Figure 1

Differential expression of SSTR2 and μ, δ, κ-ORs in human breast cancer cells. (A) Indirect immunofluorescence staining showing membrane (non-permeabilized, NP) and intracellular (permeabilized, P) expression of SSTR2 and μ, δ, κ-ORs in breast cancer cells. In the representative panels receptor expression at the cell surface is indicated by arrows whereas arrowheads indicate intracellular expression. (B) Cell membrane extracts obtained from MCF-7, MDA-MB231 and T47D breast cancer cells were subjected to Western blot analysis and probed with specific primary antibodies to detect the receptor expression. The immunoblots show differential expression of SSTR2 (~57 kDa) and μ (~50 kDa), δ (~48 kDa), κ (~46 kDa)-ORs in a cell specific manner. Histogram represents densitometric analysis of the receptor expression normalized by using tubulin as loading control. Results are expressed as mean ± SEM (n = 3). **p < 0.01, MCF-7 vs. MDA-MB231 or T47D cells; ## p < 0.01 ; MDA-MB231 vs. T47D. Scale bar 10 μm.