新型NO供体β-Gal-NONOate对C6细胞的抗肿瘤作用

目的比较研究二醇二氮烯翁(diazeniumdiolate,NONOate)与β-半乳糖基化的β-Gal-NONOate(β-galacto-syl-diazeniumdiolate)的作用方式及其抗肿瘤效应。方法以大鼠胶质瘤C6/LacZ和C6细胞为体外实验模型,以X-Gal(5-bromo-4-chloro-3-indolyl-beta-D-galactosidase)染色法检测β-半乳糖苷酶活性,Griess法比较-βGal-NONOate与NONOate在C6/LacZ和C6细胞中NO的释放量,采用细胞计数和MTT法比较β-Gal-NONOate与NONOate的抗肿瘤效应。结果β-Gal-NONOate在C6/LacZ细胞中的NO释放量与药物浓度呈剂量依赖关系,并在相同药物浓度条件下明显高于NONOate;而β-Gal-NONOate在不表达β-半乳糖苷酶的C6细胞中未检测到NO释放。β-Gal-NONOate对C6/LacZ细胞的抗肿瘤活性显著高于NONOate(P<0.01),但对C6细胞则没有明显的抑制作用;NONOate在C6/LacZ和C6细胞中的NO释放量和对这两个细胞系的作用效果均无显著差异(P>0.05)。结论β-Gal-NONOate比NONOate更加稳定并具有更高的抗肿瘤活性,其作用的发挥依赖于β-半乳糖苷酶的表达,是一个有效的定向胞内释放的NO供体,未来在肿瘤的治疗和研究中有较大的应用前景。

Antitumor activity of β-Gal-NONOate on C6 cells

Purpose To evaluate the antitumor effects of β-Gal-NONOate,a novel conjugate of NONOate and galactose,and to clarify its mechanism to act as an antitumor prodrug.Methods With C6/LacZ and C6 cells as in vitro model,β-galactosidase activity of tumor cells was determined through X-Gal staining;NO level in C6/LacZ cells released from β-Gal-NONOate and NONOate was evaluated with Griess assay;antitumor effects of β-Gal-NONOate and NONOate on the two cell lines were estimated by cell counting and MTT(Methylthiazoletetrazolium)assay,respectively.Results NO level released from β-Gal-NONOate in C6/LacZ cells was dependent on its concentration and evidently higher than that from NONOate.And similarly,its antitumor activity to C6/LacZ cells was obviously more powerful than NONOate(P<0.05),but it did not exhibit conspicuous cytotoxicity to C6 cells.However,the NO released from C6/LacZ and C6 cells and the effects of NONOate on both kinds of cells have no great difference.Conclusion β-Gal-NONOate was more stable and possessed higher antitumor activity than NONOate.In addition,its action greatly depended on β-galactosidase.β-Gal-NONOate was an effective intracellularly NO release compound,which would be very promising in tumor therapy and relevant research.