Study of the effect of methotrexate and cyclophophamide on cell cycle and cyclin DI of lymphocytes in the periphery blood and bone marrow in rats / 中华风湿病学杂志

ABSTRACT

Objective To investigate the synergistic effect of methotrexate (MTX) and cyclophos phamide (CTX) on cell cycle and cyclin D1 of periphery blood lymphocytes (PBLs) and bone marrow byflow cytometry. Methods Wistar rats were randomly divided into four groups including normal control, MTX and cyclophosphamide combination group, MTX and CTX only treatment groups respectively. PBLs were isolated for flowcytometry analysis for the changes of cell cycle and the expression of cyclin D1 at week 0, week 3,week 9, week18 and week 27. Mice were dissected and the changes of lymphoeytes cell cycle and the expressions of cyclin D1 in the bone marrow were measured at week 0, week 3, week 9, week 18 and week 27 increased and the ratio of phase S cells was decreased (P>0.05). In the CTX treatment group, there was no statistical difference in ratios of each phase. In the MTX and CTX combination treatment group, the proportion of phase G0/G1 cells decreased significantly and the percentage of phase S cells increased in both PBLs and bone marrow ceils (P<0.05). And there was no statistical significant difference in different time points after marrow between different groups or different dissecting time points. Conclusion MTX combined with CTX has been shown to have antagonistic effect on cell cycle. However, this effect is not via the cyclin DI pathway.