癌症干细胞 (CSCs) 是癌细胞的亚群，负责肿瘤的进展、转移和复发。氨基酸代谢的变化与乳腺癌复发和转移有关。本研究旨在评估 MCF-7 和 MDA-MB-231 细胞在成球过程中氨基酸谱的变化，以发现 CSCs 中特定的代谢特性。通过培养 MCF-7 和 MDA-MB-231 乳腺癌细胞成球，并对其 CSC 特性进行评估。通过检查 CSC 标记的表达和进行药物耐受性试验来评估 CSC 的特性。此外，通过高效液相色谱 (HPLC) 研究富集乳腺癌干细胞的成球过程中氨基酸谱的变化。结果表明，在分析的 20 种不同氨基酸中，有 19 种在成球过程中减少。丙氨酸、赖氨酸、苯丙氨酸、苏氨酸和甘氨酸在成球细胞和单层细胞的调节培养基中均显著降低。只有一个氨基酸在 MCF-7 和 MDA-MB-231 成球细胞中增加 (分别是组氨酸和丝氨酸)。我们的研究结果表明，本研究中鉴定的某些氨基酸可用于更好地理解与乳腺癌干细胞形成相关的分子机制。© 2023 The Authors. Cancer Reports published by Wiley Periodicals LLC.

Cancer stem cells (CSCs), subpopulations of cancer cells, are responsible for tumor progression, metastasis, and relapse. Changes in amino acid metabolism are linked to breast cancer recurrence and metastasis.This study aimed to evaluate the changes in the amino acid profile in MCF-7 and MDA-MB-231 cells during spheroid formation to discover the specific metabolic properties in CSCs.MCF-7 and MDA-MB-231 breast cancer cells were cultured as spheroids and evaluated to characterize their CSC properties. The characteristics of CSC were evaluated by examining the expression of CSC markers and conducting drug resistance assays. In addition, amino acid profile change during the enrichment of breast cancer stem cells in the spheroids was investigated by high-performance liquid chromatography (HPLC).The results indicated that out of 20 different amino acids analyzed, 19 of them decreased during the spheroid formation process. Alanine, lysine, phenylalanine, threonine, and glycine showed significant reductions in the conditioned media of both cell lines in the spheroid form compared to the monolayer cells. Only one of the amino acids increased in MCF-7 and MDA-MB-231 spheroids (histidine and serine, respectively).Our results suggest that certain amino acids identified in this study can be used for a better understanding of the molecular mechanisms associated with breast cancer stem cell formation.© 2023 The Authors. Cancer Reports published by Wiley Periodicals LLC.