TY - JOUR
T1 - Novel second mitochondria-derived activator of caspases (Smac) mimetic compounds sensitize human leukemic cell lines to conventional chemotherapeutic drug-induced and death receptor-mediated apoptosis
AU - Servida, Federica
AU - Lecis, Daniele
AU - Scavullo, Cinzia
AU - Drago, Carmelo
AU - Seneci, Pierfausto
AU - Carlo-Stella, Carmelo
AU - Manzoni, Leonardo
AU - Polli, Elio
AU - Deliliers, Giorgio Lambertenghi
AU - Delia, Domenico
AU - Onida, Francesco
PY - 2011/12
Y1 - 2011/12
N2 - The Inhibitor of Apoptosis Proteins (IAPs) are important regulators of programmed cell death. XIAP is the most potent among them and is over-expressed in several hematological malignancies. Its activity is endogenously antagonized by SMAC/DIABLO, and also by small molecules mimicking Smac that can induce apoptosis in tumor cells. Here we describe the activity of 56 newly synthesized Smac-mimetics in human leukemic cell lines and normal CD34 + progenitor cells. Our compounds bind to XIAP with high affinity, reduce the levels of cIAP1 and are cytotoxic at nanomolar or low micromolar concentrations. Furthermore, the Smac-mimetics synergize with Cytarabine, Etoposide and especially with TRAIL in combination treatments. Apoptosis activation was clearly detectable by the occurrence of sub G1 apoptotic peak and the accumulation of cleaved PARP, caspase 8 and caspase 3. Interestingly, the down-regulation of XIAP sensitized Jurkat cells to drugs too, confirming the role of this protein in drug-resistance. In conclusion, while being very active in leukemic cells, our Smac-mimetics have modest effects on normal hematopoietic progenitors, suggesting their promising therapeutic potential as a new class of anticancer drugs in onco-hematology, particularly when combined with TRAIL, to overcome the resistance of cancer cells.
AB - The Inhibitor of Apoptosis Proteins (IAPs) are important regulators of programmed cell death. XIAP is the most potent among them and is over-expressed in several hematological malignancies. Its activity is endogenously antagonized by SMAC/DIABLO, and also by small molecules mimicking Smac that can induce apoptosis in tumor cells. Here we describe the activity of 56 newly synthesized Smac-mimetics in human leukemic cell lines and normal CD34 + progenitor cells. Our compounds bind to XIAP with high affinity, reduce the levels of cIAP1 and are cytotoxic at nanomolar or low micromolar concentrations. Furthermore, the Smac-mimetics synergize with Cytarabine, Etoposide and especially with TRAIL in combination treatments. Apoptosis activation was clearly detectable by the occurrence of sub G1 apoptotic peak and the accumulation of cleaved PARP, caspase 8 and caspase 3. Interestingly, the down-regulation of XIAP sensitized Jurkat cells to drugs too, confirming the role of this protein in drug-resistance. In conclusion, while being very active in leukemic cells, our Smac-mimetics have modest effects on normal hematopoietic progenitors, suggesting their promising therapeutic potential as a new class of anticancer drugs in onco-hematology, particularly when combined with TRAIL, to overcome the resistance of cancer cells.
KW - Apoptosis
KW - IAP
KW - Leukemia
KW - Smac-mimetics
KW - TRAIL
KW - XIAP
UR - http://www.scopus.com/inward/record.url?scp=84856052029&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84856052029&partnerID=8YFLogxK
U2 - 10.1007/s10637-010-9475-6
DO - 10.1007/s10637-010-9475-6
M3 - Article
C2 - 20614162
AN - SCOPUS:84856052029
VL - 29
SP - 1264
EP - 1275
JO - Investigational New Drugs
JF - Investigational New Drugs
SN - 0167-6997
IS - 6
ER -