zm-252868 and Neoplasms

The epidermal growth factor receptor (EGFR), a long-standing drug development target, is also a desirable target for imaging. Sixteen dialkoxyquinazoline analogues, suitable for labeling with positron-emitting isotopes, have been synthesized and evaluated in a battery of in vitro assays to ascertain their chemical and biological properties. These characteristics provided the basis for the adoption of a selection schema to identify lead molecules for labeling and in vivo evaluation. A new EGFR tyrosine kinase radiometric binding assay revealed that all of the compounds possessed suitable affinity (IC50 = 0.4-51 nM) for the EGFR tyrosine kinase. All of the analogues inhibited ligand-induced EGFR tyrosine phosphorylation (IC50 = 0.8-20 nM). The HPLC-estimated octanol/water partition coefficients ranged from 2 to 5.5. Four compounds, 4-(2'-fluoroanilino)- and 4-(3'-fluoroanilino)-6,7-diethoxyquinazoline as well as 4-(3'-chloroanilino)- and 4-(3'-bromoanilino)-6,7-dimethoxyquinazoline, possess the best combination of characteristics that warrant radioisotope labeling and further evaluation in tumor-bearing mice.

Topics: Aniline Compounds; Animals; Binding, Competitive; Carbon Radioisotopes; Cell Line; DNA; ErbB Receptors; Fluorine Radioisotopes; Humans; Isotope Labeling; Ligands; Mice; Neoplasms; Phosphorylation; Quinazolines; Radioligand Assay; Radionuclide Imaging; Radiopharmaceuticals; Receptor, ErbB-2; Receptor, ErbB-4; Structure-Activity Relationship; Tyrosine