Histamine and the invasive phenotype in irradiated PANC-1 cells

SÁEZ M, MOHAMAD N, VALLI E, RIVERA E, NÚÑEZ M, GUTIÉRREZ A, CRICCO G, MARTÍN G

Fulda, Germany

Congreso; XXXVIII Meeting of the European Histamine Research Society; 2009

European Histamine Research Society

E-cadherin mediated cell-cell adhesion, metalloproteinases (MMPs) expression and activity, and cell migration are crucial features of the invasive phenotype. Ionizing radiation (IR) is known to induce an increase in invasive potential of different cancer cells. We have previously reported that human pancreatic carcinoma PANC-1 cells express H1, H2, H3 and H4 histamine (HA) receptors and that HA modulates cell invasiveness through H1R and H2R.  In this work, we studied the combined action of HA and IR on PANC-1 cells invasive phenotype. Cells were 2 and 5 Gy gamma-irradiated and incubated with HA and specific agonists for different times. In non irradiated cells HA increased ROS (reactive oxygen species) production measured by fluorescent dyes as well as cell migration evaluated by wound healing assay. E-cadherin expression was not modified. In cells treated with H1, H2, H3 or H4 agonists, intracellular MMP-2 protein detected by flow cytometry was significantly diminished while zymographic analysis revealed an increase in MMP-2 activity in conditioned media. Collectively, data suggest an enhanced secretion of MMP2. It is known that activation and secretion of MMP-2 depend on ROS production. Accordingly, in these cells MMP-2 activity was downmodulated by a ROS scavenger (N-acetyl cysteine). In irradiated cells E-cadherin was upregulated, migration was not affected. whereas ROS levels were significantly decreased. Even though IR did not significantly decrease MMP2 secretion, was able to counteract the effect of HA and HA agonists when both IR and HA agonists were combined. This combined treatment did not show differences in E-cadherin expression and cell migration compared to each treatment alone. In summary, IR does not substantially modify the studied events related to PANC-1 cells invasiveness, but is able to affect HA response on MMP-2 activity and secretion probably by altering ROS levels.