Progression of Luminal Breast Tumors Is Promoted by Ménage à Trois between the Inflammatory Cytokine TNFα and the Hormonal and Growth-Supporting Arms of the Tumor Microenvironment

Figure 3

Cell-remodeling of breast tumor cells, induced by TNFα + Estrogen + EGF, depends on Src-induced mechanisms. Breast tumor cells were stimulated by TNFα + Estrogen + EGF (concentrations as in Figure 1) for three days. Non-stimulated: cells grown with the diluents of the above factors. The cells were either not exposed or exposed to the Src inhibitor PP2 (used at the range of 2.5–5 μM). (A) The expression of FAK, determined in the absence ((A1a), (A2a)) or in the presence ((A1b), (A2b)) of PP2 (2.5 μM in this specific experiment) in non-stimulated cells ((A1a), (A1b)) or in cells stimulated by TNFα + Estrogen + EGF ((A2a), (A2b)). FAK expression was detected by specific Abs (red), actin filaments by phalloidin staining (green), and cell nuclei by DAPI staining (blue). In all panels, the results are from a representative experiment of 𝑛≥3. (B) The expression of paxillin, determined in the absence ((B1a), (B2a)) or in the presence ((B1b), (B2b)) of PP2 (2.5 μM in this specific experiment) in non-stimulated cells ((B1a), (B1b)) or in cells stimulated by TNFα + Estrogen + EGF ((B2a), (B2b)). Paxillin expression was detected by specific Abs (purple), actin filaments by phalloidin (green), and cell nuclei by DAPI staining (blue). In all panels, the results are from a representative experiment of 𝑛=3.