Group for nano and biotechnological applications, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia.
Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
Sci Rep. 2017 May 11;7(1):1761. doi: 10.1038/s41598-017-01801-5.
Triple naegative breast cancer has an increased rate of distant metastasis and consequently poor prognosis. To metastasize, breast cancer cells must detach from the main tumour mass and resist anoikis, a programmed cell death induced by lack of cell-extracellular matrix communication. Although cancer cells must detach to metastasize in vivo, the viability of floating cancer cells in vitro is rarely investigated. Here we show that co-treatment of anoikis-resistant MDA-MB-231 cells with metformin and 2-deoxy-D-glucose (2-DG) increased the percentage of floating cells, of which about 95% were viable. Floating cells resumed their proliferation once they were reseeded in the pharmacological compound-free medium. Similar effects on detachment were observed on anoikis-prone MCF-7 cells. Co-treatment of MDA-MB-231 cells with metformin and 2-DG induced a strong activation of AMP-activated protein kinase (AMPK), which was reduced by AMPK inhibitor compound C that prevented detachment of MDA-MB-231 cells. However, direct AMPK activators A-769662 and AICAR did not have any major effect on the percentage of floating MDA-MB-231 cells, indicating that AMPK activation is necessary but not sufficient for triggering detachment of cancer cells. Our results demonstrate that separate analysis of floating and attached cancer cells might be important for evaluation of anti-cancer agents.
三阴性乳腺癌远处转移率较高，预后较差。为了转移，乳腺癌细胞必须从主肿瘤块中分离出来，并抵抗失巢凋亡，这是一种由细胞-细胞外基质通讯缺失引起的程序性细胞死亡。尽管癌细胞必须脱离才能在体内转移，但很少研究体外漂浮癌细胞的活力。在这里，我们表明，耐失巢凋亡的 MDA-MB-231 细胞与二甲双胍和 2-脱氧-D-葡萄糖（2-DG）共同处理会增加漂浮细胞的百分比，其中约 95%是存活的。漂浮细胞一旦在无药理化合物的培养基中重新播种，就会恢复增殖。在对失巢凋亡敏感的 MCF-7 细胞中观察到类似的脱离效果。二甲双胍和 2-DG 共同处理 MDA-MB-231 细胞会强烈激活 AMP 激活的蛋白激酶（AMPK），而 AMPK 抑制剂化合物 C 会降低这种激活，从而阻止 MDA-MB-231 细胞脱离。然而，直接的 AMPK 激活剂 A-769662 和 AICAR 对 MDA-MB-231 细胞漂浮的百分比没有任何重大影响，这表明 AMPK 的激活是触发癌细胞脱离所必需的，但不是充分的。我们的结果表明，对漂浮和附着的癌细胞进行单独分析可能对评估抗癌药物很重要。
