Objective: To provide experimental basis for extending the indications of arsenic trioxide (As(2)O(3)) in clinical application.
Methods: MTT assay was used to detect the cytotoxicity of As(2)O(3) in combination with daunorubicin (DNR), cytosine arabinoside (Ara-C), harringtonine (H) and vincristine (VCR) respectively on leukemic cells from 23 newly diagnosed cases with acute non-promyelocytic leukemia (ANPL) and 16 cases of relapsed, refractory ANPL.
Results: (1) As(2)O(3) inhibited the growth of leukemic cells from both newly diagnosed or relapsed and refractory ANPL patients, and there was no statistical difference in cytotoxicity of the patients in the two groups [(12.6 +/-7.7 compared with 10.1 +/-6.2)%, P<0.05]. (2) There was no correlation between the cytotoxicities of As(2)O(3) and Ara-C, H or VCR (P<0.05), but a linear correlation between As(2)O(3)and DNR was found (r=0.432, P<0.05).(3) Additivity and synergism of the cytotoxicity was found in most of the ANPL patients when As(2)O(3) was combined with the four chemotherapy drugs and the combination of As(2)O(3) with DNR or VCR enhanced the cytotoxicity significantly (P<0.05).
Conclusion: The results indicate that As(2)O(3) might be used in treatment of newly diagnosed or relapsed and refractory ANPL patients;and the combination of As(2)O(3) with DNR or VCR may enhance its therapeutic efficacy.