Mossakowski Medical Research Centre, Polish Academy of Science, Electron Microscopy Platform, Warsaw, Poland.
Independent Laboratory of Genetics and Molecular Biology, Kaczkowski Military Institute of Hygiene and Epidemiology, Warsaw, Poland.
FEBS J. 2017 May;284(9):1370-1387. doi: 10.1111/febs.14064. Epub 2017 Apr 18.
Verapamil, an L-type calcium channel blocker, has been used successfully to treat cardiovascular diseases. Interestingly, we have recently shown that treatment of cancer cells with verapamil causes an effect on autophagy. As autophagy is known to modulate chemotherapy responses, this prompted us to explore the impact of verapamil on autophagy and cell viability in greater detail. We report here that verapamil causes an induction of autophagic flux in a number or tumor cells and immortalized normal cells. Moreover, we found that inhibition of autophagy in COLO 205 cells, via treatment with the chloroquine (CQ) or by CRISPR/Cas9-mediated disruption of the autophagy genes Atg7 and Atg5, causes an upregulation of apoptotic markers in response to verapamil. In search of a mechanism for this effect and because autophagy can often mitigate metabolic stress, we examined the impact of verapamil on cellular metabolism. This revealed that in normal prostate cells, verapamil diminishes glucose and glycolytic intermediate levels leading to adenosine 5'-triphosphate (ATP) depletion. In contrast, in COLO 205 cells it enhances aerobic glycolysis and maintains ATP. Importantly, we found that the autophagic response in these cells is related to the activity of l-lactate dehydrogenase A (LDHA, EC 1.1.1.27), as inhibition of LDHA reduces both basal and verapamil-induced autophagy and consequently decreases cell viability. In summary, these findings not only identify a novel mechanism of cytoprotective autophagy induction but they also highlight the potential of using verapamil together with inhibitors of autophagy for the treatment of malignant disease. ENZYMES: l-lactate dehydrogenase (LDHA, EC 1.1.1.27).
维拉帕米是一种 L 型钙通道阻滞剂，已成功用于治疗心血管疾病。有趣的是，我们最近表明，用维拉帕米治疗癌细胞会对自噬产生影响。由于自噬已知会调节化疗反应，这促使我们更详细地探讨维拉帕米对自噬和细胞活力的影响。我们在这里报告，维拉帕米在多种肿瘤细胞和永生化正常细胞中引起自噬流的诱导。此外，我们发现，通过用氯喹（CQ）处理或通过 CRISPR/Cas9 介导的自噬基因 Atg7 和 Atg5 的破坏，抑制 COLO 205 细胞中的自噬会导致对维拉帕米的凋亡标志物的上调。为了寻找这种作用的机制，并且因为自噬通常可以减轻代谢应激，我们检查了维拉帕米对细胞代谢的影响。这表明在正常前列腺细胞中，维拉帕米减少葡萄糖和糖酵解中间产物水平，导致腺苷 5'-三磷酸（ATP）耗竭。相比之下，在 COLO 205 细胞中，它增强有氧糖酵解并维持 ATP。重要的是，我们发现这些细胞中的自噬反应与 l-乳酸脱氢酶 A（LDHA，EC 1.1.1.27）的活性有关，因为 LDHA 的抑制减少了基础和维拉帕米诱导的自噬，并且因此降低了细胞活力。总之，这些发现不仅确定了细胞保护性自噬诱导的新机制，而且还强调了使用维拉帕米与自噬抑制剂联合治疗恶性疾病的潜力。酶：l-乳酸脱氢酶（LDHA，EC 1.1.1.27）。
