PURPOSE: To analyze the effect of the combination of Dasatinib, a multi-kinase inhibitor, plus Nutlin-3, a non-genotoxic activator of the p53 pathway, in primary B chronic lymphocytic leukemia (B-CLL) patient samples and B leukemic cell line models. EXPERIMENTAL DESIGN: The induction of cytotoxicity was evaluated in both primary B-CLL cell samples (n=20) and in p53wild-type (EHEB, JVM-2) and p53deleted/mutated (MEC-2, BJAB) B leukemic cell lines. The role of Akt in modulating leukemic cell survival/apoptosis in response to Dasatinib or Dasatinib+Nutlin-3 was documented by functional experiments carried out using specific pharmacological inhibitors and by over-expression of membrane-targeted constitutively active form of Akt. RESULTS: The combination of Dasatinib+Nutlin-3 exhibited a synergistic cytotoxicity in the majority (19 out of 20) of B-CLL samples, including patients carrying 17p- (n=4), and in both p53wild-type and p53deleted/mutated B leukemic cell lines. At the molecular level, Dasatinib significantly counteracted the Nutlin-3-mediated induction of the p53 transcriptional targets MDM2 and p21 observed in p53wild-type leukemic cells. Conversely, Nutlin-3 did not interfere with the ability of Dasatinib to decrease the phosphorylation levels of ERK1/2, p38/MAPK and Akt in both p53wild-type and p53deleted/mutated B leukemic cell lines. A critical role of Akt down-regulation in mediating the anti-leukemic activity of Dasatinib and Dasatinib+Nutlin-3 was demonstrated in experiments carried out by specifically modulating the Akt pathway. CONCLUSIONS: These findings suggest that Dasatinib+Nutlin-3 might represent an innovative therapeutic combination for both p53wild-type and p53deleted/mutated B-CLL.
Dasatinib plus Nutlin-3 shows synergistic anti-leukemic activity in both p53wild-type and p53mutated B chronic lymphocytic leukemias by inhibiting the Akt pathway.
ZAULI, Giorgio;VOLTAN, Rebecca;BOSCO, Raffaella;MELLONI, Elisabetta;RIGOLIN, Gian Matteo;CUNEO, Antonio;SECCHIERO, Paola
2011
Abstract
PURPOSE: To analyze the effect of the combination of Dasatinib, a multi-kinase inhibitor, plus Nutlin-3, a non-genotoxic activator of the p53 pathway, in primary B chronic lymphocytic leukemia (B-CLL) patient samples and B leukemic cell line models. EXPERIMENTAL DESIGN: The induction of cytotoxicity was evaluated in both primary B-CLL cell samples (n=20) and in p53wild-type (EHEB, JVM-2) and p53deleted/mutated (MEC-2, BJAB) B leukemic cell lines. The role of Akt in modulating leukemic cell survival/apoptosis in response to Dasatinib or Dasatinib+Nutlin-3 was documented by functional experiments carried out using specific pharmacological inhibitors and by over-expression of membrane-targeted constitutively active form of Akt. RESULTS: The combination of Dasatinib+Nutlin-3 exhibited a synergistic cytotoxicity in the majority (19 out of 20) of B-CLL samples, including patients carrying 17p- (n=4), and in both p53wild-type and p53deleted/mutated B leukemic cell lines. At the molecular level, Dasatinib significantly counteracted the Nutlin-3-mediated induction of the p53 transcriptional targets MDM2 and p21 observed in p53wild-type leukemic cells. Conversely, Nutlin-3 did not interfere with the ability of Dasatinib to decrease the phosphorylation levels of ERK1/2, p38/MAPK and Akt in both p53wild-type and p53deleted/mutated B leukemic cell lines. A critical role of Akt down-regulation in mediating the anti-leukemic activity of Dasatinib and Dasatinib+Nutlin-3 was demonstrated in experiments carried out by specifically modulating the Akt pathway. CONCLUSIONS: These findings suggest that Dasatinib+Nutlin-3 might represent an innovative therapeutic combination for both p53wild-type and p53deleted/mutated B-CLL.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
