OBJECTIVETo explore the in vitro anti-leukemia effect of endostar (recombinant human endostatin, rhES).

METHODSThe anti-leukemia effect of endostar on fresh bone marrow cell from acute leukemia patients and healthy adult was analyzed by typan-blue exclusion assay, MTT assay, transmission electron microscopy and flow cytometry with Annexin V-FITC/PI staining.

RESULTSTreatment with endostar at concentrations of 50, 100 and 200 µg/ml for 72 hours could inhibit the proliferation of HL-60 cells. The inhibition rates were 11.6%, 30.4% and 33.5%, respectively. For NB4 cells, the inhibitory rates of 100 and 200 µg/ml endostar were 12.4% and 16.4%, respectively. The inhibition of endostar on acute leukemia cells was time and dose dependent, 50 - 200 µg/ml endostar could also inhibit the growth of fresh bone marrow cell from acute leukemia patients. While 0 - 400 µg/ml endostar had no significant effect on fresh primary bone marrow cells from healthy adult. 100 µg/ml endostar could induce apoptosis of HL-60 and NB4 cells after treatment for 72 hours. The apoptotic rates of HL-60 and NB4 cells were 19.6% and 20.8%, respectively.

CONCLUSIONEndostar inhibits proliferation of leukemia cells by inducing apoptosis. It might be a potential medication for acute leukemia.