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Xue Zhi Zhao, Ph.D.

Portait Photo of Xue Zhi Zhao
Chemical Biology Laboratory
Bioorganic Chemistry Section
Staff Scientist
Center for Cancer Research
National Cancer Institute
Bldg. 376, Rm. 217
P.O. Box B
Frederick, MD 21702-1201
Phone:  
301-846-5907
Fax:  
301-846-6033
E-Mail:  
zhaoxue@mail.nih.gov

Biography

Dr. Zhao received Ph.D. degree in Organic Chemistry from Lanzhou University, China under the direction of Professor Yongqiang Tu. In 2005, he joined Dr. Terrence Burke's laboratory as visiting fellow and was appointed as staff scientist in 2010. His efforts have been focused on developing HIV-1 integrase inhibitors as potential anti-AIDS agents.

Research

The main focus of my research is to develop HIV-1 integrase (IN) as potential AIDS therapeutics. Raltegravir (RAL) (Merck, October 2007), Elvitegravir (EVG) (Gilead, August 2012) and Dolutegravir (DTG) (GSK, August 2013) are currently the only IN strand transfer inhibitors (INSTIs) approved by the FDA for the treatment of AIDS. However the ability of mutant forms of IN to exhibit drug-resistance emphasizes the need to develop additional agents that retain efficacy against resistant mutants. My work is being done in collaboration with the NCI laboratories of Dr. Yves Pommier and Stephen Hughes. Through an extensive synthetic effort, I examined 2,3-dihdroxybenzoylhydrazides and amides as new classes of diketoacid (DKA) mimetics. These agents utilized methylene and oxomethylene bridges to form bicyclic variants of these 2,3-dihdroxybenzoylhydrazides and amides in which key metal-chelating heteroatoms are conformationally-constrained to coplanarity. This work resulted in the discovery of structurally simple 2,3-dihydro-6,7-dihydroxy-1H-isoindol-1-ones and 4,5-dihydroxy-1H-isoindole-1,3(2H)-diones that exhibit potent integrase inhibition at low nanomolar concentrations and display good antiviral potencies in HIV-1 infected cells. Based on these integarse inhibitors, I further developed 6,7-dihydroxy-1-oxoisoindoline-4-sulfonamide-containing HIV-1 integrase inhibitors. Co-crystal structures of these inhibitors in complex with the Prototype Foamy Virus (PFV) intasome disclosed their binding mode. I also examined tricyclic and bicyclic hydroxy-1H-pyrrolopyridine-trione containing INSTIs in an effort to overcome cytotoxicity of our earlier series of catechol-containing inhibitors. Most recently, I have developed 1-hydroxy-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamides IN inhibitors. Members of this series show single-digit nanomolar antiviral potencies against cells transfected with wild-type (WT) IN, while having improved antiviral efficacies against a panel of cells transfected with viral constructs carrying the major forms of resistant mutant IN. Low cytotoxicity in many cases results in selectivity indices (CC50/EC50) of greater than 50,000. These compounds offer potential leads for further structural variation that may ultimately yield clinical agents capable of overcoming problems associated with the development of resistance.

This page was last updated on 11/26/2013.