Laboratory of Molecular Pathology, State University of Londrina, Londrina, PR, Brazil.
Laboratory of Experimental Immunopathology, State University of Londrina, Londrina, PR, Brazil.
Pathol Res Pract. 2020 Nov;216(11):153199. doi: 10.1016/j.prp.2020.153199. Epub 2020 Sep 6.
The ability to evade apoptosis is an important mechanism of drug resistance and tumor progression in breast cancer. The induction of different pathways of cell death could be an important strategy to limit tumor progression. Metformin, a drug used to treat type two diabetes, has demonstrated promising results in breast cancer experiments. However, little is known about the patterns of cell death induced by this drug. We analyzed the involvement of apoptosis, necroptosis and ferroptosis in the toxicity of metformin in MCF-7 cells, evaluating proliferation, viability and oxidative stress. It was used different inhibitors of cell death: Z-VAD, a pan-caspase inhibitor that blocks apoptosis; Necrostatin-1, which inhibits RIPK1 activity and blocks necroptosis; and the iron chelator, deferoxamine, that chelates iron and prevents ferroptosis. The participation of oxidative stress was analyzed through the evaluation of total thiols, reduced glutathione (GSH) and malondialdehyde (MDA). Our results showed that metformin increased cell death, reduced proliferation, thiol and GSH and increased MDA in cells. After the association between metformin and Z-VAD or Necrostatin-1, the drug toxicity was abolished. Ferroptosis did not significantly enrolled in metformin action against MCF-7 cells. The preservation of cellular antioxidants was found in all situations that cell death was blocked. Together, these results reveals that metformin induces necroptosis and apoptosis in MCF-7 cells and oxidative stress generation play a role in these two pathways of cell death. This information could help future studies to improve strategies to breast cancer treatment.
逃避细胞凋亡是乳腺癌药物耐药和肿瘤进展的重要机制。诱导不同的细胞死亡途径可能是限制肿瘤进展的重要策略。二甲双胍是一种用于治疗 2 型糖尿病的药物，在乳腺癌实验中已显示出良好的效果。然而，人们对这种药物诱导的细胞死亡模式知之甚少。我们分析了细胞凋亡、坏死性凋亡和铁死亡在二甲双胍对 MCF-7 细胞毒性中的作用，评估了细胞增殖、活力和氧化应激。使用了不同的细胞死亡抑制剂：Z-VAD，一种可阻断细胞凋亡的广谱半胱天冬酶抑制剂；Necrostatin-1，可抑制 RIPK1 活性并阻断坏死性凋亡；以及铁螯合剂去铁胺，可螯合铁并防止铁死亡。通过评估总巯基、还原型谷胱甘肽 (GSH) 和丙二醛 (MDA) 来分析氧化应激的参与。我们的结果表明，二甲双胍增加了细胞死亡，降低了细胞增殖、巯基和 GSH 水平，并增加了 MDA。在二甲双胍与 Z-VAD 或 Necrostatin-1 联合使用后，药物毒性被消除。铁死亡在二甲双胍对 MCF-7 细胞的作用中没有明显参与。在阻断细胞死亡的所有情况下，都发现细胞抗氧化剂得以保留。总之，这些结果表明，二甲双胍诱导 MCF-7 细胞发生坏死性凋亡和细胞凋亡，氧化应激的产生在这两种细胞死亡途径中发挥作用。这些信息可以帮助未来的研究改进乳腺癌治疗策略。
