Ramesh Bamezai

Bio: Ramesh Bamezai is an academic researcher from Jawaharlal Nehru University. The author has contributed to research in topics: Population & Genotype. The author has an hindex of 14, co-authored 25 publications receiving 665 citations.

Comparison of established cell lines at different passages by karyotype and comparative genomic hybridization.

Abstract: Two established cancer cell lines, MCF-7 and Ishikawa, were both obtained directly from a cell repository and through another laboratory. The karyotypes from the two MCF-7 cell lines had up to 83 chromosomes and similarities for chromosomal gain and structural abnormalities. The two Ishikawa cell lines had up to 60 chromosomes with only a missing X as the common chromosome abnormality. CGH studies were performed by co-hybridizing the two Ishikawa or MCF-7 cell lines to normal metaphases. The differences seen between the two MCF-7 cell cultures reflect changes due to passage number and culture conditions. For Ishikawa, DNA polymorphic data and mutation studies suggest that the two cell lines are not derived from the same established tumor cell line. Our study shows the utilization of CGH in comparing cell lines originating from the same specimen. Our study also demonstrates the necessity for periodically evaluating cell lines to confirm their origin.

TLR2 Arg677Trp polymorphism in leprosy: revisited

Abstract: We investigated the Toll-like receptor 2 (TLR2) Arg677Trp polymorphism, associated with lepromatous leprosy in the Korean population and shown to abrogate TLR2-mediated signalling in response to mycobacterial ligands, in 286 Indian leprosy patients and 183 ethnically matched controls. The case-control comparison also involved investigation of possible variation(s) in the promoter region of the TLR2 gene. Genotyping results after direct PCR sequencing showed that the TLR2 Arg677Trp polymorphism associated with lepromatous leprosy in the Korean population is not a true polymorphism of the TLR2 gene and has resulted from the variation present in the 93% homologous duplicated region of TLR2 exon 3 present approximately 23 kb upstream.

PGC-1α Thr394Thr and Gly482Ser variants are significantly associated with T2DM in two North Indian populations: a replicate case-control study

Abstract: The recent observations that Peroxisome proliferator activated receptor gamma coactivator 1 alpha (PGC1A) is responsible for the induction of reactive oxygen species (ROS) detoxifying agents and that ROS triggers insulin resistance, support the role that this gene could play in the onset of Type 2 diabetes mellitus (T2DM). Two PGC1A variants Thr394Thr (rs2970847) and Gly482Ser (rs8192673) were genotyped in 822 subjects (351 T2DM cases and 471 controls) from two North Indian populations, represented as Group 1 (Kashmir population) and Group 2 (Punjab and Jammu population). Both Groups 1 and 2 showed a significant association of Thr394Thr variant with T2DM after applying Bonferroni corrections (P = 0.001 and 0.012, respectively). Logistic regression analysis for Thr394Thr susceptible genotypes together (rs2970847 G/A and A/A) conferred a 1.89-(95%CI 1.25–2.85) fold higher risk for T2DM in Group 1 and 1.81-(95%CI 1.19–2.78) fold risk in Group 2. The susceptible, Ser482 (rs8192673 G/A and A/A) genotypes, gave a 2.04 (95%CI 1.47–3.03) fold higher risk for T2DM in Group 1. Mitochondrial genotype backgrounds observed in association with T2DM (Bhat et al. 2007), when studied in combination with PGC1A variants, showed an increased prevalence in controls with mt10398G and 16189T along with G/G genotype background at the two polymorphic loci of PGC1A. These observations suggest that the two genotype backgrounds together could provide protection against T2DM.

The possible role of 10398A and 16189C mtDNA variants in providing susceptibility toT2DM in two North Indian populations: a replicative study

Abstract: The role of mitochondria in causing diseases is becoming evident as more and more studies are focusing on this organelle of the cell. This is largely attributed to its reactive oxygen species (ROS) production property. In the context of diabetes, ROS is suggested to trigger different forms of insulin resistance involving different mechanisms. The suggestive role of a mtDNA variant G10398A in increasing ROS production and the impaired response to oxidative stress due to T16189C variant is worth addressing as genetic susceptibility factors in type 2 diabetes mellitus (T2DM). A case control study on 312 T2DM cases and ethnically matched 466 controls involving two North Indian populations, referred as cohort 1 and cohort 2 (in a replicative study), was undertaken to test such a genetic association. A statistically significant association was observed for 10398A allele in both the cohorts [cohort1 (OR = 2.67 95% CI 1.77–4.00); cohort2 (OR = 1.76 95%CI 1.12–2.77)]. The analysis of G10398A/T16189C haplotypic combinations revealed that 10398A/16189C haplotype provides a risk in both the cohorts. To sum up the study suggests that 10398A and 16189C alleles provide susceptiblity to T2DM independently as well as together.

Curcumin: The Indian solid gold

Abstract: Turmeric, derived from the plant Curcuma longa, is a gold-colored spice commonly used in the Indian subcontinent, not only for health care but also for the preservation of food and as a yellow dye for textiles. Curcumin, which gives the yellow color to turmeric, was first isolated almost two centuries ago, and its structure as diferuloylmethane was determined in 1910. Since the time of Ayurveda (1900 Bc) numerous therapeutic activities have been assigned to turmeric for a wide variety of diseases and conditions, including those of the skin, pulmonary, and gastrointestinal systems, aches, pains, wounds, sprains, and liver disorders. Extensive research within the last half century has proven that most of these activities, once associated with turmeric, are due to curcumin. Curcumin has been shown to exhibit antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, and anticancer activities and thus has a potential against various malignant diseases, diabetes, allergies, arthritis, Alzheimer's disease, and other chronic illnesses. These effects are mediated through the regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other enzymes. Curcumin exhibits activities similar to recently discovered tumor necrosis factor blockers (e.g., HUMIRA, REMICADE, and ENBREL), a vascular endothelial cell growth factor blocker (e.g., AVASTIN), human epidermal growth factor receptor blockers (e.g., ERBITUX, ERLOTINIB, and GEFTINIB), and a HER2 blocker (e.g., HERCEPTIN). Considering the recent scientific bandwagon that multitargeted therapy is better than monotargeted therapy for most diseases, curcumin can be considered an ideal "Spice for Life".

PGC-1alpha, SIRT1 and AMPK, an energy sensing network that controls energy expenditure.

Abstract: PURPOSE OF REVIEW: Peroxisome proliferator-activated receptor gamma coactivator-1-alpha (PGC-1alpha) has been extensively described as a master regulator of mitochondrial biogenesis. However, PGC-1alpha activity is not constant and can be finely tuned in response to different metabolic situations. From this point of view, PGC-1alpha could be described as a mediator of the transcriptional outputs triggered by metabolic sensors, providing the idea that these sensors, together with PGC-1alpha, might be weaving a network controlling cellular energy expenditure. In this review, we will focus on how disorders such as type 2 diabetes and the metabolic syndrome might be related to an abnormal and improper function of this network. RECENT FINDINGS: Two metabolic sensors, AMP-activated protein kinase (AMPK) and SIRT1 have been described to directly affect PGC-1alpha activity through phosphorylation and deacetylation, respectively. Although the physiological relevance of these modifications and their molecular consequences are still largely unknown, recent insight from different in-vivo transgenic models clearly suggests that AMPK, SIRT1 and PGC-1alpha might act as an orchestrated network to improve metabolic fitness. SUMMARY: Metabolic sensors such as AMPK and SIRT1, gatekeepers of the activity of the master regulator of mitochondria, PGC-1alpha, are vital links in a regulatory network for metabolic homeostasis. Together, these players explain many of the beneficial effects of physical activity and dietary interventions in our battle against type 2 diabetes and related metabolic disorders. Hence, understanding the mechanisms by which they act could guide us to identify and improve preventive and therapeutic strategies for metabolic diseases.

Evaluating cell lines as tumour models by comparison of genomic profiles

Abstract: Cancer cell lines are frequently used as in vitro tumour models. Recent molecular profiles of hundreds of cell lines from The Cancer Cell Line Encyclopedia and thousands of tumour samples from the Cancer Genome Atlas now allow a systematic genomic comparison of cell lines and tumours. Here we analyse a panel of 47 ovarian cancer cell lines and identify those that have the highest genetic similarity to ovarian tumours. Our comparison of copy-number changes, mutations and mRNA expression profiles reveals pronounced differences in molecular profiles between commonly used ovarian cancer cell lines and high-grade serous ovarian cancer tumour samples. We identify several rarely used cell lines that more closely resemble cognate tumour profiles than commonly used cell lines, and we propose these lines as the most suitable models of ovarian cancer. Our results indicate that the gap between cell lines and tumours can be bridged by genomically informed choices of cell line models for all tumour types.