Role of genetic variants of Vitamin D receptor, Toll-like receptor 2 and Toll-like receptor 4 in extrapulmonary tuberculosis.

BACKGROUND: Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis (MTB). Vitamin D deficiency and vitamin D receptor (VDR) gene abnormalities confer susceptibility to tuberculosis. Toll-like receptors (TLRs), such as TLR-2, are also important mediators of inflammatory response against Mycobacterium tuberculosis. We evaluated VDR, TLR-2 and TLR-4 gene polymorphisms in patients with extrapulmonary tuberculosis (EPTB). OBJECTIVES: To find out a possible association of Vitamin D receptor (VDR) (rs731236), TLR-2 (196-174 Ins > Del) and TLR-4 (Thr399Ile) gene polymorphisms with extrapulmonary tuberculosis in ethnic Kashmiri population. METHODS: A total of 100 extrapulmunary tuberculosis cases and 102 healthy controls were analyzed for Vitamin D receptor (VDR) (rs731236), TLR-2 (196-174 ins > del) and TLR-4 (Thr399Ile) gene polymorphisms using PCR-RFLP and Allele-Specific PCR methods. RESULTS: We found increased frequency of TLR-4 Thr/Ile heterozygous genotype in cases as compared with healthy controls (22% vs 5.8%). Thus acting as a risk factor for extrapulmonary tuberculosis, as was elucidated from statistical analysis [OR, 4.5; 95% CI (1.74-11.68); P < 0.001]. In case of TLR-2 (196-174 ins > del) we observed significant differences in the homozygous variant (Del/Del) genotype of cases and controls (28% in cases & 2.94% in controls). Thus, TLR-2 (Del/Del) genotype acts as a strong risk factor for extrapulmonary tuberculosis predisposition [OR, 12.2; 95% CI (3.5-42.69); P < 0.001]. We did not find any significant differences in the genotypic distribution of (VDR) (rs731236) T > C SNP between cases and controls (P > 0.05). CONCLUSION: TLR-4 (Thr/Ile) and TLR-2 (Del/Del) act as significant risk factors for extrapulmonary tuberculosis predisposition in ethnic Kashmiri population.

Implications of VEGF gene sequence variations and its expression in recurrent pregnancy loss.

RESEARCH QUESTION: What is the association between VEGF gene sequence variants and its mRNA expression in recurrent pregnancy loss (RPL)? Vascular endothelial growth factor (VEGF) has a prominent role in pregnancy and affects pregnancy outcome. The association of VEGF gene 1154G>A, 634G>C and 583C>T polymorphic variations with cases of RPL and full-term fertile women as controls was investigated. DESIGN: Two hundred women with RPL and 240 women healthy controls were included. The restriction fragment length polymorphism method was used for genotyping and quantitative real-time polymerase chain reaction was used for analysis of mRNA expression. RESULTS: In VEGF 1154G>A, significant differences were found in homozygous AA genotype between case and control participants. The variant allele A frequency was significantly more abundant in RPL cases (0.41) than controls (0.19) (P < 0.0001). Only RPL cases with the multi-generation family history of miscarriages and those without any history showed significant differences of combined genotype GA+AA (P < 0.0001). In VEGF 634 G>C, CC genotype and allele C showed significantly increased frequency in RPL cases compared with healthy controls (P < 0.0001). The association between VEGF-1154 G>A SNP and VEGF-A mRNA expression levels was significant in RPL cases (P = 0.004). Also in VEGF-583 C>T, CT genotypes were seen significantly associated with cases (P = 0.003). The heterozygous genotype GA was significantly (P = 0.03) associated with upregulation and downregulation of VEGF mRNA, whereas the homozygous variant genotype AA only leads to low expression levels of VEGF mRNA in patients with RPL. CONCLUSIONS: All the variants of VEGF play a vital role in an increased susceptibility to RPL. Also, VEGF-1154, AA genotypes are associated with its altered low mRNA expression in women with RPL and seem to affect pregnancy outcome.

Effect of steroid hormone receptor gene variants PROGINS (Alu insertion) and PGR C/T (rs1042839) as a risk factor for recurrent pregnancy loss in Kashmiri population (North India).

AIM: To unveil and evaluate the association and analyze the incidence and pattern of PGR gene polymorphisms (PROGINS insertion and PGR exon 5-C/T polymorphism) in recurrent pregnancy loss (RPL) couples of Kashmir. METHODS: In this study, analyses of PGR gene polymorphisms in RPL couples were genotyped by amplification-refractory mutation system polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. RESULTS: Molecular analysis of PGR gene polymorphisms indicated that the genotypic and allelic frequencies of PROGINS insertion and PGR exon 5 C/T polymorphisms of female group in cases and controls to be significantly different and poses risk in predisposition to RPL. Moreover, haplotype analysis in female group revealed that P1P2/CC and P1P2/CT genotype are significantly associated with RPL. CONCLUSION: Our data indicate that the PROGINS insertion and exon 5-C/T polymorphism can act as useful genetic markers in the female group, but needs to be replicated in further studies including various other single nucleotide polymorphisms of PGR gene relevant to pregnancy loss which may contribute to novel therapeutic targets with improved conclusions.

Association of strong risk of hTERT gene polymorphic variants to malignant glioma and its prognostic implications with respect to different histological types and survival of glioma cases.

BACKGROUND: Germline genetic variants of human telomerase reverse transcriptase (hTERT) are known to predispose for various malignancies, including glioma. The present study investigated genetic variation of hTERT T/G (rs2736100) and hTERT G/A (rs2736098) with respect to glioma risk. METHODS: Confirmed cases (n = 106) were tested against 210 cancer-free healthy controls by the polymerase chain reaction-restriction fragment length polymorphism technique for genotyping. RESULTS: Homozygous variant 'GG' genotype of rs2736100 frequency was > 4-fold significantly different in cases versus controls (39.6% 17.2%; p < 0.0001). Furthermore, variant 'G' allele was found to be significantly associated with cases (0.5 versus 0.2 in controls; p < 0.0001). Homozygous variant rs2736098 'AA' genotype (35.8% versus 23.8%) and allele 'A' (0.49 versus 0.34) showed a marked significant difference in cases and controls, respectively (p < 0.05). In hTERT rs2736100, the GG genotype significantly presented more in higher grades and GBM (p < 0.0001). Furthermore, the GG variant of hTERT rs2736100 had a poor probability with respect to the overall survival of patients compared to TG and TT genotypes (log rank p = 0.03). Interestingly, two haplotypes of hTERT rs2736100/rs2736098 were identified as GG and GA that conferred a > 3- and 5-fold risk to glioma patients respectively, where variant G/A haplotype was observed to have the highest impact with respect to glioma risk (p < 0.0001). CONCLUSIONS: The results of the present study indicate that hTERT rs2736098 and rs2736100 variants play an important role in conferring a strong risk of developing glioma. Furthermore, hTERT rs2736100 GG variant appears to play a role in the bad prognosis of glioma patients. Haplotypes GG and GA could prove to be vital tools for monitoring risk in glioma patients.

Serum leptin levels, leptin receptor gene (LEPR) polymorphism, and the risk of systemic lupus erythematosus in Kashmiri population.

The study is conducted to evaluate relationship between LEPRQ223R (Gln > Arg) polymorphism, serum leptin levels, soluble leptin receptor (SOb-R) levels and SLE risk in Kashmiri population.LEPR genotyping was done by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 100 unrelated SLE patients and equal number of healthy control subjects. Leptin and SOb-R levels were measured by ELISA assays. The present study showed higher frequency of variant genotype (AG + GG) in cases compared to controls [OR = 2.52, CI = 1.18-5.35, p = 0.03]. Moreover the rare (G) allele was significantly more predominant in cases than controls [OR = 1.49, p = 0.04]. Interestingly a positive association between the variant genotype and the development of arthritis [OR = 11.8, CI = 1.6-85.1, p = 0.002] and an inverse association with cardiac disorder [OR = 0.09, CI = 0.02-0.46, p = 0.001] was observed in this study. Furthermore the study showed significant differences of leptin levels in SLE patients and controls (23.9 ± 19.5 vs 14.8 ± 10.4, p < 0.001). SLE patients in the highest quartile leptin levels (≥32.5 ng/mL) were significantly more likely to have higher BMI (p = 0.001) and increased risk of developing arthritis (p = 0.02). Furthermore positive association was observed between the variant genotype(AG + GG) and leptin levels (p = 0.001) in SLE patients. Thus, it is evident from our study that LEPRQ223R polymorphism and elevated leptin levels are associated with increased susceptibility of SLE in Kashmiri population.

CagA subtyping in Helicobacter pylori isolates from gastric cancer patients in an ethnic Kashmiri population.

UNLABELLED: The association between gastric cancer and Helicobacter pylori has been well established. Among H. pylori virulence genes the most important determinant is the cytotoxin associated antigen gene (cagA) which is characterized by the presence of repeated EPIYA motifs at the C terminus of the protein. From the alignment and number of these EPIYA motifs, two major types of CagA protein have been identified. AIMS: The aim of this study was to classify the CagA into eastern or western type and to determine the number and type of motifs present. METHODS: The CagA subtyping was done by PCR and multiplex PCR for eastern/western classification and determination of EPIYA motifs respectively. RESULTS: All the isolates studied were of the western type, with 70% of the isolates having more than one EPIYA-C motifs. No statistically significant association was found between the presence of CagA and more than one EPIYA-C motifs with the clinical outcome (differentiation status of the tumour).

Study of TLR4 and IL-8 gene polymorphisms in H.pylori-induced inflammation in gastric cancer in an ethnic Kashmiri population.

BACKGROUND: TLRs play an essential role in the initial handling of H. pylori and determine the clinical outcomes that range from simple asymptomatic gastritis to peptic ulcer disease and gastric cancer. Asp299Gly and Thr399Ile polymorphisms in TLR4 have been associated with a variety of inflammatory and infectious conditions including gastric cancer. The T-251A polymorphism in the promoter region of IL-8 gene has been found to be associated with changing the in vitro levels of IL-8 production. IL-8 exhibits angiogenic activity and is responsible for tumor-associated angiogenesis in several cancers. MATERIALS AND METHODS: 130 gastric cancer patients and 200 healthy controls were included in this study. DNA extraction was followed by PCR detection of H. pylori infection, PCR-RFLP for the TLR 4 polymorphism and PCR-CTPP for IL-8 gene polymorphism. RESULTS: The adjusted OR for gastric cancer risk was 1.15 (95% CI, 0.8357-1.3463); 1.39 (0.6964-2.781) and 1.43 (0.954-2.1515) for Asp299Gly, Thr399Ile and IL-8 T_251A respectively. Odds Ratio analysis showed CT genotype and AT and AA genotypes as risk factors for the development of gastric cancer. We found the Asp299Gly polymorphism carrier to be significantly associated (p value 0.03)with the development of tumours in the distal part of the stomach and Thr399Ile polymorphism to be significantly associated(p value 0.008) with the development of well-differentiated gastric adenocarcinoma.The IL-8 T-251A polymorphism was not found to be associated with any of the clinicopathological characteristics. DISCUSSION: No correlation was found between the appearance of disease and HP infection or the presence of TLR4 and IL-8 gene polymorphisms and HP infection.

Vascular endothelial growth factor A gene (VEGFA) polymorphisms and expression of VEGFA gene in lung cancer patients of Kashmir Valley (India).

The vascular endothelial growth factor (VEGF) is a major mediator of angiogenesis involving tumor growth and metastasis. Polymorphisms in the VEGF gene may regulate VEGF production. In this case-control study, we investigated whether functional polymorphisms (+405 C > G and +936 C > T) in the VEGF gene are associated with the risk of lung cancer. Genomic DNA was isolated from the blood of 100 lung cancer patients and 150 healthy controls, and total RNA was isolated from 48 tumor tissues and adjacent normal lung tissues. Two DNA polymorphisms (+405 C > G and +936 C > T) in the 3'-untranslated regions (3'-UTR) and 5'-untranslated regions (5'-UTR) of vascular endothelial growth factor A (VEGFA) were studied using PCR-RFLP method, and mRNA expression of VEGFA was studied by quantitative real-time PCR. Polymorphisms in the 5'-UTR (+405 C > G) and 3'-UTR (+936 C > T) did not show significant difference between lung cancer cases and control samples (P = 0.11 and P = 0.09, respectively). VEGF +405 CG and GG are significantly more in age group >50 years old, in all grades, and in early pathological stages (P = 0.04, P = 0.03, and P = 0.006, respectively). Also, increased expression of VEGFA mRNA was noted in tumorous compared to non-tumorous tissue (P < 0.0001). Overexpression of the gene was considered at ΔC (T) > 6.0. Within the group of patients with conventional tumor, those with histology other than squamous cell carcinoma (SCC) had a higher level of VEGFA mRNA expression than SCC patients (P = 0.04). Overexpression of VEGFA mRNA was noted in lung cancer and more so in lung cancer with adenocarcinoma and large cell carcinoma histology and in pathological stages III and IV. VEGFA +405 C > G SNP showed an association with age, pathological grade, and stage.

Innovative in Silico Approaches for Characterization of Genes and Proteins.

Bioinformatics is an amalgamation of biology, mathematics and computer science. It is a science which gathers the information from biology in terms of molecules and applies the informatic techniques to the gathered information for understanding and organizing the data in a useful manner. With the help of bioinformatics, the experimental data generated is stored in several databases available online like nucleotide database, protein databases, GENBANK and others. The data stored in these databases is used as reference for experimental evaluation and validation. Till now several online tools have been developed to analyze the genomic, transcriptomic, proteomics, epigenomics and metabolomics data. Some of them include Human Splicing Finder (HSF), Exonic Splicing Enhancer Mutation taster, and others. A number of SNPs are observed in the non-coding, intronic regions and play a role in the regulation of genes, which may or may not directly impose an effect on the protein expression. Many mutations are thought to influence the splicing mechanism by affecting the existing splice sites or creating a new sites. To predict the effect of mutation (SNP) on splicing mechanism/signal, HSF was developed. Thus, the tool is helpful in predicting the effect of mutations on splicing signals and can provide data even for better understanding of the intronic mutations that can be further validated experimentally. Additionally, rapid advancement in proteomics have steered researchers to organize the study of protein structure, function, relationships, and dynamics in space and time. Thus the effective integration of all of these technological interventions will eventually lead to steering up of next-generation systems biology, which will provide valuable biological insights in the field of research, diagnostic, therapeutic and development of personalized medicine.

Transforming Growth Factor-Beta (TGF-ß) Signaling in Cancer-A Betrayal Within.

A ubiquitously expressed cytokine, transforming growth factor-beta (TGF-ß) plays a significant role in various ongoing cellular mechanisms. The gain or loss-of-function of TGF-ß and its downstream mediators could lead to a plethora of diseases includes tumorigenesis. Specifically, at the early onset of malignancy TGF-ß act as tumour suppressor and plays a key role in clearing malignant cells by reducing the cellular proliferation and differentiation thus triggers the process of apoptosis. Subsequently, TGF-ß at an advanced stage of malignancy promotes tumorigenesis by augmenting cellular transformation, epithelial-mesenchymal-transition invasion, and metastasis. Besides playing the dual roles, depending upon the stage of malignancy, TGF-ß also regulates cell fate through immune and stroma components. This oscillatory role of TGF-ß to fight against cancer or act as a traitor to collaborate and crosstalk with other tumorigenic signaling pathways and its betrayal within the cell depends upon the cellular context. Therefore, the current review highlights and understands the dual role of TGF-ß under different cellular conditions and its crosstalk with other signaling pathways in modulating cell fate.