New 4-thiazolidinone-based molecules Les-2769 and Les-3266 as possible PPARγ modulators

Development of cancer drug-resistance is still an ongoing problem in the modern anticancer treatment. Therefore, there is a need to search for a new active substance, which may become a potential anticancer agent. 4-Thiazolidinones are well-described substances with cytotoxicity against cancer cells in vitro. Therefore, the aim of this study was to evaluate the effect of two 4-thiazolidinone-based derivatives (Les-2769 and Les-3266) on the PPARγ-dependent cytotoxicity in normal human skin fibroblasts (BJ) and squamous cell carcinoma (SCC-15) in vitro. The data obtained showed a cytotoxic effect of Les-2769 and Les-3266 used in micromolar concentrations on SCC-15 and BJ cells, manifesting by a decrease in the metabolic activity, an increase in the release of lactate dehydrogenase, and caspase-3 activity. The co-treatment of the cells with Les-3266 and an antagonist (GW9662) or an agonist (rosiglitazone) of the PPARγ receptor induced changes in the above-mentioned parameters in the BJ and SCC-15 cells, compared to the Les-3266 alone exposure; this was not found in the Les-2769-treated cells. The further analysis of the compounds indicated changes in the expression of the PPARγ, KI67, and NF-κB genes. Moreover, the tested compounds caused an increase in the level of PPARγ mRNA expression in a similar way to rosiglitazone in SCC-15, which may indicate the affinity of the compounds for PPARγ. Molecular docking is consistent with experimental in vitro data about the potential agonistic activity of Les-2769 and Les-3266 towards PPARγ receptors. Summarizing, the anticancer effect of both compounds was observed in the SCC-15 cells in vitro; moreover, the mechanism of action of Les-3266 in cells is mediated probably by interaction with the PPARγ receptor pathway, which needs in-depth study.