Metabolic Transformation of Antitumor Acridinone C-1305 but Not C-1311 via Selective Cellular Expression of UGT1A10 Increases Cytotoxic Response: Implications for Clinical Use

Abstract

The acridinone derivates 5-dimethylaminopropylamino-8-hydroxytriazoloacridinone (C-1305) and 5-diethylaminoethylamino-8-hydroxyimidazoacridinone (C-1311) are promising antitumor agents with high activity against several experimental cellular and tumor models and are under evaluation in preclinical and early phase clinical trials. Recent evidence from our laboratories has indicated that both compounds were conjugated by several uridine diphosphate-glucuronyltransferase (UGT) isoforms, the most active being extrahepatic UGT1A10. The present studies were designed to test the ability and selectivity of UGT1A10 in the glucuronidation of acridinone antitumor agents in a cellular context. We show that in KB-3 cells, a HeLa subline lacking expression of any UGT isoforms, both C-1305 and C-1311 undergo metabolic transformation to the glucuronidated forms on overexpression of UGT1A10. Furthermore, UGT1A10 overexpression significantly increased the cytotoxicity of C-1305, but not C-1311, suggesting that the glucuronide was more potent than the C-1305 parent compound. These responses were selective for UGT1A10 because documented overexpression of UGT2B4 failed to produce glucuronide products and failed to alter the cytotoxicity for both compounds. These findings contribute to our understanding of the mechanisms of action of these agents and are of particular significance because data for C-1305 contradict the dogma that glucuronidation typically plays a role in detoxification or deactivation. In summary, these studies suggest that extrahepatic UGT1A10 plays an important role in the metabolism and the bioactivation of C-1305 and constitutes the basis for further mechanistic studies on the mode of action of this drug, as well as translational studies on the role of this enzyme in regulation of C-1305 toxicity in cancer.

Enhanced Activity of P4503A4 and UGT1A10 Induced by Acridinone Derivatives C-1305 and C-1311 in MCF-7 and HCT116 Cancer Cells: Consequences for the Drugs’ Cytotoxicity, Metabolism and Cellular Response

“…The study on cytotoxic effect triggered by C-1305 in MCF-7 cells revealed that cells overexpressing UGT1A10 were more sensitive to the drug than EV cells and IC 50 , IC 80 and IC 90 values decreased by around 20%, 30% and 40%, respectively (Table 2), which is an unusual effect, since glucuronidation is a process that typically leads to drug deactivation. This unique effect was also obtained for C-1305 toward the previously mentioned KB-3 cells [34]. On the other hand, the analysis of cell cycle distribution, nucleus morphology and membrane perturbation did not show any differences in cellular response between cell lines ( Figures 5-9).…”

“…Moreover, studies performed in KB-3 cells transiently transfected with UGT1A10 demonstrated that glucuronidation of both compounds and UGT1A10 overexpression in KB-3 cells significantly increased the cytotoxicity of C-1305 but not C-1311. It should be underlined that the last conclusion contradicted the dogma, which indicates that glucuronidation results in deactivation of xenobiotics [34].…”

“…We showed in our previous studies that under conditions of transiently enhanced activity of UGT1A10, which allows for glucuronidation of acridinone derivatives, the cytotoxicity and capacity for DNA degradation of C-1305 and C-1311 compounds were altered in KB-3 cells [34]. Therefore we decided to obtain cells with stable overexpression of UGT1A10 enzyme in MCF-7 and HCT116 cells.…”

Genome-wide DNA copy number profiling and bioinformatics analysis of ovarian cancer reveals key genes and pathways associated with distinct invasive/migratory capabilities

“…Among the "HO-8910PM-specific gain" and "HO-8910PM-specific loss" genes enriched in the KEGG AGING CTNNB1 [25], HRAS [26], ITGB7 [27], COL6A1 [28], COL6A3 [29], UGT1A1 [30], UGT1A10 [31], UGT1A3 [32], UGT1A4 [33], UGT1A6 [34], UGT1A7 [35], UGT1A8 [36], and UGT1A9 [37] were the top 16 genes with the highest connectivity degree ( Figure 4).…”

The antitumor compound triazoloacridinone C-1305 inhibits FLT3 kinase activity and potentiates apoptosis in mutant FLT3-ITD leukemia cells

“…During biotransformation, C-1305 is not a substrate www.nature.com/aps Augustin E et al Acta Pharmacologica Sinica npg of cytochrome P450 but is metabolized by the flavin monooxygenases FMO1 and FMO3 [14] and by UDP-glucuronyltransferases [15] . Selective cellular expression of UGT1A10 increases the cytotoxic response of C-1305 [16] , and this compound up-regulates selected cytochrome P450 isoenzymes in HepG2 cells [17] . Studies of the molecular mechanism of action revealed that C-1305 is a topoisomerase II inhibitor and binds covalently to DNA in tumor cells [18] .…”