We previously showed that [Pt(O,O'-acac)(g-acac)(DMS)] (Pt-acac) exerts antimetastatic responses in vitro, decreasing metalloproteases production and MCF-7 cells migration. We also showed that in human neuroblastoma SH-SY5Y cells Pt-acac exerts substantial cytotoxic effects. The present study focuses on the effects of Pt-acac in neuronal cell migration and also on the possibility that NHE1 is involved in such effect. Indeed, in addition to a role in ionic homeostasis regulation, NHE1 also plays a role in cell proliferation, death and migration.

pHi was measured using the pH sensitive fluorescent dye BCECF-AM and amiloride (5-(N,NDimethyl)hydrochloride) used to inhibit NHE activity. Activation of signal transduction kinases was investigated by Western blotting and cell migration was assessed by wounding assay.

Pt-acac decreased NHE1 activity, inhibited cell migration and activated the following signaling kinases that were interacting with each other: PKC-e, EGFR, and ERK1/2. We found that ROS generated by NADPH oxidase was responsible for the Pt-acac-mediated PKC-e activation and consequential EGFR transactivation and ERK1/2 phosphorylation. Inhibition of MEK, the kinase upstream of ERK1/2, blocked the Pt-acac-induced ERK1/2 activation, the NHE1 inhibition and restored SH-SY5Y cell motility. In conclusion, we have shown a drastic impairment in cell motility in response to NHE inhibition by Pt-acac that occurs through a novel mechanism mediated by ERK1/2 activation.