M.S. Inorganic Chemistry, University of Oklahoma, 1997
     B.S. Chemistry, University of Oklahoma, 1995

Research Activities:

Topic Area:  Red Blood Cells as Drug Carriers

L-Asparaginase (ASNase) is a drug used in treatment of acute lymphoblastic leukemia. In presence of this enzyme the asparagine, an essential amino acid for biosynthesis, is converted to aspartic acid and ammonia. The malignant cells in patients with ASNase sensitive leukemia depend on exogenous supply of asparagine for survival. Administration of ASNase results in rapid reduction of systemic asparagine causing apoptosis of cancer cells. The effect of this enzyme on normal cells is not significant compared to the malignant cells as the normal cells are capable of generating their own source of asparagine through aspartic acid by way of asparagine synthetase.

Despite its effectiveness, the use of ASNase is not without problems. Due to its bacterial origin, namely E. coli and Erwinia carotovora, ASNase causes immunogenic response in patients and requires administration in hospital setting. The problem is compounded by the fact that ASNase has short half-life which in turn necessitates frequent injection. 

In order to overcome the problems of short plasma-half life and immunogenicity of L-ASNase, we plan to encapsulate the enzyme into red blood cells (RBC). Encapsulation into RBCs can help ASNase dodge the detection of the host immune system and at the same time protect the enzyme from proteolytic degradation, thereby increasing half-life.

Recent Honors:

Upjohn Fellowship in Pharmaceutical Sciences

Publications:

''Synthesis and Characterization of Osmium Nitrosyl Porphyrins Containing Organo, Halogeno and mu-Oxo Ligands, and Extensions to the First Organometallic Thionitrosyl Porphyrins.'' Cheng, L.; Chen, L.; Chung, H.-S.; Khan, M. A.; Richter-Addo, G. B.; Young, V. G., Jr. Organometallics, 1998, 17(18), 3853-3864.

Presentations:

Hee Sun Chung, Young Min Kwon, Victor C. Yang*, ''Protein Transduction Domain Mediated Uptake of L-Asparaginase into Red Blood Cells'', 2006 AAPS Annual Meeting and Exposition, San Antonio, TX, Oct. 31, 2006.

Brief Biography:

Although Hee Sun currently calls Seattle home where her family is, she also enjoys life in Ann Arbor where fireflies abound in summer and snow in winter time. When not in lab, she can be found at an unspecified location on Franklin St. Some day she would like to learn to sail and travel to northeast to see fall foliage.