Introduction: A randomized phase 2 study was designed to compare the combination of ficlatuzumab (AV-299), a humanized hepatocyte growth factor-neutralizing monoclonal antibody, plus gefitinib versus gefitinib monotherapy in a pulmonary adenocarcinoma population clinically enriched for EFGR tyrosine kinase inhibitor-sensitizing mutations.
Methods: A total of 188 patients were randomized 1:1 to receive either gefitinib or ficlatuzumab plus gefitinib treatment. Patients who demonstrated disease control in the single-agent gefitinib arm were allowed to cross over to ficlatuzumab plus gefitinib treatment upon disease progression.
Inhibition of the checkpoint kinase Chk1, both as a monotherapy and in combination with DNA damaging cytotoxics, is a promising therapeutic approach for the treatment of a wide array of human cancers. However, much remains to be elucidated in regard to the patient populations that will respond best to a Chk1 inhibitor and the optimal therapeutics to combine with a Chk1 inhibitor. In an effort to discover sensitizing mutations and novel combination strategies for Chk1 inhibition, an siRNA screen was performed in combination with the selective Chk1 inhibitor AR458323.
View Article and Find Full Text PDFBioorg Med Chem Lett
December 2008
Efforts towards developing orally bioavailable HIV-1 maturation inhibitors starting from betulinic acid 1 are described. SAR resulted in improved potency, physicochemical properties, and enhanced oral absorption in rats.
View Article and Find Full Text PDFEfficient human immunodeficiency virus type 1 (HIV-1) budding requires an interaction between the PTAP late domain in the viral p6(Gag) protein and the cellular protein TSG101. In yeast, Vps23p/TSG101 binds both Vps28p and Vps37p to form the soluble ESCRT-I complex, which functions in sorting ubiquitylated protein cargoes into multivesicular bodies. Human cells also contain ESCRT-I, but the VPS37 component(s) have not been identified.
View Article and Find Full Text PDFThe HIV-1 Gag protein recruits the cellular factor Tsg101 to facilitate the final stages of virus budding. A conserved P(S/T)AP tetrapeptide motif within Gag (the "late domain") binds directly to the NH2-terminal ubiquitin E2 variant (UEV) domain of Tsg101. In the cell, Tsg101 is required for biogenesis of vesicles that bud into the lumen of late endosomal compartments called multivesicular bodies (MVBs).
View Article and Find Full Text PDFThe human immunodeficiency virus type 1 initially assembles and buds as an immature particle that is organized by the viral Gag polyprotein. Gag is then proteolyzed to produce the smaller capsid protein CA, which forms the central conical capsid that surrounds the RNA genome in the mature, infectious virus. To define CA surfaces that function at different stages of the viral life cycle, a total of 48 different alanine-scanning surface mutations in CA were tested for their effects on Gag protein expression, processing, particle production and morphology, capsid assembly, and infectivity.
View Article and Find Full Text PDFTo spread infection, enveloped viruses must bud from infected host cells. Recent research indicates that HIV and other enveloped RNA viruses bud by appropriating the cellular machinery that is normally used to create vesicles that bud into late endosomal compartments called multivesicular bodies. This new model of virus budding has many potential implications for cell biology and viral pathogenesis.
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