Kca3.1 Activation Via P2y2 Purinergic Receptors Promotes Human Ovarian Cancer Cell (Skov-3) Migration

L Robles-Martínez,E Garay,D Pérez-Montiel,A Cisneros-Mejorado,R O Arellano,M G Martel-Gallegos,A Lara

doi:10.1038/s41598-017-04292-6

Abstract

Disorders in cell signaling mediated by ATP or histamine, activating specific membrane receptors, have been frequently associated with tumorigenesis. Among the elements of response to purinergic (and histaminergic) signaling, ion channel activation controls essential cellular processes in cancer, such as cell proliferation, motility, and death. Here, we studied the effects that ATP had on electrical properties of human ovarian adenocarcinoma cells named SKOV-3. ATP caused increase in intracellular Ca2+ concentration ([Ca2+]i) and, concurrently, it evoked a complex electrical response with a conspicuous outward component. This current was generated through P2Y2 receptor activation and opening of K+ channels, KCa3.1, as indicated by electrophysiological and pharmacological analysis, as well as by immunodetection and specific silencing of P2Y2 or KCa3.1 gene by esiRNA transfection. Low µM ATP concentration increased SKOV-3 cell migration, which was strongly inhibited by KCa3.1 channel blockers and by esiRNA-generated P2Y2 or KCa3.1 downregulation. Finally, in human ovarian tumors, the P2Y2 and KCa3.1 proteins are expressed and co-localized in neoplastic cells. Thus, stimulation of P2Y2 receptors expressed in SKOV-3 cells promotes motility through KCa3.1 activation. Since P2Y2 and KCa3.1 are co-expressed in primary tumors, our findings suggest that they may play a role in cancer progression.

Highlights

Previous studies indicated that ion channel function might be one of the modifications suffered in cancer; their activation or inhibition, for example, affects various important functional processes in the context of cancer[7,8,9,10]
We showed that the KCa3.1 channel activation was a prompt, electrical response to Adenosine 5′-triphosphate (ATP) or histamine and that it promoted SKOV-3 cell migration, while specific silencing of KCa3.1 or P2Y2 gene downregulated protein expression and strongly reduced both the electrical response and cell motility
Responses elicited by adenosine 5′-diphosphate (ADP) were reduced compared with the control group, changes were not statistically significant in such cases. All these results indicated that downregulation of P2Y2 or KCa3.1 eliminated the electrical response to ATP or uridine 5′-triphosphate (UTP), and that strongly reduced the [Ca2+]i increase regularly generated by the same agonists

Summary

Introduction

Previous studies indicated that ion channel function might be one of the modifications suffered in cancer; their activation or inhibition, for example, affects various important functional processes in the context of cancer[7,8,9,10]. Histamine) on the electrical properties of human ovarian cancer cells named SKOV-313, a well-studied cell model that expresses molecular markers of epithelial to mesenchymal transition, a phenomenon associated with tumor metastasis[14]. We showed that the KCa3.1 channel activation was a prompt, electrical response to ATP or histamine and that it promoted SKOV-3 cell migration, while specific silencing of KCa3.1 or P2Y2 gene downregulated protein expression and strongly reduced both the electrical response and cell motility. We propose that KCa3.1 channels are important for the tumorigenic process, by promoting cellular migration. This information suggests that KCa3.1 channels might be a useful target for the development of diagnostic and therapeutic strategies against ovarian cancer

Methods

Results

Conclusion