靶向BCAT1介导的支链氨基酸代谢的小分子抑制SHOC2-RAS-ERK的激活以诱导三阴性乳腺癌细胞凋亡。

Small-molecule targeting BCAT1-mediated BCAA metabolism inhibits the activation of SHOC2-RAS-ERK to induce apoptosis of Triple-negative breast cancer cells.

作者信息

Huang Ling, Li Guanjun, Zhang Ying, Zhuge Ruishen, Qin Shijie, Qian Jinjun, Chen Ruixing, Kwan Wong Yin, Tang Huan, Wang Peili, Xiao Wei, Wang Jigang

机构信息

Department of Critical Care Medicine, Guangdong Provincial Clinical Research Center for Geriatrics, Shenzhen Clinical Research Center for Geriatrics, Shenzhen People's Hospital, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong, 518020, China; Oncology Department of Guang'anmen Hospital, China Academy of Chinese Medical Sciences, No.5 Bei Xian Ge, Xi Cheng District, Beijing 100053, China.

出版信息

J Adv Res. 2024 Oct 28. doi: 10.1016/j.jare.2024.10.021.

DOI:10.1016/j.jare.2024.10.021

PMID:39490614

Abstract

INTRODUCTION

Triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer with the worst prognosis. Exploring novel carcinogenic factors and therapeutic drugs for TNBC remains a focus to improve prognosis. Branched-chain amino acid transaminase 1 (BCAT1), a crucial enzyme in branched-chain amino acid (BCAA) metabolism, has been linked to various tumor developments, but its carcinogenic function and mechanism in TNBC remain unclear. Eupalinolide B (EB) is a naturally-derived small-molecule with anti-tumor activity, but its role in TNBC remains unknown.

OBJECTIVES

By exploring the targets and pharmacological mechanisms of EB in inhibiting TNBC, this study aimed to discover novel therapeutic targets and potential inhibitors for TNBC, and elucidate novel pathogenic mechanisms of TNBC.

METHODS

The inhibitory effect of EB on TNBC was investigated using mouse models and cellular phenotypic experiments. Activity-based protein profiling (ABPP) technology, pull down-WB, CETSA-WB and MST were utilized to discover and validate the targets of EB. The oncogenic role of BCAT1 was determined through clinical data analysis and biochemical experiments. To elucidate the mechanism by which EB inhibited TNBC, many methods, including but not limited to HPLC and proteomic sequencing were used.

RESULTS

We found that EB significantly inhibited TNBC progression. We identified BCAT1 as the direct target of EB and confirmed that BCAT1 was critical for TNBC development. EB inhibited BCAT1-involved BCAA metabolism to reduce the synthesis of BCAAs (including Leu, Ile, and Val), thereby inhibiting SHOC2 (a Leu-rich repeat protein) expression and the downstream SHOC2-participating RAS-ERK signaling pathway, ultimately leading to apoptosis of TNBC cells.

CONCLUSION

Collectively, this study not only elucidates the oncogenic role of BCAT1 and its downstream SHOC2-RAS-ERK signaling axis in TNBC progression but also opens up avenues for potential therapies targeting BCAT1 or BCAA metabolism (using EB alone or in combination with its inhibitor candesartan) for TNBC treatment.

摘要

引言

三阴性乳腺癌（TNBC）是乳腺癌中恶性程度最高、预后最差的亚型。探索TNBC的新型致癌因素和治疗药物仍然是改善预后的重点。支链氨基酸转氨酶1（BCAT1）是支链氨基酸（BCAA）代谢中的关键酶，已与多种肿瘤的发生发展相关，但其在TNBC中的致癌功能和机制仍不清楚。榄香醇内酯B（EB）是一种具有抗肿瘤活性的天然小分子，但它在TNBC中的作用尚不清楚。

目的

通过探索EB抑制TNBC的靶点和药理机制，本研究旨在发现TNBC的新型治疗靶点和潜在抑制剂，并阐明TNBC的新致病机制。

方法

使用小鼠模型和细胞表型实验研究EB对TNBC的抑制作用。利用基于活性的蛋白质谱（ABPP）技术、下拉式免疫印迹法、热蛋白质组分析-免疫印迹法（CETSA-WB）和微量热泳动技术（MST）来发现和验证EB的靶点。通过临床数据分析和生化实验确定BCAT1的致癌作用。为阐明EB抑制TNBC的机制，使用了多种方法，包括但不限于高效液相色谱法（HPLC）和蛋白质组测序。

结果

我们发现EB显著抑制TNBC的进展。我们确定BCAT1是EB的直接靶点，并证实BCAT1对TNBC的发展至关重要。EB抑制与BCAT1相关的BCAA代谢，以减少BCAAs（包括亮氨酸、异亮氨酸和缬氨酸）的合成，从而抑制富含亮氨酸重复序列蛋白（SHOC2）的表达以及下游SHOC2参与的RAS-ERK信号通路，最终导致TNBC细胞凋亡。