The utility of a differentiated preclinical liver model, HepaRG cells, in investigating delayed toxicity via inhibition of mitochondrial-replication induced by fialuridine.

The utility of a differentiated preclinical liver model, HepaRG cells, in investigating delayed toxicity via inhibition of mitochondrial-replication induced by fialuridine. Toxicol Appl Pharmacol. 2020 Jul 27;:115163 Authors: Jolly CE, Douglas O, Kamalian L, Jenkins RE, Beckett AJ, Penman SL, Williams DP, Monshouwer M, Simic D, Snoeys J, Park BK, Chadwick AE Abstract During its clinical development fialuridine caused liver toxicity and the death of five patients. This case remains relevant due to the continued development of mechanistically-related compounds against a back-drop of simple in vitro models which remain limited for the preclinical detection of such delayed toxicity. Here, proteomic investigation of a differentiated, HepaRG, and proliferating, HepG2 cell model was utilised to confirm the presence of the hENT1 transporter, thymidine kinase-1 and -2 (TK1, TK2) and thymidylate kinase, all essential in order to reproduce the cellular activation and disposition of fialuridine in the clinic. Acute metabolic modification assays could only identify mitochondrial toxicity in HepaRG cells following extended dosing, 2 weeks. Toxic effects were observed around 10 μM, which is within a range of 10-15 X approximate Cmax. HepaRG cell death was accompanied by a significant decrease in mitochondrial DNA content, indicative of inhibition of mitochondrial replication, and a subsequent reduction in mitochondrial respiration and the acti...
Source: Toxicology and Applied Pharmacology - Category: Toxicology Authors: Tags: Toxicol Appl Pharmacol Source Type: research