Study of inhibition activity of new antitumor drugs against chosen isoforms of cytochromes P450

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Mgr. Pavla Kroulíková Supervisor: RNDr. Jakub Hofman, Ph.D. Title of Thesis: Study of inhibitory activity of new anticancer drugs toward selected isoforms of cytochromes P450 Cytochromes P450 are important biotransformation enzymes that affect pharmacokinetic behavior of many clinically used drugs and are the cause of many major drug interactions. They may have a role in overcoming multidrug resistance of cancer cells because many cytostatic drugs are deactivated by them. Aim of this thesis was in vitro study of inhibition of selected isoforms (CYP3A4, CYP3A5, CYP1A2, CYP2C8, CYP2D6, CYP2C9, CYP2C19 and CYP2B6) by substances from the group of tyrosine kinase inhibitors - alectinib, brivanib, osimertinib and selumetinib. We used commercially available Vividâ CYP Screening kits for the study. In these kits, human cytochromes P450 are recombinantly inserted into insect microsomes. The advantage of this method is that during the experiment no other reaction catalyzed by a different enzyme occurs simultaneously. The principle of this method is conversion of fluorogenic substrate into fluorescent product by CYP450. We determined the inhibition by measuring fluorescence in the 15th minute from start..