TY - JOUR
T1 - Caspase-independent cell death in AML
T2 - Caspase inhibition in vitro with pan-caspase inhibitors or in vivo by XIAP or Survivin does not affect cell survival or prognosis
AU - Carter, Bing Z.
AU - Kornblau, Steven M.
AU - Tsao, Twee
AU - Wang, Rui Yu
AU - Schober, Wendy D.
AU - Milella, Michele
AU - Sung, Hsi Guang
AU - Reed, John C.
AU - Andreeff, Michael
PY - 2003/12/1
Y1 - 2003/12/1
N2 - Survivin and XIAP, members of the protein family known as the inhibitors of apoptosis, interfere with the activation of caspases, called the "cell death executioners." We examined Survivin (n = 116) and XIAP (n = 172) expression in primary acute myeloid leukemia (AML) blasts and assessed the impact of their expression on prognosis. They were detected in all samples analyzed. However, no correlation was observed with cytogenetics, remission attainment, or overall survival of patients with AML. To investigate the importance of caspases in chemotherapy-induced apoptosis in AML, we treated OCI-AML3 cells with Ara-C, doxorubicin, vincristine, and paclitaxel, which induced caspase cleavage and apoptosis. Blocking of caspase activation by pan-caspase inhibitor abolished poly(adenosine diphosphate [ADP]-ribose) polymerase cleavage and DNA fragmentation but did not prevent chemotherapy-induced cell death and did not Inhibit, or only partially inhibited, mitochondrial release of cytochrome c, Smac, apoptosis-inducing factor (AIF), or loss of mitochondrial membrane potential. Caspase inhibition also did not protect AML blasts from chemotherapy-induced cell death in vitro. These results suggest that expression levels of Survivin or XIAP have no prognostic impact in AML patients. Although anticancer drugs induced caspase cleavage and apoptosis, cell killing was caspase independent. This may partially explain the lack of prognostic impact of XIAP and Survivin and may suggest caspase-independent mechanisms of cell death in AML.
AB - Survivin and XIAP, members of the protein family known as the inhibitors of apoptosis, interfere with the activation of caspases, called the "cell death executioners." We examined Survivin (n = 116) and XIAP (n = 172) expression in primary acute myeloid leukemia (AML) blasts and assessed the impact of their expression on prognosis. They were detected in all samples analyzed. However, no correlation was observed with cytogenetics, remission attainment, or overall survival of patients with AML. To investigate the importance of caspases in chemotherapy-induced apoptosis in AML, we treated OCI-AML3 cells with Ara-C, doxorubicin, vincristine, and paclitaxel, which induced caspase cleavage and apoptosis. Blocking of caspase activation by pan-caspase inhibitor abolished poly(adenosine diphosphate [ADP]-ribose) polymerase cleavage and DNA fragmentation but did not prevent chemotherapy-induced cell death and did not Inhibit, or only partially inhibited, mitochondrial release of cytochrome c, Smac, apoptosis-inducing factor (AIF), or loss of mitochondrial membrane potential. Caspase inhibition also did not protect AML blasts from chemotherapy-induced cell death in vitro. These results suggest that expression levels of Survivin or XIAP have no prognostic impact in AML patients. Although anticancer drugs induced caspase cleavage and apoptosis, cell killing was caspase independent. This may partially explain the lack of prognostic impact of XIAP and Survivin and may suggest caspase-independent mechanisms of cell death in AML.
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U2 - 10.1182/blood-2003-03-0960
DO - 10.1182/blood-2003-03-0960
M3 - Article
C2 - 12920030
AN - SCOPUS:0344394469
VL - 102
SP - 4179
EP - 4186
JO - Blood
JF - Blood
SN - 0006-4971
IS - 12
ER -