Cathy C. Zhang

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Despite abundant evidence that aberrant Rho-family GTPase activation contributes to most steps of cancer initiation and progression, there is a dearth of inhibitors of their effectors (e.g., p21-activated kinases). Through high-throughput screening and structure-based design, we identify PF-3758309, a potent (K(d) = 2.7 nM), ATP-competitive, pyrrolopyrazole(More)
The glycinamide ribonucleotide formyltransferase (GARFT) inhibitor, 4-[2-(2-amino-4-oxo-4,6,7,8-tetrahydro-3H-pyrimidino[5,4-6][1,4]thiazin-6-yl)-(S)-ethyl]-2,5-thienoyl-L-glutamic acid (AG2034), was designed from the X-ray structure of the GARFT domain of the human tri functional enzyme. AG2034 inhibits human GARFT (Ki = 28 nM), has a high affinity for the(More)
PURPOSE [(18)F]FLT (3'-Fluoro-3' deoxythymidine)-PET imaging was proposed as a tool for measuring in vivo tumor cell proliferation. The aim of this article was to validate the use of [(18)F]FLT-PET imaging for measuring xenograft proliferation and subsequent monitoring of targeted therapy. EXPERIMENTAL DESIGN In exponentially growing xenografts, factors(More)
PURPOSE P-cadherin is a membrane glycoprotein that functionally mediates tumor cell adhesion, proliferation, and invasiveness. We characterized the biological properties of PF-03732010, a human monoclonal antibody against P-cadherin, in cell-based assays and tumor models. EXPERIMENTAL DESIGN The affinity, selectivity, and cellular inhibitory activity of(More)
Purpose: [F]FLT (30-Fluoro-30 deoxythymidine)–PET imaging was proposed as a tool for measuring in vivo tumor cell proliferation. The aim of this article was to validate the use of [F]FLT–PET imaging for measuring xenograft proliferation and subsequent monitoring of targeted therapy. Experimental Design: In exponentially growing xenografts, factors that(More)
PURPOSE Checkpoint kinase 1 (Chk1) plays a critical role in the activation of mitotic spindle checkpoint and DNA damage checkpoint. We examined the preclinical use of the Chk1 inhibitor PF-00477736 as a docetaxel-sensitizing agent. Specifically, we investigated the correlation between PF-00477736-mediated modulation of biomarkers and the sensitization of(More)
PURPOSE We aimed to assess the biologic activity of PF-03084014 in breast xenograft models. The biomarkers for mechanism and patient stratification were also explored. EXPERIMENTAL DESIGN The in vitro and in vivo properties of PF-03084014 were investigated. The mRNA expressions of 40 key Notch pathway genes at baseline or after treatment were analyzed to(More)
Purpose: We studied the effects of purine depletion on the cell cycle using a specific inhibitor of de novo purine biosynthesis, AG2034, an inhibitor of glycinamide ribonucleotide formyltransferase (GARFT). Methods: Cytotoxicity was determined by clonogenic assays, and cell cycle perturbations by flow cytometry. Ribonucleotide pools were measured by anion(More)
Phase II attrition of clinical candidates in the drug development cycle is currently a major issue facing the pharmaceutical industry. To decrease phase II attrition, there is an increased emphasis on validation of mechanism of action, development of efficacy models and measurement of drug levels at the site of action. PD 0332991, a highly specific(More)
A series of novel compounds have been designed that are potent inhibitors of poly(ADP-ribose) polymerase-1 (PARP-1), and the activity and physical properties have been characterized. The new structural classes, 3,4,5,6-tetrahydro-1H-azepino[5,4,3-cd]indol-6-ones and 3,4-dihydropyrrolo[4,3,2-de]isoquinolin-5-(1H)-ones, have conformationally locked benzamide(More)