The effect of heparin on the cell cycle in human B-lymphoblasts: An in vitro study.

OBJECTIVE Heparin has been shown to be a strong inhibitor of the proliferation of several cell types. In this in vitro study, we investigated whether different heparin concentrations can affect the cell cycle of lymphoblasts in newly diagnosed acute lymphoblastic leukemia (ALL) patients. METHODS Lymphoblasts were incubated in different heparin concentrations (0, 10, 20 U/ml), and the percentages of lymphoblasts in each phase of the cell cycle were simultaneously measured by flow cytometry at 0, 1, and 2 hours (h). RESULTS The percentages of lymphoblasts at the G2/M and S phases were significantly increased in 20 U/ml heparin concentration at 1 h compared to 0 U/ml (without heparin) concentration. We demonstrated that heparin increases the percentages of lymphoblasts in the S and G2/M phases in a concentration- and time-dependent manner. CONCLUSION It was shown that heparin expands the proliferation of lymphoblasts by increasing the transition to G2/M and S phases and the S-phase fraction ratio. Heparin thus appears promising for its contribution to new treatment fields such as by providing a synergistic effect with chemotherapeutic drugs.