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Ray A.,Indian Association for The Cultivation of Science | Ray S.,13 Regent Estate | Mukhopadhyay S.,University of Calcutta | Ray M.,Bose Institute of India
Biologia Plantarum | Year: 2013

The aim of this study was to evaluate the influence of methylglyoxal (MG) on organogenesis and regeneration of tobacco (Nicotiana tabacum L.) plants from callus in media containing glycine or succinate. The best improvement in shoot proliferation and shoot length was obtained in the medium supplemented with 0. 1 mM MG and 0. 5 mM glycine or 0. 25 mM succinate. The histological studies showed vigorous development of corm like structures and shoot organogenesis from callus tissues cultured in MG supplemented media. Biochemical studies also revealed higher content of δ-aminolaevulinic acid (a precursor of chlorophyll) and of chlorophyll. © 2013 Springer Science+Business Media B.V. Source


Ghosh A.,Indian Association for The Cultivation of Science | Bera S.,Indian Association for The Cultivation of Science | Ghosal S.,Indian Association for The Cultivation of Science | Ray S.,13 Regent Estate | And 2 more authors.
Biochemistry (Moscow) | Year: 2011

Methylglyoxal strongly inhibited mitochondrial respiration of a wide variety of malignant tissues including sarcoma of mice, whereas no such significant effect was noted on mitochondrial respiration of normal tissues with the exception of cardiac cells. This inhibition by methylglyoxal was found to be at the level of mitochondrial complex I (NADH dehydrogenase) of the electron transport chain. L-Lactaldehyde, which is structurally and metabolically related to methylglyoxal, could protect against this inhibition. NADH dehydrogenase of submitochondrial particles of malignant and cardiac cells was inhibited by methylglyoxal. This enzyme of these cells was also inactivated by methylglyoxal. The possible involvement of lysine residue(s) for the activity of NADH dehydrogenase was also investigated by using lysine-specific reagents trinitrobenzenesulfonic acid (TNBS) and pyridoxal 5′ phosphate (PP). Inactivation of NADH dehydrogenase by both TNBS and PP convincingly demonstrated the involvement of lysine residue(s) for the activity of the sarcoma and cardiac enzymes, whereas both TNBS and PP failed to inactivate the enzymes of skeletal muscle and liver. Together these studies demonstrate a specific effect of methylglyoxal on mitochondrial complex I of malignant cells and importantly some distinct alteration of this complex in cancer cells. © 2011 Pleiades Publishing, Ltd. Source


Das M.R.,Indian Association for The Cultivation of Science | Bag A.K.,Indian Institute of Chemical Technology | Saha S.,Indian Association for The Cultivation of Science | Ghosh A.,Texas A&M University | And 7 more authors.
BMC Cancer | Year: 2016

Background: For a long time cancer cells are known for increased uptake of glucose and its metabolization through glycolysis. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a key regulatory enzyme of this pathway and can produce ATP through oxidative level of phosphorylation. Previously, we reported that GAPDH purified from a variety of malignant tissues, but not from normal tissues, was strongly inactivated by a normal metabolite, methylglyoxal (MG). Molecular mechanism behind MG mediated GAPDH inhibition in cancer cells is not well understood. Methods: GAPDH was purified from Ehrlich ascites carcinoma (EAC) cells based on its enzymatic activity. GAPDH associated proteins in EAC cells and 3-methylcholanthrene (3MC) induced mouse tumor tissue were detected by mass spectrometry analysis and immunoprecipitation (IP) experiment, respectively. Interacting domains of GAPDH and its associated proteins were assessed by in silico molecular docking analysis. Mechanism of MG mediated GAPDH inactivation in cancer cells was evaluated by measuring enzyme activity, Circular dichroism (CD) spectroscopy, IP and mass spectrometry analyses. Result: Here, we report that GAPDH is associated with glucose-6-phosphate isomerase (GPI) and pyruvate kinase M2 (PKM2) in Ehrlich ascites carcinoma (EAC) cells and also in 3-methylcholanthrene (3MC) induced mouse tumor tissue. Molecular docking analyses suggest C-terminal domain preference for the interaction between GAPDH and GPI. However, both C and N termini of PKM2 might be interacting with the C terminal domain of GAPDH. Expression of both PKM2 and GPI is increased in 3MC induced tumor compared with the normal tissue. In presence of 1 mM MG, association of GAPDH with PKM2 or GPI is not perturbed, but the enzymatic activity of GAPDH is reduced to 26.8 ± 5 % in 3MC induced tumor and 57.8 ± 2.3 % in EAC cells. Treatment of MG to purified GAPDH complex leads to glycation at R399 residue of PKM2 only, and changes the secondary structure of the protein complex. Conclusion: PKM2 may regulate the enzymatic activity of GAPDH. Increased enzymatic activity of GAPDH in tumor cells may be attributed to its association with PKM2 and GPI. Association of GAPDH with PKM2 and GPI could be a signature for cancer cells. Glycation at R399 of PKM2 and changes in the secondary structure of GAPDH complex could be one of the mechanisms by which GAPDH activity is inhibited in tumor cells by MG. © 2016 Das et al. Source


Cancer cells are usually thought to originate from mutation of protooncogene to oncogene and deregulation by mutated tumor suppressor gene. However I propose that carcinogen-induced plasma membrane structural alteration resulting in enhanced glucose and nutrients uptake is the primary event in malignancy. Structurally similar chemical and hormonal carcinogens are usually water insoluble but lipid soluble compounds and might anchor in plasma membrane. Hormones, growth factors and carcinogenic viruses bind to receptors at the cell surface and initiate cellular responses; one of these is enhanced nutrient uptake, causing at first upregulation of catabolic activity, mainly glycolysis and oxidative phosphorylation and subsequently enhanced ATP production. This increases anabolic reactions by 1) coupling the energy of ATP breakdown to endergonic transformation of substrates, 2) as a precursor of both RNA and DNA and 3) further increase in nutrient uptake. Through simultaneous overexpression of existing genes and de novo expression of some specific genes the enhancement of ATP formation and its cellular consequences, more growth and division, the hallmark of malignancy appears and is maintained. In this model glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and complex I (NADH dehydrogenase) of mitochondrial electron transport chain play pivotal roles. The increased pyruvate and NADH generated from increased glycolytic activity are very efficiently oxidized by mitochondria with the involvement of NADH dehydrogenase. Various experimental approaches to validate the hypothesis have been discussed. Source


Patra S.,Indian Association for The Cultivation of Science | Ghosh A.,Indian Association for The Cultivation of Science | Roy S.S.,Indian Association for The Cultivation of Science | Bera S.,Indian Association for The Cultivation of Science | And 5 more authors.
Amino Acids | Year: 2012

The creatine/creatine kinase (CK) system plays a key role in cellular energy buffering and transport. In vertebrates, CK has four isoforms expressed in a tissue-specific manner. In the process of creatine biosynthesis several other important metabolites are formed. The anticancer effect of creatine had been reported in the past, and recent literature has reported low creatine content in several types of malignant cells. Furthermore, creatine can protect cardiac mitochondria from the deleterious effects of some anticancer compounds. Previous work from our laboratory showed progressive decrease of phosphocreatine, creatine and CK upon transformation of skeletal muscle into sarcoma. It was convincingly demonstrated that prominent expression of creatine-synthesizing enzymes l-arginine: glycine amidinotransferase and N-guanidinoacetate methyltransferase occurs in sarcoma, Ehrlich ascites carcinoma and sarcoma 180 cells; whereas, both these enzymes are virtually undetectable in skeletal muscle. Creatine transporter also remained unaltered in malignant cells. The anticancer effect of methylglyoxal had been known for a long time. The present work shows that this anticancer effect of methylglyoxal is significantly augmented in presence of creatine. On creatine supplementation the effect of methylglyoxal plus ascorbic acid was further augmented and there was no visible sign of tumor. Moreover, creatine and CK, which were very low in sarcoma tissue, were significantly elevated with the concomitant regression of tumor. © 2011 Springer-Verlag. Source

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