Abstract: Objective To investigate the effects of monoclonal antibodies against stathmin 1 combined vinblastine on the proliferation of K562 cells. Methods K562 cells were treated with monoclonal antibodies against stathmin 1, vinblastine alone or their combination , with the untr- eated cells used as the control, 24,48, 72,96hours later, inhabitation rate was studied by MTT assay ; The apoptosis was analyzed by invert microscope and also by flow cytometry with Annexin V/PI.Results The quantity decreased and shape, size changed after treating with different concentration of experimental groups. Monoclonal antibodies against stathmin 1 and vinblastine used alone or in combination both inhibited the proliferation of K562 cells，the inhibition ratio of their combination is more higher(P<0.05),and a synergistic effect of the two agents was noted in their combined action (P<0.05). Combined treatment of the cells resulted in significantly higher apoptsis rate than that in the other groups (P<0.05). Conclusion Monoclonal antibodies against stathmin 1 and vinblastine used alone or in combination both can inhibite proliferation of K562 cells and induce apoptsis. A synergistic effect is observed between the monoclonal antibodies against stathmin 1 and vinblastine in their inhibition of K562 cell proliferation.

Key words: Monoclonal antibodies against stathmin 1, Vinblastine, Leukemia, Proliferation, Apoptosis