壳寡糖对S180肉瘤细胞凋亡、细胞周期以及凋亡相关蛋白Bcl-2、Bax的影响

Effects of chito-oligosaccharide on tumor apoptosis,cell cycle and changes of apoptosis-related proteins Bcl-2 and Bax in sarcoma 180 cells

目的探讨壳寡糖对S180肉瘤细胞的生物学效应,为其治疗肿瘤提供新的理论基础。方法体外实验:用流式细胞仪测壳寡糖作用下S180肉瘤细胞周期、细胞凋亡情况。体内实验:建立S180肉瘤小鼠皮下移植瘤模型,给予壳寡糖后,测瘤体积,并用免疫组化法测瘤组织Bax、Bcl-2蛋白的表达情况。结果体外实验:高浓度壳寡糖作用后S180肉瘤细胞阻滞于G0/G1期,同时S180肉瘤细胞凋亡增加。体内实验:壳寡糖对小鼠S180肉瘤有明显的抑制作用并能提高促凋亡基因Bax的表达,降低抑凋亡基因Bcl-2的表达。结论壳寡糖可抑制S180肉瘤细胞的生长,使S180细胞阻滞于G0/G1期并诱导其发生凋亡,其机制可能与Bcl-2蛋白下调而Bax蛋白上调有关。

Objective To investigate the biological effect of chito - oligosaccharide on Sarcoma 180（S180） cells to assess the possibility and potential value of chito - oligosaccharide in tumor therapy. Methods In the experiment in vitro, suspended S180 cells were treated with chito- oligosaccharide. Flow cytometry was used to study the changes in tumor cell apoptosis and cell cycle consequential to the treatment. For experiment in vivo, Kunming mice bearing S180 in groups were given varied doses of chito - oligosaccharide for 7 days. The mice were then killed to determine the tumor volume and to determine the expression of apoptosis - related proteins （Bcl - 2 and Bax） by immunohistochemistry. Results Experiment in vitro showed relatively high concentration of chitooligosacharride arrested the growth of S180 cells at G0/G1 phase and increased the apoptotic rate of tumor cells. Experiment in vivo showed the growth of S180 cells was inhibited by chito- oligosaccharide （in a concentration- dependent manner）. The expression of antiapoptotic protein Bcl- 2 was decreased and the expression of proapoptotic protein Bax was increased. Conclusion Chito- oligosaccharide can inhibit the growth of S180 cells, arresting them at G0/G1 - phase and stim- ulating an increase of their apoptosis, possibly through downregulation of Bcl - 2 and upregulation of Bax.