scispace - formally typeset
Search or ask a question

Showing papers by "Rama Shanker Verma published in 2015"


Journal ArticleDOI
TL;DR: The recent advancements in immunosensing techniques that were developed exploiting the unique properties of gold nanoparticles are explored and the possible future trends with respect to gold nanoparticle-coupled microfluidic sensors; paper based analytical devices and the single-molecule biosensing are discussed.

145 citations


Journal ArticleDOI
21 Aug 2015-PLOS ONE
TL;DR: The genome wide expression profile showed significant dysregulation of post transcriptional gene silencing machinery and multiple microRNA host genes that are potential tumor suppressors and proto-oncogenes including MIR22HG, MIR17HG and MIR21HG.
Abstract: Zero gravity causes several changes in metabolic and functional aspects of the human body and experiments in space flight have demonstrated alterations in cancer growth and progression. This study reports the genome wide expression profiling of a colorectal cancer cell line-DLD-1, and a lymphoblast leukemic cell line-MOLT-4, under simulated microgravity in an effort to understand central processes and cellular functions that are dysregulated among both cell lines. Altered cell morphology, reduced cell viability and an aberrant cell cycle profile in comparison to their static controls were observed in both cell lines under microgravity. The process of cell cycle in DLD-1 cells was markedly affected with reduced viability, reduced colony forming ability, an apoptotic population and dysregulation of cell cycle genes, oncogenes, and cancer progression and prognostic markers. DNA microarray analysis revealed 1801 (upregulated) and 2542 (downregulated) genes (>2 fold) in DLD-1 cultures under microgravity while MOLT-4 cultures differentially expressed 349 (upregulated) and 444 (downregulated) genes (>2 fold) under microgravity. The loss in cell proliferative capacity was corroborated with the downregulation of the cell cycle process as demonstrated by functional clustering of DNA microarray data using gene ontology terms. The genome wide expression profile also showed significant dysregulation of post transcriptional gene silencing machinery and multiple microRNA host genes that are potential tumor suppressors and proto-oncogenes including MIR22HG, MIR17HG and MIR21HG. The MIR22HG, a tumor-suppressor gene was one of the highest upregulated genes in the microarray data showing a 4.4 log fold upregulation under microgravity. Real time PCR validated the dysregulation in the host gene by demonstrating a 4.18 log fold upregulation of the miR-22 microRNA. Microarray data also showed dysregulation of direct targets of miR-22, SP1, CDK6 and CCNA2.

43 citations


Journal ArticleDOI
TL;DR: In this paper, the morphological characteristics of bioaerosols from marine urban and high altitude continental regions in Southern India were analyzed using Scanning Electron Microscope (SEM) coupled with Energy-dispersive Spectra Detector (EDX/EDS).

29 citations


Journal ArticleDOI
TL;DR: A Bio-Hybrid scaffold with non-cross linked DBPECM in its native structure coated with a layer of Polycaprolactone-Chitosan (PCL-CH) nanofibers that displayed superior mechanical properties is developed.

28 citations


Journal ArticleDOI
TL;DR: The data suggest that the upregulation of EMT promoting factors in FA may contribute to predisposing FA patients to cancer, thereby providing new insights into possible therapeutic interventions.
Abstract: Fanconi anemia (FA) is a rare autosomal recessive genetic disorder associated with a bone-marrow failure, genome instability, hypersensitivity to DNA crosslinking agents and a predisposition to cancer Mutations have been documented in 16 FA genes that participate in the FA-BRCA DNA repair pathway, a fundamental pathway in the development of the disease and the presentation of its symptoms FA cells have been characterized by an overproduction of cytokines, MAPKs, and Interleukins Through this study we have identified the overexpression of additional secretory factors such as IL-6, IL-8, MMP-2, and MMP-9 in FA cells and in cells depleted of FANCA or FANCC and proved that their expression is under the control of NF-κB/TNF-α signaling pathways We also demonstrated that these overexpressed secretory factors were effective in promoting the proliferation, migration, and invasion of surrounding tumor cells a fundamental event in the process of epithelial mesenchymal transition (EMT) and that they also modulated the expression of EMT markers such as E-cadherin and SNAIL Overall our data suggest that the upregulation of EMT promoting factors in FA may contribute to predisposing FA patients to cancer, thereby providing new insights into possible therapeutic interventions

28 citations


Journal ArticleDOI
TL;DR: The role of ROMO1 is revealed and its link in regulating RedOx states and in the activation of NF-κB-dependent EMT factors in FA is demonstrated.

21 citations


Journal ArticleDOI
TL;DR: The aim of this study was to identify key steps in the isolation and culture of such early stage-neonatal mouse hearts to allow maximum migration of cardiomyocytes from the explant and their maintenance as functional, long term cultures.

17 citations


Journal ArticleDOI
TL;DR: It is demonstrated that the formulated aqueous dispersible glyceryl monooleate coated magnetic nanoparticles (MNPs) can act as a better labeling and efficient tracking agent without affecting the inherent properties of MSCs.
Abstract: Mesenchymal stem cells (MSCs) have gained much interest to be used as targeting vehicle in cancer therapy due to the intrinsic tumor-homing behavior associated with them. In this scenario, superparamagnetic nanoparticles are emerging as an ideal probe for noninvasive cell tracking for different stem cell applications. In the study, it is demonstrated that the formulated aqueous dispersible glyceryl monooleate coated magnetic nanoparticles (MNPs) can act as a better labeling and efficient tracking agent without affecting the inherent properties of MSCs. The MNPs-MSCs facilitate the stem cell tracking by magnetic resonance imaging at a very low cell number having high T2 relaxivity and potentiates the use of MNPs-MSCs as a prospective diagnostic tool. Most importantly, the homing of MNPs-MSCs toward inflammation site, subcutaneous prostate tumor (small as well as large tumor), and in orthotopic prostate tumor suggests the clinical relevance of the system. In addition, intraperitoneal delivery of MNPs-MSCs shows enhanced tumor accumulation and less sequestration in liver as revealed by in vivo imaging and histological studies. The results here demonstrate that MNPs-MSCs may prove as a better targeted delivery agent for early diagnosis of tumors even of smaller size.

12 citations


Book ChapterDOI
TL;DR: 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 theCardiomyocyte enrichment step.
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.

5 citations


BookDOI
01 Jan 2015
TL;DR: This volume is a guide to understanding resistance against targeted therapeutic approaches for cancer using immunotoxins and includes an in-depth description of the molecular and cellular mechanisms involved in cancer resistance and several novel methods to overcome resistance.
Abstract: This volume is a guide to understanding resistance against targeted therapeutic approaches for cancer using immunotoxins. It contains a detailed review of the history and development of targeted therapy. As well, it includes an in-depth description of the molecular and cellular mechanisms involved in cancer resistance and several novel methods to overcome resistance. Each chapter discusses different aspects of resistance and covers all the factors that may contribute to resistance in cancer cells. Finally, this volume highlights the recent findings and advances associated with tackling cancer resistance

2 citations


Journal ArticleDOI
TL;DR: A reproducible, efficient protocol for isolation of LDSCs with functional hepatocytes differentiation potential is developed, which further can be used as in vitro model system for assessing drug toxicity assays in various preclinical trials.
Abstract: The success of liver regeneration depends on the availability of suitable cell types and their potential to differentiate into functional hepatocytes. To identify the stem cells which have the ability to differentiate into hepatocytes, we used neonatal liver as source. However, the current protocol for isolating stem cells from liver involves enzymes like collagenase, hyaluronidase exposed for longer duration which limits the success. This results in the keen interest to develop an easy single step enzyme digestion protocol for isolating stem cells from liver for tissue engineering approaches. Thus, the unlimited availability of cell type favors setting up the functional recovery of the damaged liver, ensuring ahead success towards treating liver diseases. We attempted to isolate liver stem derived cells (LDSCs) from mouse neonatal liver using single step minimal exposure to enzyme followed by in vitro culturing. The cells isolated were characterized for stem cell markers and subjected to lineage differentiation. Further, LDSCs were induced to hepatocyte differentiation and validated with hepatocyte markers. Finally, we developed a reproducible, efficient protocol for isolation of LDSCs with functional hepatocytes differentiation potential, which further can be used as in vitro model system for assessing drug toxicity assays in various preclinical trials.

Proceedings ArticleDOI
05 Nov 2015
TL;DR: A novel microfluidic device which can generate FSS on cells of five different orders with single inflow of fluid which can cover the whole range of physiological fluid shear stresses in one run is designed.
Abstract: Cells sense external mechanical stimulus and respond to it through mechanotransduction mechanism. Fluid shear stress (FSS) has been found to be an important element among the mechanical stimuli. Recent advancements in microfluidics made mechanotransduction studies possible in near physiological conditions using microfluidic devices. FSS on human cells covers a broad range from very low level experienced due to interstitial flows (0.1 mPa) to very high level in aorta (10 Pa). In the present communication, we have designed a novel microfluidic device which can generate FSS on cells of five different orders with single inflow of fluid which can cover the whole range of physiological fluid shear stresses in one run. The dimensions of the device were calculated taking a resistance model for the micro channels. Flow velocities and wall shear stress were predicted through computer simulation. Shear stress values were analyzed for two different depths of channels and different inlet flow rates ranging from 50 to 0.5 µl/s. FSS was found to increase linearly with inlet flow rate and the stress profile was flatter for lesser depth of channel.

Book ChapterDOI
01 Jan 2015
TL;DR: The various factors and cellular mechanisms responsible for resistance against conventional therapies and targeted approaches like recombinant immunotoxins and different means of targeting resistant cancer stem cells that could be used in the future are discussed.
Abstract: Cancer relapse or recurrence has been the greatest challenge in the treatment of this life threatening disease, which occurs due to resistance of cancer cells to drug or radiation therapy Most often this resistance is developed during treatment, which makes it even more complicated, leading to the failure of chemo or radiation therapy in the majority of cases To circumvent these problems associated with conventional therapies, newer strategies were adopted like targeted therapy using monoclonal antibodies, immunotoxins and antibody-drug conjugates However, targeted therapy also showed failure in many in vitro and in vivo studies that was again attributed to the emergence of resistant cells Here, we discuss the various factors and cellular mechanisms responsible for resistance against conventional therapies and targeted approaches like recombinant immunotoxins Cancer stem cells (CSC’s) were identified as the major reason for resistance and their role in cancer relapse has been proved convincingly in recent studies Hence, resistance mechanisms involved in CSC’s have been elaborated We also summarize the strategies being adopted currently to overcome resistance and different means of targeting resistant cancer stem cells that could be used in the future