Agonist dependent complex formation between SSTR2/ORs and inhibition of EGFR phosphorylation. Co-immunoprecipitation showing the expression of μOR (A), δOR (B) and κOR (C) in SSTR2 immunoprecipitate obtained from MCF-7, MDA-MB231 and T47D cells following indicated treatment. The agonist-induced heterodimerization between SSTR2 and μOR, δOR or κOR is receptor and cell-specific. (D) Western blot showing SSTR2 and ORs mediated inhibition of EGFR phosphorylation in breast cancer cells. MCF-7 cells displayed EGFR phosphorylation comparable to control without any discernible difference upon indicated treatment. Note the lack of EGFR phosphorylation in MDA-MB231 despite basal EGFR expression whereas T47D cells were devoid of EFGR expression and phosphorylation. Tubulin was used as a loading control.