三氧化二砷对胰腺癌细胞的作用

Experimental research of arsenic trioxide on human pancreatic carcinoma cell

目的：探讨三氧化二砷（亚砷酸，As2O3）对胰腺癌细胞增殖的抑制作用及其机制。方法：采用Cell Counting Kit-8法（CCK-8法）观察不同浓度和不同作用时间的As2O3对人类胰腺癌细胞株PC-3细胞增殖的抑制作用；采用荧光显微镜和流式细胞仪观察细胞的凋亡及生长周期的变化；采用透射电镜观察其超微结构的变化；采用免疫组织化学的方法，观察凋亡相关基因蛋白（Bcl-2和Pax）表达的变化。结果：不同剂量（0．25，0．5，1，2，4mg·L^-1）的As2O3均可抑制PC-3细胞的增殖．而且抑制率呈浓度一作用时间依赖关系；荧光显微镜检测显示大量早期凋亡细胞（FITC＋／PI-），流式细胞仪观察显示明显的凋亡峰出现，并使细胞周期主要被阻滞在G1期（55．19％～85．80％）；电镜观察显示了As2O3作用后的PC-3细胞具有典型的凋亡细胞形态学特征：细胞膜完整、胞浆浓缩、染色质固缩、核碎裂等；免疫组化研究表明As2O3注射液对PC-3细胞表达的凋亡相关基因具有一定调节作用，即可下调Bcl-2的表达，上调Pax的表达。结论：As2O3注射液既能有效地抑制人类胰腺癌PC-3细胞株的生长，又可以诱导癌细胞凋亡，这可能与其能够调节PC-3细胞的Bcl-2和Pax等凋亡相关基因蛋白的表达有关。

OBJECTIVE To explore the inhibition effect of arsenic trioxide （As2O3） on human pancreatic carcinoma cell line PC-3 and its mechanism. METItODS CCK-8 assay was used to observe the inhibitory actions of As2O3 on PC-3 ceils at various concentrations and for various times. The apoptotic rate and growth cycle of the cells were detected by flow cytometry and fluorescence microscope. The changes of the cells ultrastructures were observed under electron microscope. The expression of apoptosis-related gene protein （Bcb2 and Bax） was detected by immunohistochemical staining. RESULTS As2O3 inhibited the proliferation of PC-3 cells in a concentration- and time-dependent manner. Lots of early apoptotic cell （FITC ＋/PI-） were detected by fluorescence microscope. Marked apoptosis peak was observed and the cells were mainly blocked in G1 phase （55. 19% - 85. 80%）. PC-3 cells showed obvious feature of apoptosis under electron microscope, such as intact cell membrane,concentration of plasma, pyknosis of chromatin and nuclear fragmentation. Bcl-2 protein were strongly expressed （ ＋ ＋ ＋ ） in controls, but weakly expressed （ ＋ ） in As2O3 -treated cells. Bax protein were weakly （ ＋ ） expressed in controls respectively, but strongly expressed （ ＋ ＋ ＋ ） in As2 O3-treated cells. CONCLUSION As2O3 can not only inhibit the proliferation but also induce the apoptosis of human pancreatic carcinoma cell PC-3. The mechanism is probably related to its effect on the regulation of Bcl-2 and Pax expression.