Badi R M, Khaleel E F, El-Bidawy M H, Satti H H, Mostafa D G
Department of Physiology, College of Medicine, King Khalid University, Abha, Saudi Arabia.
Department of Physiology, Faculty of Medicine, University of Khartoum, Khartoum, Sudan.
Folia Biol (Praha). 2020;66(5-6):186-203. doi: 10.14712/fb2020066050186.
Activation of autophagy suppresses ovarian cancer (OC). This in vitro study investigated whether the anti-tumour effect of exendin-4 against OC involves modulation of autophagy and figured out the possible mechanisms of action. SKOV-3 and OVCAR-3 cells (1 × 105/ml) were cultured in DMEM medium and treated with exendin-4 in the presence or absence of chloroquine (CQ), an autophagy inhibitor. In some cases, cells were also treated with exendin- 4 with or without pre-treatment with compound C (CC), an AMPK inhibitor, or insulin-like growth factor (IGF-1), a PI3K/Akt activator. Exendin-4 increased expression of beclin-1 and LC3I/II, suppressed expression of p62, reduced cell survival, migration, and invasion, and increased cell apoptosis and LDH release in both SKOV-3 and OVCAR-3 cells. Besides, exendin-4 reduced phosphorylation of mTORC1, 6SK, 4E-BP1, and Akt but increased phosphorylation of AMPK in both cell lines. These effects were associated with down-regulation of Bcl-2, suppression of nuclear phosphorylation of NF-κB p65, and increased expression of Bax and cleaved caspases 3/8. Chloroquine completely prevented the inhibitory effects of exendin-4 on the cell survival, Bcl-2, NF-κB, and cell invasiveness and abolished its stimulation of cell apoptosis and LDH release. Moreover, only the combined treatment with IGF-1 and CC completely abolished the observed effect of exendin-4 on the expression of beclin-1, LC3I/II, p62, as well as on cell survival, apoptosis, and LDH release. Exendin-4 exhibits a potent anti-tumour cytotoxic effect in SKOV-3 and OVCAR-3 cells by activating the markers of autophagy, mediated by activation of AMPK and inhibition of Akt.
自噬的激活可抑制卵巢癌（OC）。本体外研究调查了艾塞那肽-4对OC的抗肿瘤作用是否涉及自噬调节，并阐明了可能的作用机制。将SKOV-3和OVCAR-3细胞（1×105/ml）培养于DMEM培养基中，并在存在或不存在自噬抑制剂氯喹（CQ）的情况下用艾塞那肽-4处理。在某些情况下，细胞还用艾塞那肽-4处理，同时或不预先用AMPK抑制剂化合物C（CC）或PI3K/Akt激活剂胰岛素样生长因子（IGF-1）处理。艾塞那肽-4增加了beclin-1和LC3I/II的表达，抑制了p62的表达，降低了细胞存活、迁移和侵袭能力，并增加了SKOV-3和OVCAR-3细胞的细胞凋亡和乳酸脱氢酶（LDH）释放。此外，艾塞那肽-4降低了mTORC1、6SK、4E-BP1和Akt的磷酸化，但增加了两种细胞系中AMPK的磷酸化。这些作用与Bcl-2的下调、NF-κB p65核磷酸化的抑制以及Bax和裂解的半胱天冬酶3/8表达增加有关。氯喹完全阻止了艾塞那肽-4对细胞存活、Bcl-2、NF-κB和细胞侵袭性的抑制作用，并消除了其对细胞凋亡和LDH释放的刺激作用。此外，只有IGF-1和CC联合处理完全消除了观察到的艾塞那肽-4对beclin-1、LC3I/II、p62表达以及对细胞存活、凋亡和LDH释放的影响。艾塞那肽-4通过激活自噬标志物，在SKOV-3和OVCAR-3细胞中表现出强大的抗肿瘤细胞毒性作用，这是由AMPK激活和Akt抑制介导的。
