Novel YAP1 Activator, Identified by Transcription-Based Functional Screen, Limits Multiple Myeloma Growth

Abstract

Yes-associated protein 1 (YAP1) interacts with numerous transcription factors, including TEA-domain family proteins (TEAD) and p73. YAP1 is negatively regulated by the tumor suppressor Hippo pathway. In human cancers, the deregulation of the Hippo pathway and YAP1 gene amplification lead to the activation of YAP1, which induces epithelial-mesenchymal transition (EMT) and drug resistance. YAP1 inhibitors are expected to be useful in cancer therapy. On the other hand, in certain cancers, YAP1 upregulates p73-dependent gene transcription and behaves as a tumor suppressor. Moreover, as YAP1 regulates self-renewal and differentiation of tissue stem cells and plays an important role in tissue homeostasis, YAP1 activators may contribute to the regenerative medicine. With this in our mind, we screened for YAP1 activators by using human retinal pigment epithelial ARPE-19 cells expressing the TEAD-responsive fluorescence reporter under the coexpression of YAP1. From an extensive chemical compound library ( = 18,606) 47 candidate YAP1 activators were identified. These compounds were characterized to determine whether this assay provides YAP1 activators. Importantly, one YAP1 activator was effective against the human multiple myeloma IM-9 cells and chronic myeloid leukemia K562 cells. YAP1 activation limits growth, induces apoptosis, and may be useful at suppressing hematological cancers. .

Discovery of a Small Molecule to Increase Cardiomyocytes and Protect the Heart After Ischemic Injury

“… For fluorescence reporter-based assay for YAP-TEAD activators, ARPE-19 cells were transfected with the pLL3.7-K122 FH-YAP1-ires-GFP-TEADs-responsive-promoter-H2B-mCherry reporter using Lipofectamine 2000 (Thermo Fisher Scientific, Waltham, Massachusetts). The YAP1-expressing ARPE-19 cells were treated with 10 μmol/l of each compound for 72 h, and the H2B-mCherry signal inside the nucleus was measured (11) . For sphere formation assay for TAZ activators, human breast epithelial MCF10A cells expressing TAZ (MCF10A-TAZ) were cultured with 10 μmol/l of each compound for 10 days, and TAZ activators enabled TAZ-expressing MCF10A cells to form spheres (12) .…”

“…For fluorescence reporter-based assay for YAP-TEAD activators, ARPE-19 cells were transfected with the pLL3.7-K122 FH-YAP1-ires-GFP-TEADs-responsive-promoter-H2B-mCherry reporter using Lipofectamine 2000 (Thermo Fisher Scientific, Waltham, Massachusetts). The YAP1-expressing ARPE-19 cells were treated with 10 μmol/l of each compound for 72 h, and the H2B-mCherry signal inside the nucleus was measured (11) .…”

YAP/TAZ Activation as a Target for Treating Metastatic Cancer

“…A dipyrrin derivative called dipyrrin 19 was also found to inhibit YAP/TAZ-TEAD mediated transcriptional activity in metastatic breast cancer cells [ 199 ], and another compound called cerivastatin could prevent YAP/TAZ nuclear entry [ 209 ]. A cell-based screen of 48 chemical compounds identified dobutamine as a potent inhibitor of YAP activity [ 210 ], and subsequent studies from the same group using larger chemical compound libraries revealed several others that potently inhibit YAP [ 211 ] or TAZ [ 212 ] transcriptional activity. A small molecule, C19, can promote TAZ degradation through Hippo pathway activation, but this compound also inhibits Wnt and Transforming Growth Factor β (TGFβ) signaling [ 213 ].…”

Long noncoding RNA NEAT1 suppresses hepatocyte proliferation in fulminant hepatic failure through increased recruitment of EZH2 to the LATS2 promoter region and promotion of H3K27me3 methylation

“…Previously, Cottini et al explained that genetic inhibition or diminished expression of the Hippo cotranscription factor YAP1 could prevent tumor cells from undergoing the pathologic process of apoptosis 43 . Moreover, YAP1 also possesses the ability to modulate stem cell self-renewal and differentiation and tissue homeostasis, as well as upregulate p73-dependent pro-apoptotic gene transcription 44 . Specifically, the interaction between LATS2 and YAP1 resulted in YAP1 dephosphorylation and nuclear translocation, thereby protecting YAP1 from ubiquitination in the cytoplasm and inducing the expression of pro-proliferation genes in colorectal cancer by working as a transcriptional coactivator 45 .…”