Effects of Selected Organotin Halides on Human Breast Cancer Cell Line MDA-MB-231 Growth and Migration

Background and aims. Organotins represent a group of organic pollutants with potent endocrine-disrupting properties. The aim of the study was to assess the cytotoxicity of tributyltin chloride (TBT-Cl), tributyltin bromide (TBT-Br), tributyltin iodide (TBT-I), and non-halide tributyltin hydride (TBT-H) in human triple-negative MDA-MB-231 cell line as well as their ability to influence migration of cancer cells.

Methods. MTT assay and the INCUCYTE™ Kinetic Imaging System were used to measure cytotoxicity of tested compounds and growth characteristics of cells. The migration assay used the 96-well WoundMaker to generate a cell-free zone in a monolayer of cells with subsequent cell imaging set to scan the experiment every hour using “Scratch Wound” experiment type. CD44 expression was determined by Flow cytometry.

Results. The IC50 values determined by MTT assay revealed the toxicity order of tested endocrine-disrupting organic pollutants, which was confirmed also by observation of growth inhibition based on high-quality phase-contrast imaging confluence assessment. Their cytotoxicity was in this order: tributyltin chloride ≥ tributyltin bromide ≥ tributyltin iodide > tributyltin hydrid. TBT-Cl was able to slow migration of MDA-MB-231 cells, which was accompanied by the surface CD44 down-regulation.

Conclusions. Our work suggests that observed cytotoxicity of tributyltin halides could depend on type of halogen atom in the organotin molecule and TBT-Cl may modulate the metastatic properties of MDA-MB-231 cells.

This work was supported by the APVV-0160-11, VEGA 2/0080/15 and VEGA 2/0171/14 as well as by RfL2012 program funded by the Cancer Research Foundation, Slovakia.