P2X7 receptor activation enhances SK3 channels- and cystein cathepsin-dependent cancer cells invasiveness

The adenosine 5′-triphosphate (ATP)-gated P2X7 receptor is a membrane-bound, non-selective cation channel, expressed in a variety of cell types. The P2X7 senses high extracellular ATP concentrations and seems to be implicated in a wide range of cellular functions as well as pathophysiological processes, including immune responses and inflammation, release of gliotransmitters and cytokines, cancer cell growth or development of neurodegenerative diseases. In the present study, we identified natural compounds and analogues that can block or sensitize the ATP (1 mM)-induced Ca 2+ response using a HEK293 cell line stably expressing human P2X7 and fluorometric imaging plate reader technology. For instance, teniposide potently blocked the human P2X7 at sub-miromolar concentrations, but not human P2X4 or rat P2X2. A marked block of ATPinduced Ca 2+ entry and Yo-Pro-1 uptake was also observed in human A375 melanoma cells and mouse microglial cells, both expressing P2X7. On the other hand, agelasine (AGL) and garcinolic acid (GA) facilitated the P2X7 response to ATP in all three cell populations. GA also enhanced the YO-PRO-1 uptake, whereas AGL did not affect the ATP-stimulated intracellular accumulation of this dye. According to the pathophysiological role of P2X7 in various diseases, selective modulators may have potential for further development, e.g. as neuroprotective or antineoplastic drugs.

Section: Discussionmentioning

confidence: 99%

Natural compounds with P2X7 receptor-modulating properties

Fischer

Urban

Immig

et al. 2013

“…It was demonstrated that P2X7 receptor activation enhances invasiveness through a mechanism involving Ca 2+ -activated SK3 K + -channel activity in the mammary carcinoma cell line MDA-MB-435 s [65]. In addition, P2X7 receptor activation in T47D breast cancer cells induces an increase in cell invasiveness associated with the expression of EMT markers, such as E-cadherin and MMP-13, via the AKT pathway [66].…”

Section: Adora2amentioning

confidence: 99%

Nucleotides and nucleoside signaling in the regulation of the epithelium to mesenchymal transition (EMT)

Martinez-Ramirez

Dı́az-Muñoz

Butanda-Ochoa

et al. 2016

The epithelium-mesenchymal transition (EMT) is an important process of cell plasticity, consisting in the loss of epithelial identity and the gain of mesenchymal characteristics through the coordinated activity of a highly regulated informational program. Although it was originally described in the embryonic development, an important body of information supports its role in pathology, mainly in cancerous and fibrotic processes. The purinergic system of inter-cellular communication, mainly based in ATP and adenosine acting throughout their specific receptors, has emerged as a potent regulator of the EMT in several pathological entities. In this context, cellular signaling associated to purines is opening the understanding of a new element in the complex regulatory network of this phenotypical differentiation process. In this review, we have summarized recent information about the role of ATP and adenosine in EMT, as a growing field with high therapeutic potential.Keywords P2 receptors . P1 receptors . Purinergic signaling . Cell migration . EMTThe purinergic system of intercellular communication General aspects The term purine (from: pure urine) was created more than 130 years ago by Emil Fischer after detailed analytical characterization of the uric acid molecule [1]. Purine molecular structure is the result of fusing pyrimidine and imidazole rings, and it exists as four N-H tautomeric forms [2]. Tautomerism of purine bases in DNA is one of the earliest reasons for mutations [3][4][5]. The interconversion of the different adenine or guanine tautomers produced mispairing with pyrimidines (which also show tautomeric forms) that may lead to changes in DNA sequence [6].Purine molecules appeared very early in the history of our planet, in the period known as Borganic evolution^, before the establishment of living systems. It has been postulated that purines could be formed by a eutectic (denoting a mixture of substances in fixed proportions that melts and freezes at a single temperature that is lower than the melting points of any of the separate constituents) concentration of HCN at extremely low temperature over a period of dozens of years [7]. Purine molecules, such as adenine and guanine, are components of the genetic material (DNA and RNA) of all living beings. Purine and pyrimidine tautomeric equilibria in nucleic acids was postulated to be significant in events such as DNA replication and repair as well as in the occurrence of point mutations [8].As nucleosides and nucleotides, purines play other highly strategic roles, acting as energy intermediates, allosteric regulators of key metabolic activities, redox molecules, and chemical messengers for signal transduction events. The two most important purines serving as extracellular ligands for paracrine and autocrine signaling are ATP and its dephosphorylated form, adenosine (ADO). ATP and ADO act as intracellular intermediate metabolites, and their presence in the

“…Various cancer cells over-express P2X7 receptors [84][85][86][87] that regulate their motility (e.g., C6 glioma cells [88] and breast cancer cells [89]). ATP enhances the migration of TGFβ1-treated A549 lung cancer cells, although the precise receptor responsible for this effect has not yet been identified [90].…”

Section: Cancer Cellsmentioning

confidence: 99%

New insights regarding the regulation of chemotaxis by nucleotides, adenosine, and their receptors

Corriden

Insel

2012

The directional movement of cells can be regulated by ATP, certain other nucleotides (e.g., ADP, UTP), and adenosine. Such regulation occurs for cells that are "professional phagocytes" (e.g., neutrophils, macrophages, certain lymphocytes, and microglia) and that undergo directional migration and subsequent phagocytosis. Numerous other cell types (e.g., fibroblasts, endothelial cells, neurons, and keratinocytes) also change motility and migration in response to ATP, other nucleotides, and adenosine. In this article, we review how nucleotides and adenosine modulate chemotaxis and motility and highlight the importance of nucleotide-and adenosine-regulated cell migration in several cell types: neutrophils, microglia, endothelial cells, and cancer cells. We also discuss difficulties in conducting experiments and drawing conclusions regarding the ability of nucleotides and adenosine to modulate the migration of professional and non-professional phagocytes.