Monitoring the Effect of Tributyltin Salicylate and Propionate, Retinoid X Receptor Ligands, on Heat Shock Protein Expression in MDA‐MB‐231 Cells by MALDI MS/MS

Organotin (IV) compounds are known to induce apoptosis via the intrinsic mitochondrial pathway, which is a key mechanism of effective anticancer therapy. Their ability to selectively promote apoptotic cell death highlights their potential as chemotherapeutic agents. In this study, the in vitro effects of two triorganotin compounds, tributyltin propionate and tributyltin salicylate, on the human breast cancer cell line MDA-MB-231 were evaluated. In addition to their proven antitumor activity, these compounds may act as synthetic ligands for nuclear retinoid X receptors. Protein expression profiles were examined using gel electrophoresis and MALDI-TOF mass spectrometry, with a particular focus on heat shock proteins (HSPs), which are commonly overexpressed in cancer cells and contribute to tumor progression and therapeutic resistance. Both triorganotin derivatives significantly reduced HSP expression, suggesting that HSPs could be a promising target in cancer therapy.