Up-regulation of Orai1 expression and store operated Ca 2+ entry following activation of membrane androgen receptors in MCF-7 breast tumor cells

Background Membrane androgen receptors (mAR) are functionally expressed in a variety of tumor-cells including the breast tumor-cell line MCF-7. They are specifically activated by testosterone albumin conjugates (TAC). The mAR sensitive signaling includes activation of Ras-related C3 botulinum toxin substrate 1 (Rac1) and reorganization of the actin filament network. Signaling of tumor-cells may further involve up-regulation of pore forming Ca2+ channel protein Orai1, which accomplishes store operated Ca2+ entry (SOCE). This study explored the regulation of Orai1 abundance and SOCE by mAR.