骨肉瘤细胞株阿霉素耐药与错配修复基因1基因甲基化的关系

The relationship between mismatch repair gene 1 gene methylation and adriamycin resistance of osteosarcoma

目的探讨错配修复基因1（hMLH1）基因的启动子甲基化与骨肉瘤耐阿霉素（ADR）细胞株MG63/ADR的ADR耐药是否相关。方法噻唑蓝（MTT）法及流式细胞术检测浓度分别为0、2、4、8、16、32 μmol/L的ADR干预48 h后对MG63及MG63/ADR细胞增殖的影响，以及MG63/ADR细胞对ADR的耐药指数，5-氮-2’-脱氧胞苷对MG63/ADR细胞的毒性作用以及MG63/ADR细胞经0、50、100 μmol/L的5-氮-2’-脱氧胞苷干预48 h后其对ADR的半数抑制浓度及耐药逆转指数。结果MG63和MG63/ADR细胞对ADR的半数抑制浓度分别为（2.28±0.12） μmol/L和（11.18±0.11） μmol/L，MG63/ADR的耐药指数为4.90；MTT和流式细胞术检测5-氮-2’-脱氧胞苷作用48 h，50 μmol/L 5-氮-2’-脱氧胞苷为MG63/ADR细胞的无毒剂量，100 μmol/L 5-氮-2’-脱氧胞苷为其低毒剂量；MG63/ADR细胞被无毒剂量及低毒剂量5-氮-2’-脱氧胞苷处理后，ADR对MG63/ADR细胞的半数抑制浓度分别降至（6.18±0.13） μmol/L和（4.42±0.12） μmol/L；耐药逆转指数分别为1.81、2.53。结论hMLH1基因启动子的甲基化可能参与了骨肉瘤MG63/ADR细胞的ADR耐药。

Objective To investigate whether human mismatch repair gene 1 （ hMLH1 ） gene pro- moter methylation correlate with adriamycin resistance of osteosarcoma MG63/ADR cell. Methods Methyl thiazol tetrazolium （MTI＇） method and flow cytometry was used to test the influence of MG63 and MG63/ ADR cell proliferation which were dealed with 0, 2, 4, 8, 16, 32 txmol/L of adriamycin for 48 hours, and adriamycin resistance index of MG63/ADR cell, the cytotoxicity of 5 - Aza - dc on MG63/ADR, half max- imal inhibitory concentration （ ICs0 ） and adriamycin resistance reversal index of MG63/ADR cell 48 h after MG63/ADR cell dealed with 0, 5, 10 μmol/L of 5 - Aza - dc. Results The IC50 of adriamycin in MG63 cells and MG63/ADR cells were （2. 28 ± 0. 12） μmol/L, （11.18±0. 11） μmol/L, MG63/ADR cells＇ resistance index was 4. 90. MTT method and flow cytometry showed that after 48 h intervened by 5 - Aza - de, non - toxic dose and low - toxic dose of MG63/ADR cell were 50 μmol/L and 100 μmol/L. non - toxic dose and low-toxic dose reduced ICs0 of adriamycin to （6. 18 ±0. 13） , （4. 42 ±0. 12） μmol/L; adria- mycin resistance reversal index were 1.81, 2. 53. Conclusion hMLH1 promoter methylation may be in- volved in the adriamycin resistance of osteosarcoma.