Xu Tinghua, Liu Pengxi, Li Qingming, Shi Changbin, Wang Xinjie
Guangzhou University of Chinese Medicine, Guangzhou, 510405, China; Guizhou University of Traditional Chinese Medicine, Guiyang, 550025, China.
Guangzhou University of Chinese Medicine, Guangzhou, 510405, China; The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China.
Taiwan J Obstet Gynecol. 2020 Nov;59(6):828-834. doi: 10.1016/j.tjog.2020.09.008.
We aimed to evaluate the therapeutic effects of paclitaxel in combination with mTOR inhibitor everolimus on adriamycin-resistant breast cancer cell line MDA-MB-231 (MDA-MB-231/ADR).
MDA-MB-231/ADR cells were treated with different concentrations of paclitaxel and everolimus. The IC values after 48 h of treatment were measured by the MTT assay. The apoptosis rate and cell cycle were detected by flow cytometry. The protein expressions of Akt, PI3K, mTOR, p-pI3K, p-AKT and p-mTOR were detected by Western blot.
When paclitaxel at ≥1.56 μg/ml was used, the growth of MDA-MB-231/ADR cells was inhibited more significantly than that of control group (P < 0.05). After treatment with ≥6.25 μg/ml everolimus, the cell growth was also suppressed more significantly (P < 0.05). The IC values of everolimus and paclitaxel were 32.50 μg/ml and 7.80 μg/ml, respectively. The inhibition rate of paclitaxel plus everolimus was significantly enhanced with increasing paclitaxel concentration (P < 0.001). After treatment with 7.80 μg/ml paclitaxel, the two drugs had best synergistic inhibitory effects on proliferation. Compared with drugs alone, the combination significantly promoted apoptosis (P < 0.001). The paclitaxel + everolimus group had significantly more cells in the G0-G1 phase than those of control and individual drug groups (P < 0.001). Everolimus significantly decreased mTOR and p-mTOR expressions compared with those of control group (P < 0.001). Compared with everolimus alone, the combination reduced the expressions more significantly (P < 0.05). Paclitaxel decreased the expression levels of PI3K, p-PI3K and p-AKT. Compared with paclitaxel alone, the combination significantly promoted the reduction of PI3K, p-PI3K and p-AKT expressions (P < 0.05).
Everolimus can enhance the effect of paclitaxel on MDA-MB-231/ADR cells, inhibit cell proliferation, induce apoptosis and arrest cell cycle in the G1 phase mainly by down-regulating the expressions of key proteins in the mTOR signaling pathway.
我们旨在评估紫杉醇联合mTOR抑制剂依维莫司对阿霉素耐药乳腺癌细胞系MDA-MB-231（MDA-MB-231/ADR）的治疗效果。
用不同浓度的紫杉醇和依维莫司处理MDA-MB-231/ADR细胞。通过MTT法测定处理48小时后的IC值。通过流式细胞术检测凋亡率和细胞周期。通过蛋白质印迹法检测Akt、PI3K、mTOR、p-pI3K、p-AKT和p-mTOR的蛋白表达。
当使用≥1.56μg/ml的紫杉醇时，MDA-MB-231/ADR细胞的生长受到的抑制比对照组更显著（P<0.05）。用≥6.25μg/ml的依维莫司处理后，细胞生长也受到更显著的抑制（P<0.05）。依维莫司和紫杉醇的IC值分别为32.50μg/ml和7.80μg/ml。随着紫杉醇浓度的增加，紫杉醇加依维莫司的抑制率显著提高（P<0.001）。用7.80μg/ml的紫杉醇处理后，两种药物对增殖具有最佳的协同抑制作用。与单独用药相比，联合用药显著促进凋亡（P<0.001）。紫杉醇+依维莫司组处于G0-G1期的细胞明显多于对照组和单药组（P<0.001）。与对照组相比，依维莫司显著降低mTOR和p-mTOR的表达（P<0.001）。与单独使用依维莫司相比，联合用药使表达降低更显著（P<0.05）。紫杉醇降低PI3K、p-PI3K和p-AKT的表达水平。与单独使用紫杉醇相比，联合用药显著促进PI3K、p-PI3K和p-AKT表达的降低（P<0.05）。
依维莫司可增强紫杉醇对MDA-MB-231/ADR细胞的作用，抑制细胞增殖，诱导凋亡并使细胞周期停滞于G1期，主要是通过下调mTOR信号通路关键蛋白的表达来实现的。
