紫草素抑制人甲状腺髓样癌TT细胞增殖及其机制的研究

目的：了解紫草素抑制甲状腺癌TT细胞增殖的作用及机制。方法采用MTT法分析紫草素对人甲状腺癌TT细胞增殖的影响；流式细胞术分析紫草素对TT细胞周期分布和凋亡的影响；透射电镜观察紫草素对TT细胞凋亡和自噬的调控。结果不同浓度紫草素作用24-72h对TT细胞均有抑制增殖的作用，并随药物浓度增加和作用时间延长而增强。紫草素作用24h，2、4滋g/ml紫草素组细胞出现凋亡峰（亚二倍体峰），与空白对照组比较差异有统计学意义（P＜0.05），但未见明显的细胞周期阻滞。Annex-inV- PE/7- AAD双染法分析细胞凋亡，2滋g/ml紫草素作用TT细胞24h，早期凋亡细胞增至8.0%；而空白对照组为0.2%，凋亡后期继发坏死细胞为11.3%，空白对照组为0.1%；作用48h后，早期凋亡细胞为24.9%，凋亡后期继发坏死细胞上升为14.2%。2滋g/ml紫草素作用TT细胞24h，透射电镜观察可见典型的细胞凋亡和自噬结构。结论紫草素具有抑制人甲状腺癌TT细胞增殖的作用，呈剂量和时间依赖关系；其作用机制与诱导细胞凋亡和自噬有关。

Shikonin induces apoptosis of human thyroid carcinoma TT cells

Objective To investigate the effect of shikonin on proliferation of human thyroid carcinoma TT cells. Methods Human thyroid carcinoma TT cells were treated with shikonin in vitro. cellproliferation was examined by MTT method, cellapop-tosis was detected by flow cytometry. Results MTT assay showed that shikonin inhibited TT cellproliferation in a dose- and time- dependent manner （P〈0.01）. Flow cytometry revealed sub- diploid （apoptosis） peaks in TT cells after treated with shikonin 2μg/ml and 4μg/ml for 24h; however, there was no cellcycles arrest. Annexin V- PE/7- AAD staining also demonstrated cellapoptosis. Electron microscopy showed typical morphological characteristics of autophagy and cell apoptosis after treatment of shikonin. Conclusion Shikonin can inhibit proliferation of human thyroid carcinoma TT cells, which is associated with the cellapoptosis and autophagy.