Thapsigargin, Inhibitor of Sarco-Endoplasmic Ca2+-ATPase, Effectively Suppresses the Expression of S100A4 Protein in Human Breast Cancer Cell Line.

Thapsigargin (SERCA ATPase inhibitor) inhibited the S100A4 metastatic marker expression in MDA-MB231 breast cancer cells. We found that S100A4 gene transcription is regulated by Ca²⁺ signaling pathways. We found that the synthesis of S100A4 mRNA and S100A4 protein in MDA-MB231 cells was effectively suppressed by thapsigargin at a concentration of 0.4-4 μM with retaining cell viability. We assume that the change in the gene transcription in response to disturbance of Ca²⁺ homeostasis is directly involved in the remodeling of Ca²⁺ signaling pathways.