全反式维甲酸对NPM1突变的白血病细胞系U937细胞的作用及其机制研究

OBJECTIVE: To investigate the effect and mechanism of all-trans retinoic acid (ATRA) on leukemic cell line U937 cells with NPM1 mutation. METHODS: Human acute myeloid leukemia cell line U937 was explored, NPM1 mutated (A type) plasmids were transfected into U937 to form stable clones A1 and A2, which were identified by Western blot and Co-immunoprecipitation. The cell proliferation was measured by methylthiazolyl tetrazolium bromide (MTT); cell cycle and cell apoptosis were explored by flow cytometric; cell colony formation was measured by microscope count, the molecular pathways related to cell proliferation were measured by Western blot. RESULTS: ①The cell proliferations of mutant A1 and A2 were inhibited significantly by 52.6% and 35.8% (P<0.05), respectively under ATRA exposure. ②The percentages of G(0)/G(1) stage of mutant A1 and A2 increased by 20.1% and 35.8%, respectively under ATRA exposure. ③All the U937 leukemic cells were inhibited under ATRA exposure; the decreased percentages of vector, wild-type and mutant NPM1 cells were 32.7%, 57.9% and 90.9% respectively. ④p-ERK decreased obviously after ATRA exposure in NPM1 mutated leukemic cells. ⑤More mutant NPM1 cells inclined to apoptosis under the exposure of ATRA and cytotoxic drugs than cytotoxic drugs alone, meanwhile more cells apoptosis occurred when ATRA was administrated after cytotoxic drugs exposure. CONCLUSION: ATRA could inhibit cell proliferation and colony formation, blocked the cell cycle in the G(0)/G(1) stage accompanied by the significant reduction of p-ERK in U937 leukemic cells with NPM1 mutation. Besides, ATRA could synergize with drugs to suppress the leukemic cells survival more effectively when ATRA was administered after the cytotoxic drugs exposure in U937 leukemic cells with NPM1 mutation.