BackgroundIncreased flux through both glycolytic and oxidative metabolic pathways is a hallmark of breast cancer cells and is critical for their growth and survival. As such, targeting this metabolic reprograming has received much attention as a potential treatment approach. However, the heterogeneity of breast cancer cell metabolism, even within classifications, suggests a necessity for an individualised approach to treatment in breast cancer patients.MethodsThe metabolic phenotypes of a diverse panel of human breast cancer cell lines representing the major breast cancer classifications were assessed using real-time metabolic flux analysis. Flux linked to ATP production, pathway reserve capacities and specific macromolecule oxidation rates were quantified. Suspected metabolic vulnerabilities were targeted with specific pathway inhibitors, and relative cell viability was assessed using the crystal violet assay. Measures of AMPK and mTORC1 activity were analysed through immunoblotting.ResultsBreast cancer cells displayed heterogeneous energy requirements and utilisation of non-oxidative and oxidative energy-producing pathways. Quantification of basal glycolytic and oxidative reserve capacities identified cell lines that were highly dependent on individual pathways, while assessment of substrate oxidation relative to total oxidative capacity revealed cell lines that were highly dependent on individual macromolecules. Based on these findings, mild mitochondrial inhibition in ESH-172 cells, including with the anti-diabetic drug metformin, and mild glycolytic inhibition in Hs578T cells reduced relative viability, which did not occur in non-transformed MCF10a cells. The effects on viability were associated with AMPK activation and inhibition of mTORC1 signalling. Hs578T were also found to be highly dependent on glutamine oxidation and inhibition of this process also impacted viability.ConclusionsTogether, these data highlight that systematic flux analysis in breast cancer cells can identify targetable metabolic vulnerabilities, despite heterogeneity in metabolic profiles between individual cancer cell lines.

中文翻译：

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一种系统的通量分析方法，用于识别人类乳腺癌细胞系中的代谢脆弱性

背景通过糖酵解和氧化代谢途径的通量增加是乳腺癌细胞的标志，对它们的生长和存活至关重要。因此，针对这种代谢重编程作为一种潜在的治疗方法受到了广泛关注。然而，即使在分类范围内，乳腺癌细胞代谢的异质性也表明有必要对乳腺癌患者进行个体化治疗。方法代表主要乳腺癌分类的不同人类乳腺癌细胞系的代谢表型使用实时代谢通量分析。量化了与 ATP 生产、通路储备能力和特定大分子氧化率相关的通量。特定的通路抑制剂针对可疑的代谢脆弱性，使用结晶紫测定评估相对细胞活力。通过免疫印迹分析AMPK和mTORC1活性的测量值。结果乳腺癌细胞表现出异质的能量需求以及对非氧化和氧化能量产生途径的利用。基础糖酵解和氧化储备能力的量化确定了高度依赖于个体途径的细胞系，而相对于总氧化能力的底物氧化评估揭示了高度依赖于个体大分子的细胞系。基于这些发现，ESH-172 细胞中的轻度线粒体抑制（包括抗糖尿病药物二甲双胍）和 Hs578T 细胞中的轻度糖酵解抑制降低了相对活力，这在未转化的 MCF10a 细胞中没有发生。对活力的影响与 AMPK 激活和 mTORC1 信号传导的抑制有关。还发现 Hs578T 高度依赖于谷氨酰胺氧化，抑制这一过程也会影响生存能力。结论 总之，这些数据强调了乳腺癌细胞中的系统通量分析可以识别可靶向的代谢脆弱性，尽管个体癌细胞系之间的代谢谱存在异质性。