Role of human organic cation transporter-1 (OCT-1/SLC22A1) in modulating the response to metformin in patients with type 2 diabetes.

BACKGROUND: Organic cation transporter 1 primarily governs the action of metformin in the liver. There are considerable inter-individual variations in metformin response. In light of this, it is crucial to obtain a greater understanding of the influence of OCT1 expression or polymorphism in the context of variable responses elicited by metformin treatment. RESULTS: We observed that the variable response to metformin in the responders and non-responders is independent of isoform variation and mRNA expression of OCT-1. We also observed an insignificant difference in the serum metformin levels of the patient groups. Further, molecular docking provided us with an insight into the hotspot regions of OCT-1 for metformin binding. Genotyping of these regions revealed SNPs 156T>C and 1222A>G in both the groups, while as 181C>T and 1201G>A were found only in non-responders. The 181T>C and 1222A>G changes were further found to alter OCT-1 structure in silico and affect metformin transport in vitro which was illustrated by their effect on the activation of AMPK, the marker for metformin activity. CONCLUSION: Taken together, our results corroborate the role of OCT-1 in the transport of metformin and also point at OCT1 genetic variations possibly affecting the transport of metformin into the cells and hence its subsequent action in responders and non-responders.

Evaluation of biomarkers, genetic mutations, and epigenetic modifications in early diagnosis of pancreatic cancer.

BACKGROUND: Pancreatic cancer (PC) is one of the deadliest malignancies with an alarming mortality rate. Despite significant advancement in diagnostics and therapeutics, early diagnosis remains elusive causing poor prognosis, marred by mutations and epigenetic modifications in key genes which contribute to disease progression. AIM: To evaluate the various biological tumor markers collectively for early diagnosis which could act as prognostic biomarkers and helps in future therapeutics of PC in Kashmir valley. METHODS: A total of 50 confirmed PC cases were included in the study to evaluate the levels of carbohydrate antigen 19-9 (CA 19-9), tissue polypeptide specific antigen (TPS), carcinoembryonic antigen (CEA), vascular endothelial growth factor-A (VEGF-A), and epidermal growth factor receptor (EGFR). Mutational analysis was performed to evaluate the mutations in Kirsten rat sarcoma (KRAS), Breast cancer type 2 (BRCA-2), and deleted in pancreatic cancer-4 (DPC-4) genes. However, epigenetic modifications (methylation of CpG islands) were performed in the promoter regions of cyclin-dependent kinase inhibitor 2A (p16; CDKN2A), MutL homolog 1 (hMLH1), and Ras association domain-containing protein 1(RASSF1A) genes. RESULTS: We found significantly elevated levels of biological markers CA 19-9 (P ≤ 0.05), TPS (P ≤ 0.05), CEA (P ≤ 0.001), and VEGF (P ≤ 0.001). Molecular genetic analysis revealed that KRAS gene mutation is predominant in codon 12 (16 subjects, P ≤ 0.05), and 13 (12 subjects, P ≤ 0.05). However, we did not find a mutation in DPC-4 (1203G > T) and BRCA-2 (617delT) genes. Furthermore, epigenetic modification revealed that CpG methylation in 21 (P ≤ 0.05) and 4 subjects in the promoter regions of the p16 and hMLH1 gene, respectively. CONCLUSION: In conclusion, CA 19-9, TPS, CEA, and VEGF levels were significantly elevated and collectively have potential as diagnostic and prognostic markers in PC. Global data of mutation in the KRAS gene commonly in codon 12 and rare in codon 13 could augment the predisposition towards PC. Additionally, methylation of the p16 gene could also modulate transcription of genes thereby increasing the predisposition and susceptibility towards PC.

Improved pulmonary function test (PFT) after 1 one year of Sublingual Immunotherapy (SLIT) in unison with pharmacotherapy in mild allergic asthmatics.

BACKGROUND: Allergen immunotherapy (AIT) is a promising treatment for allergic disease that induces immunological tolerance through the administration of specific allergens. The study of AIT is in its early stage and its clinical effects are not well elucidated. The present study was aimed at determining the effect of AIT on pulmonary function and serum variables of mild allergic asthma patients. METHODS: A total of 80 patients with mild allergic asthma were recruited for the study. Allergen Specific Immunotherapy was administered in the form of Sublingual Immunotherapy and consisted of a build up phase followed by a maintenance phase (six months each respectively). Total serum IgE and vitamin D levels were quantified by ELISA. The percent eosinophill count was determined by cell analyzers. Pulmonary function test was performed at the baseline and after the end of study period. Subjective symptom score was recorded in the form of asthma control questionnaire score. RESULTS: There was a significant increase in the pre FEV1% and pre FEV1/FVC post AIT administration. A significant decrease in the total serum IgE was found post AIT. A decrease in Asthma control Questionnaire (ACQ) scores indicated an improvement in clinical symptoms. Besides there was a significant effect on ICS discontinuation after AIT. CONCLUSION: The study supports SLIT as an effective treatment for Immunomodulation in mild allergic asthmatics besides it gives us significant information regarding the safety and efficacy of SLIT in such patients.

Hypermethylation Status of E-Cadherin Gene in Gastric Cancer Patients in a High Incidence Area.

Gastric cancer (GC) is the fourth most prevalant cancer and the second leading cause of cancer-related mortality worldwide. As in other cancers gastric carcinogenesis is multifactorial involving environmental, genetic and epigenetic components. Epigenetic silencing due to hypermethylation of tumour suppressor genes is one of the key events in gastric carcinogenesis. This study was aimed to analyse the hypermethylation status of the E-Cadherin (CDH1) gene promoter in GCs in the ethnic Kashmiri population. In this study a total of 80 GC patients were recruited. Hypermethylation in tumour tissue was detected by methylation specific PCR (MS-PCR). Hypermethylation of CDH1 promoter was observed in 52 (65%) of gastric carcinoma cases which was significantly much higher than adjacent normal tissue [p≤0.0001]. Further the frequency of CDH1 promoter methylation was significantly different with intestinal and diffuse types of gastric cancer [55.7% vs 82.1%; <0.05]. Moreover females and cases with lymph node invasion had higher frequencies of CDH1 hypermethylation [P≤0.05]. Thus the current data indicate a vital role of epigenetic alteration of CDH1 in the causation and development of gastric cancer, particularly of diffuse type, in our population.

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.