Dr. Orsolya Polgar’s mission is to deliver high quality personalized care to her patients with emphasis on preventive medicine and health education. She established Howard County Direct Primary Care after leading a successful internal medicine practice at Johns Hopkins Community Physicians. Dr. Polgar’s philosophy is that the relationship with your primary care physician should be one based on mutual trust and open communication. To facilitate this, she is available as needed and offers ample time for each patient visit.

Born and raised in Hungary, Dr. Polgar graduated “summa cum laude” from the Albert Szent-Gyorgyi Medical School (University of Szeged) in 1994. She completed her internal medicine residency training and subsequently worked as an internist in Hungary’s most prestigious military hospital.

Dr. Polgar moved to the United States and joined the National Cancer Institute in Bethesda, Maryland in 2002. In subsequent years, she earned a Ph.D. in biology and published extensively on the topic of multidrug resistance in cancer.  These years in cancer research have enabled Dr. Polgar to take a more analytical approach to patient care in today’s fast-changing world of medicine.

She completed an additional two-year residency in internal medicine in 2011 at Harbor Hospital in Baltimore, Maryland and is board certified by the American Board of Internal Medicine.

Dr. Polgar currently lives in Howard County, Maryland with her husband and two daughters (both fluent in Hungarian). She loves to hike, play tennis, and travel. Each summer, she and her family visit their relatives in Hungary.

Dr. Polgar’s Publications


Book Chapters
  • Polgar O, Robey RW, To KW, Deeken J, Fetsch PA, and Bates SE, Chapter 3: ABCG2: A new challenge in cancer drug resistance ABC Transporters and Multidrug Resistance, Wiley, 2009
  • Szakacs G, To KW, Polgar O, Robey RW, and Bates SE, Chapter 1: Multidrug Resistance Mediated by MDR-ABC Transporters, Drug Resistance in Cancer Cells, Springer, 2009
  • Robey RW, Polgar O, Deeken J, To KW, and Bates SE, Chapter 12: Breast Cancer Resistance Protein (BCRP), Drug Transporters: Molecular Characterization and Role in Drug Disposition, Wiley, 2007
Peer-Reviewed PubMed Articles
  • Polgar O, Ierano C, Tamaki A, Stanley B, Ward Y, Xia D, Tarasova N, Robey RW, Bates SE. Mutational analysis of threonine 402 adjacent to the GXXXG dimerization motif in transmembrane segment 1 of ABCG2. Biochemistry. 2010 Mar 16;49(10):2235-45.
  • Polgar O, Ediriwickrema LS, Robey RW, Sharma A, Hegde RS, Li Y, Xia D, Ward Y, Dean M, Ozvegy-Laczka C, Sarkadi B, Bates SE.Arginine 383 is a crucial residue in ABCG2 biogenesis. Biochim Biophys Acta. 2009 Jul;1788(7):1434-43. Epub 2009 May 3.
  • Robey RW, To KK, Polgar O, Dohse M, Fetsch P, Dean M, Bates SE. ABCG2: a perspective. Adv Drug Deliv Rev. 2009 Jan 31;61(1):3-13. Epub 2008 Dec 16.
  • Robey RW, Obrzut T, Shukla S, Polgar O, Macalou S, Bahr JC, Di Pietro A, Ambudkar SV, Bates SE. Becatecarin (rebeccamycin analog, NSC 655649) is a transport substrate and induces expression of the ATP-binding cassette transporter, ABCG2, in lung carcinoma cells. Cancer Chemother Pharmacol. 2009 Aug;64(3):575-83.
  • Polgar O, Deeken JF, Ediriwickrema LS, Tamaki A, Steinberg SM, Robey RW, Bates SE. The 315-316 deletion determines the BXP-21 antibody epitope but has no effect on the function of wild type ABCG2 or the Q141K variant. Mol Cell Biochem. 2009 Feb;322(1- 2):63-71.
  • Polgar O, Robey RW, Bates SE. ABCG2: structure, function and role in drug response. Expert Opin Drug Metab Toxicol. 2008 Jan;4(1):1-15.
  • To KK, Polgar O, Huff LM, Morisaki K, Bates SE. Histone modifications at the ABCG2 promoter following treatment with histone deacetylase inhibitor mirror those in multidrug- resistant cells. Mol Cancer Res. 2008 Jan;6(1):151-64.
  • Liao Z, Robey RW, Guirouilh-Barbat J, To KK, Polgar O, Bates SE, Pommier Y. Reduced expression of DNA topoisomerase I in SF295 human glioblastoma cells selected for resistance to homocamptothecin and diflomotecan. Mol Pharmacol. 2008 Feb;73(2):490-7.
  • Robey RW, Polgar O, Deeken J, To KW, Bates SE. ABCG2: determining its relevance in clinical drug resistance. Cancer Metastasis Rev. 2007 Mar;26(1):39-57.
  • Li YF, Polgar O, Okada M, Esser L, Bates SE, Xia D.Towards understanding the mechanism of action of the multidrug resistance-linked half-ABC transporter ABCG2: a molecular modeling study. J Mol Graph Model. 2007 Mar;25(6):837-51.
  • Robey RW, Fetsch PA, Polgar O, Dean M, and Bates SE. The livestock photosensitizer, phytoporphyrin (phylloerythrin), is a substrate of the ATP-binding cassette transporter ABCG2. Res. Vet. Sci., 2006 Dec;81(3):345-9.
  • Polgar O, Ozvegy-Laczka C, Robey RW, Morisaki K, Masaki Okada, Tamaki A, Koblos G, Elkind NB, Ward Y, Dean M, Sarkadi B, and Bates SE. Mutational Studies of G553 in TM5 of ABCG2: a Residue Potentially Involved in Dimerization. Biochemistry. 2006 Apr 25;45(16):5251-60.
  • Morisaki K, Robey RW, Ozvegy-Laczka C, Honjo Y, Polgar O, Steadman K, Sarkadi B, Bates SE. Single nucleotide polymorphisms modify the transporter activity of ABCG2. Cancer Chemother. Pharmacol. 2005 Aug;56(2):161-72.
  • Robey RW, Steadman K, Polgar O, Bates SE. ABCG2-mediated transport of photosensitizers: potential impact on photodynamic therapy. Cancer Biol. Ther. 2005 Feb;4(2):187-94.
  • Polgar O, Bates SE. ABC transporters in the balance: is there a role in multidrug resistance? Biochem. Soc. Trans. 2005 Feb;33(Pt 1):241-5.
  • Polgar O, Robey RW, Morisaki K, Dean M, Michejda C, Sauna ZE, Ambudkar SV, Tarasova N, Bates SE. Mutational analysis of ABCG2: role of the GXXXG motif. Biochemistry. 2004 Jul 27;43(29):9448-56.
  • Robey RW, Steadman K, Polgar O, Morisaki K, Blayney M, Mistry P, Bates SE. Pheophorbide a is a specific probe for ABCG2 function and inhibition. Cancer Res. 2004 Feb 15;64(4):1242-6.
  • Leonard GD, Polgar O, Bates SE. ABC transporters and inhibitors: new targets, new agents. Curr. Opin. Investig. Drugs. 2002 Nov;3(11):1652-9.
Posters / Oral presentations
  • Mutational Studies Aimed at Understanding the Structure and Function of ABCG2, Orsolya Polgar, Akina Tamaki, Okada Masaki., Robey W. Robey, Yvona Ward, Yongfu Li, Di Xia, and Susan E. Bates, poster presentation, 3rd Annual North American ABC Genetic Workshop, Frederick, MD, 2006
  • Mutational Analysis of ABCG2: Aiming at Residues Involved in Trafficking and/or Dimerization, oral presentation, 2nd Annual North American ABC Genetic Workshop, Frederick, MD, 2005
  • Mutational Analysis of ABCG2: Aiming at Residues Involved in Trafficking or Dimerization, Orsolya Polgar, Robert W. Robey, Csilla Ozvegy-Laczka, Di Xia, Yongfu Li, Kuniaki Morisaki, Yvona Ward, Michael Dean, Balazs Sarkadi, and Susan E. Bates, poster presentation, 2nd Gordon Research Conference on Multi-Drug Efflux Systems, Oxford, England, 2005
  • Mutational studies of G553 in TM5 of ABCG2: a residue potentially involved in dimerization, Orsolya Polgar, Robert W. Robey, Csilla Ozvegy-Laczka, Kuniaki Morisaki, Yvona Ward, Michael Dean, Balazs Sarkadi, and Susan E. Bates, poster presentation, AACR, Anaheim, CA, 2005
  • Studies of the GXXXG dimerization motif in ABCG2, Orsolya Polgar, Robert W. Robey, Kuniaki Morisaki, Michael Dean, Christopher Michejda, Zuben E. Sauna, Suresh V. Ambudkar, Nadya Tarasova, and Susan E. Bates, poster presentation, AACR, Orlando, FL, 2004
  • Studies of ABCG2 Dimerization and Function, Orsolya Polgar, Robert W. Robey, Kuniaki Morisaki, Michael Dean, Tito Fojo, Nadya Tarasova, Chris Michejda, and Susan E. Bates, poster presentation, 1st Gordon Research Conference on Multi-Drug Efflux Systems, Ventura CA, 2003
Menu Title