Discovery of aurovertin B as a potent metastasis inhibitor against triple-negative breast cancer: Elucidating the complex role of the ATF3-DUSP1 axis.

Triple-negative breast cancer (TNBC) is characterized by high mortality rates, primarily due to its propensity for metastasis. Addressing this challenge necessitates the development of effective antimetastatic therapies. This study aimed to identify natural compounds with potential antimetastatic properties mainly based on the high-throughput phenotypic screening system. This system, utilizing luciferase reporter gene assays combined with scratch wound assays, evaluates compounds based on their influence on the epithelial-mesenchymal transition (EMT) marker E-cadherin. Through this approach, aurovertin B (AVB) was revealed to have significant antimetastatic capability. Notably, AVB exhibited substantial metastasis suppression in many TNBC cell lines, including MDA-MB-231, HCC1937, and 4T1. Also, its remarkable antimetastatic activity was demonstrated in vivo via the orthotopic breast cancer mouse model. Further exploration revealed a pronounced association between AVB-induced upregulation of dual-specificity phosphatase 1 (DUSP1) and its inhibitory effect on TNBC metastasis. Additionally, microarray analysis conducted to elucidate the underlying mechanism of the AVB-DUSP1 interaction identified activating transcription factor 3 (ATF3) as a critical transcription factor instrumental in DUSP1 transcriptional activation. This discovery, coupled with observations of enhanced ATF3-DUSP1 expression and consequent reduction in TNBC metastatic foci in response to AVB, provides novel insights into the metastatic mechanisms of TNBC. SIGNIFICANCE STATEMENT: This study constructs a high-throughput phenotypic screening system utilizing epithelial-mesenchymal transition marker E-cadherin promoter luciferase reporter gene combined with scratch wound assays. Aurovertin B was revealed to possess significant antimetastatic activity through this approach, which was further demonstrated via in vivo and in vitro experiments. The discovery of the regulatory role of the ATF3-DUSP1 pathway enriches our understanding of TNBC metastasis mechanism and suggests the potential of ATF3 and DUSP1 as biomarkers for diagnosing TNBC metastasis.