Sketch: My research as a cell biologist and biochemist currently centers about the microtubule cytoskeleton in the development of anti-cancer drugs. I considered graduate school, intending to study cell biology. In my opinion, the best cell biologist with whom I interviewed in my eventual department was working in plant cells. I assumed the frontier challenge of investigating microtubule- associated proteins in plant cells (virtually nothing was known). My first publication in The Plant Cell (a premier journal in plant sciences) sparked further published, refereed debates, and we were invited to publish a review in another journal popular in the field. These exercises directed our research so that we eventually published work on primary questions that arose. Subsequently as a USDA postdoc, I studied plant microtubule organization and microtubule- organizing centers more generally using herbicide perturbations observed via electron and confocal immunofluorescence microscopy. Presently, I am studying the in vitro molecular interactions and cellular effects of potential anti-cancer drugs for which the microtubule cytoskeleton is the target. Biochemical, biophysical, and cell biological methods are being used to elucidate modes of action and likely binding sites.

Research Interests

General
Bases for cellular responses to endogenous and exogenous signals and compounds by applications of cellular biochemistry and protein chemistry in a preclinical biotechnology or pharmaceutical environment.

Post-doctoral
Bases for cytoskeletal disruption by, and resistance to, microtubule-interacting agents, including microtubule-disrupting herbicides, and anti-cancer drugs.

Doctoral
Organization and regulation of the microtubule arrays and microtubule-associated proteins of higher plant cells. (abbreviated tour)

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Postdoctoral Positions & Education Background

1997-Present, NCI Cancer Research Training Award (CRTA) postdoctoral fellow (try here or here; formerly IRTA - try here). Screening Technologies Branch > Developmental Therapeutics Program > Division of Cancer Treatment and Diagnosis > National Cancer Institute > Frederick Cancer Research and Development Center. <Hierarchy sketch> (NCI-FCRDC | P.O. Box B | Bldg 469/Rm 237 | Frederick, MD 21702)

1995-1997, Postdoctoral Cell Biologist, GS-11, U.S. Department of Agriculture (USDA), Agricultural Research Services (ARS), Southern Weed Sciences Laboratory (SWSL), Stoneville, Mississippi 

The Pennsylvania State University, University Park, PA.
Ph.D. Biology, September 1995 (formally January 1996). GPA 4.00/4.00

University of Notre Dame, Notre Dame, IN.
B.S. Biology, 1990. GPA 3.01/4.00

Susquehanna Community High School, Susquehanna, PA
Diploma, 1986, Advanced Placement Curriculum. Valedictorian.

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Conferences and Presentations

AACR-NCI-EORTC Symposium on New Drugs in Cancer Therapy: The International Conference on Molecular Targets and Cancer Therapeutics; Discovery, Development, and Clinical Validation. 1999 Poster: Biochemical and cytotoxic comparisons of the sponge-derived natural product hemiasterlin, an antimitotic tripeptide, with other cytotoxic compounds. (Abs [appears in Clinical Cancer Res, 5:Supp, Nov 1999]) (Abs link broken? see copy here)[related data]

American Association for Cancer Research (AACR), Annual Meetings. Posters [related data for both (redundant)]:

• 1999: The antimitotic tripeptide hemiasterlin. (Abs [appears in Proc Amer Assoc Cancer Res 40, 3/99])
• 1998: Interaction of the antimitotic sponge-derived tripeptide hemiasterlin with tubulin. (Abs [appears in Proc Amer Assoc Cancer Res 39, 3/98]) (Abs link broken? see copy here)

American Society of Cell Biology (ASCB), Annual Meetings. Posters (if applicable):

• 1998 Tubulin interactions with the antimitotic tripeptide hemiasterlin, an anticancer candidate. [related data (redundant)]
• 1997
• 1992 Affinity isolation of microtubule-binding proteins from carrot cells; preliminary characterization and immunolocalization. (abstract in Mol Biol Cell, 3-suppl: 260a)

Foundation for Advanced Cancer Studies, Inc. (FACSI) First Annual Meeting on The Experimental Therapeutics of Human Cancer, 1998. Characterization of interactions between the antimitotic tripeptide hemiasterlin and tubulin. [Abstract; related data (redundant)]

American Society of Plant Physiologists (ASPP), Annual Meetings. Posters (portions of the data here):

• 1997
  (1) The herbicidal manipulation of callose levels in cell plates radically affects cell plate structure.
  (2) Cell wall alterations in BY-2 tobacco cells after long-term habituation to dichlobenil.
• 1996 Microtubule recovery from mitotic disrupter herbicide in fern spermatogenous cells. (here, revised abstract vs. original in Plant Physiol, 111:2-suppl: 658)

Sixteenth Annual Missouri Symposium: Signs and Roadways, Protein Traffic and the Cytoskeleton. 1997. Poster: Life Without Cellulose – Tobacco cell responses to short-term and long-term inhibition of cellulose synthesis. (All here.)

Gordon Research Conferences, conference titles and posters:

• 1995 Plant and Fungal Cytoskeleton. Microtubule-associated EF-1a in carrot cells.
• 1993 Cellular and Molecular Biology of the Plant and Fungal Cytoskeleton. Affinity isolation of microtubule-binding proteins from carrot cells.

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Publications

Gamble, WR, Durso, NA, Fuller, RW, Westergaard, CK, Johnson, TR, Sackett, DL, Hamel, E, Cardellina, JH II, and MR Boyd (1999) Cytotoxic and tubulin-interactive hemiasterlins from Auletta sp. and Siphonochalina spp. sponges. Bioorganic & Medicinal Chemistry 7 (8), 1611-1615 (refereed) [Abstract (PubMed medline)] [some related data/figures]

Sabba, RP, Durso, NA, and KC Vaughn (1999). Structural and immunocytochemical characterization of the walls of dichlobenil-habituated BY-2 tobacco cells. Int J Plant Sci 160 (2), 275-290. (refereed) [summarized, related/included excerpts (some color figures that are b/w in publication)]

Moore, RC, Durso, NA, and RJ Cyr (1998). Elongation factor-1-alpha stabilizes microtubules in a calcium/calmodulin-dependent manner. Cell Motil Cytoskel 41 (2), 168-180. (refereed) [full article in PDF] [abstract and figures in web format]

Durso, NA, Leslie, JD, and RJ Cyr (1996). In situ immunocytochemical evidence that a homolog of elongation factor EF-1-alpha is associated with microtubules in carrot cells. Protoplasma 190 (3-4), 141-150. (refereed)

Marc, J, Sharkey, DE, Durso, NA, Zhang, M, and RJ Cyr (1996). Isolation of a 90-kD microtubule-associated protein from tobacco membranes. Plant Cell 8, 2127-2138 (refereed)

Durso, NA, and RJ Cyr (1994). Beyond translation: Elongation factor-1-alpha and the cytoskeleton. Protoplasma 180 (3-4), 99-105. (refereed)

Durso, NA, and RJ Cyr (1994). A MAP by any other name would still bind to microtubules. Plant Cell 6, 1699-1702. (refereed)

Durso, NA, and RJ Cyr (1994). A calmodulin-sensitive interaction between microtubules and a higher plant homolog of elongation factor-1-alpha. Plant Cell 6 (6), 893-905. (refereed) [citations]

Marc, J, Durso, N, Zhang, M, and R Cyr (1994). Microtubule-binding proteins from tobacco membranes. Mol Biol Cell, 5-supplement: 289a. (abstract)

Dunski, JF, Durso, NA, Hay, JM, and RJ Cyr (1994). Writing in the Biology Curriculum, Department of Biology, Pennsylvania State University. (instructional) (Required manual for more than 1,000 undergraduates per year in undergraduate courses; authored 3 of 5 chapters: Introduction, Scientific Protocols, Conventions of English Composition. Still in use in 1998. Now in Second Edition.)

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Technical Skills

Protein and protein-ligand biochemistry:

• Radiolabeled ligand (drug or nucleotide [e.g., GTP]) competition analyses, via centrifugal gel filtration, of binding to purified tubulin.
• Dissociation constant determination for ligand (drug) binding to tubulin via kinetic colorimetry based on altered accessibility to tubulin's 20 Cys sulfhydryls.
• Ligand (drug)-induced oligimerization of tubulin evaluated by gel filtration HPLC.
• Protein purification from, e.g., mammalian brain or suspension-cultured carrot.
• Chromatography: ion-exchange, gel filtration (including centrifugal) and sizing; construction/use of protein-ligand (e.g., microtubules, tubulin, calmodulin) affinity chromatography matrices; HPLC.
• Electrophoresis: standard SDS-PAGE; one-dimensional peptide mapping by limited proteolysis; 2-D electrophoresis (IEF/PAGE); protein electroelution from acrylamide gels for use as antigen; peptide electrotransfer and subsequent amino acid sequencing and identification.

Immuno-methods:

• Western transfer and immunoblotting; ELISA; monoclonal antibody screening; production of antiserum in rabbit; affinity purification of antibodies.

Cell biology:

• Cytotoxicity screens: Growth inhibition/cell kill (IC50), clonogenicity (%-survival), and quantitative/qualitative mitotic index analyses for drug candidate compounds.
• Microscopy: laser scanning confocal installation and use; indirect immunofluorescence (whole cell and embedded section); dark-field; transmission electron
• Digital imaging (CCD, SIT, video), processing, and analyses; photomicrography.

Misc. analyses:

• Microtubule assembly and dynamic instability assays in vitro.
• Microtubule binding and bundling assays in vitro.
• Rabbit reticulocyte in vitro translation assays.
• Also see 'Protein and protein-ligand biochemistry.'

Molecular biology:

• Graduate-level experience in PCR amplification, plasmid construction, transformation, restriction and Southern analyses.

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Teaching Experience

The Pennsylvania State University, Department of Biology, Teaching Assistantship Awards (instructor for laboratory portions of courses):

• Principles of Biology 101 F1990, 2 sec.
• Embryology 440 S1991, 2 sec.
• Plant Biology 027 F1991, 2 sec.
• Principles of Biology 101 F1992, 2 sec.
• Principles of Biology 102 S1994, 1 sec.*
• Biology 110: Basic Concepts and Biodiversity F1994, 4 sec.

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Hierarchy sketch: National Institutes of Health, National Cancer Institute...

• U.S. Department of Health and Human Services (DHHS) (e.g., Administration on Aging)
  • Public Health Service (PHS) [agency e.g.s: Centers for Disease Control and Prevention (CDC), Food and Drug Administration (FDA)]
    • National Institutes of Health (NIH) (e.g.s: Aging, Diabetes, Drug Abuse)
      • National Cancer Institute, and perhaps another, better page
        • Frederick Cancer Research and Development Center (FCRDC)
          • Developmental Therapeutics Program (DTP)
            • NCI Postdoctoral Fellow

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