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Research Interests

Non-tubulin disruptors of mitosis

The current major focus of my laboratory is the identification of chemical agents that disrupt mitosis by targeting proteins other than tubulin as do the currently used spindle disrupting drugs used for cancer chemotherapy. Using homology model structures for key components of the anaphase promoting complex/cyclosome, we used in silico techniques to screen virtual libraries of candidate compounds for the ability to block a key interaction required for complex formation. Initial screening of identified compounds suggested that several compounds induced mitotic arrest and cell death in a variety of cancer cells including from melanoma, ovarian and pancreatic cancers.  We hope to develop these agents into effective chemotherapeutics to treat cancers, especially those that are resistant to the current drugs. A patent application on the use of these compounds is pending.

Arsenic toxicology

Arsenic is a human carcinogen and recently was approved as a chemotherapeutic agent. I became interested in arsenic because it was reported to interfere with DNA repair. Our work has led us to discover that arsenic disrupts cell cycle control and induces mitotic arrest and apoptosis in SV40 immortalized cells. Our investigations have led us to hypothesize that p53 plays a significant role in modulating arsenic toxicity. Understanding how arsenic induces apoptosis in mitotically arrested cells will also provide important information on how arsenic acts as a chemotherapeutic. We also have examined how arsenic co-treatment might enhance the sensitivity of cancer cells to cisplatin. Publications from this project include:

  1. Waalkes, MP, Fox, DA, States, JC, Patierno, SR and McCabe, MJ Jr, " Metals and Disorders of Cell Accumulation: Modulation of Apoptosis and Cell Proliferation ", Toxicolog. Sci. 56: 255-261 (2000).
  2. McCabe, MJ, Jr, Singh, K, Reddy, SA, Chelladurai, B, Pounds, JG, Reiners, JJ, Jr and States, JC "Sensitivity of Myelomonocytic Leukemia Cells to Arsenite-induced Cell Cycle Disruption, Apoptosis and Enhanced Differentiation on the Inter-Relationship between Arsenic concentration, duration of treatment and cell cycle phase", J. Pharmacol. Exp. Therap. 295: 724-733 (2000).
  3. States, JC, McCabe, MJ, Jr., Pounds, JG, Reiners, JJ, Jr., Kaplan, DJ, Mathieu, P and Sowder, HG Arsenite Disrupts Mitosis and Induces Apoptosis in Phenotypically p53 Negative Human Skin Fibroblasts", International Conference on Heavy Metals in the Environment August 6-10, 2000, Ann Arbor, MI, manuscript #1025
  4. States, JC, Reiners, JJ, Jr., Pounds, JG, Kaplan, DJ, Beauerle, BD, McNeely, SC, Mathieu, P and McCabe, MJ, Jr "Arsenite Disrupts Mitosis and Induces Apoptosis in SV40-Transformed Human Skin Fibroblasts", Toxicol Appl Pharmacol 180: 83-91 (2002)
  5. Taylor, BF, McNeely, SC, Miller, HL, Lehmann, GM, McCabe, MJ, Jr., States, J. C. (2006) p53 suppression of arsenite-induced mitotic catastrophe is mediated by p21CIP1/WAF1, J. Pharmacol. Exp. Ther. 318, 142-151
  6. McNeely, SC, Xu, X, Taylor, BF, Zacharias, W, McCabe, MJ, Jr., States, JC. (2006) Exit from arsenite-induced mitotic arrest is p53 dependent, Environ. Health Perspect. 114, 1401-1406. PMC1570045
  7. McNeely SC, Belshoff AC, Taylor BF, Fan TW, McCabe, Jr. MJ, Pinhas AR and States JC. (2008) Sensitivity to sodium arsenite in human melanoma cells depends upon susceptibility to arsenite-induced mitotic arrest. Toxicol. Appl. Pharmacol., 229, 252-261 (2008). PMC2474465.
  8.  Taylor BF, McNeely SC, Miller HL and States JC. (2008) Arsenite-induced mitotic death involves stress response and is independent of tubulin polymerization. Toxicol. Appl. Pharmacol. 230: 235-246 (2008) PMC2504415.
  9. McNeely SC, Taylor BF and States JC.(2008) Mitotic arrest-associated apoptosis induced by Sodium Arsenite in A375 Melanoma cells is BUBR1-dependent. Toxicol. Appl. Pharmacol. 231: 61-67 (2008)
  10. Salazar, AM, Miller, HL, McNeely, SC, Sordo, M, Ostrosky-Wegman, P, States, JC. Suppression of p53 and p21CIP1/WAF1 reduces arsenite-induced aneuploidy. Chemical Research in Toxicology 23:357-64 (2010) PMCID: PMC2825144
  11. Muenyi CS, States VA, Masters JH, Fan TW, Helm CW, States JC. Sodium arsenite and hyperthermia modulate cisplatin-DNA damage responses and enhance platinum accumulation in murine metastatic ovarian cancer xenograft after hyperthermic intraperitoneal chemotherapy (HIPEC). J Ovarian Res. Jun 22; 4:9 (2011).
  12. Muenyi CS, Pinhas AR,. Fan TW, Brock GN, Helm CW, States JC. Sodium arsenite ± hyperthermia sensitizes p53 expressing human ovarian cancer cells to cisplatin by modulating platinum DNA damage responses. Toxicological Sciences 27:139-49 (2012).

Another aspect of arsenic toxicology is the induction of cardiovascular diseaese. People chronically exposed to arsenic contaminated drinking water show increased mortality and morbidity from cardiovascular disease with increased incidence of myocardial infarction, stroke and peripheral vascular disease. We have developed murine models of arsenic accelerated cardiovascular disease. Using these models, we show that arsenic exposure induces changes in liver gene expression that may be linked to increased inflammation and development of chronic diseases related to diabetes. Publications from this project include:

 

  1. Srivastava, S, D’Souza, SE, Sen, U and States, JC. In utero arsenic exposure induces early onset of atherosclerosis in ApoE-/- mice. Reproductive Toxicology (special issue Fetal Basis of Adult Disease) 23:449-56 (2007)
  2. States JC, Srivastava S, Chen Y and Barchowsky A. Arsenic and Cardiovascular Disease. Toxicolog. Sci. 107:312-23 (2009) doi:10.1093/toxsci/kfn236
  3. Srivastava, S, Vladykovskaya, EN, Haberzettl, P, Sithu, SD, D’Souza, SE, States, JC. Arsenic Exacerbates Atherosclerotic Lesion Formation And Inflammation In APOE-/-  Mice. Toxicol. Appl. Pharmacol. 241:90-100 (2009)
  4. States JC, Singh AV, Knudsen TB, Rouchka EC, Ngalame NO, Arteel GE, Piao Y, Ko MS. Prenatal Arsenic Exposure Alters Gene Expression in the Adult Liver to a Proinflammatory State Contributing to Accelerated Atherosclerosis. PLoS ONE 7(6): e38713 (2012). doi:10.1371/journal.pone.0038713
  5. Ngalame N, Micciche A, Feil M, States JC. Delayed temporal increase of hepatic Hsp70 in ApoE knockout mice after prenatal arsenic exposure. Toxicol Sci. 131: 225-233 (2012)

 

Molecular genetics of DNA repair in humans

My major research interest for a long time was the molecular biology and molecular genetics of DNA repair in humans. I established my research program and pursued this interest over the years with extramural funding from the National Institutes of Health and from foundations. My laboratory has made significant contributions to the understanding of the molecular genetics of human nucleotide excision repair. We characterized mutations in the essential nucleotide excision repair gene XPA in genomic DNAs from cell lines established from patients and contributed to a compendium of mutations in human DNA repair genes. More recently, we have identified polymorphisms in XPA and performed preliminary characterizations of these polymorphic alleles. Publications from this project during the past five years include:

  1. Cleaver, JE and JC States, "The DNA Damage Recognition Problem in Human and other Eukaryotic Cells: the XPA Damage Binding Protein", Biochem. J., 328: 1-12 (1997)
  2. States, JC, ER McDuffie, SP Myrand, McDowell, M. and JE Cleaver "Distribution of Mutations in the Human XPA Gene and Their Relationships to the Functional Regions of the DNA Damage Recognition Protein", Human Mutation 12: 103-113 (1998)
  3. Cleaver, JE, Thompson LH, Richardson, AS, States, JC, "Distribution of Mutations in the Excision Repair Complementation Groups of Xeroderma Pigmentosum, Cockayne syndrome and Trichothiodystrophy - a summary", Human Mutation 14: 9-22 (1999).
  4. Mellon, I, Hock, T, Reid, R, Porter, PC and States, JC "Polymorphisms in the human xeroderma pigmentosum group A gene and their impact on cell survival and nucleotide excision repair", DNA Repair 1: 531-546 (2002)

 

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