Targeting Membrane HDM-2 by PNC-27 Induces Necrosis in Leukemia Cells But Not in Normal Hematopoietic Cells.

Abstract

Anticancer peptide PNC-27 binds to HDM-2 protein on cancer cell membranes inducing the formation of cytotoxic transmembrane pores. Herein, we investigated HDM-2 membrane expression and the effect of PNC-27 treatment on human non-stem cell acute myelogenous leukemia cell lines: U937, acute monocytic leukemia; OCI-AML3, acute myelomonocytic leukemia and HL60, acute promyelocytic leukemia. We measured cell surface membrane expression of HDM-2 using flow cytometry. Cell viability was assessed using MTT assay while direct cytotoxicity was measured by lactate dehydrogenase (LDH) release and induction of apoptotic markers annexin V and caspase-3. HDM-2 is expressed at high levels in membranes of U937, OCI-AML3 and HL-60 cells. PNC-27 can bind to membrane HDM-2 to induce cell necrosis and LDH release within 4 h. Targeting membrane HDM-2 can be a potential strategy to treat leukemia. PNC-27 targeting membrane HDM-2 demonstrated significant anti-leukemia activity in a variety of leukemic cell lines.