTSV RNA genome consists of 12,171 nt without the poly(A) tail, encoding a putative typical polyprotein of 3,470 amino acids. Furthermore, cleavage sites and sequence motifs of the polyprotein were predicted. Multiple alignment with other RTSV isolates showed a nucleotide sequence identity of 95% to east Indian isolates and 90% to Philippines isolates. A phylogenetic tree based on complete genome sequence showed that Indian isolates clustered together, while Vt6 and PhilA isolates of Philippines formed two separate clusters. Twelve recombination events were detected in RNA genome of RTSV using the Recombination Detection Program version 3. Recombination analysis suggested significant role of 5' end and central region of genome in virus evolution. Further, AP and Odisha isolates appeared as important RTSV isolates involved in diversification of this virus in India through recombination phenomenon. The new addition of complete genome of first south Indian isolate provided an opportunity to establish the molecular evolution of RTSV through recombination analysis and phylogenetic relationship.

MMP 9 Gene Promoter Polymorphism in Gastric Cancer.

Matrix metalloproteinase-9 (gelatinase B) plays a key role in cancer invasion and metastasis by degrading the extracellular matrix and basement membrane barriers. A cytosine (C) > thymidine (T) single nucleotide polymorphism (SNP) at position -1562 in the MMP-9 promoter is reported to influence the expression of the gene. Genotyping of MMP-9 -1562 C→T promoter polymorphism in 140 gastric cancer patients and 132 healthy control subjects was carried out in order to evaluate its association with progression and development of gastric cancer. The SNP was genotyped by tetra-primer amplification refractory mutation system-polymerase chain reaction followed by agarose gel electrophoresis. Statistical methods were adopted to test for the significance of the results. Risk factor profile of the patients revealed age above 50 years, smoking, alcoholism as the factors associated with the disease. The distribution of genotype frequencies in gastric cancer patients were 28.7 % of CC, 45.5 % of CT and 25.7 % of TT, whereas in control subjects 31.8 % of CC, 53.03 % of CT and 15.15 % of TT, respectively. The allelic frequencies were 51.51 % of C and 48.48 % of T in patient group and 58.33 % of C and 41.66 % of T in controls respectively. The present study shows the possible association of epidemiological risk factors with gastric cancer. There is an increased frequency of T allele in the disease compared to control subjects. However, there is no association of the MMP-9 -1562 C→T promoter polymorphism in the development of gastric cancer.

Role of matrix metalloproteinase 3 gene promoter polymorphism in chronic pancreatitis.

AIM: To study the role of 5A/6A polymorphism of matrix metalloproteinase (MMP-3) and their levels in the pathogenesis of chronic pancreatitis (CP). METHODS: One hundred and twenty CP patients and an equal number of age and sex-matched healthy controls were included in the study. Genotypes were determined for 5A/6A allele of MMP-3 gene by allele specific PCR (AS-PCR). The serum MMP-3 levels were estimated using sandwich ELISA method. RESULTS: The distribution of the genotypes of the 5A/6A polymorphism in both control and study patients was similar (p = 0.523). Within the disease group, patients with older age, early onset of the disease, and addictions such as smoking and alcohol consumption had higher levels as compared to those who did not have these features. CONCLUSION: We conclude that functional polymorphism of MMP-3 (5A/6A) is not associated with CP. However, the higher levels within the disease group indicate its possible role in the disease process.

Helicobacter pylori infection in relation to gastric cancer progression.

Gastric cancer is a major cause of cancer death worldwide, especially in developing countries. The incidence of gastric cancer varies from country to country, probably as a result of genetic, epigenetic, and environmental factors. H. pylori infection is considered as a major risk factor in the development of gastric cancer. However, the scenario varies in Asian countries, exhibiting a higher rate of H. pylori infection and low incidence of gastric cancer, which could be attributed to strain-specific virulence factors and host genetic makeup. In this review, we discuss the various virulence factors expressed by this bacterium and their interaction with the host factors, to influence pathogenesis.