Department of Medical Biophysics, Institute of Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
Department of Medical Biophysics, Institute of Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
Phytomedicine. 2019 Aug;61:152847. doi: 10.1016/j.phymed.2019.152847. Epub 2019 Jan 31.
Epothilones are microtubule-targeting agents that induce death in a variety of cancer cell types. Here, we focus on the cellular and molecular mechanisms underlying epothilone A (Epo A) and epothilone B (Epo B)-induced autophagy and apoptosis in ovarian cancer cells, compared to the actions of the widely used clinical chemotherapy drug paclitaxel (PTX).
Autophagy was examined in two cell lines, SKOV-3 (human ovarian adenocarcinoma) and OV-90 (human ovarian papillary serous adenocarcinoma), which differ in the levels of p-glycoprotein and drug resistance, based on the LC3 ELISA assay, fluorescence detection of autophagosome formation, morphological changes evaluated via acridine orange staining, and visualization of LC3 protein using confocal microscopy. Cell viability was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. Apoptosis was measured via the caspase-3/7 assay and immunofluorescence labeling of caspase-3. Differences in microtubule organization in epothilone-treated cells were investigated using specific antibodies against β-tubulin. All probes were analyzed both in the presence and absence of the autophagy inhibitor, bafilomycin A1 (Baf), and apoptosis inhibitor, Z-FA-FMK.
Epothilone and PTX treatment induced a dose-dependent decrease in cell viability, along with increased apoptosis and disruption of microtubule dynamics. Furthermore, under conditions of inhibition of autophagy with Baf, apoptosis triggered by these compounds was significantly increased.
Our collective results suggest that treatment with epothilones in combination with autophagy inhibitors present a potentially more effective chemotherapeutic approach for ovarian cancer.
埃坡霉素是一种微管靶向药物，能诱导多种癌细胞死亡。在这里，我们专注于埃坡霉素 A（Epo A）和埃坡霉素 B（Epo B）诱导卵巢癌细胞自噬和凋亡的细胞和分子机制，与广泛使用的临床化疗药物紫杉醇（PTX）的作用进行比较。
在 SKOV-3（人卵巢腺癌）和 OV-90（人卵巢乳头状浆液性腺癌）这两个细胞系中检查自噬，这两个细胞系在 P-糖蛋白水平和耐药性上存在差异，基于 LC3 ELISA 测定、自噬体形成的荧光检测、吖啶橙染色评估的形态变化以及共聚焦显微镜下 LC3 蛋白的可视化。使用 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）测定法检测细胞活力。通过 caspase-3/7 测定法和 caspase-3 的免疫荧光标记法测量细胞凋亡。使用针对 β-微管蛋白的特异性抗体研究埃坡霉素处理细胞中微管组织的差异。所有探针均在自噬抑制剂巴弗霉素 A1（Baf）和凋亡抑制剂 Z-FA-FMK 的存在和不存在下进行分析。
埃坡霉素和 PTX 处理诱导细胞活力呈剂量依赖性下降，同时增加细胞凋亡和破坏微管动力学。此外，在自噬抑制的条件下，这些化合物引发的细胞凋亡显著增加。
我们的综合结果表明，埃坡霉素联合自噬抑制剂的治疗可能为卵巢癌提供一种更有效的化疗方法。
