P2X7 receptor activation mediates organic cation uptake into human myeloid leukaemic KG-1 cells

Purinergic Signal. 2012 Dec;8(4):669-76. doi: 10.1007/s11302-012-9320-9. Epub 2012 Jun 5.


The P2X7 purinergic receptor is an ATP-gated cation channel with an emerging role in neoplasia. In this study we demonstrate that the human KG-1 cell line, a model of acute myelogenous leukaemia, expresses functional P2X7. RT-PCR and immunochemical techniques demonstrated the presence of P2X7 mRNA and protein respectively in KG-l cells, as well as in positive control multiple myeloma RPMI 8226 cells. Flow cytometric measurements demonstrated that ATP induced ethidium(+) uptake into KG-l cells suspended in sucrose medium (EC(50) of ≈ 3 μM), but not into cells in NaCl medium. In contrast, ATP induced ethidium(+) uptake into RPMI 8226 cells suspended in either sucrose or NaCl medium (EC(50) of ≈ 3 or ≈ 99 μM, respectively), as well as into RPMI 8226 cells in KCl medium (EC(50) of ≈ 18 μM). BzATP and to a lesser extent ATPγS and αβ-methylene ATP, but not ADP or UTP, also induced ethidium(+) uptake into KG-1 cells. ATP-induced ethidium(+) uptake was completely impaired by the P2X7 antagonists, AZ10606120 and A-438079. ATP-induced ethidium(+) uptake was also impaired by probenecid but not by carbenoxolone, both pannexin-1 antagonists. ATP induced YO-PRO-1(2+) and propidium(2+) uptake into KG-1 cells. Finally, sequencing of full-length P2X7 cDNA identified several single nucleotide polymorphisms (SNPs) in KG-1 cells including H155Y, A348T, T357S and Q460R. RPMI 8226 cells contained A348T, A433V and H521Q SNPs. In conclusion, the KG-1 cell line expresses functional P2X7. This cell line may help elucidate the signalling pathways involved in P2X7-induced survival and invasiveness of myeloid leukaemic cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • Cations / metabolism
  • Cell Line
  • Humans
  • Myeloid Cells / metabolism*
  • Polymorphism, Single Nucleotide / genetics
  • Purinergic P2X Receptor Antagonists / pharmacology*
  • Receptors, Purinergic P2X7 / metabolism*


  • Cations
  • P2RX7 protein, human
  • Purinergic P2X Receptor Antagonists
  • Receptors, Purinergic P2X7
  • Adenosine Triphosphate