Thiruvananthapuram, India
Thiruvananthapuram, India

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Rajiv Gandhi Center For Biotechnology | Date: 2016-05-05

This invention relates to a simple end point assay for detection of transient intracellular Ca^(2+) with broad applicability to many Ca^(2+) channel proteins comprising, Generation of expression constructs for the fusion proteins having the Ca^(2+)/calmodulin dependent protein kinase II (CaMKII) phosphorylation sites of NR2A or NR2B subunits of N-methyl-D-aspartate receptor (NMDAR) or the voltage gated potassium channel of Drosophila (Eag) or any protein sequence which binds to the T-site of CaMKII similar to NR2B, conjugated to mitochondrial localizing signal sequence, or mutants of these sequences as described herein. Generation of mammalian expression constructs of -CaMK11 as a chimera with green fluorescent protein (GFP--CaMKII) or its mutants as described herein. Site-Directed mutagenesis, Transfection, Ca^(2+) stimulation, imaging and quantification of the number of cells with Ca^(2+)-dependent signal, wherein, NMDA receptor activity assay, TRPVI receptor activity assay, GluR4 receptor activity assay are performed to detect the activity of Ca^(2+) channel proteins.

Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: HEALTH.2011.2.4.1-3 | Award Amount: 4.19M | Year: 2011

Human papillomavirus (HPV) is responsible for approximately 25% of head and neck cancer (HNC) worldwide and appears to be associated with a better response to treatment and improved prognosis. Evidence suggests that HPV-induced HNC has steadily increased in the USA and some European countries in the last decades. However, whether this is a worldwide phenomenon and specific risk factors are associated with it remains to be proven. In addition, little is known on the natural history and risk factors of oral HPV infection. HPV-AHEAD network aims to address these and other unanswered questions on HNC etiology and epidemiology with a focus on the role of HPV. We will assemble and analyze a large collection of plasma/sera and HNC tissues from 42 centres in 16 European countries as well as HNC tissues from 7 Indian centres together with epidemiological and clinical data. HPV status in human specimens will be evaluated by different assays in central laboratories. Epidemiological studies will be conducted to establish the overall proportion and type distribution of HPV-positive HNC at different anatomical sites in European and Indian regions as well as the time trend of the proportion of HPV-positive HNC in recent decades. Using the follow-up information on HNC patients, we will further investigate whether HPV positivity confers a better prognosis and survival. We will also conduct a study in HPV-vaccinated and non-vaccinated women in order to determine risk factors and natural history of oral HPV infections. In addition, we will search for new surrogate markers for oral HPV infection to facilitate novel screening strategies. Finally, the HPV-AHEAD consortium aims to transfer technology to Indian centres as well as to develop several strategies for the training of European and Indian researchers in infections and cancers. This study will provide important insights for the screening, diagnosis, treatment and prophylaxis of HPV-associated HNC in Europe, India and elsewhere.

Sreekanth C.N.,Integrated Cancer Research Program | Bava S.V.,Integrated Cancer Research Program | Sreekumar E.,Rajiv Gandhi Center for Biotechnology | Anto R.J.,Integrated Cancer Research Program
Oncogene | Year: 2011

The microtubule-targeting antineoplastic agent, paclitaxel, is highly efficacious against a wide spectrum of human cancers. However, dose-limiting toxicity and development of drug resistance limit its clinical application. Development of novel strategies that overcome chemoresistance and sensitize cancer cells to paclitaxel can enhance the therapeutic effect of this drug. We have previously shown that curcumin, a natural polyphenol, enhances paclitaxel-induced cytotoxicity in vitro through downregulation of nuclear factor (NF)-B and Akt pathways. This study was undertaken to determine whether this synergism exists in vivo and to elucidate the underlying molecular mechanisms. Mouse cervical multistage squamous cell carcinoma model using 3-methylcholanthrene (3-MC) and a xenograft model of human cervical cancer in nonobese diabetic severe combined immunodeficient (NOD-SCID) mice using HeLa cells were used to evaluate the synergism. We observed that the combined treatment of curcumin and paclitaxel induced a synergestic reduction in the tumor incidence as well as tumor volume of animals compared with the individual treatments of paclitaxel or curcumin, although curcumin alone could not induce any significant effect at the concentration used. The results suggest that a suboptimal concentration of curcumin augments the antitumor action of paclitaxel by downregulating the activation and downstream signaling of antiapoptotic factors and survival signals such as NF-B, Akt and mitogen-activated protein kinases that have significant roles in proliferation, survival, angiogenesis and metastasis. This study revealed for the first time that 3-MC-induced tumorigenesis in mice is associated with a strong constitutive activation of NF-B activity. Furthermore, we also observed that pre-exposure of carcinoma cells isolated from 3-MC-induced tumors to curcumin potentiates paclitaxel-induced apoptosis. Overall, the findings of this preclinical study provide a strong rationale for the validation of this combination through clinical trials. As curcumin could effectively downregulate all these survival signals induced by paclitaxel, we suggest it as a potent chemosensitizer to improve the therapeutic index of paclitaxel. © 2011 Macmillan Publishers Limited All rights reserved.

Kim E.J.,Hanyang University | Lee C.H.,Hanyang University | Nair G.B.,Rajiv Gandhi Center for Biotechnology | Kim D.W.,Hanyang University
Trends in Microbiology | Year: 2015

The analysis of the whole-genome sequences of Vibrio cholerae strains from previous and current cholera pandemics has demonstrated that genomic changes and alterations in phage CTX (particularly in the gene encoding the B subunit of cholera toxin) were major features in the evolution of V. cholerae. Recent studies have revealed the genetic mechanisms in these bacteria by which new variants of V. cholerae are generated from type-specific strains; these mechanisms suggest that certain strains are selected by environmental or human factors over time. By understanding the mechanisms and driving forces of historical and current changes in the V. cholerae population, it would be possible to predict the direction of such changes and the evolution of new variants; this has implications for the battle against cholera. © 2015 Elsevier Ltd.

The present study describes the synthesis of different mole densities of poly(propylene glycol)dimethacrylate cross-linked resins using monomer units such as styrene and 4-chloromethyl styrene and its evaluation as an ideal support toward different stages of solid-phase peptide synthesis. Free radical generated aqueous suspension polymerization has been followed for polymerization and the formation of resin was characterized using infrared and carbon-13 spectroscopic techniques. Surface morphology of resin was examined by scanning electron microscopy. The polymerization reaction was investigated with respect to the effect of amount of cross-linking agent to verify the swelling, loading, and the mechanical stability of resin. Solvent imbibition abilities in commonly used solvents were measured and compared to commercially available Merrifield as well as reported styrene-acryloyloxyhydroxypropyl methacrylate-tripropyleneglycol diacrylate (SAT resins. The chemical inertness of the support was also checked with different reagents used for solid-phase peptide synthesis. The suitability of support was demonstrated by synthesizing biologically potent Endothelin class of linear peptides by Fmoc strategy and compared to SAT resin. The purities of synthetic peptides were analyzed by high-performance liquid chromatography and corresponding masses by matrix-assisted laser desorption/ionisation-time of flight analysis. Copyright © 2012 Wiley Periodicals, Inc.

Nair K L.,Rajiv Gandhi Center for Biotechnology
International journal of nanomedicine | Year: 2011

Nanoscaled devices have great potential for drug delivery applications due to their small size. In the present study, we report for the first time the preparation and evaluation of antitumor efficacy of 5-fluorouracil (5-FU)-entrapped poly (D, L-lactic-co-glycolic acid) (PLGA) nanoparticles with dependence on the lactide/glycolide combination of PLGA. 5-FU-loaded PLGA nanoparticles with two different monomer combinations, 50-50 and 90-10 were synthesized using a modified double emulsion method, and their biological evaluation was done in glioma (U87MG) and breast adenocarcinoma (MCF7) cell lines. 5-FU-entrapped PLGA 50-50 nanoparticles showed smaller size with a high encapsulation efficiency of 66%, which was equivalent to that of PLGA 90-10 nanoparticles. Physicochemical characterization of nanoparticles using differential scanning calorimetry and X-ray diffraction suggested the presence of 5-FU in molecular dispersion form. In vitro release studies showed the prolonged and sustained release of 5-FU from nanoparticles with both the PLGA combinations, where PLGA 50-50 nanoparticles showed faster release. Nanoparticles with PLGA 50-50 combination exhibited better cytotoxicity than free drug in a dose- and time-dependent manner against both the tumor cell lines. The enhanced efficiency of PLGA 50-50 nanoparticles to induce apoptosis was indicated by acridine orange/ethidium bromide staining. Cell cycle perturbations studied using flow cytometer showed better S-phase arrest by nanoparticles in comparison with free 5-FU. All the results indicate that PLGA 50-50 nanoparticles possess better antitumor efficacy than PLGA 90-10 nanoparticles and free 5-FU. Since, studies have shown that long-term exposure of ailing tissues to moderate drug concentrations is more favorable than regular administration of higher concentration of the drug; our results clearly indicate the potential of 5-FU-loaded PLGA nanoparticles with dependence on carrier combination as controlled release formulation to multiplex the therapeutic effect of cancer chemotherapy.

Joseph I.,Rajiv Gandhi Center for Biotechnology
Journal of Public Health Policy | Year: 2015

Developing countries are at risk of importing Middle East Respiratory Syndrome Corona Virus (MERS CoV) from the Middle East. Hospitals in the Middle East currently reporting the disease are staffed by immigrants. In the current hot spots for MERS CoV a sizeable portion of the population is from other countries, but many of these countries have yet to detect any importation of MERS CoV. To assess the disease transmission in these countries, supplemental surveillance strategies are urgently needed beyond the currently recommended measures. A few strategies to address the situation are: (i) improving preparedness with enhanced surveillance in particular regions; (ii) targeting certain sentinel groups for surveillance in hot spots; and (iii) limited use of serosurveillance. Recovered, immune patients can be employed to give patient care during outbreaks. © 2015 Macmillan Publishers Ltd.

Dutta D.,Rajiv Gandhi Center for Biotechnology
International Journal of Developmental Biology | Year: 2013

Embryonic Stem Cells (ESCs) are derived from the inner cell mass of blastocysts. They have the unique potency to differentiate into diverse lineages. Hence, they are bestowed with the term pluripotency. Several mechanisms have been implicated in maintaining the pluripotency of ESCs. This review will focus on the role of signaling pathways in regulating ESC pluripotency among diverse mammalian species. A novel phylogenetic approach has been designed to understand the structural basis of divergence in the signaling pathways which modulate pluripotency among different species. Detailed insight into different signaling mechanisms indicates inhibition of Extracellular Related Kinase 1/2 (ERK 1/2) signaling as the key component regulating the pluripotency of ESCs. On the basis of recent advances made in this field, it can be hypothesized that expression of the transcription factor KLF4 and inhibition of ERK signaling may promote the establishment and maintenance of true ESCs from different mammalian species. © 2013 UBC Press.

Joy N.,Rajiv Gandhi Center for Biotechnology | Soniya E.V.,Rajiv Gandhi Center for Biotechnology
Functional and Integrative Genomics | Year: 2012

Plant miRNAs (18-24nt) are generated by the RNase III-Type Dicer endonuclease from the endogenous hairpin precursors ('pre-miRNAs') with significant regulatory functions. The transcribed regions display a higher frequency of microsatellites, when compared to other regions of the genomic DNA. Simple sequence repeats (SSRs) resulting from replication slippage occurring in transcripts affect the expression of genes. The available experimental evidence for the incidence of SSRs in the miRNA precursors is limited. Considering the potential significance of SSRs in the miRNA genes, we carried out a preliminary analysis to verify the presence of SSRs in the pri-miRNAs of black pepper (Piper nigrum L.). We isolated a (CT) dinucleotide SSR bearing transcript using SMARTstrategy. The transcript was predicted to be a 'pri-miRNA candidate' with Dicer sites based on miRNA prediction tools and MFOLD structural predictions. The presence of this 'miRNA candidate' was confirmed by real-Time TaqMan assays. The upstream sequence of the 'miRNA candidate' by genome walking when subjected to PlantCARE showed the presence of certain promoter elements, and the deduced amino acid showed significant similarity with NAP1 gene, which affects the transcription of many genes. Moreover the hairpin-like precursor overlapped the neighbouring NAP1 gene. In silico analysis revealed distinct putative functions for the 'miRNA candidate', of which majority were related to growth. Hence, we assume that this 'miRNA candidate' may get activated during transcription of NAP gene, thereby regulating the expression of many genes involved in developmental processes. © Springer-Verlag 2012.

Sanalkumar R.,Rajiv Gandhi Center for Biotechnology | Dhanesh S.B.,Rajiv Gandhi Center for Biotechnology | James J.,Rajiv Gandhi Center for Biotechnology
Cellular and Molecular Life Sciences | Year: 2010

Evolutionarily conserved Notch signaling orchestrates diverse physiological mechanisms during metazoan development and homeostasis. Classically, ligand-activated Notch receptors transduce the signaling cascade through the interaction of DNA-bound CBF1-co-repressor complex. However, recent reports have demonstrated execution of a CBF1-independent Notch pathway through signaling cross-talks in various cells/tissues. Here, we have tried to congregate the reports that describe the non-canonical/CBF1-independent Notch signaling and target gene activation in vertebrates with specific emphasis on their functional relevance. © 2010 Springer Basel AG.

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