Chemical Carcinogenesis Research

Located in Lab Module 450 on Level 4 of Avedisian Hall

Overview

Our research focuses on chemical carcinogenesis with emphasis on the structural and conformational aspects of DNA-adduct formation. We are interested in how environmental carcinogens, upon metabolism, interact with cellular DNA to initiate mutagenesis/carcinogenesis.  The long-range goal of our research is to elucidate the mechanisms of mutation and repair at the atomic and molecular-genetic level.   In addition, we recently turned our attention to the emerging contaminants per- and polyfluoroalkyl substances (PFASs) and their interactions with certain essential proteins.

The animation above illustrates the major conformational motifs of arylamine modified DNA duplexes: modified dG and the complementary dC are shown in cyan and green, respectively, and the carcinogenic moiety is highlighted with red. In the B conformer (far left), anti-[AF]dG maintains Watson−Crick hydrogen bonds, thereby placing the arylamine in the major groove. The arylamine moiety of the S conformer (middle) stacks (base-displaced) into the helix with the modified dG in the syn conformation. The ‘wedge’ (W) conformation (far right) conformation forces the hydrophobic arylamine to be positioned within the minor groove.          


  • URI awarded $20 million to further expand biomedical research capacity in R.I. - A University of Rhode Island-based initiative that has successfully expanded biomedical research capacity at nearly all of Rhode Island’s universities and colleges has been awarded another $20 million in federal funding to further expand the program over the next five years.
  • Providence Journal- R.I. businesses can tap into URI’s Business Engagement Center for help - PROVIDENCE — When The Pizza Gourmet, a Warwick-based maker of wood-grilled pizza crusts, started planning how to keep up with growing sales, co-owner Jack Parente called the University of Rhode Island for some help.Parente, a URI graduate, wanted to know if anyone at the university could design a more efficient grill to cook the crusts […]
  • URI’s YouTube Site - 3D biomedical science videos receives 1 million hits KINGSTON, R.I. – Dec. 10, 2012 – It can be difficult to understand how drugs like Iressa and Prozac work in the body just from reading a textbook. That’s why students at the University of Rhode Island have been creating 3D models and animations to explain complex […]
  • Join the fight against cancer - Grilling season is in full swing, and the age-old question hangs in the air:  Would you like a side of carcinogenic heterocyclic amines with your porterhouse?  That black stuff you love so much on your grilled meat is nearly as bad as eating soot from your fireplace and can actually be hazardous to your health. […]
  • URI researchers ask, ‘Is your health at steak?’ - URI researchers ask, ‘Is your health at steak?’ KINGSTON, R.I. – Nothing goes better with your Fourth of July fireworks than a backyard barbecue. But if you’re not careful, your grilled meats could be a health hazard. According to two URI scientists, the charring on your steaks and burgers are heterocyclic amines or, if you’ve […]
  • Discovering the Configuration of Cancer - Dr Bongsup Cho offers an insight into his current research into environmentally-induced cancer, which will expose how aromatic amines mutate DNA and interfere with its repair mechanisms. Could you briefly describe your current research project? Formation of aromatic amine-DNA adducts is believed to initiate cancer. We are concerned with elucidating the mechanisms by which amine-DNA […]
  • New Printer to Make 3D Models - New printer to make 3D models at URI College of Pharmacy Can render solid, touchable versions of drug, virus molecules, architectural models, and artificial limbs…. February 28, 2011 – Professor Bongsup Cho sat at his desk discussing a new 3-dimensional printer that will soon be a part of the University of Rhode Island’s College of […]
  • 3-D printer to offer hands-on experience for students, create models of molecules - The University of Rhode Island will be introducing a new 3-D printer for the next academic year, which will provide a hands-on approach in learning about chemicals and drugs, and how they affect the human body. Professor of biomedical sciences Bongsup Cho said the printer will most likely be housed in the new pharmacy building […]
  • New printer to make 3D models at URI College of Pharmacy - Can render solid, touchable versions of drug, virus molecules, architectural models, and artificial limbs…. KINGSTON, R.I. – February 28, 2011 – Professor Bongsup Cho sat at his desk discussing a new 3-dimensional printer that will soon be a part of the University of Rhode Island’s College of Pharmacy. As he explained how the printer will […]
  • URI biomedical scientist concerned about effects of oil spill on human health - KINGSTON, R.I. – June 21, 2010—University of Rhode Island Pharmacy Professor Bongsup Cho knows there are cancer-causing chemicals in diesel fumes and cigarette smoke. The biomedical scientist also knows that some of the same chemicals are found in the gooey tar balls that are being produced as a result of the oil spill in the […]

Research

  • Arylamine DNA adduct recognition in eukaryotic nucleotide excision repair (NIH/NIEHS 5R21 ES028384) in collaboration with Dr. Jung Hyun Min at Baylor University

    Aromatic amines are among the most notorious environmental chemicals. At pathologically relevant concentrations, their reactive metabolites can react with cellular DNA to produce bulky lesions. If not efficiently repaired, these lesions can result in mutations that lead to various sporadic cancers. Understanding the mechanisms by which these lesions are recognized by the XPC nucleotide excision repair complex is the focus of this proposal.

    Project Summary

    The human genome is under constant assault by environmental factors that include sunlight and chemicals. Arylamines are diverse and ubiquitous environmental mutagens implicated in the etiology of various sporadic cancers. Direct exposure to arylamines, such as 4-aminobiphenyl (ABP), increases the risk of bladder cancer, the fourth most common cancer in men in the US. Arylamines absorbed into the cells are activated and react with cellular DNA to produce bulky DNA adducts. If not efficiently repaired, these lesions can result in mutations and tumorigenesis. Nucleotide excision repair (NER) is a key repair pathway that protects the integrity of the genome against diverse DNA lesions including arylamine adducts. To initiate NER, the xeroderma pigmentosum C (XPC) protein complex first detects the lesions and recruits downstream factors, which in turn verify, excise and restore the damaged portion of the DNA. Though it has been generally believed that stable, specific binding to XPC is required for efficient repair, we recently found that it is not always true: for certain arylamine lesions in a highly mutagenic sequence context, an extremely tight binding to XPC (due to a slow dissociation rate) may, in fact, hamper NER (Hilton et al., PLos One e0157784 (2016)). In this project we will collaborate with Dr. Junghyun Min at Baylor University to investigate the structural and mechanistic basis underlying this intriguing relationship between the XPC-binding and repair potentials of arylamine lesions. We will use a powerful multidisciplinary approach that combines the complementary strengths of 19F-NMR, surface plasmon resonance (SPR), and X-ray crystallography. The knowledge gained on how certain lesions evade repair while tightly binding to repair proteins, may also lead to novel ideas and agents to combat cancer.

  • Mutational spectra of bulky DNA lesions (NIEHS 5R01ES028865) in collaboration with Dr. Deyu Li (PI) at The University of Rhode Island

    Many aromatic amines are environmental toxins and human carcinogens. They damage genome and form different bulky DNA lesions, which give rise to different mutation patterns. This application will study the mutational spectra of bulky DNA lesions generated from aromatic amine exposure and provide insights into the development of tumors.

    Project Summary

    Many environmental toxins damage DNA and cause diseases. The exposure of cells with DNA damaging agents results in the formation of a host of different DNA lesions, a subset of which can give rise to mutations. If one were to plot the frequency and type of mutation as a function of the position along a gene, a distribution is generated that is commonly referred to as a mutational spectrum. It is reasonable to speculate that mutational hotspots are modulated by the local sequence environment surrounding the base to be modified, or the DNA lesion to be repaired or replicated. It is important for environmental scientists to provide insights into the evolutionary changes that foreshadow tumor development before overt clinical symptoms appear. This goal is crucial because some diseases, such as tumors, show few clinical symptoms until the disease has reached a late, usually fatal stage. Early onset genomic biomarkers might enable intervention to eliminate or curtail development of the disease. The biomarkers of a disease caused by a specific toxin can be obtained by studying the mutational spectra of DNA lesions generated from the toxin. Experimental studies of the mutations and mutation spectra induced by environmental toxins have traditionally focused on single mutations. However, the origins of mutational hotspots is complicated by the neighboring contexts. The selective formation, replication, and repair of a DNA lesion can, in principle, be influenced by the surrounding nucleotide environment from both 5’ and 3’ ends. A nearest-neighbor analysis of a certain DNA lesion (NXN, X = lesion, N = one of the four nucleotides) will provide a structural rationale for mutational spectra in environmental toxin related human tumors. In this proposal, we will study individual lesions of environmental toxins under all the genetic and epigenetic relevant contexts. In this project, we select two important environmental toxins, 4-amino biphenyl (ABP) and amino alpha carboline (AaC) to study the mutational spectra of their major DNA lesions and correlate with mutational signatures of diseases caused by them. The central hypothesis of this project is that DNA lesions generated by environmental toxins will cause different mutational spectra in a sequence dependent manner. The Specific Aims are: Specific Aim 1: Chemical synthesis and identification of bulky DNA adduct containing oligonucleotides. Specific Aim 2: Mutational spectra of bulky lesions in cell. Specific Aim 3: Replication bypass of lesions by translesion synthesis polymerases. At the conclusion of this project we will have demonstrated how the interaction between environmental toxins and mutational spectra. These studies shall utilize in a combination of genetic, chemical, and spectroscopic tools to understand and manipulate biological systems at the molecular level.

  • Protein binding of per- and polyfluoroalkyl substances (PFASs) as part of URI/Harvard Superfund STEEP (NIH/NIEHS 3P42ES027706)


    Per- and polyfluoroalkyl substances (PFASs) are used to make surfaces water and oil resistant and can be found in cookware and fabric, as well as firefighting foam. They are ubiquitous and are contaminating water supplies near manufacturing plants and fire training sites.  PFASs are present in blood serum of 99% of human population worldwide. To make matters worse, there are almost 5,000 PFASs in the environment. US EPA has recently declared PFASs as a national priority. PFASs have been found epidemiologically to cause cancer and cardiovascular risk, thyroid disease, and immune system disorders, but their mode of actions is not understood.  We hypothesize that PFASs may occupy important pockets of certain essential enzymes and receptors disrupting their regular functions. These chemicals can have long lasting adverse effects because of their unusually long half lives (years). To this end, we will use a powerful combination of microcalorimetry (ITC and DSC) and real time binding measurements such as surface plasmon resonance (SPR) to study systematically their specific interactions with human serum albumin protein (HAS) and transthyretin.  We will collaborate with the project leaders involved in the URI/Harvard joint STEEP Superfund Research Program (SRP) (https://web.uri.edu/steep/). Dr. Cho is Training Core leader of the URI/Harvard STEEP Collaboration.

Publications

Complete List of Peer-Reviewed Publications (*corresponding authorship)

  1. Crisalli, S., Chen, Y.-T., Cai, A., Li, D., and Cho, BP* Conformation-dependent lesion bypass of bulky arylamine-dG adducts generated from 2-nitrofluorene in epigenetic sequence contexts. Nucleic Acids Res., 2023 Dec 11 (22), 12043-12053.
  2. Crisalli, S., Cai, A., and Cho, BP* Probing the interactions of perfluorocarboxilyc acids of various chain length with human serum albumin: Calorimetric and spectroscopic investigations. Chem. Res. Toxicol. 2023 Apr 17. 36, 703-713. PMID: 37001030.
  3. Hemme CL, Carley R, Norton A, Ghumman M, Nguyen H, Ivone R, Menon JU, Shen J, Bertin M, King R, Leibovitz E, Bergstrom R, Cho BP* Developing virtual and augmented reality applications for science, technology, engineering, and math education. Biotechniques. 2023 Jul;75(1):343-352.
  4. Liu C, Cai A, Li H, Cho BP, Seeram NP, Ma H. Characterization of molecular interactions between cannabidiol and human plasma proteins (serum albumin and γ-globulin) by surface plasmon resonance, microcalorimetry, and molecular docking. J of Pharm Biomed Anal. 214, 114750 (2022).
  5. Li H, Xu F, Liu C, Cai, A, Dain J, Li D, Seeram NP, Cho BP, Ma H. Inhibitory Effects and Surface Plasmon resonance-based Binding Affinities of Dietary Hydrolysable Tannins and Their Gut Microbial Metabolites on SARS-CoV-2 Main Protease. J. Agric Food Chem. 12197-12208 (2021).
  6. Padbury JF*, Cho BP.* Translational Research: The Time is Now. RI Med. J. 2021 Apr 1;104(3):16.
  7. Cho BP*, Padbury JF.* Impact of NIH’s Institutional Development Award (IDeA) Programs in Rhode Island. RI Med. J. 2021 Mar 1;104(2):22-24.
  8. Hemme CL, Bellavia L, Meenach S, Howlett NG, Cho BP.* RI-INBRE: A Statewide NIH Program Grant to Improve Institutional Biomedical Research Capacity in Rhode Island. RI Med. J. 2021 Mar 1;104(2):25-29.
  9. Cai, K. Bian, F. Chen, Q. Tang, R. Carley, D. Li,* and B.P. Cho.* Probing the Effect of Bulky Lesion-Induced Replication Fork Conformational Heterogeneity Using 4-Aminobiphenyl-Modified DNA. Molecule, 24(8), 1566; https://doi.org/10.3390/molecules24081566 (2019). Special Issue on Structural and Functional Aspects of DNA Polymerases.
  10. Liua, A. Cai, R. Carley, R. Rocchiob, Z. M. Petrovasb, C. A. Chartierb, X. Mengd, J. Sud, B. P. Cho, J. A. Dainc, H. Ma and N. P. Seeram.* Bioactive anthraquinones found in plant foods interact with human serum albumin and inhibit the formation of advanced glycation endproducts J Food Bioact.: 4, 130-138 (2018).
  11. Cai, K. A. Wilson, S. Patnaik, S. D. Wetmore, B. P. Cho.* DNA base sequence effects on bulky lesion-induced conformational heterogeneity during DNA replication. Nucleic Acids Res. 40, 3939-3951 (2018).
  12. Liu, Z. Wei, H. Ma, A. Cai, Y. Y. Liu, J. Sun, N. A. DaSilva, S. L. Johnson, L. J. Kirschenbaum, B. P. Cho, J. A. Dain, D. C. Rowley, Z. A. Shaikh, N. P. Seeram.* Anti-glycation and anti-oxidative effects of a phenolic-enriched maple syrup extract and its protective effects on normal human colon cells. Food Funct. 22, 757-766 (2017).
  13. Tang, A. Cai, K. Bian, F. Chen, J. C. Delaney, S. Adusumalli, A. C. Bach, F. Akhlaghi, B. P. Cho, D. Li.* Characterization of Byproducts from Chemical Syntheses of Oligonucleotides Containing 1-Methyladenine and 3-Methylcytosine. ACS Omega. 2, 8205-8212 (2017).
  14. M. Giulietti, P. M. Tate, A. Cai, B. P. Cho, S. P. Mulcahy.* DNA-binding studies of the natural β-carboline eudistomin U. Bioorg Med Chem Lett. 26, 4705-4708 (2016).
  15. Xu and B. P. Cho.* Conformational Insight on the Mechanism of Acetylaminofluorene-dG induced Frameshifts Mutation in the NarI Mutational Hotspot. Chem. Res. Toxicol. 29, 213-226 (2016).
  16. Hilton, S. Gopal, L. Xu, S. Mazumder, P. R. Musich, and B. P. Cho*, Y. Zou.* Dissociation dynamics of XPC-HR23B from damaged DNA is a determining factor of NER efficiency.   PLOS, http://dx.doi.org/10.1371/journal.pone.0157784. Published: June 21, 2016
  17. Ma, L. Wang, D. B. Niesen, A. Cai, B. P. Cho, W. Tan,* Q. Gu, J. Xu* and N. P. Seeram.* Structure activity related, mechanistic, and modeling studies of gallotannins containing a glucitol-core and a-glucosidase. RSC Advances 5, 107904-107915 (2015).
  18. Xu, V. G. Vaidyanathan, B. P. Cho.* Real-time surface plasmon resonance study of biomolecular interactions between polymerase and bulky mutagenic DNA lesions. Chem. Res. Toxicol. 27, 1796-807 (2014).
  19. Jain, V. G. Vaidyanathan, S. Patnaik, S. Gopal, and B. P. Cho.* Conformational Insights into the Lesion and Sequence Effects for Arylamine-Induced Translesion DNA Synthesis: 19F NMR, Surface Plasmon Resonance, and Primer Kinetic Studies. Biochemistry 53, 4059-71 (2014).
  20. Jain, B. Hilton, B. Lin, A. Jain, A. D. MacKerell, Y. Zou, and B. P. Cho.* Structural and thermodynamic insight into E. coli UvrABC mediated incision of cluster di-acetylaminofluorene adducts on the NarI sequence. Chem. Res. Toxicol. 1251-1261 (2013).
  21. Jean-Gilles, L. Li, V.G. Vaidyanathan, R. K. King, B. P. Cho, D. R. Worthen, C. O. Chichester III, and N. P. Seeram.* Inhibitory effects of polyphenol punicalagin on type-II collagen degradation in vitro and inflammation in vivo. Chem-Biol Interact. 205, 90-99 (2013).
  22. G. Vaidyanathan, F. Liang, W. A. Beard, D. D. Shock, S. H. Wilson and B. P. Cho.* Insights into the Conformation of Aminofluorene-dG Adduct in a DNA Polymerase Active Site. J. Biol. Chem. 23573-85 (2013).
  23. Sandineni, B. Lin, A. D. Mackerell, B. P. Cho.* Structure and thermodynamic insights on acetylaminofluorene-modified deletion DNA duplexes as models for frameshift mutagenesis. Chem. Res. Toxicol. 26, 937-951 (2013).
  24. G. Vaidyanathan, Lifang Xu, and Bongsup P. Cho.* Binding kinetics of DNA-protein interaction using surface plasmon resonance. Nature Protocol Exchange. Online. May 22, 2013. doi:10.1038/protex.2013.054 http://www.nature.com/protocolexchange/protocols/2721. (2013)
  25. Jain, B. Hilton, B. Lin, S. Patnaik, F. Liang, E. Darian, Y. Zou, A D. MacKerell Jr., and B.P. Cho.* Unusual sequence effects on nucleotide excision repair of arylamine lesions: DNA bending/distortion as a primary recognition factor. Nucleic Acids Res., 41, 869-880 (2012).
  26. P. Cho* and N.J. Owens.* The University of Rhode Island College of Pharmacy. Editorial. Med. Health R.I., 95, 272 (2012).
  27. G. Vaidyanathan, L. Xu, B. P. Cho.* Binary and ternary binding affinities between exonuclease-deficient Klenow Fragment (Kf-exo(-)) and various arylamine DNA lesions characterized by surface plasmon resonance. Chem. Res. Toxicol. 25, 1568-70 (2012).
  28. G. Vaidyanathan and B. P. Cho.* Sequence effects on translesion synthesis of an aminofluorene-DNA adduct: conformational, thermodynamic, and primer extension kinetic studies. Biochemistry, 51, 1983-1995 (2012).
  29. Jain, B. Hilton, S. Patnaik, Y. Zou, M. P. Chiarelli, and B. P. Cho.* Conformational and thermodynamic properties modulate the nucleotide excision repair of 2-aminofluorene and 2-acetylaminofluorene dG adducts in the NarI sequence. Nucleic Acids Res., 37, 1-13 (2012).
  30. Liang and B. P. Cho.* Conformational and Thermodynamic Impact of the Bulky Aminofluorene Adduction on a Simulated Translesion DNA Synthesis. Chem. Res. Toxicol., 24, 597-605 (2011).
  31. Patnaik, and B. P. Cho.* Structures of 2-Acetylaminofluorene Modified DNA Revisited: Insight into Conformational Heterogeneity. Chem. Res. Toxicol., 23, 1650-1652 (2010).
  32. Cho.* The Chemical Biology of DNA Damage. “Structure-function characteristics of aromatic amine-DNA adducts.” Edited by N.E. Geacintov & S. Broyde. Wiley-VCH. (2010).
  33. Liang and B. P. Cho.* Enthalpy-entropy Contribution to Carcinogen-induced DNA Conformational Heterogeneity. Biochemistry, 49, 259-266 (2010).
  34. Jain, S. Meneni, and B. P. Cho.* Influence of flanking sequence context on the conformational flexibility of aminofluorene-modified dG adduct in dA mismatch DNA duplexes. Nucleic Acids Res. 37, 1628-1637 (2009).
  35. Liang, N. Jain, T. Hutchens, D. D. Shock, W. A. Beard, S. H. Wilson, M. P. Chiarelli, and B. P. Cho* a,β-Methylene-2’-deoxynucleoside 5’-triphosphates as non-cleavable substrates for DNA polymerases: Isolation, characterization, and stability studies of novel 2’-deoxycyclonucleosides, 3,5’-anhydro-dG and 2,5’-anhydro-dT. J. Med. Chem., 51, 6460 (2008)
  36. Gao, L. Zhang, B. P. Cho, and M. P. Chiarelli.* Sequence Verification of Oligonucleotides Containing Multiple Arylamine Modifications by Enzymatic Digestion and Liquid Chromatography Mass Spectrometry (LC/MS). J. Am. Mass. Spectrom., 19, 1147-1155 (2008).
  37. Jain, Y. K. Reshetnyak, L. Gao, M. P. Chiarelli, and B. P. Cho.* Fluorescence probing of aminofluorene-induced conformational heterogeneity in DNA duplexes. Chem. Res. Toxicol. 21, 445-452 (2008).
  38. Nidhi Jain, Yuyuan Li, Li Zhang, Srinivasa Meneni, and Bongsup Cho. * Probing the Sequence Effects on NarI-Induced -2 Frameshift Mutagenesis by Dynamic 19F NMR, UV, and CD Spectroscopy. Biochemistry, 46, 13310-13321 (2007).
  39. Liang and B. P. Cho.* Probing the Thermodynamics of Aminofluorene-Induced Translesion DNA Synthesis by Differential Scanning Calorimetry. J. Am. Chem. Soc., 129, 12108-12109 (2007).
  40. Meneni, S. M. Shell, L. Gao, P. Jurecka, W. Lee, J. Sponer, Y. Zou, M. P. Chiarelli, and B. P. Cho.* Spectroscopic and Theoretical Insights into Sequence Effects of Aminofluorene-induced Conformational Heterogeneity and Nucleotide Excision Repair. Biochemistry, 40, 11263-11278 (2007).
  41. Meneni, F. Liang and B. P. Cho. * Examination of the long-range effects of aminofluorene-induced conformational heterogeneity and its relevance to the mechanisms of translesion DNA synthesis. J. Mol. Biol., 366, 1387-1400 (2007).
  42. Meneni, S. M. Shell, Y. Zou, and B. P Cho.* Conformation-specific Recognition of Carcinogen-DNA Adduct in E. coli. Nucleotide Excision Repair. Chem.. Res. Toxicol., 20, 6-10 (2007).
  43. Liang, S. Meneni and B. P. Cho.* Induced Circular Dichroism Characteristics as Conformational Probes for Carcinogenic Aminofluorene-DNA Adducts. Chem. Res. Toxicol., 19, 1040-1043 (2006).
  44. R. Meneni, R. D’Mello, G. Norigian, G. Baker, L. Gao, M. P. Chiarelli, and B. P. Cho.* Sequence effects of aminofluorene- modified DNA duplexes: UV thermodynamic and circular dichroism properties. Nucleic Acids Res., 34, 755-763 (2006).
  45. Yang, Y. Huang, and B. P. Cho.* Synthesis and Characterization of Enantiomeric anti-2-Fluorobenzo[a]pyrene- 7,8-dihydrodiol-9,10-epoxides and their 2’-Deoxyguanosine and Oligodeoxynucleotide Adducts. Chem. Res. Toxicol., 19, 242-254 (2006).
  46. Linge, H.-F. Chang, K. W. Olsen, B. P. Cho, and M. P. Chiarelli.* Product Ion Studies of Diastereomeric Benzo[ghi]fluoranthene Adducts of Deoxyadenosine by Electrospray Ionization and Quadrupole Ion Trap Mass Spectrometry. Acta Chemica Acta, 557, 191-197 (2006).
  47. Del Signore, M. A. McGregor and B. P. Cho.* 1H NMR Analysis of GHB and GBL: Further Findings on the Interconversion and a Preliminary Report on the Analysis of GHB in Serum and Urine. J. Forensic Sci., 50, 81-86 (2005)
  48. Cho.* Dynamic Conformational Heterogeneities of Carcinogen-DNA Adducts and Their Mutagenic Relevance. J. of Environ. Sci. and Health, Part C-Environmental Carcinogenesis & Ecotoxicology Reviews, 22, 57-90 (2004).
  49. P. Chiarelli, H-F. Chang, K. W. Olson, D. Barbacci and B. P. Cho.* Structural Differentiation of Diastereomeric Benzo[ghi]fluoranthene Adducts of Deoxyadenosine by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry and Post-Source Decay. Chem. Res. Toxicol., 16, 1236-1241 (2003).
  50. Yang and B. P. Cho.* Preparation of Diarylamines by a Novel Aryllithium-mediated Carbon-Nitrogen Bond-forming Reaction with Nitroarenes. Tetrahedron Letters, 44, 7549-7552 (2003).
  51. P. Cho,* T.Yang, L. R. Blankenship, J. D. Moody, M. Churchwell, F. A. Beland, and S. J. Culp. Synthesis and Characterization of N-Demethylated Metabolites of Malachite Green and Leucomalachite Green. Chem. Res. Toxicol., 16, 285-294 (2003).
  52. -F. Chang, D. M. Huffer, M. P. Chiarelli, L. R. Blankenship, S. J. Culp, and B. P. Cho.* Characterization of DNA Adducts Derived from syn-Benzo[ghi]fluoranthene-3,4-Dihydrodiol-5,5a Epoxide and Comparative DNA Binding Studies with Structurally-Related anti-Diolepoxides of Benzo[ghi]fluoranthene and Benzo[c]phenanthrene. Chem. Res. Toxicol., 15, 198-208 (2002).
  53. -F. Chang, D. M. Huffer, M. P. Chiarelli, and B. P. Cho.* Characterization of DNA Adducts and Tetraols Derived from anti-Benzo[ghi]fluoranthane-3,4-Dihydrodiol-5,5a-Epoxide. Chem. Res. Toxicol., 15, 187-197 (2002).
  54. Huffer, H.-F. Chang, B. P. Cho, M. P. Chiarelli.* Differentiation of Diastereomeric Benzo[ghi]fluoranthene Tetraols by Matrix-Assisted Lase Desorption Ionization Time-of-Flight Mass Spectromerty (MALDI) and Post-source Decay (PSD). J. Am. Soc. Mass Spectrom., 12, 376-380 (2001).
  55. P. Cho,* L. R. Blankenship, J. D. Moody, D. R. Doerge, F. A. Beland S. J. Culp, Synthesis and Characterization of 4´-Amino and 4´-Nitro Derivatives of 4-N,N-Dimethylaminotriphenylmethane as Precursors for a Proximate Malachite Green Metabolite. Tetrahedron, 58, 7379-7388 (2000).
  56. -F. Chang and B. P. Cho.* Synthesis of anti- and syn-Diol Epoxides of trans-3,4-Dihydroxy-3,4-dihydrobenzo[ghi]fluoranthene: Model planar Diol Epoxides. J. Org. Chem., 64, 9051-9056 (1999).
  57. Liu and B. P. Cho.* Dimethyldioxirane Epoxidation of Polycyclic Fluoranthene Hydrocarbons. Biorg. & Biomed. Chem. Letters, 9, 2181-2184 (1999).
  58. B. P. Cho and L. Zhou.* Probing the Conformational Heterogeneity of the Acetylaminofluorene-modified 2’-Deoxyguanosine and DNA by 19F NMR Spectroscopy, Biochemistry, 38, 7572-7583 (1999).
  59. Y.-H. Chae, B.-Y. Ji, J.-M. Lin, P. P. Fu, B. P. Cho, and K. El-Bayoumy.* Nitroreduction of 4-Nitropyrene is Primarily Responsible for DNA Adduct Formation in the Mammary Gland of Female CD Rats. Chem. Res. Toxicol., 12, 180-186 (1999).
  60. Zhou and B. P. Cho.* Comparative Conformational Analyses of N-(Deoxyguanosin-8- yl)aminopyrene Adducts Derived from the Isomeric Carcinogens 1, 2, and 4-Nitropyrene. Chem. Res. Toxicol., 11, 35-43 (1998).
  61. Zhou, M. Rajabzadeh, D. D. Traficante, and B. P. Cho.* Conformational Heterogeneity of Arylamine-Modified DNA: 19F NMR Evidence. J. Am. Chem. Soc., 119, 5384-5389 (1997).
  62. Pandey, J. R. Powell, W. E. Acree, Jr., B. P. Cho, J. Kum, C. Y. Yang, and R. G., Harvey.* Spectroscopic Properties of Polycyclic Aromatic Compounds. Part 5. The Nitromethane Selective Quenching Rule Revisited in Aqueous Micellar Solvent Media. Polycyclic Aromat. Compds., 12, 1-19 (1997).
  63. Pandey, J. R. Powell, W. E. Acree, Jr., B. P. Cho, and J. C. Fetzer.* Spectroscopic Properties of Polycyclic Aromatic Compounds. Part 6. The Nitromethane Selective Quenching Rule Revisited in Aqueous Micellar Zwitterionic Surfactant Solvent Media. Talanta, 44, 413-421 (1997).
  64. P. Cho* and L. Zhou. A New Synthesis of Polycyclic Fluoranthenes of Cyclodehydration of a Keto-adduct Formed by Michael Reaction. Polycyclic Aromat. Compds., 11, 261-266 (1996).
  65. P. Cho* and L. Zhou. Attempted Synthesis of Fjord-region Containing Polycyclic Fluoranthenes Reveals A Steric-Driven Double Wagner-Meerwein Rearrangement. Tetrahedron Letters, 37, 1535-1538 (1996).
  66. B. Hansen Jr., B. P. Cho, W. A. Korfmacher, and C. E. Cerniglia.* Fungal Transformations of Antihistamines: Metabolism of Bromopheniramine, Chloropheniramine, and Pheniramine to N-Oxide and N-Demethylated Derivatives by the Fungus Cunninghamella Elegans. Xenobiotica, 25, 1081-1092 (1995).
  67. P. Cho.* Recent Progress in the Syntheses of Nitropolyarenes. A Review. Org. Prep. Proc. Int., 27, 243-272 (1995).
  68. P. Cho.* A Novel and Practical Synthesis of Polycyclic Fluoranthenes. Tetrahedron Letters, 36, 2403-2406 (1995).
  69. P. Cho* and M. A. McGregor. Tautomerism, Protonation and Ionization of Formycin in Aqueous Solution by the pH Dependence of 13C Chemical Shifts and 13C-1H Coupling Constants. Nucleosides & Nucleotides, 13, 481-490 (1994).
  70. P. Cho,* F. A. Beland, and M. M. Marques. NMR Structural Studies of a 15-mer DNA Duplex from ras Protooncogene Modified with the Carcinogen 2-Aminofluorene: Conformational Heterogeneity. Biochemistry, 33, 1373-1384 (1994).
  71. P. Cho.* Structure of Oxidatively Damaged Nucleic Acid Adducts: The pH Dependence of the 13C NMR Spectra of 8-Oxoguanosine and 8-Oxoadenosine. Mag. Reson. Chem., 31, 1048-1053 (1993).
  72. P. Cho,* M. Kim, and R. G. Harvey. Synthesis and Conformational Analysis of Nitropolycyclic Fluoranthenes. J. Org. Chem., 58, 5788-5796 (1993).
  73. P. Cho,* F. A. Beland, and M. M. Marques. One-dimensional Multiple Quantum Filtration 1H NMR Spectra of a 15-Mer DNA Duplex Modified by the Carcinogen 4-Aminobiphenyl. Mag. Reson. Chem., 31, 1008-1010 (1993).
  74. P. Cho,* F. A. Beland, and M. M. Marques. NMR Structural Studies of a 15-mer DNA Sequence from ras Protooncogene, Modified at the First Base of Codon 61 with the Carcinogen 4-Aminobiphenyl. Biochemistry, 31, 9587-9602 (1992).
  75. A. Tucker, W. E. Acree, Jr., B. P. Cho, R. G. Harvey, J. C. Fetzer.* Spectroscopic Properties of Polycyclic Aromatic Hydrocarbons: Effect of Solvent Polarity on the Fluorescence Emission Behaviour of Selected Fluoranthene, Fluorenochrysene, Indenochrysene, and Indenopyrene Derivatives. Applied Spectroscopy, 45, 1699-1705 (1991).
  76. P. Cho and F. E. Evans.* Correlation between NMR Parameters of Nucleosides and Its Implication about the Glycosyl Bond. Biochem. Biophys. Res. Commun., 180, 273-278 (1991).
  77. P. Cho and F. E. Evans.* Structure of Oxidatively Damaged Nucleic Acid Adducts. 3. Tautomerism, Ionization, and Protonation of 8-Hydroxyadenosine Studied by 15N NMR Spectroscopy. Nucleic Acids Research, 19, 1041-1047 (1991).
  78. P. Cho and F. E. Evans. Complete 1H and 13C Chemical Shift Assignments of 1-Nitropyrene. Spectroscopy Letters, 24, 1-7 (1991).
  79. H. Weyand, S. Patel, E. J. LaVoie, B. P. Cho, and R. G. Harvey.* Relative Tumor-initiating Activity of Benzo[a]fluoranthene, Benzo[b]fluoranthene, Naphtho[1,2-b]fluoranthene, and Naphtho[2,1-a]fluoranthene on Mouse Skin. Cancer Letters, 52, 229-233 (1990).
  80. P. Cho,* S. J. Culp, F. E. Evans, and F. F. Kadlubar. 15N Nuclear Magnetic Resonance Studies on the Tautomerism of 8-Hydroxy-2′-deoxyguanosine, 8-Hydroxyguanosine and Other C8-substituted Guanine Nucleosides. Chem. Res. Toxicol., 3, 445-452 (1990).
  81. J. Culp,* B. P. Cho, F. E. Evans, and F. F. Kadlubar. Structural and Conformational Analyses of 8-Hydroxy-2′-deoxyguanosine. Chem. Res. Toxicol., 2, 416-422 (1989).
  82. Minabe, B. P. Cho, and R. G. Harvey.* Electrophilic Substitution of Polycyclic Fluoranthene Hydrocarbons. J. Am. Chem. Soc., 111, 3809-3812 (1989).
  83. P. Cho and R. G. Harvey.* Complete 1H and 13C NMR Assignment of Polycyclic Aromatic Fluoranthene Hydrocarbons by Long-range Optimized Homo- and Hetero-nuclear Correlation Spectroscopy. J. Org. Chem., 52, 5679-5684 (1987).
  84. P. Cho and R. G. Harvey.* Polycyclic Fluoranthene Hydrocarbons. 2. A New General Synthesis. J. Org. Chem., 52, 5668-5678 (1987).
  85. P. Cho and R. G. Harvey.* Synthesis of Polycyclic Aromatic Fluoranthenes. Tetrahedron Letters, 28, 861-864, 2906 (1987).
  86. P. Cho, V. K. Chada, G. C. LeBreton, and D. L. Venton.* Synthesis of 9-Hydroxy-14-azaprostanoic Acids. J. Org. Chem., 51, 4279-4284 (1986).
  87. K. Arora, B. P. Cho, V. K. Chada, A. J. Bauer, C. T. Lim, G. C. LeBreton, and D. L. Venton.* An Interesting By-product Obtained from Reaction of 4-Butoxy-2-butenoate with the Alkoxide Anion of Methyl Glycolate. J. Heterocyclic Chem., 23, 963-964 (1986).
  88. K. Arora, B. Cho, R. J. Anderson, and D. L. Venton.* A Convenient Single Step Preparation of Dopamine-4-O-sulfate. Synthesis, 884 (1984).
  89. Lyu,* B. Youn, and B. Cho. Synthesis of heterocyclic fused-ring mesoisonic compounds. J. Nat. Sci. Res. Institute, 3, 85-92 (1979).
 

Research Team

From Left to Right:
  • Bongsup Cho
  • Ang Cai
  • Rachel Carley
  • Alicia Crisalli
  • Allen Schroeder
  • Mimi Ji

Bongsup Cho, Ph.D.

Full Bio