Effect Of Arsenic Trioxide On Primary Acute Lymphoblastic Leukemia Cells

Objective: To investigate the effects and the mechanisms of As2O3 on acute lymphoblastic leukemia (ALL) primary cells, and obtain some theoretic evidences for using As2O3 to treat ALL in clinic. Methods: The effect of As2O3 on the proliferation of the primary ALL cells was evaluated by b y MTT colorimetric and typan-blue exclusion assays. The apoptosis of the primary ALL cells was detected by morphological assay, flow cytometry (FCM) and DNA electrophoresis. The levels of Caspase-3 in the primary ALL cells before and after treatment with As2O3 ,and the levels of Bcl-2 in ALL primary cells were detected by FCM. Results: ①0.5μmol/L As2O3 had not significantly effect on the proliferation of the primary ALL cells, but 1.0-10.0μmol/L could significantly inhibit the proliferation of the primary ALL cells in concentration-dependent and time-dependent manners. ②After treatment with 1.0-10.0μmol/L As2O3 for 48 hours, the primary ALL cells underwent chromatin aggregation, nucleus condensation, cytoplasm vacuous degradation and membrane shrinkage ,typical DNA ladder appeared in DNA electrophoresis, sub-diploid region in FCM analysis. ③The level of Caspase-3 of the primary ALL cells was 4.11±1.93, the level of Caspase-3 was markedly increased in ALL primary cells treated with 2.0μmol/L As2O3 for 48 hours than that in control group (26.39±8.36vs11.54±2.78, p<0.001).④In the 16 cases of ALL ,9 cases had clinical curative effect and 7 cases had not. The caspase-3 levels of the two groups were 4.83±0.98 and 3.19±2.50 respectively, there was no significant difference between them. (P>0.05)⑤The caspase-3 levels of the group who had clinical curative effect and that who had no clinical curative effect were 29.67 ±7.93 and 20.59 ±4.63 respectively, there was significant difference between them. (P<0.05)⑥The Bcl-2 level of the primary ALL cells was 28.93±6.35,the levels of the group who had clinical curative effect and that who had no clinical curative effect were 26.32±5.79 and 32.63±5.47 respectively ,there was significant difference between them. (P<0.05) ⑦Before and after treatment with As2O3 ,the levels of caspase-3 of the group who had high expression level of Bcl-2 were 4.07±1.26,22.10±5.64 respectively, and the levels of caspase-3 of the group who had low expression level of Bcl-2 were 4.14±2.41 , 32.63±5.47 respectively, there was significant difference between the caspase-3 changing level of the two group after treatment with As2O3. (P<0.05) ⑧The levels of leukocyte,hemoglobin,platelets count of peripheral blood were not correlated with the levels of caspase-3 in the primary cells of ALL. (P>0.05)Conclusions:①As2O3 can inhibit the primary ALL cells proliferation and in concentration-dependent and time-dependent manners. ②As2O3 can induce the primary ALL cells apoptosis . ③The apoptosis of the primary ALL cells induced by As2O3 was via activating caspase-3. ④The Bcl-2 level of the primary ALL cells was correlated with the prognostic of ALL ,and Bcl-2 could partly inhibit the activating of caspase-3 induced by As2O3 in the primary ALL cells.⑤The caspase-3 level of ALL primary cells treatment with As2O3 was correlated with the prognostic of ALL .