Pharmacological and biochemical characterization of adenosine receptors in the human malignant melanoma A375 cell line

Abstract

1 The present work characterizes, from a pharmacological and biochemical point of view, adenosine receptors in the human malignant melanoma A375 cell line. 3 The pharmacological pro®le of radioligand binding on A375 cells was established using typical adenosine ligands which displayed a rank order of potency typical of the di erent adenosine receptor subtype. 4 Thermodynamic data indicated that radioligand binding to adenosine receptor subtypes in A375 cells was entropy-and enthalpy-driven. 5 In functional assays the high a nity A 2A agonists HE-NECA, CGS 21680 and A 2A ± A 2B agonist NECA were able to increase cyclic AMP accumulation in A375 cells whereas A 3 agonists Cl-IB-MECA, IB-MECA and NECA were able to stimulate Ca 2+ mobilization. 6 In conclusion, all these data indicate, for the ®rst time, that adenosine receptors with a pharmacological and biochemical pro®le typical of the A 1 , A 2A , A 2B and A 3 receptor subtype are present on A375 melanoma cell line.

An in vivo model of melanoma: treatment with ATP

“…It has been shown recently that melanoma cells express P1 receptors [11] and P2X 7 receptors [12]. Our work confirms this [13,14] and also identifies the presence of other P2 receptors; in particular, the P2Y 1 and P2Y 2 subtypes.…”

Targeting Adenosine Receptors for the Treatment of Melanoma

“…Human malignant melanoma A375 cells expressed high levels of A 3 AR, as determined by radioligand binding assays. Activation of these receptors did not decrease forskolin-stimulated adenylyl cyclase activity (Merighi et al, 2001), suggesting coupling of these receptors to an alternate signaling system. In fact, A 3 AR activation increased intracellular calcium release which was suppressed by an A 3 AR antagonist.…”

“…These receptors are involved in promotion of the tumor growth (Ryzhov et al, 2008). A 2B AR has been characterized in A375 human malignant melanoma cells where its activation led to increases in cyclic AMP levels (Merighi et al, 2001). As with the A 2A ARs, A 2B ARs are also expressed by the normal as well as activated Tlymphocytes .…”

“…Expression of A 2A ARs in melanoma cell line A375 was first reported by Merighi et al (2001). These cells express A 2A AR, as determined by RT-PCR and radioligand binding assays.…”

Automatisation and First Evaluation of [18F]FE@SUPPY:2, an Alternative PET-Tracer for the Adenosine A3 Receptor: A Comparison with [18F]FE@SUPPY

“…The A3AR is the most recently identified adenosine receptor and its involvement in tumors has recently been shown: the A3ARs are highly expressed on the cell surface of tumor cells [11][12][13][14][15][16] and in human enteric neurons [17] but not in the majority of normal tissues [15]. In a very comprehensive study, A3AR mRNA expression in various tumor tissues was tested using reverse transcription-PCR analysis and A3AR protein expression was studied in fresh tumors and was correlated with that of the adjacent normal tissue.…”