Search

Pooja, Vandana Sharma, Manish Sharma, Rajeev Varshney, Bhuvnesh Kumar, and Niroj Kumar Sethy. Association between 17β-estradiol receptors and nitric oxide signaling augments high-altitude adaptation of Ladakhi highlanders.

Millions of people worldwide visit, live, or work in the hypoxic environment encountered at high altitudes and it is important to understand the biomolecular responses to this stress. This would help design mitigation strategies for High Altitude Illnesses (HAIs). Inspite of a number of studies spanned over 100 years, complex mechanisms controlling acclimatization to hypoxia remain largely unknown. Some biomolecules, though, have been proposed as potential diagnostic, therapeutic and predictive markers for HA stress. HighAltitudeOmicsDB is a unique resource that provides a comprehensive, curated, user- friendly and detailed compilation of various genes/proteins which have been experimentally validated to be associated with various HA conditions; their Protein Protein Interactions (PPI) and Gene Ontology (GO) semantic similarities. For each database entry, HighAltitudeOmicsDB stores the level of regulation (up/down-regulation), fold change, control (low landers or high landers), duration and altitude of exposure, tissue of expression, source organism, level of hypoxia, experimental validation, place/country of study, ethnicity, geographical location, link to respective publication etc.Tthe database also collates information on disease and drug association, Gene Ontology and KEGG pathway associations. The web resource is a unique server platform which constructs PPI networks and extracts GO semantic similarities among the interactors. These unique features help to offer mechanistic insights in disease pathology. Hence, HighAltitudeOmicsDB is a unique platform for researchers working in this area to explore, fetch, compare and analyze HA associated gens/proteins, their PPI networks and GO semantic similarities. The database is available at http://www.altitudeomicsdb.in

In the ongoing COVID-19 pandemic, the global fraternity of researchers has been assiduously investigating pharmacological interventions against the SARS-CoV2. This novel virus is known to gain entry through the ACE 2 receptor of pulmonary epithelial cells lining the respiratory tract. Many of its initial symptoms (e.g. difficulty breathing) resemble acute high altitude illnesses, particularly HAPE. Based on these overt symptoms, a number of high altitude researchers have speculated on repurposing of drugs used to treat acute altitude illnesses (especially HAPE). However, eminent high altitude researchers with medical expertise as well as some studies on the deeper causes underlying the overt symptoms have found that such repurposing maybe counter-productive. Other factors, (e.g. contra-indications of these drugs), make their use in COVID-19 patients hazardous. The fit-for-repurposing options maybe experimental prophylactic interventions (e.g. silymarin, curcumin) which have proven anti-oxidant and anti-inflammatory effects. Another line of thought focuses on proteomics-based investigations of such patients. However, apart from the logistical and safety issues, a targeted proteomics approach based on prior sound molecular investigations is a more logical approach instead of mere shotgun proteomics. In this commentary, we shed light on such issues associated with COVID-19.

BackgroundGiven the worldwide spread of the novel Severe Acute Respiratory Syndrome Coronavirus 2 (nSARS-CoV-2) infection pandemic situation, research to repurpose drugs, identify novel drug targets, vaccine candidates have created a new race to curb the disease. While the molecular signature of nSARS-CoV-2 is still under investigation, growing literature shows similarity among nSARS-CoV-2, pulmonary edema, and thromboembolic disorders due to common symptomatic features. A network medicine approach is used to to explore the molecular complexity of the disease and to uncover common molecular trajectories of edema and thrombosis with nSARS-CoV-2.Results and conclusionA comprehensive nSARS-CoV-2 responsive miRNA: Transcription Factor (TF): gene co-regulatory network was built using host-responsive miRNAs and it’s associated tripartite, Feed-Forward Loops (FFLs) regulatory circuits were identified. These regulatory circuits regulate signaling pathways like virus endocytosis, viral replication, inflammatory response, pulmonary vascularization, cell cycle control, virus spike protein stabilization, antigen presentation, etc. A unique miRNA-gene regulatory circuit containing a consortium of four hub FFL motifs is proposed to regulate the virus-endocytosis and antigen-presentation signaling pathways. These regulatory circuits also suggest potential correlations/similarity in the molecular mechanisms during nSARS-CoV-2 infection, pulmonary diseases and thromboembolic disorders and thus could pave way for repurposing of drugs. Some important miRNAs and genes have also been proposed as potential candidate markers. A detailed molecular snapshot of TGF signaling as the common pathway, that could play an important role in controlling common pathophysiologies among diseases, is also put forth.

Gene regulation is viewed as a complex process where regulatory elements and their targets form highly complex network interactions thus affecting normal biological physiology and also disease-initiation and progress. Transcription factors (TF) and microRNA (miRNA) are fundamental transcriptional and post-transcriptional regulators of the gene expression controlling important biological processes. In recent years, many high throughput studies revealed that the complex regulatory interactions are mediated by the complex interplay between miRNA and TF regulating a Target Gene (TG) in conjunction. miRNAs and TFs are also known to regulate each other. This complex coregulatory mechanism may be represented in the form of miRNA:TF:TG coregulatory network. This network can be used to identify several small recurring subgraphs known as regulatory-circuits. One of these regulatory-circuits also called the Feed-Forward Loops (FFLs) is a three-node pattern which is composed of a miRNA and a TF, one of which regulates the other and both jointly regulate a TG. These regulatory-circuits have proven useful in elucidating the complex interplay of gene regulation during many physiological and pathological conditions.Human.miRFFL.DB is a comprehensive integrated resource for human miRNA:TF:TG coregulatory directed networks and their associated regulatory-circuits. In-house scripts based on the graph theory principle have been used to identify both types of FFL motifs i.e. miRNA-FFL and TF-FFL. The database additionally provides an interactive visualization of the coregulatory networks and associated FFLs. Human.miRFFL.DB can be used as a comprehensive ready reference for human miRNA:TF:TG coregulatory networks and associated FFLs for decrypting complex cellular interactions of these regulatory biomolecules. Human.miRFFL.DB is available online at http://mirffldb.in/human/

High altitude pulmonary edema (HAPE) is experienced by non-acclimatized sea level individuals on exposure to high altitude hypoxic conditions. Available evidence suggests that genetic factors and perturbed mitochondrial redox status may play an important role in HAPE pathophysiology. However, the precise mechanism has not been fully understood. In the present study, sequencing of mitochondrial DNA (mtDNA) from HAPE subjects and acclimatized controls was performed to identify pathogenic mutations and to determine their role in HAPE. Hypobaric hypoxia induced oxidative stress and metabolic alterations were also assessed in HAPE subjects. mtDNA copy number, mitochondrial oxidative phosphorylation (mtOXPHOS) activity, mitochondrial biogenesis were measured to determine mitochondrial functions. The data revealed that the mutations in Complex I genes affects the secondary structure of protein in HAPE subjects. Further, increased oxidative stress during hypobaric hypoxia, reduced mitochondrial biogenesis and mtOXPHOS activity induced metabolic reprogramming appears to contribute to mitochondrial dysfunctions in HAPE individuals. Haplogroup analysis suggests that mtDNA haplogroup H2a2a1 has potential contribution in the pathobiology of HAPE in lowlanders. This study also suggests contribution of altered mitochondrial functions in HAPE susceptibility.

The Indian soldiers guard the border regions located at extreme elevations in cold, often snow-covered conditions. Protecting their feet from life-threatening cold injuries is a primary objective as well as a matter of national security. As a solution, a new cold-condition “snow boot” design based on ergonomic principles was developed indigenously. The present study was conducted to assess the efficacy of the newly developed snow boot through the application of both objective and subjective tools. The new snow boot was as effective as an existing imported boot. Users preferred the new design and appreciated the boot’s relative lightweight.

Our previous studies on simultaneous inhibition of glycolysis by 2-deoxy-D-glucose (2-DG) and pentose phosphate activity by 6-aminonicotinamide (6-AN) have been shown to induce oxidative stress mediated selective radiosensitization in wide range of human malignant cells. However, the mechanism of radiosensitization induced by this combination (2-DG+6-AN) is not completely understood. Since activation of apoptotic signal regulating kinase (ASK1) and subsequent apoptosis are implicated in oxidative stress response, the role of ASK1 activation in radiosensitization by this combination was investigated in the present study. Our results demonstrated that redox alterations induced by this combination activated ASK1 and subsequent apoptosis during radiosensitization of head and neck carcinoma cells (KB). In addition, mRNA and protein expression of thioredoxin and thioredoxin reductase decreased significantly under similar treatment conditions. Further, the downstream targets such as JNK and p38MAPK were also activated by this combination, and their pharmacological inhibition by SP600125 and SB201291 respectively resulted in suppression of 2-DG+6-AN mediated apoptosis in irradiated KB cells. Interestingly, the activation of ASK1 was mediated by hydrogen peroxide rather than superoxide anions as PEG-catalase but not PEG-SOD suppressed its activation. Our observations clearly suggest that redox alterations by inhibition of glucose metabolism serves as a molecular switch that activate ASK1-JNK/p38MAPK signaling in malignant cells during radiosensitization by 2-DG+6-AN. The present study emphasizes the importance of redox alterations in determining radiosensitivity of tumor cells that may greatly influence the outcome of radiation therapy.

Background: Thyroid hormones are major regulators of energy metabolism and increased levels of the hormones (hyperthyroidism) results in an increase in the metabolic rate. Thyroid dysfunction causing alteration in hormone secretion leads to perturbations in the metabolic status. The hypermetabolic state may cause increased generation of reactive oxygen species (ROS), leading to oxidative stress in these patients. This study was carried out to verify our proposition by measuring the ROS in the terminally differentiated cells like the peripheral blood mononuclear cells of the patients. Methods: Flow-cytometric analysis of the ROS was carried out using 2 0 ,7 0 dichlorofluorescein diacetate in the isolated peripheral blood mononuclear cells of the subjects. Results: ROS generation was found to be 3-folds higher in hyperthyroids as compared with euthyroids and hypothyroids and this was not found to be gender specific. Conclusions: Hyperthyroidism results in ROS generation in patients, which can be detected flow cytometrically in the peripheral blood mononuclear cells. Hence, this could complement the other thyroid function tests facilitating the diagnosis and design of appropriate therapy. q 2005 International Society for Analytical Cytology Key terms: hyperthyroidism; hypothyroidism; euthyroid; reactive oxygen species; oxidative stress; mononuclear cells; 2 0 ,7 0 dichlorofluorescein diacetate; flow cytometry

Ghost membranes prepared from erythrocytes of Swiss albino mice were irradiated with gamma rays at a dose rate of 0.9 Gy/s. The fluidity of membrane decreased with radiation dose and in the presence of calmodulin antagonists (CA) like chlorpromazine (CPZ), promethazine (PMZ) and trimeprazine (TMZ) it increased. Radiation induced release of Ca 2+ from membranes. This release was inhibited by CA mainly by CPZ and PMZ. Being Ca 2+ dependent, the changes in the activity of acetylcholine estrase (AchE) following irradiation was also studied. Radiation decreased the activity of AchE in dose dependent manner. Presence of CPZ and PMZ diminished the radiation induced inhibition of AchE but not in the presence of TMZ at the lower concentration tested. It is suggested that apart from scavenging of free radicals, CA perhaps exert their euxoic radioprotective effect through Ca 2+ dependent processes.

Ghost membranes prepared from erythrocytes of Swiss albino mice were irradiated with 0.9 Gy s −1 . Lipid peroxidation initiated by ionizing radiation was enhanced by phospholipase A 2 , and required both phospholipase A 2 and GSH-peroxidase for consecutive action to convert fatty acid peroxides into corresponding alcohols. The ability of phospholipase A 2 to enhance lipid peroxidation was increased in presence of Ca 2+ . However, in combination, phospholipase A 2 and GSH-peroxidase were effective in inhibiting lipid peroxidation. These findings show that free fatty acid peroxides considerably increase the peroxidation. Calmodulin antagonists inhibit lipid peroxidation and decrease the radiation induced release of Ca 2+ from the membranes. Our results suggest the importance of Ca 2+ dependent phospholipase A 2 in detoxification of fatty acid peroxides in the membranes. It is quite possible that scavenging of free radicals by calmodulin antagonists lower the formation of hydroperoxides, resulting in the decrease in activity of phospholipase A 2 . Alternatively, decrease in Ca 2+ release due to the calmodulin antagonists might have affected the activity of phospholipase A 2 . Our observations might be of considerable significance in the understanding of post irradiation effect on biological membranes.

Enhanced level of nuclear erythroid-related factor-2 (Nrf2) has been associated with cancer chemo/radioresistance. Therefore, the role of Nrf2 in radiosensitization of malignant cells induced by a combination of 2-deoxy-D-Glucose (2-DG) and 6-aminonicotinamide (6-AN) was investigated. Two established human malignant cells lines namely KB (head and neck squamous carcinoma) and BMG-1 (cerebral glioma) were used. Following treatment with a combination of 2-DG (5 mM) and 6-AN (5 μM), irradiated (2Gy) KB and BMG-1 cells were assessed for protein level of Nrf2, Keap1 and γ-glutamylcysteine synthetase (γ-GCS) by western blotting and mRNA expression of γ-GCS, glutathione reductase (GR) and glutathione peroxidase (GPx1) by RT-PCR at 24 hours post treatment. A significant decrease in the level of Nrf2 with a concomitant increase in Keap1 was observed in both the irradiated malignant cells at 24 hours following treatment with combination (2-DG + 6-AN). Down regulation of γ-GCS, GR and GPx1 at 24 hours following treatment with combination (2-DG + 6-AN) resulted in abrogation of glutathione (GSH)-mediated defense in both the irradiated malignant cells. Eventual accumulation of ROS led to radiosensitization of both the malignant cells. These results indicate that deregulated Nrf2-Keap1 signalling leads to the radiosensitization of malignant cells due to abrogated glutathione defense. Metabolic modification-mediated down regulation of Nfr2 and its downstream signalling may have a potential of improving tumour radiotherapy.

Previously, we have shown that a combination of metabolic modifiers 2-deoxy-D-glucose (2-DG) and 6-aminonicotinamide (6-AN) results in oxidative stress mediated radiosensitization of malignant cells via mitochondrial dysfunction and non-coordinated expression of antioxidant defense, besides inhibition of repair and recovery. In the present study, our objective was to study, in a panel of human malignant cells of various origins (lung carcinoma, squamous carcinoma, oral carcinoma, and glioblastoma), if the inhibitory activity of combination (2-DG+6-AN+2Gy) against tumor growth could be considered a general phenomenon and to determine its effect on the cell cycle. The results revealed that combination (2-DG+6-AN+2Gy) treatment result in significant cell growth inhibition and induced ROS generation in all cancer cells studied. The anti-proliferative effect was related to the ability of combination (2-DG+6-AN+2Gy) to provoke growth inhibition at the G2/M arrest and apoptosis. Furthermore, combination (2-DG+6-AN+2Gy) induced G2/M arrest is closely correlated to decreased cyclin A, cyclin B1, and cdc2 levels. Refereed/Peer-reviewed

Oxidative stress-mediated mitochondrial dysfunction is known to induce intrinsic pathway of apoptosis. Previously, we have shown that a combination of metabolic modifiers 2-deoxy-D-glucose (2-DG) and 6-aminonicotinamide (6-AN) results in oxidative stress-mediated radiosensitization of malignant cells via noncoordinated expression of antioxidant defense. We now show that the combination (2-DG + 6-AN + 2Gy) induces significant alterations in mitochondrial membrane potential and oxidative damage to lipid and proteins selectively in malignant cells resulting in the release of cytochrome c from mitochondria and increase in Bax/Bcl-2 ratio stimulating intrinsic pathway of apoptosis, besides enhancing the mitotic death linked to cytogenetic damage. These results highlight the role of mitochondrial dysfunction in selective radiosensitization by 2-DG + 6-AN, besides inhibition of energy-linked DNA repair processes and generation of oxidative stress reported earlier. Refereed/Peer-reviewed

Articular degenerative diseases like osteoarthritis significantly affect the life quality of worldwide populations including Singaporean communities. Traditional approaches, typically transplantation of autologous tissue grafts, exhibit many limitations in clinic because of implants resorption and poor shaping with articular defects, as well as lack of sufficient materials donors. In the recent decade, novel strategies with tissue engineering and gene therapy have been developed from laboratory-based investigation to clinical applications. With the development of gene delivery to chondrocytic/progenitor therapeutic cells such as mesenchymal stem cells, treating disorders of articular cartilage by tissue engineering has borne much promise. Mesenchymal stem cells (MSCs) have been proven to be efficacious in articular cartilage repair and have even been used in a few in vivo clinical trials. Recently the focus has extended to synovium-derived MSCs (SMSCs) owing to their excellent chondrogenic potential. These cells are highly proliferative and can be expanded to sufficiently large numbers. Research has been carried out to induce chondrogenesis and engineer cartilaginous constructs from SMSCs using gene therapy and tissue engineering, with some degree of success. This study focuses on SMSCs and transgenic chondrocytes based co-culture system for engineered chondrogenesis. DOCTOR OF PHILOSOPHY (SCBE)

Oxidative stress and mitochondrial dysfunction in cancer cells represent features that may be exploited therapeutically. We determined whether minor groove binding ligand Hoechst 33342, known to induce mitochondrial dysfunction via increase in reactive oxygen species (ROS), enhances killing of human head and neck cancer (KB) cells mediated by impaired expression of mitochondrial protein involved in electron transfer. Elevation in ROS generation, increase in ΔΨm, down regulation of cytochrome c oxidase (CO), alteration in expression of antioxidant enzymes viz. Mn-SOD and Catalase, and release of cytochrome c into the cytosol, were observed in time-dependent manner when cells were irradiated (5 Gy) in presence of Hoechst 33342. Persistent increase in ROS observed till 48 h following treatment decreased the clonogenic survival and viability to a large extent via increase in ΔΨm, release of cytochrome c and non-coordinated expression of antioxidant enzymes. Treatment with antioxidants PEG-MnSOD and PEG-catalase inhibited the increase in ROS and loss of cell survival, suggesting the involvement of ROS in the Hoechst 33342-induced cell death. The result demonstrated significant sensitization of cancer cells to radiation-induced toxicity in presence of Hoechst 33342 via increasing ROS to a toxic level and impairing CO expression and antioxidant enzymes. This understanding is expected to benefit both in elucidating the detailed mechanisms of actions of DNA interacting drug and designing better molecules for enhancing radiation-induced cell death among cancer cells.

Forty-eight isolates of FOC collected from different chickpea growing regions in India were evaluated for genetic variations using amplified fragment length polymorphism (AFLP). Out of 48 isolates, 41 werefound pathogenic and seven non-pathogenic. Pathogenic isolates differ in their virulence however; there was no apparent correlation between geographical origin and virulence of the isolates. The genetic variation was evaluated by the AFLP analysis. A total 339 fragments were scored following selective amplification with five EcoR1 and Mse1 primer combinations E-TC/M-CAT, E-TC/M-CAC, EAC/ M-CAG, E-TA/MCAG, E-TA/M-CAG, out of which 331 fragments were polymorphic. UPGMA cluster analysis and principle coordinate analysis distinctly classified 48 isolates into two major groups; pathogenic and non-pathogenic. The pathogenic isolates could be further clustered into six majorgroups at 0.77 genetic similarities. Region specific grouping was observed with in few isolates. The results of the present study provide evidence of the high discriminatory power of AFLP analysis,suggesting the applicability of this method to the molecular characterization of Fusarium oxysporum f.sp. ciceris.

Mitochondrial DNA plays an important role in cellular sensitivity to cancer therapeutic agents. Hoechst 33342, a DNA minor groove binding ligand, has shown radiosensitizing effects in different cancer cell lines. In the present study, the possible binding of Hoechst 33342 with mitochondrial DNA, isolated from human cerebral glioma (BMG-1) cells, was investigated and consequences of this binding on excessive reactive oxygen species (ROS) generation in irradiated BMG-1 cells were studied. Alteration in the fluorescence spectroscopic characteristics of Hoechst 33342 suggested binding of Hoechst 33342 with isolated mitochondria and mitochondrial DNA. Persistent increase in level of ROS in the presence of Hoechst 33342 has been observed, which was further enhanced in irradiated cells. Investigations using inhibitors of ETC complex I suggested that mitochondrial bound Hoechst 33342 contributed to increased ROS, which was associated with alteration in DeltaPsim and antioxidant machinery. These factors appeared to contribute in potentiating radiation-induced cell death in BMG-1 cells. The finding from these studies will be useful in designing better anti-cancer strategies.

Our earlier studies have shown that simultaneous inhibition of glycolysis and pentose phosphate pathway using 2-deoxy-d-glucose (2-DG, an inhibitor of glycolysis) and 6-aminonicotinamide (6-AN, an inhibitor of pentose phosphate pathway) lead to metabolic oxidative stress (MOS), resulting in radiosensitization in malignant cells. Present study was carried out to investigate the effects of 2-DG and 6-AN on intricately regulated endogenous antioxidant defense against MOS during radiosensitization by this combination. Two human tumor cell lines {Head and Neck Squamous carcinoma (KB) and Glioma (BMG-1)} and one non-malignantly transformed cell line (human embryonic kidney, HEK) were used in this study. The presence of 2-DG and 6-AN (added just before irradiation) for 4h, significantly decreased the clonogenicity and metabolic viability of KB and BMG-1 cell lines, while no significant change was seen in HEK cells. Accumulation of ROS was observed only in malignant cell lines, which displayed a compromised redox status evident from enhanced NADP+/NADPH and GSSG/GSH ratios and a concomitant decrease in glutathione reductase level and activity at 24h following treatment. The levels and activities of Cu, Zn-SOD and Mn-SOD increased with MOS and were accompanied by a decreased GPx and unaltered catalase activity and level. These results suggest that non-coordinated expression of antioxidant defense, besides compromised redox status, led to selective radiosensitization in the malignant cells. Refereed/Peer-reviewed

Aluminium (Al) toxicity is a major threat to agricultural production world wide wherever acid soil exists. Wheat and barley, the major food and feed crops, are severely affected and this necessitates investigations that could help to improve the yield by utilising the available genetic diversity for Al tolerance with the aid of several molecular platforms. We investigated the quantitative trait loci (QTL) conferring tolerance to Al toxicity in three different mapping populations of wheat and barley. Using a set of D genome (Ae. tauschii) introgression lines, a major Al tolerance locus was assigned to chromosome arm 4DL, explaining 31% of the phenotypic variation displayed by the population. A second major QTL was mapped to chromosome arm 3BL using a set of doubled haploid progeny lines. This major QTL, QaltCS.ipk-3B, originated from ‘Chinese Spring’ accounted for 49% of the variation in the population. The inheritance for Al tolerance in barley was dissected based on a genetic map constructed with genic markers. QTLs were identified on chromosomes 2H, 3H and 4H. A sequence homology search was used to derive the putative function of the genes linked to the QTL, in order to identify potential candidate genes for Al tolerance. Some of these candidates are implicated in stress/defence responses, in particular, stress signal transduction, transcription regulation factors and cell metabolism.

The aim was to exploit simultaneous inhibition of glycolytic and pentose phosphate pathways of energy production for radiosensitization using 2-deoxy-D-glucose (2-DG) and 6-aminonicotinamide (6-AN) in transformed mammalian cells. Two human tumour cell lines (cerebral glioma, BMG-1 and squamous carcinoma cells 4197) were investigated. 2-DG and/or 6-AN added at the time of irradiation were present for 4 h after radiation. Radiation-induced cell death (macrocolony assay), cytogenetic damage (micronuclei formation), cell cycle delay (bromodeoxyuridne (BrdU) pulse chase), apoptosis (externalization of phosphotidylserine (PS) by annexin V), chromatin-bound proliferation cell nuclear antigen (PCNA) and cellular glutathione (GSH) levels were investigated as parameters of radiation response. The presence of 2-DG (5 mM) during and for 4 h after irradiation increased the radiation-induced micronuclei formation and cell death, and caused a time-dependent decrease in GSH levels in BMG-1 cells while no significant effects could be observed in 4197 cells. 6-AN (5 microM) enhanced the radiosensitivity of both cell lines and reduced the GSH content by nearly 50% in gamma-irradiated 4197 cells. Combining 2-DG and 6-AN caused a profound decrease in the GSH content and enhanced the radiation damage in both the cell lines by increasing mitotic and apoptotic cell death. Further, the combination (2-DG + 6-AN) enhanced the radiation-induced G2 block, besides arresting cells in S phase and inhibited the recruitment of PCNA. The combination of 2-DG and 6-AN enhances radiation damage by modifying damage response pathways and has the potential for improving radiotherapy of cancer.

We report results of the studies relating to development of an aptamer-based electrochemical biosensor for detection of human lung adenocarcinoma A549 cells. The aminated 85-mer DNA aptamer probe specific for the A549 cells has been covalently immobilized onto silane self assembled monolayer (SAM) onto ITO surface using glutaraldehyde as the crosslinker. The results of cyclic voltammetry and differential pulse voltammetry studies reveal that the aptamer functionalized bioelectrode can specifically detect lung cancer cells in the concentration range of 103 to 107 cells/ml with detection limit of 103 cells/ml within 60 s. The specificity studies of the bioelectrode have been carried out with control KB cells. No significant change in response is observed for control KB cells as compared to that of the A549 target cells.

During the last decade microsatellites or SSRs (simple sequence repeats) have been proven to be the markers of choice in plant genetics research and for breeding purposes because of their hypervariability and ease of detection. However, development of these markers is expensive, labour intensive and time consuming, in particular, if they are being developed from genomic libraries. In the context of large-scale sequencing and genomics programmes in various cereal species at different laboratories, a large set of expressed sequence tags (ESTs) is being generated, which can be used to search for microsatellites. Keeping in view the importance of such type of SSRs, available ESTs of some cereal species like barley, maize, oats, rice, rye and wheat were investigated for a study of abundance, frequency and distribution of various types of microsatellites. SSRs were present in about 7% to 10% of the total ESTs in the investigated cereal genomes. On the basis of surveying EST sequences amounting to 75.2 Mb in barley, 54.7 Mb in maize, 43.9 Mb in rice, 3.7 Mb in rye, 41.6 Mb in sorghum and 37.5 Mb in wheat, the frequency of SSRs was 1/7.5 kb in barley, 1/7.5 kb in maize, 1/6.2 kb in wheat, 1/5.5 kb in rye and sorghum and 1/3.9 kb in rice. The overall average SSR frequency for these species is 1/6.0 kb. Trimeric repeats are the most abundant (54% to 78%) class of microsatellites followed by dimeric repeats (17% to 40%). Among the trimeric repeats the motifs CCG are the most common in all the cases ranging from 32% in wheat to 49% in sorghum. When all these SSRs were analysed for assessing their potential to develop new markers, unique primer pairs could be designed for 30% to 70% of the total non-redundant microsatellites which are up to 3% of total ESTs in the studied species.

Enhanced radiosensitizing effects of a combination of 2-deoxy-D-glucose (2-DG), a glycolytic inhibitor and 6-aminonicotinamide (6-AN) an analogue of nicotinamide, which inhibits hexose monophosphate shunt (HMP) have been demonstrated in vitro. The purpose of the present studies is to investigate in vivo effects of this combination in Ehrlich ascites tumor (EAT) bearing mice. EAT tumor was grown in Swiss albino strain A mice. Treatment induced growth delay and tumor free animal survival were evaluated as parameters of radiation response. Focal irradiation of the tumor with a single fraction of 10 Gy induced a moderate delay in tumor growth but did not lead to complete regression of the tumor. Intravenous administration of either 6-AN or 2-DG immediately before irradiation enhanced radiation-induced growth delay with a cure rate of 45%. However, administration of a combination of 2-DG (2 g/kg b.wt.) and 6-AN (2 mg/kg b.wt.) immediately before irradiation led to complete regression of tumor in 80% animals resulting in survival of more than 300 days. A similar response (≈80%) was observed when 2-DG dose was reduced to 1 g/kg in combination with 6-AN. It is concluded that 6-AN enhances the radiosensitizing effects of 2-DG and the combination may have potential application in improving radiotherapy of tumors.