H4 receptor is involved in epithelial to mensenchymal transition-related responses via Src/ERK signaling in MDA-MB-231 cells.

N. MOHAMAD, F. MAURO, V. MEDINA, G. CRICCO, G. MARTÍN.

Congreso; European Histamine Research Society 43rd Annual Meeting; 2014

In previous studies we demonstrated in MDA-MB-231 breast cancer cells that 1 µM histamine (HA) and H4 agonists stimulate some cellular events concerning the epithelial-mensenchymal transition (EMT), a program activated during tumor progression. We also determined that 1µM HA stimulates Src phoshorylation,crucial for MDA-MB-231 cells migration. The aim of this work was to evaluate whether H4 receptor activation is involved in EMT related responses. We examined the expression and subcellular localization of beta-catenin, and the phosporylation/activation of Src and ERK1/2. Cells were serum-starvedand then treated with 1µM HA or 10 μM H4 agonists (Clobenpropit or VUF 8430,p<0.05 vs control) plus 10% FBS for 15 min. Src phosphorylation evaluated byWestern blot showed a similar increase in P-Src levels in cells treated with HAor H4 agonists. Cells treated with H4 agonists showed Src labeling on cell membrane by indirect immunofluorecence (IIF) confirming the Src activation. There was also an increase in the number of migrated cells in the presence of HA or the H4 agonists, determined by transwells units (p< 0.05). This increase was blocked by the H4 antagonist JNJ7777120 (10μM). The Src inhibitor PP2 reduced the enhancement of P-Src expression and also cell migration (p<0.05 vs control). P-Src phosphorylates substrates such as beta-catenin which translocates to nucleus and modulates EMT related genes expression. Nuclear and perinuclear beta-catenin localization was observed by IIF in cells treated for 24 h with HA or H4 agonists. The combined treatment with PP2 or JNJ7777120 reversed these effects. Src  phosphorylation induced by H4 agonists was not modified by the MEK inhibitor PD98059. However, ERK1/2 phosphorylation induced by H4 agonists was decreased in the presence of PP2 after 15 min (p<0.05). Besides, PD98059 hindered the enhancement of cell migration induced by H4 agonists (p<0.01). Our results support the involvement of the H4 receptor in MDA-MB-231 cells migration via Src/ERKsignaling.