BACKGROUND Triple-negative breast cancer (TNBC) is known for Warburg effect and defects in the mitochondria. AMP-dependent kinase (AMPK) activates the downstream transcription factors PGC-1α, PGC-1β, or FOXO1, which participate in mitochondrial biogenesis. 5- aminoimidazole-4-carboxamide riboside (AICAR) is an analog of adenosine monophosphate and is a direct activator of AMPK. OBJECTIVES In the present study, we have made an attempt to understand the influence of AICAR on TNBC cells, MDA-MB-231, and the underlying changes in mitochondrial biogenesis, if any. METHODS We investigated AICAR induced changes in cell viability, apoptosis, migratory potential, and changes in the sensitivity of doxorubicin. RESULTS In response to the treatment of MDA-MB-231 breast cancer cells with 750 μM of AICAR for 72 hours, followed by 48 hours in fresh media without AICAR, we observed a decrease in viability via MTT assay, reduction in cell numbers along with the apoptotic appearance, increased cell death by ELISA, decreased lactate in conditioned medium and decrease in migration by scratch and transwell migration assays. These changes in the cancer phenotype were accompanied by an increase in mitochondrial biogenesis, as observed by increased mitochondrial DNA to nuclear DNA ratio, a decrease in lactic acid concentration, an increase in MitoTracker green and red staining, and increased expression of transcription factors PGC-1α, NRF-1, NRF-2, and TFAM, contributing to mitochondrial biogenesis. Pre-treatment of cells with AICAR for 72 hours followed by 48 hours treatment with 1 μM doxorubicin showed an increased sensitivity to doxorubicin as assessed by the MTT assay. CONCLUSION Our results show that AICAR exerts beneficial effects on TNBC cells, possibly via switching off the Warburg effect and switching on the anti-Warburg effect through mitochondrial modulation.

中文翻译：

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5-Aminoimidazole-4-Carboxamide-1-β-D-Ribofuranoside (AICAR) 对三阴性乳腺癌 (TNBC) 细胞的抗癌作用：线粒体调节作为潜在机制。

背景 三阴性乳腺癌 (TNBC) 因 Warburg 效应和线粒体缺陷而闻名。AMP 依赖性激酶 (AMPK) 激活参与线粒体生物发生的下游转录因子 PGC-1α、PGC-1β 或 FOXO1。5-氨基咪唑-4-甲酰胺核苷 (AICAR) 是单磷酸腺苷的类似物，是 AMPK 的直接激活剂。目的 在本研究中，我们试图了解 AICAR 对 TNBC 细胞 MDA-MB-231 的影响，以及线粒体生物发生的潜在变化（如果有的话）。方法 我们研究了 AICAR 引起的细胞活力、细胞凋亡、迁移潜力的变化以及阿霉素敏感性的变化。结果 750 μM AICAR 对 MDA-MB-231 乳腺癌细胞治疗 72 小时后，然后在没有 AICAR 的新鲜培养基中培养 48 小时后，我们通过 MTT 测定观察到活力降低、细胞数量减少以及凋亡外观、ELISA 细胞死亡增加、条件培养基中的乳酸减少以及刮擦和跨孔迁移减少了迁移化验。癌症表型的这些变化伴随着线粒体生物合成的增加，如线粒体 DNA 与核 DNA 比率的增加、乳酸浓度的降低、MitoTracker 绿色和红色染色的增加以及转录因子 PGC- 的表达增加所观察到的。 1α、NRF-1、NRF-2 和 TFAM，有助于线粒体生物发生。通过 MTT 试验评估，用 AICAR 预处理细胞 72 小时，然后用 1 μM 阿霉素处理 48 小时显示对阿霉素的敏感性增加。结论 我们的研究结果表明，AICAR 对 TNBC 细胞发挥有益作用，可能是通过关闭 Warburg 效应并通过线粒体调节开启抗 Warburg 效应。