Preclinical toxicology profile of squalene epoxidase inhibitors.

Preclinical toxicology profile of squalene epoxidase inhibitors. Toxicol Appl Pharmacol. 2020 Jun 06;:115103 Authors: Nagaraja R, Olaharski A, Narayanaswamy R, Mahoney C, Pirman D, Gross S, Roddy TP, Popovici-Muller J, Smolen GA, Silverman L Abstract Small cell lung cancer (SCLC) is a particularly aggressive subset of lung cancer, and identification of new therapeutic options is of significant interest. We recently reported that SCLC cell lines display a specific vulnerability to inhibition of squalene epoxidase (SQLE), an enzyme in the cholesterol biosynthetic pathway that catalyzes the conversion of squalene to 2,3-oxidosqualene. Since it has been reported that SQLE inhibition can result in dermatitis in dogs, we conducted a series of experiments to determine if SQLE inhibitors would be tolerated at exposures predicted to drive maximal efficacy in SCLC tumors. Detailed profiling of the SQLE inhibitor NB-598 showed that dogs did not tolerate predicted efficacious exposures, with dose-limiting toxicity due to gastrointestinal clinical observations, although skin toxicities were also observed. To extend these studies, two SQLE inhibitors, NB-598 and Cmpd-4″, and their structurally inactive analogs, NB-598.ia and Cmpd-4″.ia, were profiled in monkeys. While both active SQLE inhibitors resulted in dose-limiting gastrointestinal toxicity, the structurally similar inactive analogs did not. Collectively, our data demonstrate that signif...
Source: Toxicology and Applied Pharmacology - Category: Toxicology Authors: Tags: Toxicol Appl Pharmacol Source Type: research