血清素正在成为色氨酸羟化酶 1 阳性肿瘤的一个有前途的治疗靶点，但需要进一步的机制研究来有效地针对失调的血清素代谢。一项挑战是缺乏研究血清素代谢动态性质的方法。在这里，我们报告了一种称为 iSero-Rluc 的基因编码发光生物传感器的开发，用于实时检测活细胞中的血清素。工程化的血清素结合域 (iSero) 和海肾荧光素酶 (Rluc) 报告基因被克隆到酵母中，并在哺乳动物表达载体创建一种融合蛋白，该融合蛋白可以充当生物传感器来检测活细胞中的内源性血清素水平。 iSero-Rluc 生物传感器在 BON 细胞系中稳定表达，并使用荧光素酶测定、质谱、免疫荧光和蛋白质印迹来研究不同细胞培养条件下的血清素代谢。 iSero-Rluc 传感器在酵母模型中检测外源血清素。当 iSero-Rluc 在 BON 细胞系中稳定表达时，表明血清素生物合成在不依赖贴壁的生长状态下增加，并在血清饥饿时诱导。iSero-Rluc 生物传感器是研究肿瘤血清素代谢的强大工具。它能够实时检测各种生长条件下活细胞中血清素合成的变化，并有可能更深入地了解肿瘤进展不同阶段的血清素代谢，并确定针对癌症转移和类癌危机的治疗策略。版权所有© 2023 Elsevier Inc. 保留所有权利。

Serotonin is emerging as a promising therapeutic target in tryptophan hydroxylase 1-positive tumors, but further mechanistic studies are needed to effectively target dysregulated serotonin metabolism. One challenge is a lack of methods for studying the dynamic nature of serotonin metabolism. Here, we report the development of a genetically encoded luminescent biosensor, termed iSero-Rluc, for the real-time detection of serotonin in live cells.The engineered serotonin binding domain (iSero) and Renilla luciferase (Rluc) reporter were cloned into yeast and mammalian expression vectors to create a fusion protein that could act as a biosensor to detect endogenous serotonin levels in live cells. The iSero-Rluc biosensor was stably expressed in the BON cell line and luciferase assays, mass spectroscopy, immunofluorescence, and Western blotting were used to study serotonin metabolism under different cell culture conditions.The iSero-Rluc sensor detected exogenous serotonin in a yeast model. When stably expressed in the BON cell line, iSero-Rluc revealed that serotonin biosynthesis is increased in an anchorage-independent growth state and is induced upon serum starvation.The iSero-Rluc biosensor is a powerful tool in the study of tumor serotonin metabolism. It enabled real-time detection of alterations in serotonin synthesis in living cells under various growth conditions and has the potential to provide greater insight into serotonin metabolism in different stages of tumor progression and to identify therapeutic strategies to target cancer metastases and carcinoid crises.Copyright © 2023 Elsevier Inc. All rights reserved.