NUcleophosmin (NPM1) is a nucleolar protein implicated in ribogenesis and export, DNA damage response and response to stress stimuli. The NPM1 gene is mutated in one third of acute myeloid leukemia (AML) patients. Mutations map to the C-terminal domain of the protein and lead to its aberrant cytoplasmic localization. N6L is a synthetic pseudopeptide that interacts with cell–surface nucleolin and inhibits cell growth. N6L also binds NPM1 and this could explain, at least in part, its toxicity. Here, we investigate the interaction between N6L and NPM1and show that N6L binds the N-terminal domain of the protein at two sites with high affinity. One of these sites overlaps with the NPM1 protein-protein interaction surface, as assessed by competition studies. We also analyzed the effect of N6L treatment in AML cells with mutated NPM1 (OCI-AML3) in comparison with cells bearing the WT protein (OCI-AML2). N6L is shown to be more effective in OCI-AML2, when administered alone. However, we also show that N6L strongly sinergizes with doxorubicin in inducing cell death in OCI-AML3 cells, suggesting that this compound might sensitize cells harbouring NPM1 mutation to chemotherapeutic treatment.
Analysis of N6L interaction with nucleophosmin and its effect on AML cell lines
DE COLA, ANTONELLA;FRANCESCHINI, MIMMA;DE LAURENZI, Vincenzo;FEDERICI, Luca
2016-01-01
Abstract
NUcleophosmin (NPM1) is a nucleolar protein implicated in ribogenesis and export, DNA damage response and response to stress stimuli. The NPM1 gene is mutated in one third of acute myeloid leukemia (AML) patients. Mutations map to the C-terminal domain of the protein and lead to its aberrant cytoplasmic localization. N6L is a synthetic pseudopeptide that interacts with cell–surface nucleolin and inhibits cell growth. N6L also binds NPM1 and this could explain, at least in part, its toxicity. Here, we investigate the interaction between N6L and NPM1and show that N6L binds the N-terminal domain of the protein at two sites with high affinity. One of these sites overlaps with the NPM1 protein-protein interaction surface, as assessed by competition studies. We also analyzed the effect of N6L treatment in AML cells with mutated NPM1 (OCI-AML3) in comparison with cells bearing the WT protein (OCI-AML2). N6L is shown to be more effective in OCI-AML2, when administered alone. However, we also show that N6L strongly sinergizes with doxorubicin in inducing cell death in OCI-AML3 cells, suggesting that this compound might sensitize cells harbouring NPM1 mutation to chemotherapeutic treatment.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
