- Gene delivery system (Gene therapy for cancer using non-viral techniques (Liposome)), signal transduction.
- Utilization of Indian medicinal plant for cancer targeted therapeutics
- Molecular biodiversity analysis of microorganisms of agricultural importance
- Inter-strain competition of microorganisms of agricultural importance
- Application of bacteriocin for the development of biofertilizers
Accomplishment in Postdoctoral Research
Targeted delivery of bio-actives to cancer cells via glucocorticoid receptor: Glucocorticoid receptor (GR) is a ubiquitous protein and is functionally very important protein involved in glucose homeostasis in all cells, protein and fat metabolism, etc. It functions through its association with hormones in its conserved domains (HBD) followed by nuclear localization and gene expression/repression via transcriptional regulation on glucocorticoid response element (GRE). However, there is no evidence showing any functional difference between GR in cancer and non-cancer cells. Through my current research endeavor we have developed a GR-targeting gene delivery formulation that can receptor-specifically deliver genes to cancer cells’ nuclei, whereas in spite of the presence of GR the normal cells could not be targeted. Upon questioning the integrity of HBD in cancer cells we have shown that even an exogenous GR behaves similarly in cancer cells in contrast to normal cells. This thereby questions the role of HBD-stabilizing chaperones in the context of cancer. Detailed nude and immunodeficient mice based tumor model studies are also undertaken to deliver anticancer gene to tumor in a target specific manner. Moreover, we have shown that even cancer genes can be up-regulated many folds more than the same gene in human, non-cancer cells using the same formulation thereby showing that this aberrant behavior of cancer cells becomes a recipe for targeting cancer genome. [Molecular Therapy (2009) 17(4):623-31)]
Molecular biodiversity analysis of Cyanobacterial germplasm: Cyanobacterial strains from Nostoc, Anabaena and Calothrix were examined for pigments, carbohydrates, total proteins and enzyme related to N-metabolism. Based upon similarity matrix calculated, dendrogram was made using SIMQUAL software. All the clusters showed strains from more than one genus, hence the genera cannot be differentiated based upon physiological parameters alone. Isolation of DNA and molecular analysis using RAPD and AFLP fingerprinting is needed to establish inter and intra generic diversity of cyanobacteria. (Curr Sci (2006); 91: 497-451)
Accomplishment in Doctoral Research
Inter-strain competition for improving Chickpea - Rhizobium Symbiosis: A germplasm of 170 cultures of chickpea-rhizobia (Mezorhizobium ciceri) from diverse origin was developed, authenticated and characterized. Some strains of bacteria produce bacteriocin, a toxin of narrow inhibitory spectrum. To harness this property, chickpea-rhizobia were screened for bacteriocin production as well as sensitiveness.
1. The ability to produce bacteriocin was prevalent in about 30 per cent strains of chickpea-rhizobia, though the spectrum of antagonism varied. Bacteriocin producing strains (Cin+) were found more competitive than non-bacteriocin producing strains in sterile soil and unsterile soil in pots as well as in field.
2. Cin+ strain produced highly diffusible acidic substance, which could be used as phenotypic marker to select bacteriocinogenic strains. The acidic nature of the antagonistic substance was not fully responsible to impart competitiveness to the strain as a few non acid-producing mutants retained their antagonistic property.
3. Inoculation with strains, producing bacteriocin as well as fixing high nitrogen, also improved plant biomass and grain yield even in field conditions.
4. The antagonistic substance was found to be a protein of 29 kD.
(Ind J Microbiol (2004). 44:1-30, In: Chickpea Production and Productivity Constraints. (Singh A et al. eds). NCIPM & TIFAC, New Delhi, India (2005) 53-62.)