Normal fibroblasts induce a mesenchymal phenotype in mammary epithelial tumor cells which is blocked by histamine treatment of fibroblasts

J. PORRETTI, N. MOHAMAD, E. BADENAS, M. ESNAOLA, MICAELA SANTORO, D. MARTINEL LAMAS, G. MARTÍN, G. CRICCO

LODZ

Congreso; XLII Annual Meeting of the European Histamine Research Society (EHRS); 2013

European Histamine Research Society (EHRS)

Interactions between neoplastic and stromal cells are crucial for tumor growth and also for defining the metastasic behavior. Previously, we determined that histamine exerts a direct action in normal human fibroblasts CCD-1059Sk modulating its proliferation, migration and gelatinolytic activity. Epithelial to mesenchymal transition (TEM) is a biological process for cancers to be more aggressive and invasive. As fibroblasts are the main cellular component in the stroma, we proposed to evaluate the mesenchymal phenotype induced in mammary epithelial tumor cells when they were cultured with the conditioned medium (CM) derived from normal fibroblasts untreated or treated with histamine (0.1 uM and 20 uM), studying the expression of epithelial (E-cadherin) and mesenchymal markers beta-catenin, alpha- smooth muscle actin), TGF-beta, gelatinolytic activity and cell migration. We employed the mammary epithelial cell lines MDA-MB-231 and MCF-7, and fibroblasts CCD-1059Sk. In MDA-MB-231 cells, CM from control fibroblasts (CM(+)) induced morphological changes characterized by spindle-shaped cells and scattered colonies. There was an increase in alpha-smooth muscle actin, beta-catenin and TGF-beta1 by Western blot, an increase in MMP2 activity by zymography (400% vs 100%(CM(-), p<0.05) and an enhancement of cell migration using transwells units (135% vs 100%(CM(-), p<0.05). In MCF-7 cells, CM(+) induced morphological changes in cells and colonies; there was no change in total protein levels of cell markers by Western blot but an altered subcellular distribution. Besides, no increase in MMP2 activity or cell migration was observed. Notably, the distinctive and the intermediate mesenchymal phenotype induced by CM(+) in MDA-MB-231 and MCF-7 cells respectively were reverted by CM from histamine-treated fibroblasts. In summary, HA might modify tumor microenvironment and therefore contribute to design future antineoplastic therapies.