114 results on '"Sankar N. Maity"'
Search Results
102. DNA binding specificity of CBF
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Weimin Bi, Sankar N. Maity, B de Crombrugghe, and Françoise Coustry
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Dna binding specificity ,Chemistry ,Molecular Biology ,Molecular biology - Published
- 1996
103. An 18-bp sequence in the mouse Proα1(II) collagen gene is sufficient for cartilage expression and binds nuclear proteins that are selectively expressed in chondrocytes
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Sankar N. Maity, Xin Zhou, Setrajit Sinha, Guang Zhou, Chad Smith, B de Crombrugghe, Zhaoping Zhang, Heidi Eberspaecher, K. Mukhopadhyay, and Véronique Lefebvre
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Collagen, type I, alpha 1 ,medicine.anatomical_structure ,Chemistry ,Cartilage ,medicine ,Nuclear protein ,Molecular Biology ,Molecular biology ,Gene ,Sequence (medicine) - Published
- 1996
104. Dual mode of activation of transcription by CBF, a physiological activator of the two type I collagen genes
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Satrajit Sinha, Sankar N. Maity, Françoise Coustry, and Benoit de Crombrugghe
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Activator (genetics) ,Chemistry ,Transcription (biology) ,Dual mode ,Molecular Biology ,Gene ,Type I collagen ,Cell biology - Published
- 1996
105. Role of B-ring of colchicine in its binding to Zn(II)-induced tubulin-sheets
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Sankar N. Maity, Sukla Ray Chaudhuri, Asok Banerjee, and B. Bhattacharyya
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chemistry.chemical_classification ,biology ,Stereochemistry ,Microtubule assembly ,Dimer ,chemistry.chemical_element ,macromolecular substances ,General Medicine ,Polymer ,Zinc ,Ring (chemistry) ,General Biochemistry, Genetics and Molecular Biology ,Crystallography ,chemistry.chemical_compound ,Tubulin ,chemistry ,biology.protein ,Colchicine ,General Agricultural and Biological Sciences - Abstract
Colchicine-tubulin dimer comPlex, a Potent inhibitor of normal microtubule assembly undergoes extensive self-assembly in the Presence of 1 X 10-4 M zinc sulPhate. Polymers assembled from colchicine-tubulin dimer comPlexes are sensitive to cold.
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- 1987
106. Properties of B-ring analogues of colchicine
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Sankar N. Maity and B. Bhattacharyya
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Absorption spectroscopy ,Photochemistry ,Ultraviolet Rays ,Stereochemistry ,Molecular Conformation ,Biophysics ,Substituent ,Biochemistry ,Colchicine analog ,Structure-Activity Relationship ,chemistry.chemical_compound ,Structural Biology ,Tubulin ,Absorption spectrum ,Genetics ,Colchicine ,Rearrangement reaction ,Molecular Biology ,biology ,Cell Biology ,Chromophore ,chemistry ,biology.protein ,Spectrophotometry, Ultraviolet ,Tropone ,Absorption (chemistry) - Abstract
Absorption spectra of colchicine and its analogues are affected by the presence of the B-ring, although it is not part of the chromophore (C-ring). Thus, 2-methoxy-5-(2′,3′4′-trimethoxyphenyl)tropone has absorption maxima at 341 nm, whereas that of desacetamidocolchicine is at 353 nm. A similar red shift in the λmax of colchicine, desacetamidocolchicine and 2-methoxy-(2′,3′,4′-trimethoxyphenyl)tropone also occurs when they are immobilized in the binding site to tubulin or in pure glycerol. We also observed that the B-ring of colchicine alone or with substituent does not affect the UV-induced rearrangement of colchicine to lumicolchicine. However, in the absence of the B-ring, as in the case of 2-methoxy-5-(2′,3′4′-trimethoxyphenyl)tropone, the rearrangement reaction of the C-ring slows down significantly.
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107. B-ring of colchicine and its role in taxol-induced tubulin polymerization
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Bhabatarak Bhattacharyya, Goutam Ghosh Choudhury, Sankar N. Maity, and Birendra B. Biswas
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Chemical Phenomena ,Paclitaxel ,Stereochemistry ,Macromolecular Substances ,Biophysics ,Taxol Tubulin Polymerization Colchicine binding ,macromolecular substances ,Ring (chemistry) ,Biochemistry ,Tropolone ,chemistry.chemical_compound ,Structure-Activity Relationship ,Alkaloids ,Structural Biology ,Tubulin ,Genetics ,Molecule ,Colchicine ,Tubulin polymerization ,Animals ,Molecular Biology ,chemistry.chemical_classification ,Brain Chemistry ,biology ,Goats ,Cell Biology ,Polymer ,Chemistry ,Spectrometry, Fluorescence ,chemistry ,biology.protein ,Tropone - Abstract
Taxol-induced assembly of purified tubulin is not inhibited by the colchicine analogue 2-methoxy-5-(2',3',4'-trimethoxyphenyl)tropone. Colchicine analogues having intact A, C and B-rings (without NH-CO-CH3) such as desacetamidocolchicine have also been found to be inactive. It has been observed that these two colchicine analogues are incorporated into polymers when incubated in the presence of taxol. Furthermore, preformed taxol-induced polymers of tubulin have been found to bind these two colchicine analogues. These results suggest that colchicine-binding domains on the tubulin molecule are mostly (if not completely) exposed in the taxol-induced polymers.
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108. Selective activation of transcription by a novel CCAAT binding factor
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Benoit de Crombrugghe, Paul T. Golumbek, Sankar N. Maity, and Gerard Karsenty
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Transcription, Genetic ,Macromolecular Substances ,CAAT box ,In Vitro Techniques ,Regulatory Sequences, Nucleic Acid ,DNA-binding protein ,Mice ,Transcription (biology) ,medicine ,Animals ,Promoter Regions, Genetic ,Transcription factor ,Cell Nucleus ,Rous sarcoma virus ,Multidisciplinary ,biology ,Nuclear Proteins ,Promoter ,biology.organism_classification ,Molecular biology ,Long terminal repeat ,Rats ,DNA-Binding Proteins ,Cell nucleus ,medicine.anatomical_structure ,Collagen ,Transcription Factors - Abstract
A novel CCAAT binding factor (CBF) composed of two different subunits has been extensively purified from rat liver. Both subunits are needed for specific binding to DNA. Addition of this purified protein to nuclear extracts of NIH 3T3 fibroblasts stimulates transcription from several promoters including the alpha 2(I) collagen, the alpha 1(I) collagen, the Rous sarcoma virus long terminal repeat (RSV-LTR), and the adenovirus major late promoter. Point mutations in the CCAAT motif that show either no binding or a decreased binding of CBF likewise abolish or reduce activation of transcription by CBF. Activation of transcription requires, therefore, the specific binding of CBF to its recognition sites.
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- 1988
109. The role of the B-ring of colchicine on taxol-induced tubulin polymerization
- Author
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Birendra B. Biswas, G. Ghoshchaudhuri, Sankar N. Maity, and B. Bhattacharyya
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Paclitaxel ,Macromolecular Substances ,Kinetics ,Antineoplastic Agents ,Ring (chemistry) ,Microtubules ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,Structure-Activity Relationship ,Alkaloids ,History and Philosophy of Science ,Microtubule ,Tubulin ,Structure–activity relationship ,Colchicine ,Animals ,biology ,General Neuroscience ,Goats ,Brain ,chemistry ,biology.protein ,Biophysics - Published
- 1986
110. Prioritizing genes associated with prostate cancer development
- Author
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H. Zhao, Curtis A. Pettaway, Jin Young Byun, Kanishka Sircar, Patricia Troncoso, Christopher J. Logothetis, Nora M. Navone, Olga Y. Gorlova, Sankar N. Maity, and Ivan P. Gorlov
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Male ,Candidate gene ,Cancer Research ,Bone Neoplasms ,Biology ,Bioinformatics ,medicine.disease_cause ,lcsh:RC254-282 ,03 medical and health sciences ,Prostate cancer ,0302 clinical medicine ,Prostate ,Surgical oncology ,medicine ,Genetics ,Humans ,Neoplasm Metastasis ,030304 developmental biology ,0303 health sciences ,Models, Statistical ,Gene Expression Profiling ,Prostatic Neoplasms ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,medicine.disease ,Phenotype ,3. Good health ,Gene Expression Regulation, Neoplastic ,Gene expression profiling ,medicine.anatomical_structure ,Oncology ,030220 oncology & carcinogenesis ,Meta-analysis ,Carcinogenesis ,Algorithms ,Research Article - Abstract
Background The genetic control of prostate cancer development is poorly understood. Large numbers of gene-expression datasets on different aspects of prostate tumorigenesis are available. We used these data to identify and prioritize candidate genes associated with the development of prostate cancer and bone metastases. Our working hypothesis was that combining meta-analyses on different but overlapping steps of prostate tumorigenesis will improve identification of genes associated with prostate cancer development. Methods A Z score-based meta-analysis of gene-expression data was used to identify candidate genes associated with prostate cancer development. To put together different datasets, we conducted a meta-analysis on 3 levels that follow the natural history of prostate cancer development. For experimental verification of candidates, we used in silico validation as well as in-house gene-expression data. Results Genes with experimental evidence of an association with prostate cancer development were overrepresented among our top candidates. The meta-analysis also identified a considerable number of novel candidate genes with no published evidence of a role in prostate cancer development. Functional annotation identified cytoskeleton, cell adhesion, extracellular matrix, and cell motility as the top functions associated with prostate cancer development. We identified 10 genes--CDC2, CCNA2, IGF1, EGR1, SRF, CTGF, CCL2, CAV1, SMAD4, and AURKA--that form hubs of the interaction network and therefore are likely to be primary drivers of prostate cancer development. Conclusions By using this large 3-level meta-analysis of the gene-expression data to identify candidate genes associated with prostate cancer development, we have generated a list of candidate genes that may be a useful resource for researchers studying the molecular mechanisms underlying prostate cancer development.
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111. The transcription factor NF-YA is crucial for neural progenitor maintenance during brain development.
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Tomoyuki Yamanaka, Masaru Kurosawa, Aya Yoshida, Tomomi Shimogori, Akiko Hiyama, Sankar N. Maity, Nobutaka Hattori, Hideaki Matsui, and Nobuyuki Nukina
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TRANSCRIPTION factors , *CEREBRAL cortical thinning , *NEURAL development , *CELL cycle , *NEURONAL differentiation - Abstract
In contrast to stage-specific transcription factors, the role of ubiquitous transcription factors in neuronal development remains a matter of scrutiny. Here, we demonstrated that a ubiquitous factor NF-Y is essential for neural progenitor maintenance during brain morphogenesis. Deletion of the NF-YA subunit in neural progenitors by using nestin-cre transgene in mice resulted in significant abnormalities in brain morphology, including a thinner cerebral cortex and loss of striatum during embryogenesis. Detailed analyses revealed a progressive decline in multiple neural progenitors in the cerebral cortex and ganglionic eminences, accompanied by induced apoptotic cell death and reduced cell proliferation. In neural progenitors, the NF-YA short isoform lacking exon 3 is dominant and co-expressed with cell cycle genes. ChIP-seq analysis from the cortex during early corticogenesis revealed preferential binding of NF-Y to the cell cycle genes, some of which were confirmed to be downregulated following NF-YA deletion. Notably, the NF-YA short isoform disappears and is replaced by its long isoform during neuronal differentiation. Forced expression of the NF-YA long isoform in neural progenitors resulted in a significant decline in neuronal count, possibly due to the suppression of cell proliferation. Collectively, we elucidated a critical role of the NF-YA short isoform in maintaining neural progenitors, possibly by regulating cell proliferation and apoptosis. Moreover, we identified an isoform switch in NF-YA within the neuronal lineage in vivo, which may explain the stage-specific role of NF-Y during neuronal development. [ABSTRACT FROM AUTHOR]
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- 2024
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112. Combined Inhibition of IGF-1R/IR and Src family kinases enhances antitumor effects in prostate cancer by decreasing activated survival pathways.
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Farshid Dayyani, Nila U Parikh, Andreas S Varkaris, Jian H Song, Shhyam Moorthy, Tanushree Chatterji, Sankar N Maity, Adam R Wolfe, Joan M Carboni, Marco M Gottardis, Christopher J Logothetis, and Gary E Gallick
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Medicine ,Science - Abstract
Treatment of metastatic prostate cancer (PCa) with single agents has shown only modest efficacy. We hypothesized dual inhibition of different pathways in PCa results in improved tumor inhibition. The Src family kinases (SFK) and insulin-like growth factor-1 (IGF-1) signaling axes are aberrantly activated in both primary PCa and bone metastases and regulate distinct and overlapping functions in PCa progression. We examined the antitumor effects of combined inhibition of these pathways.Src andIGF-1 receptor (IGF-1R) inhibition was achieved in vitro by short hairpin (sh)RNA and in vitro and in vivo by small molecule inhibitors (dasatinib and BMS-754807, against SFK and IGF-1R/Insulin Receptor(IR), respectively).In vitro, inhibition of IGF-1 signaling affected cell survival and proliferation. SFK blockade alone had modest effects on proliferation, but significantly enhanced the IGF-1R blockade. These findings correlated with a robust inhibition of IGF-1-induced Akt1 phophorylation by dasatinib, whereas Akt2 phosphorylation was SFK independent and only inhibited by BMS-754807. Thus, complete inhibition of both Akt genes, not seen by either drug alone, is likely a major mechanism for the decreased survival of PCa cells. Furthermore, dasatinib and BMS-754807 inhibited in vivo growth of the primary human xenograft MDA PCa 133, with corresponding inhibition of Akt in tumors. Also, both orthotopic and intratibial tumor growth of PC-3 cells were more potently inhibited by dual SFK and IGF-1R/IR blockade compared to either pathway alone, with a corresponding decrease in bone turnover markers.Dual IGF-1R/IR and SFK inhibition may be a rational therapeutic approach in PCa by blocking both independent and complementary processes critical to tumor growth.
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- 2012
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113. Androgen regulation of 5α-reductase isoenzymes in prostate cancer: implications for prostate cancer prevention.
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Jin Li, Zhiyong Ding, Zhengxin Wang, Jing-Fang Lu, Sankar N Maity, Nora M Navone, Christopher J Logothetis, Gordon B Mills, and Jeri Kim
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Medicine ,Science - Abstract
The enzyme 5α-reductase, which converts testosterone to dihydrotestosterone (DHT), performs key functions in the androgen receptor (AR) signaling pathway. The three isoenzymes of 5α-reductase identified to date are encoded by different genes: SRD5A1, SRD5A2, and SRD5A3. In this study, we investigated mechanisms underlying androgen regulation of 5α-reductase isoenzyme expression in human prostate cells. We found that androgen regulates the mRNA level of 5α-reductase isoenzymes in a cell type-specific manner, that such regulation occurs at the transcriptional level, and that AR is necessary for this regulation. In addition, our results suggest that AR is recruited to a negative androgen response element (nARE) on the promoter of SRD5A3 in vivo and directly binds to the nARE in vitro. The different expression levels of 5α-reductase isoenzymes may confer response or resistance to 5α-reductase inhibitors and thus may have importance in prostate cancer prevention.
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- 2011
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114. Identification of SOX9 interaction sites in the genome of chondrocytes.
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Chun-do Oh, Sankar N Maity, Jing-Fang Lu, Jiexin Zhang, Shoudan Liang, Francoise Coustry, Benoit de Crombrugghe, and Hideyo Yasuda
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Medicine ,Science - Abstract
Our previous work has provided strong evidence that the transcription factor SOX9 is completely needed for chondrogenic differentiation and cartilage formation acting as a "master switch" in this differentiation. Heterozygous mutations in SOX9 cause campomelic dysplasia, a severe skeletal dysmorphology syndrome in humans characterized by a generalized hypoplasia of endochondral bones. To obtain insights into the logic used by SOX9 to control a network of target genes in chondrocytes, we performed a ChIP-on-chip experiment using SOX9 antibodies.The ChIP DNA was hybridized to a microarray, which covered 80 genes, many of which are involved in chondrocyte differentiation. Hybridization peaks were detected in a series of cartilage extracellular matrix (ECM) genes including Col2a1, Col11a2, Aggrecan and Cdrap as well as in genes for specific transcription factors and signaling molecules. Our results also showed SOX9 interaction sites in genes that code for proteins that enhance the transcriptional activity of SOX9. Interestingly, a strong SOX9 signal was also observed in genes such as Col1a1 and Osx, whose expression is strongly down regulated in chondrocytes but is high in osteoblasts. In the Col2a1 gene, in addition to an interaction site on a previously identified enhancer in intron 1, another strong interaction site was seen in intron 6. This site is free of nucleosomes specifically in chondrocytes suggesting an important role of this site on Col2a1 transcription regulation by SOX9.Our results provide a broad understanding of the strategies used by a "master" transcription factor of differentiation in control of the genetic program of chondrocytes.
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- 2010
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