Peppicelli S, Kersikla T, Menegazzi G, Andreucci E, Ruzzolini J, Nediani C, Bianchini F, Calorini L
Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.
Front Pharmacol. 2024 Aug 8;15:1422281. doi: 10.3389/fphar.2024.1422281. eCollection 2024.
Circulating tumor cells (CTCs) represent the sub-population of cells shed into the vasculature and able to survive in the bloodstream, adhere to target vascular endothelial cells, and re-growth into the distant organ. CTCs have been found in the blood of most solid tumor-bearing patients and are used as a diagnostic marker. Although a complex genotypic and phenotypic signature characterizes CTCs, the ability to survive in suspension constitutes the most critical property, known as resistance to , e.g., the ability to resist apoptosis resulting from a loss of substrate adhesion. Here, we selected melanoma cells resistant to , and we studied their metabolic reprogramming, with the aim of identifying new metabolic targets of CTCs. Subpopulations of melanoma cells expressing a high -resistant phenotype were selected by three consecutive rocking exposures in suspension and studied for their phenotypic and metabolic characteristics. Moreover, we tested the efficacy of different metabolic inhibitors targeting glycolysis (2DG), LDHA (LDHA-in-3), the mitochondrial electron transport chain complex I (rotenone), glutaminase (BPTES), fatty acid transporter (SSO), fatty acid synthase (denifanstat), CPT1 (etomoxir), to inhibit cell survival and colony formation ability after 24 h of rocking condition. resistant cells displayed higher ability to grow in suspension on agarose-covered dishes respect to control cells, and higher cell viability and colony formation capability after a further step in rocking condition. They showed also an epithelial-to-mesenchymal transition associated with high invasiveness and a stemness-like phenotype. -resistant melanoma cells in suspension showed a metabolic reprogramming from a characteristic glycolytic metabolism toward a more oxidative metabolism based on the use of glutamine and fatty acids, while re-adhesion on the dishes reversed the metabolism to glycolysis. The treatment with metabolic inhibitors highlighted the effectiveness of rotenone, BPTES, SSO, and etomoxir in reducing the viability and the colony formation ability of cells capable of surviving in suspension, confirming the dependence of their metabolism on oxidative phosphorylation, using glutamine and fatty acids as the most important fuels. This finding opens up new therapeutic strategies based on metabolic inhibitors of glutaminase and fatty acid oxidation for the treatment of CTCs and melanoma metastases.
循环肿瘤细胞(CTCs)是脱落进入脉管系统并能在血流中存活、黏附于靶血管内皮细胞并在远处器官重新生长的细胞亚群。在大多数实体瘤患者的血液中都发现了CTCs,它们被用作诊断标志物。尽管复杂的基因型和表型特征可表征CTCs,但在悬浮状态下存活的能力是其最关键的特性,即抗(例如,抵抗因失去底物黏附而导致的细胞凋亡的能力)。在此,我们筛选出了抗的黑色素瘤细胞,并研究了它们的代谢重编程,旨在确定CTCs的新代谢靶点。通过在悬浮状态下连续三次摇晃暴露,筛选出表达高抗性表型的黑色素瘤细胞亚群,并研究其表型和代谢特征。此外,我们测试了不同代谢抑制剂(靶向糖酵解的2 - 脱氧葡萄糖(2DG)、乳酸脱氢酶A(LDHA - in - 3)、线粒体电子传递链复合物I(鱼藤酮)、谷氨酰胺酶(BPTES)、脂肪酸转运蛋白(SSO)、脂肪酸合酶(地尼法司他)、肉碱棕榈酰转移酶1(依托莫昔))在摇晃条件下作用24小时后抑制细胞存活和集落形成能力的效果。抗性细胞相对于对照细胞在覆盖有琼脂糖的培养皿上悬浮生长的能力更高,并且在进一步的摇晃条件下具有更高的细胞活力和集落形成能力。它们还表现出与高侵袭性和干细胞样表型相关的上皮 - 间质转化。悬浮状态下的抗性黑色素瘤细胞显示出代谢重编程,从典型的糖酵解代谢转变为基于使用谷氨酰胺和脂肪酸的更氧化的代谢,而重新黏附在培养皿上则使代谢逆转回糖酵解。用代谢抑制剂处理突出了鱼藤酮、BPTES、SSO和依托莫昔在降低能够在悬浮状态下存活的细胞的活力和集落形成能力方面的有效性,证实了它们的代谢依赖于氧化磷酸化,以谷氨酰胺和脂肪酸作为最重要的燃料。这一发现为基于谷氨酰胺酶和脂肪酸氧化代谢抑制剂的治疗CTCs和黑色素瘤转移开辟了新的治疗策略。