Showing papers by "Mohane Selvaraj Coumar published in 2016"

P-Glycoprotein Mediated Multidrug Resistance Reversal by Phytochemicals: A Review of SAR & Future Perspective for Drug Design.

Abstract: A major impediment for cancer chemotherapy is the development of multidrug-resistance (MDR). Continuous use of chemotherapeutic drugs during cancer therapy induces the expression of PGlycoprotein (P-gp, MDR1), an ATP dependant transporter, which in turn reduces the intracellular accumulation of chemotherapeutic drugs leading to MDR. Extensive research over the years has identified several potential P-gp inhibitors, both synthetic as well as natural origin, to overcome the MDR during cancer chemotherapy. In this review, we discuss the cellular pathways involved and transcription factors regulating the expression of P-gp. A number of phytochemicals are reported to inhibit P-gp activity and MDR1 expression; the structure-activity relationship (SAR) among the phytochemicals for P-gp inhibition and the effect of these phytochemicals on cellular signaling pathways regulating P-gp expression are discussed in detail. Moreover, structural biology and mutagenesis studies on P-gp along with docking studies throw light on the structural requirements for P-gp inhibition. Insight provided in the review about the phytochemicals molecular mechanism and SAR could catalyze the design of potent P-gp inhibitors in the future and could help to overcome MDR in cancer chemotherapy.

Disruption of protein–protein interactions: hot spot detection, structure-based virtual screening and in vitro testing for the anti-cancer drug target – survivin

Abstract: Survivin is a member of the inhibitor of the apoptosis (IAP) family of proteins, and plays a crucial role in both cell division and apoptosis. As it is overexpressed in many human solid tumors, it has become an attractive drug target for cancer therapy. Survivin is involved in protein–protein interactions (PPI) with several of its substrate proteins, and disruption of these interactions could be a possible means to target the function of survivin in cancer. To this end, we sought and were able to detect hot spot residues in the survivin dimer and Chromosomal Passenger Complex (CPC; survivin/borealin/INCENP) using simple knowledge based physical models implemented in the Robetta server (http://robetta.bakerlab.org/), KFC server (http://kfc.mitchell-lab.org/) and the HotRegion database (http://prism.ccbb.ku.edu.tr/hotregion/). Then, extensive molecular dynamics simulations were applied to generate an ensemble of conformations and were used to quantitatively estimate the binding free energy of the identified hot spot residues using MM-PBSA alanine scanning mutagenesis and per-residue energy decomposition. Based on the frequency of occurrence of the hot spot residues and the estimated binding free energy, the survivin dimer and CPC interface residues were designated as “hot spots” and “warm spots”. Finally, based on the identified hot spots of survivin (Leu6A, Trp10A, Leu98A, Phe101A, Asp105A, and Arg106A), a pharmacophore model was derived and used to virtually screen database compounds to identify indinavir as potential inhibitor that could target survivin PPI. A preliminary biochemical investigation shows that the treatment of MDA-MB-231 breast cancer cells with indinavir resulted in Aurora B and XIAP downregulation and caspase-3 activation, hallmarks of survivin PPI inhibition.

Discovery of BPR1K871, a quinazoline based, multi-kinase inhibitor for the treatment of AML and solid tumors: Rational design, synthesis, in vitro and in vivo evaluation

Abstract: // Yung Chang Hsu 1, * , Mohane Selvaraj Coumar 2, * , Wen-Chieh Wang 1, * , Hui-Yi Shiao 1, * , Yi-Yu Ke 1 , Wen-Hsing Lin 1 , Ching-Chuan Kuo 1 , Chun-Wei Chang 1 , Fu-Ming Kuo 1 , Pei-Yi Chen 1 , Sing-Yi Wang 1 , An-Siou Li 1 , Chun-Hwa Chen 1 , Po-Chu Kuo 1 , Ching-Ping Chen 1 , Ming-Hsine Wu 1 , Chen-Lung Huang 1 , Kuei-Jung Yen 1 , Yun-I Chang 1 , John T.-A. Hsu 1 , Chiung-Tong Chen 1 , Teng-Kuang Yeh 1 , Jen-Shin Song 1 , Chuan Shih 1 , Hsing-Pang Hsieh 1,3 1 Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Taiwan, ROC 2 Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Kalapet, Puducherry, India 3 Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan, ROC * These authors contributed equally to this work Correspondence to: Hsing-Pang Hsieh, email: hphsieh@nhri.org.tw Keywords: acute myeloid leukemia, aurora kinase, FLT3, quinazoline, multi-kinase inhibitor Received: July 25, 2016 Accepted: November 07, 2016 Published: November 15, 2016 ABSTRACT The design and synthesis of a quinazoline-based, multi-kinase inhibitor for the treatment of acute myeloid leukemia (AML) and other malignancies is reported. Based on the previously reported furanopyrimidine 3, quinazoline core containing lead 4 was synthesized and found to impart dual FLT3/AURKA inhibition (IC 50 = 127/5 nM), as well as improved physicochemical properties. A detailed structure-activity relationship study of the lead 4 allowed FLT3 and AURKA inhibition to be finely tuned, resulting in AURKA selective (5 and 7; 100-fold selective over FLT3), FLT3 selective (13; 30-fold selective over AURKA) and dual FLT3/AURKA selective (BPR1K871; IC 50 = 19/22 nM) agents. BPR1K871 showed potent anti-proliferative activities in MOLM-13 and MV4-11 AML cells (EC 50 ~ 5 nM). Moreover, kinase profiling and cell-line profiling revealed BPR1K871 to be a potential multi-kinase inhibitor. Functional studies using western blot and DNA content analysis in MV4-11 and HCT-116 cell lines revealed FLT3 and AURKA/B target modulation inside the cells. In vivo efficacy in AML xenograft models (MOLM-13 and MV4-11), as well as in solid tumor models (COLO205 and Mia-PaCa2), led to the selection of BPR1K871 as a preclinical development candidate for anti-cancer therapy. Further detailed studies could help to investigate the full potential of BPR1K871 as a multi-kinase inhibitor.

Therapeutic polymeric nanoparticles and the methods of making and using thereof: a patent evaluation of WO2015036792

Abstract: Evaluation of the patent application WO2015036792 claiming therapeutic polymeric nanoparticles loaded with AZD1152-hqpa (aurora kinase inhibitor), and methods of making and using same for the treatment of cancer, is described. The claimed polymeric nano-formulations containing hydrophobic acid significantly improved the pharmacokinetic profiles (slow/sustained drug release profile) of the drug AZD1152-hqpa, as compared to the control agent (AZD1152). Drug efficacy and tolerability were also improved, and toxicity decreased in in vivo animal experiments, resulting in a better therapeutic index for the nano-formulation. Hence, the nano-formulated AZD1152-hqpa could be tested in the clinic at a dose level similar to, or higher than, that used for AZD1152, with lower incidence of toxicity.

Protein-Protein Interactions (PPIs) as an Alternative to Targeting the ATP Binding Site of Kinase: In Silico Approach to Identify PPI Inhibitors

Abstract: Most of the developed kinase inhibitor drugs are ATP competitive and suffer from drawbacks such as off-target kinase activity, development of resistance due to mutation in the ATP binding pocket and unfavorable intellectual property situations. Besides the ATP binding pocket, protein kinases have binding sites that are involved in Protein-Protein Interactions (PPIs); these PPIs directly or indirectly regulate the protein kinase activity. Of recent, small molecule inhibitors of PPIs are emerging as an alternative to ATP competitive agents. Rational design of inhibitors for kinase PPIs could be carried out using molecular modeling techniques. In silico tools available for the prediction of hot spot residues and cavities at the PPI sites and the means to utilize this information for the identification of inhibitors are discussed. Moreover, in silico studies to target the Aurora B-INCENP PPI sites are discussed in context. Overall, this chapter provides detailed in silico strategies that are available to the researchers for carrying out structure-based drug design of PPI inhibitors.

Mining Plutella xylostella's expressed sequence tags (EST) for a functionally annotated candidate gene index

Abstract: Diamondback moths, Plutella xylostella (Linnaeus) are one of the major pests of cruciferous plants such as cabbage and cauliflower (Brassica oleracea) in India. These insect show resistance against commonly used pest management practices such as, chemical insecticides and bacterial pathogens, including Bacillus thuringiensis (Bt). To overcome the resistance problem, develop new pesticides that can act through specific drug targets. To identify such drug targets specific to this insect, data mining and annotation of Expressed Sequence Tags (ESTs) were performed in this study. Expressed Sequence Tags (ESTs, 37,915) of the insect obtained from GenBank were clustered and consensus sequences (4224) were constructed using mining tool (CAP3). Out of it 256 sequences were functionally annotated using three Gene Ontologies (GO) terms, molecular function, biological process and cellular component using similarity search methods (BLASTOGO). By mapping the candidate genes to KEGG Pathway, 38 insect metabolic pathways, inclusive of xenobiotic metabolism by Cytochrome P450 were generated. One of the mapped candidate gene codes for aldehyde dehydrogenase enzyme, which is potentially involved in xenobiotic detoxification of synthetic insecticides, and play a role in the development of resistance to pesticides. Data mining and functional annotation helped to narrow down the choices for potential drug targets, which could aid in the development of new pesticides to overcome resistance in Diamondback moths. This methodology can be extended to other agriculturally important pests to identify the drug targets using EST data.