Extracellular ATP is a mitogen for 3T3, 3T6, and A431 cells and acts synergistically with other growth factors.

Abstract

Extracellular ATP in concentrations of 5-50 gLM displayed very little mitogenic activity by itself but it caused synergistic stimulation of [3H]thymidine incorporation in the presence of phorbol 12-tetradecanoate 13-acetate, epidermal growth factor, platelet-derived growth factor, insulin, adenosine, or 5'-(N-ethyl) These findings raise the possibility that exogenous ATP acts as a growth factor, and this was implied in two recent papers (23, 24), where ATP was compared to "more conventional mitogens." However, it is premature to call ATP a mitogen without more evidence than has been available. One must be careful to rule out the possibility that ATP is converted to adenosine by ubiquitous hydrolytic enzymes on the cell surface (ectoenzymes) (32). It was demonstrated some years ago in Rozengurt's laboratory (11-13) and by others (33) that adenosine is a potent mitogen for Swiss 3T3 cells, and this is also true for certain adenosine analogues such as NECA.In this paper, we show that exogenous ATP is a mitogen for 3T3, 3T6, A431, HFF (34), and DDT1-MF2 (35) cells. We confirm that adenosine is also mitogenic, but several lines of evidence show that ATP acts independently, in its own right, and not by being first converted to adenosine by ectoenzymes. MATERIALS AND METHODS Materials. [3H]Thymidine was purchased from Amersham.Culture media and fetal bovine serum (FBS) were from GIBCO. ATP, adenosine, epidermal growth factor (EGF), adenosine 5'-[8,y-imido]triphosphate (AdoPP[NH]P), and all other nucleotides were from Boehringer Mannheim. Bovine insulin, NECA, and phorbol 12-tetradecanoate 13-acetate (PTA) were from Sigma. Platelet-derived growth factor (PDGF) was obtained from Amgen Biologicals. All other chemicals were of the highest purity available.Cell Culture. Swiss 3T3 and 3T6 mouse fibroblasts, human A431 epidermoid carcinoma cells (14), and DDT1-MF2 cells (35), derived from a vas deferens tumor of the hamster, were maintained in Dulbecco's modified Eagle's medium (DMEM; GIBCO) containing 10 mM Hepes, 44 mM NaHCO3, penicillin (110 units/ml), streptomycin (100 ,ug/ml), and 0.5% (vol/vol) (3T6), 5% (A431, DDT1-MF2), or 10% (3T3) FBS.Cells were grown at 37°C in a humidified atmosphere containing 5% CO2 and 95% air. Two days after seeding, the 3T3 cells were given fresh medium supplemented as before and then allowed to become confluent and quiescent for 5 days. The A431, DDT1-MF2, and 3T6 cultures were used 4, 5, or 7904The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

Stimulation by extracellular ATP and UTP of the mitogen‐activated protein kinase cascade and proliferation of rat renal mesangial cells

“…Moreover, extracellular ATP may be of importance in the growth regulation of mammalian cells. Stimulation of DNA synthesis has been reported for a variety of cultured cells including mouse fibroblasts, A431 epidermoid carcinoma cells and DDT,-MF-2 vas deferens cells (Huang et al, 1989), in aortic smooth muscle cells (Malam-Souley et al, 1993;Erlinge et al, 1993), endothelial cells (Van Daele et al, 1992) and mesangial cells (Schulze-Lohoff et al, 1992). It has been reported that activation of PKC and phospholipase A2 and subsequent production of prostaglandin E2 and cyclic AMP formation are obligatory early steps in a pathway resulting in ATPdependent mitogenesis Huang et al, 1991).…”

Purinergic signaling in inflammatory cells: P2 receptor expression, functional effects, and modulation of inflammatory responses

“…Early observations, from the late 1970s on, already indicated nucleotides to equivocally affect thymocytes/lymphocyte mitogenesis/blastogenesis [147,[155][156][157][158][159][160][161]. Barankiewicz et al suggested that extracellular ATP catabolism may serve as a means of communication between B and T cells in lymphoid organs, with B lymphocytes but not T lymphocytes being the producers of adenosine via ATP breakdown, and T lymphocytes being the recipients of this signal [162].…”

Extracellular nucleotides stimulate proliferation in MCF-7 breast cancer cells via P2-purinoceptors

“…At lower concentrations, however, mitogenic actions of extracellular ATP, mediated by P2-purinoceptors, have been reported in numerous cell types, including aortic smooth muscle cells (Wang et al, 1992), mesangial cells (SchulzeLohoff et al, 1992;Ishikawa et al, 1994) and the human ovarian cancer cell lines, OVCAR-3 (Popper and Batra, 1993) and SKOV-3 (Batra and Fadeel, 1994). ATP has also been shown to act as a co-mitogen in concert with other growth factors to enhance cellular proliferation in transformed mouse fibroblasts and epidermoid carcinoma A431 cells (Huang et al, 1989) and aortic smooth muscle (Wang et al, 1992).…”