Effects of H4 histamine receptor ligands on the migratory capacity and mammosphere formation in breast cancer cells. Role of Src phosphorylation

TAMARA GALARZA, MOHAMAD NORA, GABRIELA MARTIN, GRACIELA CRICCO

Congreso; LXIII Reunión Científica Anual de la Sociedad Argentina de Investigación Clínica; 2018

The inhibitory effect on cell proliferation exerted by the selective H4 histamine receptor (H4R) agonists is well documented in breast cancer. However, we reported that histamine (HA) in low doses as well as the HR4 agonist VUF8430 enhances the gelatinolytic activity, cell migration and invasion in MDA-MB-231 breast cancer cells. Recently, we also demonstrated that HA dose-dependently modulates the radio-induced epithelial to mesenchymal transition (EMT) events in mammary tumor cells via Src phosphrorylation. Evidence shows that cells undergoing EMT acquire characteristics of cancer stem cells (CSCs) which may be involved in radio- and chemoresistance, tumor recurrence and cell spreading.We proposed to investigate the action of H4R ligands on the migratory capacity and mammosphere formation in MCF-7 and MDA-MB-231 cells, the Src involvement and a potential link between EMT and CSCs.MCF-7 and MDA-MB-231 cells were treated with H4R agonists (10 μM), the H4R antagonist JNJ7777120 (10 μM) and the selective Src inhibitor PP2 (2 μM). We performed cell migration assays using transwell units, Western blot to evaluate phospho-Src levels, indirect immunofluorescence for the EMT transcription factor Slug and one of the Stem cell markers (CD44), and a functional assay for CSC (mammosphere formation). Results showed that H4R agonists significantly increase MCF-7 and MDA cell migration (p