含精氨酸-甘氨酸-天冬氨酸肽白细胞介素-24突变体蛋白对肝癌细胞抑制作用

目的 观察含精氨酸-甘氨酸-天冬氨酸(RGD)肽模体的白细胞介素(IL)-24突变体蛋白(RGD-IL-24)对肝癌细胞的抑制作用.方法 肝癌HepG2细胞分别加入各10μl的RGD-IL-24(8 mg/L)、IL-24(8 mg/L)和磷酸盐缓冲液(PBS),噻唑蓝(MTT)比色法检测HepG2细胞生长抑制作用;DAPI染色检测HepG2细胞凋亡;免疫印迹法检测HepG2细胞bax、bcl-2及Caspase-3蛋白表达;黏附实验检测与HepG2细胞的靶向黏附.结果 RGD-IL-24、IL-24治疗4 d后HepG2细胞存活率分别为(0.219±0.015)、(0.397±0.009),与对照组(0.823±0.013)比较差异有统计学意义(P<0.01).RGD-IL-24、IL-24治疗组细胞凋亡率分别为(0.631±0.027)、(0.472±0.031),与对照组(0.082±0.013)比较差异有统计学意义(P<0.01).RGD-IL-24抑制HepG2细胞生长、诱导凋亡效果均比IL-24显著增强(P<0.05).与IL-24治疗组比较,RGD-IL-24治疗组HepG2细胞促凋亡蛋白bax增加、抗凋亡蛋白bcl-2减少、活化Caspase-3蛋白量增加.黏附实验证实RGD-IL-24与HepG2细胞的靶向结合作用增强.结论 含RGD肽模体的IL-24蛋白能通过与肝癌HepG2细胞的靶向结合增强其凋亡诱导作用.

The study of the therapic effect of RGD-IL-24, a IL-24 mutant protein, on hepatocareinoma cell in vitro

Objective To evaluate the therapic effect of RGD-IL-24,a IL-24 mutant protein,on hepatocarcinoma cell HepG2 in vitro.Methods HepG2 cells were treated with RGD-IL-24 (8 mg/L) , IL-24 (8 mg/L) and PBS, respectively.The antitumor effect of RGD-IL-24 were evaluated on cell proliferation in vitro using MTT uptake.HepG2 cells apoptosis by staining with DAPI.The levels of pro-apoptotic protein bax and anti-apoptotic protein bcl-2 were determined by western blotting.The activation of caspase 3 was also studied by western blot.Tumor-targeting of RGD-IL-24 was assayed using cell adhesion experiments.Results The results showed that RGD-IL-24 inhibited the proliferation.6f HepG2 cells.Staining with DAPI indicated that RGD-IL-24 could induce apoptosis more effectively in HepG2 cells than IL-24.The HepG2 cells treated by RGD-IL-24 showed a higher levels of bax protein and lower levels of bcl-2 protein than that of HepG2 cells treated by IL-24.Moreover,the cleavaged caspase3 showed a higher level in HepG2 cells treated by RGD-IL-24 than that of HepG2 cells treated by IL-24.Cell adhesion assay showed RGD motif targets IL-24 to HepG2 cells.Conclusion These results demonstrate that RGD-IL-24 significantly enhanced IL-24 therapeutic efficacy in HepG2 cells in vitro.