College of Life Sciences, Shenzhen University, Shenzhen, 518060, People's Republic of China.
Biometals. 2010 Dec;23(6):1179-89. doi: 10.1007/s10534-010-9368-3. Epub 2010 Aug 1.
Lanthanides possess diverse biological effect and have been shown to promote cell proliferation and induce apoptosis. Our previous studies showing that lanthanide citrate complex has significant antitumor activity in human cervical cancer HeLa cells. This study aims at determining if LaCit(2) have the activity against another type of human cervical cancer cell line SiHa and the changes in protein expression that contribute to the mechanism(s) of LaCit(2)-mediated apoptosis in SiHa cells. Cell growth inhibition was measured by MTT method, and apoptosis was detected by means of Hoechst 33258 staining and flow cytometry analysis. After LaCit(2)-treatment the results show that the growth of SiHa cells was inhibited, the cells displayed typical apoptosis morphological changes, and increase in the rates of apoptosis. Using proteomics approaches, a variety of differentially expressed proteins were identified in SiHa cells before and after treatment with LaCit(2). There were profound changes in 10 proteins relating to mitochondrial function and oxidative stress, suggesting that mitochondrial dysfunction plays a key role in LaCit(2)-induced apoptosis. This was confirmed by a decrease in the mitochondrial transmembrane potential (Δψ(m)), and increases in H(2)O(2) generation in LaCit(2)-treated cells. Among them the alerted proteins, Prx I, ANXA1 and TRAF5 were validated by western blotting analyses. These results suggest that there is an intrinsic molecular pathway of cell apoptosis in LaCit(2)-treated SiHa cells. This observation is in accordance with our previous reports about the effects of LaCit(2) and YbCit(2) on HeLa cells and it provide a molecular mechanism underlying lanthanide citrate complex-mediated cell apoptosis.
镧系元素具有多种生物学效应，已被证明能促进细胞增殖并诱导细胞凋亡。我们之前的研究表明，柠檬酸镧复合物在人宫颈癌 HeLa 细胞中具有显著的抗肿瘤活性。本研究旨在确定柠檬酸镧复合物LaCit(2)是否对另一种人宫颈癌 SiHa 细胞系具有活性，以及导致LaCit(2)-介导的 SiHa 细胞凋亡的机制中蛋白质表达变化。通过 MTT 法测定细胞生长抑制率，通过 Hoechst 33258 染色和流式细胞术分析检测细胞凋亡。结果表明，LaCit(2)处理后 SiHa 细胞的生长受到抑制，细胞呈现典型的凋亡形态学变化，凋亡率增加。通过蛋白质组学方法，在LaCit(2)处理前后鉴定出 SiHa 细胞中多种差异表达的蛋白质。与线粒体功能和氧化应激相关的 10 种蛋白质发生深刻变化，表明线粒体功能障碍在LaCit(2)诱导的凋亡中起关键作用。这一点通过LaCit(2)处理细胞中线粒体跨膜电位（Δψ(m)）降低和 H(2)O(2)生成增加得到证实。其中，Prx I、ANXA1 和 TRAF5 等被预警的蛋白质通过 Western blot 分析得到验证。这些结果表明，LaCit(2)处理的 SiHa 细胞中存在内在的细胞凋亡分子途径。这一观察结果与我们之前关于LaCit(2)和YbCit(2)对 HeLa 细胞的影响的报告一致，并为镧系元素柠檬酸复合物介导的细胞凋亡提供了分子机制。
