Rama Shanker Verma

Bio: Rama Shanker Verma is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Mesenchymal stem cell & Stem cell. The author has an hindex of 30, co-authored 159 publications receiving 3160 citations. Previous affiliations of Rama Shanker Verma include University of Pennsylvania & Thapar University.

Specific targeting of Ep-CAM in various carcinomas by novel monoclonal antibodies.

Abstract: Epithelial cell adhesion molecule (Ep-CAM) is a 40 kDa transmembrane glycoprotein overexpressed in majority of tumor epithelial cells and has a major morphoregulatory function, relevant not only to epithelial tissue development, but also in carcinogenesis and tumor progression. Since Ep-CAM localizes at the cell surface of most carcinomas, the molecule is an attractive target for immunotherapy and several strategies have been deployed to treat cancer using Ep-CAM targeting, including MAb therapy. For improving effective targeting of this protein for diagnostics in various clinical samples, we generated and characterized an anti-Ep-CAM MAb (C4) using recombinant Ep-CAM protein, comprising the highly immunogenic domain. The specificity of C4-MAb was characterized in Ep-CAM positive cell lines (PC3 and MCF-7) by flow cytometry and immunofluorescence. The immunohistochemistry analysis in clinical tissue samples showed specific detection of epithelial antigens in breast, colon, stomach, and prostate carcinomas...

Effect of choline, ethanolamine and serine supplementation on the membrane properties of Microsporum gypseum.

Abstract: Phospholipid bases, choline and ethanolamine, when supplemented in the growth medium of Microsporum gypseum resulted in an increase in the corresponding phospholipid and total phospholipid content However, when serine was supplemented, marginal changes were observed The fatty acid profile of phospholipids remained almost unchanged The uptake of lysine, leucine and aspartic acid in the spheroplasts of choline- and ethanolamine-grown cells was higher as compared to the control 1-Anilinonaphathalene-8-sulfonate (ANS) binding to the spheroplast membrane, as calculated from Scatchard plots, demonstrated an increase in the number of binding sites in choline- and ethanolamine-grown cells, while a decrease was observed in the serine-supplemented cells The results are discussed in terms of the effect of phospholipid polar head group composition on the membrane structure and function of this fungus

A Multiparametric Fluorescence Probe to Understand the Physicochemical Properties of Small Unilamellar Lipid Vesicles in Poly(ethylene glycol)-Water Medium

Abstract: FDAPT (2-formyl-5-(4′-N,N-dimethylaminophenyl)thiophene) efficiently senses the minimum alteration of lipid bilayer microenvironment with all six different fluorescence parameters namely emission w...

Enrichment of cardiomyocytes in primary cultures of murine neonatal hearts.

Abstract: In vitro culture of neonatal murine cardiomyocytes is vital for understanding the functions of the heart. Cardiomyocyte cultures are difficult to maintain because they do not proliferate after birth. The maintenance of primary cultures of viable and functional cardiomyocytes is considerably affected by the yield from initial steps of isolation procedures. This protocol describes an efficient and rapid method for isolation and maintenance of long-term cultures of neonatal murine cardiomyocytes by effectively shortening the trypsin enzyme digestion period and the cardiomyocyte enrichment step.

Microwave-Assisted Synthesis of Quasi-Pyramidal CuInS2 -ZnS Nanocrystals for Enhanced Near-Infrared Targeted Fluorescent Imaging of Subcutaneous Melanoma.

Abstract: Near-infrared (NIR) fluorescent CuInS2 -ZnS nanocrystals (CIZS NCs) are synthesized via an ultra-fast, non-injection microwave (MW)-assisted nanoalloying process at 230 oC within 5 min using 1-dodecanethiol (DDT) as both the sulfur source and solvent under solvothermal (ST) condition. The structural and surface analyses reveal that DDT-functionalized CIZS NCs exhibit quasi-pyramids of tetragonal-phase with well-defined facets. The DDT-functionalized CIZS NCs present a photoluminescence quantum yield (PLQY) of 76% and a long-lived fluorescence lifetime of ≈0.6 µs in organic-phase. Subsequently, DDT-functionalized CIZS NCs are phase-transferred via ligand-exchange using 11-mercaptoundecanoic acid (MUA) into water-soluble MUA-CIZS NCs that exhibit a substantial PLQY of 55%. In addition, the NIR-fluorescent MUA-functionalized CIZS NCs in conjugation with folic acid (FA), as a tumor-targeting ligand, demonstrates enhanced tumor-targeted imaging ability. The FA-MUA-CIZS NC conjugates exhibit a cell viability of ≈75% even at the highest concentration of 1 mg mL-1 and a labeling efficiency of 95.4%. The in vivo imaging results corroborate that FA-MUA-CIZS NCs conjugates are actively targeted to folate receptor-positive B16F10 tumor-bearing C57BL/6 mice in 2 h. The histopathological and hematological studies confirm no significant changes in tissue architecture and blood biochemical parameters. The confocal microscopy studies reveal deep penetration and uniform distribution of FA-MUA-CIZS NCs conjugates in subcutaneous melanoma.

Osteoblastic cells regulate the haematopoietic stem cell niche

Abstract: Stem cell fate is influenced by specialized microenvironments that remain poorly defined in mammals. To explore the possibility that haematopoietic stem cells derive regulatory information from bone, accounting for the localization of haematopoiesis in bone marrow, we assessed mice that were genetically altered to produce osteoblast-specific, activated PTH/PTHrP receptors (PPRs). Here we show that PPR-stimulated osteoblastic cells that are increased in number produce high levels of the Notch ligand jagged 1 and support an increase in the number of haematopoietic stem cells with evidence of Notch1 activation in vivo. Furthermore, ligand-dependent activation of PPR with parathyroid hormone (PTH) increased the number of osteoblasts in stromal cultures, and augmented ex vivo primitive haematopoietic cell growth that was abrogated by gamma-secretase inhibition of Notch activation. An increase in the number of stem cells was observed in wild-type animals after PTH injection, and survival after bone marrow transplantation was markedly improved. Therefore, osteoblastic cells are a regulatory component of the haematopoietic stem cell niche in vivo that influences stem cell function through Notch activation. Niche constituent cells or signalling pathways provide pharmacological targets with therapeutic potential for stem-cell-based therapies.

Reactive oxygen species in cell signaling

Abstract: Reactive oxygen species (ROS) are generated as by-products of cellular metabolism, primarily in the mitochondria. When cellular production of ROS overwhelms its antioxidant capacity, damage to cellular macromolecules such as lipids, protein, and DNA may ensue. Such a state of “oxidative stress” is thought to contribute to the pathogenesis of a number of human diseases including those of the lung. Recent studies have also implicated ROS that are generated by specialized plasma membrane oxidases in normal physiological signaling by growth factors and cytokines. In this review, we examine the evidence for ligand-induced generation of ROS, its cellular sources, and the signaling pathways that are activated. Emerging concepts on the mechanisms of signal transduction by ROS that involve alterations in cellular redox state and oxidative modifications of proteins are also discussed.

G1 events and regulation of cell proliferation.

Abstract: Cells prepare for S phase during the G1 phase of the cell cycle. Cell biological methods have provided knowledge of cycle kinetics and of substages of G1 that are determined by extracellular signals. Through the use of biochemical and molecular biological techniques to study effects of growth factors, oncogenes, and inhibitors, intracellular events during G1 that lead to DNA synthesis are rapidly being discovered. Many cells in vivo are in a quiescent state (G0), with unduplicated DNA. Cells can be activated to reenter the cycle during G1. Similarly, cells in culture can be shifted between G0 and G1. These switches in and out of G1 are the main determinants of post-embryonic cell proliferation rate and are defectively controlled in cancer cells.

Widespread requirement for Hedgehog ligand stimulation in growth of digestive tract tumours

Abstract: Activation of the Hedgehog (Hh) signalling pathway by sporadic mutations or in familial conditions such as Gorlin's syndrome is associated with tumorigenesis in skin, the cerebellum and skeletal muscle. Here we show that a wide range of digestive tract tumours, including most of those originating in the oesophagus, stomach, biliary tract and pancreas, but not in the colon, display increased Hh pathway activity, which is suppressible by cyclopamine, a Hh pathway antagonist. Cyclopamine also suppresses cell growth in vitro and causes durable regression of xenograft tumours in vivo. Unlike in Gorlin's syndrome tumours, pathway activity and cell growth in these digestive tract tumours are driven by endogenous expression of Hh ligands, as indicated by the presence of Sonic hedgehog and Indian hedgehog transcripts, by the pathway- and growth-inhibitory activity of a Hh-neutralizing antibody, and by the dramatic growth-stimulatory activity of exogenously added Hh ligand. Our results identify a group of common lethal malignancies in which Hh pathway activity, essential for tumour growth, is activated not by mutation but by ligand expression.