Cancer Institute

  • Larry A. Walker

    Director, National Center for Natural Products Research
    Research Professor of Pharmacology
    Molecular Cancer Therapeutics
    Associate Director for Basic Research, Oxford Campus

    PhD, Pharmacology, 1979, Vanderbilt University, Nashville, TN
    Postdoc, 1979-81, Dartmouth Medical School, Hanover, NH
    Postdoc, 1979, Bosch Institute for Klin. Pharmakologie, Stuttgart, Germany

    Contact information 
    P.O. Box 1848
    Thad Cochran Research Center, Room 1019
    Phone: (662) 915-1005
    E-mail: lwalker@olemiss.edu

     walker_larry.jpg

    Research interests

    • Drug discovery and development from natural products
    • Efficacy and hematological toxicity of 8-aminoquinoline anti-infectives
    • Medicinal plants and their pharmacology and toxicology

    Research synopsis

    Dr. Walker is the director of the National Center for Natural Products Research (NCNPR) at The University of Mississippi (UM). In 1987 he was tapped to lead a natural products discovery biological screening program at UM, and this unit was transferred to form the core of the discovery operation when the NCNPR opened in 1995. At that time he assumed responsibilities as Associate Director of NCNPR, and in 2001, he was named Director. He is thus currently responsible for overall scientific direction of a multidisciplinary program (chemistry, biochemistry, botany, microbiology, cell biology, pharmacology/toxicology), with a current staff of 85 (35 PhD level research scientists and faculty). He maintains an active research program in the discovery of natural products and mechanisms of action, and in the development of the 8-aminoquinoline anti-infectives, probing their pharmacology, bioactivation, pharmacokinetics, and toxicity issues. The discovery efforts of the NCNPR have recently been expanded to include pathways/targets relevant to cancer. In 2008/9, Dr. Walker served on the steering committee for the UM Medical Center Cancer Institute and participated in the search for selection of a new director. In 2010 he was named Associate Director for Basic Science (Oxford campus) for the Cancer Institute, and in early 2011, a Cancer Drug Discovery Core was established at the NCNPR.

    Recent accomplishments and honors

    •  2009 - FDA Commissioner's Special Citation Award
    • 2009 - University of Mississippi Distinguished Research and Creative Achievement Award
    • 2005/07 - National Cancer Institute's PDQ Cancer Complementary and Alternative Medicine Editorial Board

    Selected publications

     

    • A New Metabolite with a Unique 4-Pyranone-γ-Lactam-1,4-Thiazine Moiety from a Hawaiian-Plant Associated Fungus; Li CS, Ding Y, Yang BJ, Miklossy G, Yin HQ, Walker LA, Turkson J, Cao S.; Org Lett. 2015 Jul 17; 17(14):3556-9. doi: 10.1021/acs.orglett.5b01650. Epub 2015 Jun 24.
    • Differential Cytochrome P450 2D Metabolism Alters Tafenoquine Pharmacokinetics; Vuong C, Xie LH, Potter BM, Zhang J, Zhang P, Duan D, Nolan CK, Sciotti RJ, Zottig VE, Nanayakkara NP, Tekwani BL, Walker LA, Smith PL, Paris RM, Read LT, Li Q, Pybus BS, Sousa JC, Reichard GA, Smith B, Marcsisin SR.; Antimicrob Agents Chemother. 2015 Jul;59 (7):3864-9. doi: 10.1128/AAC.00343-15. Epub 2015 Apr 13.
    • Differential CYP 2D6 Metabolism Alters Primaquine Pharmacokinetics; Potter BM, Xie LH, Vuong C, Zhang J, Zhang P, Duan D, Luong TL, Bandara Herath HM, Dhammika Nanayakkara NP, Tekwani BL, Walker LA, Nolan CK, Sciotti RJ, Zottig VE, Smith PL, Paris RM, Read LT, Li Q, Pybus BS, Sousa JC, Reichard GA, Marcsisin SR;  Antimicrob Agents Chemother. 2015 Apr;59(4):2380-7. doi: 10.1128/AAC.00015-15. Epub 2015 Feb 2.
    • Anti-vancomycin-resistant Enterococcus faecium and E. faecalis activities of (-)-gossypol and derivatives from Thespesia garckeana;  Masila VM, Midiwo JO, Zhang J, Gisacho BM, Munayi R, Omosa LK, Wiggers FT, Jacob MR, Walker LA, Muhammad I.; Nat Prod Commun. 2015 Apr;10(4):613-6.
    • Computational Study on the Effect of Exocyclic Substituents on the Ionization Potential of Primaquine: Insights into the Design of Primaquine-Based Antimalarial Drugs with Less Methemoglobin Generation; Liu H, Ding Y, Walker LA, Doerksen RJ; Chem Res Toxicol. 2015 Jan 27.
    • Evaluation of wild yam (Dioscorea villosa) root extract as a potential epigenetic agent in breast cancer cells;  Aumsuwan P, Khan SI, Khan IA, Avula B, Walker LA, Helferich WG, Katzenellenbogen BS, Dasmahapatra AK.;  In Vitro Cell Dev Biol Anim. 2015 Jan;51(1):59-71. doi: 10.1007/s11626-014-9807-5. Epub 2014 Aug 23.
    • Enantioselective Pharmacokinetics of Primaquine in Healthy Human Volunteers; Tekwani BL, Avula B, Sahu R, Chaurasiya ND, Khan SI, Jain S, Fasinu PS, Herath HB, Stanford D, Nanayakkara ND, McChesney JD, Yates TW, ElSohly MA, Khan IA, Walker LA; Drug Metab Dispos. 2015 Jan 30. pii: dmd.114.061127
    • Induction of GST and Related Enzymes by Dietary Phytochemicals: Sources, Chemistry, and Possible Contribution to Chemoprevention; Galal AM, Walker LA, Khan IA;  Curr Top Med Chem. 2015;14(24):2802-21.
    • Monoamine oxidase inhibitory constituents of propolis: kinetics and mechanism of inhibition of recombinant human MAO-A and MAO-B; Chaurasiya ND, Ibrahim MA, Muhammad I, Walker LA, Tekwani BL; Molecules. 2014 Nov 18;19(11):18936-52. doi: 10.3390/molecules191118936. 
    • In vitro and in vivo anti-malarial activity of tigecycline, a glycylcycline antibiotic, in combination with chloroquine; Sahu R, Walker LA, Tekwani BL. Malar J.; 2014 Oct 21;13(1):414. doi: 10.1186/1475-2875-13-414.