一氧化氮抑制洛莫司汀对BT-325胶质瘤细胞的细胞毒作用

Suppression of nitric oxide on cytotoxicity of Lomustine in glioma cell line BT-325

目的 :研究一氧化氮 (nitric oxide,NO)在体外实验中对洛莫司汀 (L omustine,CCNU)细胞毒作用的影响。方法 :使用不同浓度的细胞因子或 NO供体分别与 CCNU作用于 BT- 32 5细胞 ,用 Griess法测定 NO浓度 ,MTT法测定实验处理后肿瘤细胞的生存率 ,以此观察 NO对 CCNU细胞毒作用的影响。结果 :1IL - 1β和 LPS能刺激 BT- 32 5细胞生成 NO增加 ,并使 BT- 32 5细胞对 CCNU耐受性增强 (P<0 .0 5 ) ,这个作用能被 L- NAME所抑制。2 DETA NONOate能抑制 CCNU对 BT- 32 5细胞的细胞毒作用 (P<0 .0 5 ) ,在一定程度内呈剂量效应关系。3CCNU与 SNAP共培养 2 4 h后 ,其对 BT- 32 5细胞的细胞毒作用比单用 CCNU组明显增强 (P<0 .0 5 )。结论 :NO使 BT- 32 5细胞对 CCNU的耐受性增强 ,从而部分抑制 CCNU的细胞毒作用 ,这可能是 CCNU耐药的一个新机制 ;同时 NO能够缓解 CCNU在水溶液里的降解。

Objective: To investigate the effect of nitric oxide (NO) on cytotoxicity of Lomustine (CCNU) in vi-tro. Methods: CCNU was used to treat human glioma cell line BT-325 with different concentration of cytokines or NO donors, NO levels was measured by Griess assay and cell survival was evaluated by MTT assay. Results: ①Pretreatment with IL-1β and LPS markedly suppressed CCNU cytotoxicity in BT-325 cells with a significant increase in NO production(P<0.05). This function could be inhibited by L-NAME. ②DETA NONOate suppressed cytotoxicity of CCNU to BT-325 cells in a dose-dependent manner (P<0.05). ③CCNU co-cultured with SNAP for 24 h showed higher cytotoxic to BT-325 cells(P<0.05). Conclusion: NO partly suppresses cytotoxicity of Lomustine, which might be associated with chemoresistance of BT-325 cells against CCNU in vitro. NO can also slow the degradation of CCNU in water solution.