SP1-independent inhibition of FOXM1 by modified thiazolidinediones.

This research article describes an approach to modify the thiazolidinedione scaffold to produce test drugs capable of binding to, and inhibit, the in vitro transcriptional activity of the oncogenic protein FOXM1. This approach allowed us to obtain FOXM1 inhibitors that bind directly to the FOXM1-DNA binding domain without targeting the expression levels of Sp1, an upstream transcription factor protein known to activate the expression of FOXM1. Briefly, we modified the chemical structure of the thiazolidinedione scaffold present in anti-diabetic medications such as pioglitazone, rosiglitazone and the former anti-diabetic drug troglitazone, because these drugs have been reported to exert inhibition of FOXM1 but hit other targets as well. After the chemical synthesis of 11 derivatives possessing a modified thiazolidinedione moiety, we screened all test compounds using in vitro protocols to measure their ability to (a) dissociate a FOXM1-DNA complex (EMSA assay); (b) decrease the expression of FOXM1 in triple negative-breast cancer cells (WB assay); (c) downregulate the expression of FOXM1 downstream targets (luciferase reporter assays and qPCR); and inhibit the formation of colonies of MDA-MB-231 cancer cells (colony formation assay). We also identified a potential binding mode associated with these compounds in which compound TFI-10, one of the most active molecules, exerts binding interactions with Arg289, Trp308, and His287. Unlike the parent drug, troglitazone, compound TFI-10 does not target the in vitro expression of Sp1, suggesting that it is possible to design FOXM1 inhibitors with a better selectivity profile.

New desulfured troglitazone derivatives: Improved synthesis and biological evaluation.

Breast cancer is a major medical threat which cannot be sufficiently addressed by current therapies because of spontaneous or acquired treatment resistance. Besides, triple-negative breast cancer (TNBC) tumors do not respond to targeted therapies, thus new therapeutic strategies are needed. In this context, we designed and prepared new desulfured troglitazone (TGZ)-derived molecules and evaluated them in vitro for their anti-proliferative activity, with a special focus on triple-negative breast cancer cell lines. Optimization of the synthetic strategies and deracemization of the lead compound were performed to give highly active compound 10 with low-micromolar potency. Further studies revealed that this compound triggers apoptosis rather than cell cycle arrest as observed with TGZ.

Comprehensive Evaluation of Bile Acid Homeostasis in Human Hepatocyte Co-Culture in the Presence of Troglitazone, Pioglitazone, and Acetylsalicylic Acid.

Interruption of bile acid (BA) homeostasis has been hypothesized for a variety of liver diseases and for drug-induced liver injury (DILI). Consequently, BA is gaining increasing prominence as a potential biomarker. The objective of this work was to evaluate the effect of troglitazone (TZN, associated with severe DILI), pioglitazone (PZN, rarely associated with DILI), and acetylsalicylic acid (ASA, or aspirin, not associated with DILI) on the in vitro BA homeostasis in hepatocytes co-cultured with nonparenchymal cells by monitoring the disposition of 36 BAs. The cells were supplemented with 2.5 µM d4-cholic acid, d4-chenodeoxycholic acid, d4-lithocholic acid, d4-deoxycholic acid, d4-ursodeoxycholic acid, and hyodeoxycholic acid. Concentration-time profiles of BAs were used to determine the area under the curve from the supernatant, lysate, or bile compartments, in the presence or absence of TZN, PZN, or ASA. When applicable, IC50 describing depletion of individual BAs was calculated, or accumulation greater than 200% of dimethyl sulfoxide control was noted. Thiazolidinediones significantly altered the concentration of glycine and sulfate conjugates; however, more BAs were impacted by TZN than with PZN. For commonly shared BAs, TZN exhibited 3- to 13-fold stronger inhibition than PZN. In contrast, no changes were observed with ASA. Modulation of BA disposition by thiazolidinediones and ASA was appropriately differentiated. Particularly for thiazolidinediones, TZN was more potent in interrupting BA homeostasis, and, when also considering its higher dose, may explain differences in their clinical instances of DILI. This is one of the first works which comprehensively evaluated the disposition of primary and secondary BAs along with their metabolites in an in vitro system. Differing degrees of BA homeostasis modulation was observed with various perpetrators associated with varying clinical instances of DILI. These data indicate that in vitro systems such as hepatocyte co-cultures may be a promising tool to gain a detailed insight into how drugs affect BA handling to further probe into the mechanism of DILI related to BA homeostasis.