4-aminopyridine Induces Apoptosis of Human Acute Myeloid Leukemia Cells via Increasing [Ca2+](i) Through P2X7 Receptor Pathway

Department of Hematology, the First Affiliated Hospital of Harbin Medical University, Harbin, P.R. China.
Cellular Physiology and Biochemistry (Impact Factor: 3.55). 01/2011; 28(2):199-208. DOI: 10.1159/000331731
Source: PubMed

ABSTRACT 4-AP, a voltage-gated potassium channel blocker, was identified to exert critical pro-apoptotic properties in various types of cancer cells. The present study aims to explore the effect of 4-AP on the apoptosis of human AML cells and the underlying mechanism. We found 4-AP inhibited the proliferation and induces apoptosis in both AML cell lines and primary cultured human AML cells. The apoptosis of AML cells after 4-AP treatment was further confirmed by the disruption of mitochondrial membrane potential (MMP) and activation of caspase 3 and 9. 4-AP inhibited Kv currents in NB(4), HL-60 and THP-1 cells. Furthermore, 4-AP induced significant increment in [Ca(2+)](i), which were inhibited by KN-62, a specific blocker of P(2)X(7) receptors. KN-62 also abrogated 4-AP induced apoptosis. Knockdown of P(2)X(7) receptor by small interfering RNA blocked the effect of 4-AP. Conclusively, this study indicated that 4-AP promotes apoptosis in human AML cells via increasing [Ca(2+)](i) through P(2)X(7) receptor.

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