TY - JOUR
T1 - Myeloperoxidase expression as a potential determinant of parthenolide-induced apoptosis in leukemia bulk and leukemia stem cells
AU - Kim, Yu Ri
AU - Eom, Ju In
AU - Kim, Soo Jeong
AU - Jeung, Hoi Kyung
AU - Cheong, June Won
AU - Kim, Jin Seok
AU - Min, Yoo Hong
PY - 2010/11
Y1 - 2010/11
N2 - Given that parthenolide (PTL) is an effective antileukemic agent, identifying molecular markers that predict response to PTL is important. We evaluated the role of myeloperoxidase (MPO) in determining the sensitivity of leukemia cells to PTL-induced apoptosis. In this study, the level of PTL-induced generation of reactive oxygen species (ROS) and apoptosis was significantly higher in the MPO-high leukemia cell lines compared with the MPO-low leukemia cell lines. Pretreatment of MPO-high leukemia cells with a MPO-specific inhibitor, 4-aminobenzoic acid hydrazide, or a MPO-specific small interfering RNA (siRNA) abrogated the PTL-induced ROS generation and apoptosis, indicating that MPO plays a crucial role in PTL-induced apoptosis in leukemia cells. PTL-induced apoptosis was accompanied by down-regulation of nuclear factor-κB, Bcl-xL, Mcl-1, X-linked inhibitor of apoptosis protein, and survivin and selectively observed in primary acute myeloid leukemia (AML) cells expressing higher levels of MPO (≥50%) while sparing both AML cells with lower MPO and normal CD34-positive (CD34+) normal bone marrow cells. The extent of PTL-induced apoptosis of the CD34+CD38- cell fraction was significantly greater in the MPO-high AML cases, compared with the MPO-low AML (P < 0.01) and normal CD34+ marrow cells (P < 0.01). Nonobese diabetic/severe combined immunodeficient human leukemia mouse model also revealed that PTL preferentially targets the MPO-high AML cells. Our data suggest that MPO plays a crucial role in determining the susceptibility of leukemia cells to PTL-induced apoptosis. PTL can be considered a promising leukemic stem cell-targeted therapy for AML expressing high levels of MPO.
AB - Given that parthenolide (PTL) is an effective antileukemic agent, identifying molecular markers that predict response to PTL is important. We evaluated the role of myeloperoxidase (MPO) in determining the sensitivity of leukemia cells to PTL-induced apoptosis. In this study, the level of PTL-induced generation of reactive oxygen species (ROS) and apoptosis was significantly higher in the MPO-high leukemia cell lines compared with the MPO-low leukemia cell lines. Pretreatment of MPO-high leukemia cells with a MPO-specific inhibitor, 4-aminobenzoic acid hydrazide, or a MPO-specific small interfering RNA (siRNA) abrogated the PTL-induced ROS generation and apoptosis, indicating that MPO plays a crucial role in PTL-induced apoptosis in leukemia cells. PTL-induced apoptosis was accompanied by down-regulation of nuclear factor-κB, Bcl-xL, Mcl-1, X-linked inhibitor of apoptosis protein, and survivin and selectively observed in primary acute myeloid leukemia (AML) cells expressing higher levels of MPO (≥50%) while sparing both AML cells with lower MPO and normal CD34-positive (CD34+) normal bone marrow cells. The extent of PTL-induced apoptosis of the CD34+CD38- cell fraction was significantly greater in the MPO-high AML cases, compared with the MPO-low AML (P < 0.01) and normal CD34+ marrow cells (P < 0.01). Nonobese diabetic/severe combined immunodeficient human leukemia mouse model also revealed that PTL preferentially targets the MPO-high AML cells. Our data suggest that MPO plays a crucial role in determining the susceptibility of leukemia cells to PTL-induced apoptosis. PTL can be considered a promising leukemic stem cell-targeted therapy for AML expressing high levels of MPO.
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U2 - 10.1124/jpet.110.169367
DO - 10.1124/jpet.110.169367
M3 - Article
C2 - 20699435
AN - SCOPUS:78149254492
VL - 335
SP - 389
EP - 400
JO - Journal of Pharmacology and Experimental Therapeutics
JF - Journal of Pharmacology and Experimental Therapeutics
SN - 0022-3565
IS - 2
ER -