Small-Molecule Cyanamide Pan-TEAD·YAP1 Covalent Antagonists

Towards the design of ligands of the internal pocket TEADs C-terminal domain

The Hippo pathway controls in organ size and tissue homeostasis through regulating cell growth, proliferation and apoptosis. Phosphorylation of the transcription co-activator YAP (Yes associated protein) and TAZ (Transcriptional coactivator with PDZ-binding motif) regulates their nuclear import and therefore their interaction with TEAD (Transcriptional Enhanced Associated Domain). YAP, TAZ and TEADs are dysregulated in several solid cancers making YAP/TAZ-TEAD interaction a new anti-cancer target. We identified by screening a small in-house library, 5-benzyloxindole which binds to hTEAD2 at its internal/palmitate pocket. Its optimization led to covalent inhibitors bearing different warhead. Soaking with hTEAD2 gave seven new crystal structures where the ligands occupied palmitate pocket. 5-Benzyloxyindoles armed with vinylsulfamide moiety inhibit YAP/TAZ-TEAD target genes expression and breast cancer cell proliferation at micromolar concentration.

Strategies that regulate Hippo signaling pathway for novel anticancer therapeutics

As a highly conserved signaling network across different species, the Hippo pathway is involved in various biological processes. Dysregulation of the Hippo pathway could lead to a wide range of diseases, particularly cancers. Extensive researches have demonstrated the close association between dysregulated Hippo signaling and tumorigenesis as well as tumor progression. Consequently, targeting the Hippo pathway has emerged as a promising strategy for cancer treatment. In fact, there has been an increasing number of reports on small molecules that target the Hippo pathway, exhibiting therapeutic potential as anticancer agents. Importantly, some of Hippo signaling pathway inhibitors have been approved for the clinical trials. In this work, we try to provide an overview of the core components and signal transduction mechanisms of the Hippo signaling pathway. Furthermore, we also analyze the relationship between Hippo signaling pathway and cancers, as well as summarize the small molecules with proven anti-tumor effects in clinical trials or reported in literatures. Additionally, we discuss the anti-tumor potency and structure-activity relationship of the small molecule compounds, providing a valuable insight for further development of anticancer agents against this pathway.

Targeted degradation of specific TEAD paralogs by small molecule degraders

The transcription factors, TEAD1-4 together with their co-activator YAP/TAZ function as key downstream effectors of the Hippo pathway. Hyperactivation of TEAD-YAP/TAZ activity is observed in many human cancers. TEAD1-4 possess distinct physiological and pathological functions, with conserved sequences and structures. Targeting specific isoforms within TEAD1-4 can serve as valuable chemical probes for investigating TEAD-related functions in both development and diseases. We report the TEAD-targeting proteolysis targeting chimera (PROTAC), HC278, which achieves effective and specific targeting of TEAD1 and TEAD3 at low nanomolar doses while weakly degrading TEAD2 and TEAD4 at higher doses. Proteomic analysis of >6000 proteins confirmed their highly selective TEAD1 and TEAD3 degradation. Consistently, HC278 can suppress the proliferation of YAP-dependent NCI-H226 mesothelioma cells. Mechanistic exploration revealed that both CRBN and proteasome systems are involved in the TEAD degradation induced by HC278. Moreover, RNA-seq and Gene Set Enrichment Analysis (GSEA) revealed that the YAP signature genes such as CTGF, CYR61, and ANKRD1 are significantly downregulated by HC278 treatment. Overall, HC278 serves as a valuable chemical tool for unraveling the intricate biological roles of TEAD1 and TEAD3 and holds the potential as a lead compound for developing targeted therapy for TEAD1/3-driven pathologies.

Development of Novel Indole-Based Covalent Inhibitors of TEAD as Potential Antiliver Cancer Agents

Abnormal activation of the YAP transcriptional signaling pathway drives proliferation in many hepatocellular carcinoma (HCC) and hepatoblastoma (HB) cases. Current treatment options often face resistance and toxicity, highlighting the need for alternative therapies. This article reports the discovery of a hit compound C-3 from docking-based virtual screening targeting TEAD lipid binding pocket, which inhibited TEAD-mediated transcription. Optimization led to the identification of a potent and covalent inhibitor CV-4-26 that exhibited great antitumor activity in HCC and HB cell lines in vitro, xenografted human HCC, and murine HB in vivo. These outcomes signify the potential of a highly promising therapeutic candidate for addressing a subset of HCC and HB cancers. In the cases of current treatment challenges due to high upregulation of YAP-TEAD activity, these findings offer a targeted alternative for more effective interventions against liver cancer.

Development of HC-258, a Covalent Acrylamide TEAD Inhibitor That Reduces Gene Expression and Cell Migration

The transcription factor YAP-TEAD is the downstream effector of the Hippo pathway which controls cell proliferation, apoptosis, tissue repair, and organ growth. Dysregulation of the Hippo pathway has been correlated with carcinogenic processes. A co-crystal structure of TEAD with its endogenous ligand palmitic acid (PA) as well as with flufenamic acid (FA) has been disclosed. Here we report the development of HC-258, which derives from FA and possesses an oxopentyl chain that mimics a molecule of PA as well as an acrylamide that reacts covalently with TEAD's cysteine. HC-258 reduces the CTGF, CYR61, AXL, and NF2 transcript levels and inhibits the migration of MDA-MB-231 breast cancer cells. Co-crystallization with hTEAD2 confirmed that HC-258 binds within TEAD's PA pocket, where it forms a covalent bond with its cysteine.

Verteporfin Suppresses YAP-Induced Glycolysis in Breast Cancer Cells

OBJECTIVE

The inhibition of the Hippo pathway through targeting the Yes-associated protein (YAP) presents a novel and promising approach for treating tumors. However, the efficacy of YAP inhibitors in the context of breast cancer (BC) remains incompletely understood. Here, we aimed to investigate the involvement of YAP in BC's metabolic reprogramming and reveal the potential underlying mechanisms. To this end, we assessed the function of verteporfin (VP), a YAP-TEAD complex inhibitor, on the glycolytic activity of BC cells.

METHODS

We evaluated the expression of YAP by utilizing immunohistochemistry (IHC) in BC patients who have undergone 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) prior to biopsy/surgery. We employed RNA immunoprecipitation (RIP) and fluorescent in situ hybridization (FISH) assays to assess the interaction between YAP mRNA and human antigen R (HuR) in BC cells. The biological importance of YAP in the metabolism and malignancy of BC was evaluated in vitro. Finally, the effect of VP on glycolysis was determined by using 18F-FDG uptake, glucose consumption, and lactate production assays.

RESULTS

Our studies revealed that high expression of YAP was positively correlated with the maximum uptake value (SUVmax) determined by 18F-FDG PET/CT imaging in BC samples. Inhibition of YAP activity suppressed glycolysis in BC. The mechanism underlying this phenomenon could be the binding of YAP to HuR, which promotes glycolysis in BC cells. Treatment with VP effectively suppressed glycolysis induced by YAP overexpression in BC cells.

CONCLUSION

VP exhibited anti-glycolytic effect on BC cells, indicating its therapeutic value as an FDA-approved drug.

Rapid assembly of structurally diverse cyanamides and disulfanes via base-mediated aminoalkylation of aryl thiourea

A general method for the preparation of cyanamides and disulfanes from aryl thiourea and halide through a base-mediated strategy is described. Mercaptan and N-aryl cyanamide are the key intermediates in the reaction. The current method is convenient, eco-friendly, and has high yields for the synthesis of substituted cyanamide and functional disulfanes in a one-pot procedure from readily available starting materials.

Development of LM-41 and AF-2112, two flufenamic acid-derived TEAD inhibitors obtained through the replacement of the trifluoromethyl group by aryl rings

The Hippo pathway regulates organ size and tissue homeostasis by controlling cell proliferation and apoptosis. The YAP-TEAD transcription factor, the downstream effector of the Hippo pathway, regulates the expression of genes such as CTGF, Cyr61, Axl and NF2. Aberrant Hippo activity has been identified in multiple types of cancers. Flufenamic acid (FA) was reported to bind in a liphophilic TEAD palmitic acid (PA) pocket, leading to reduction of the expression of Axl and NF2. Here, we show that the replacement of the trifluoromethyl moiety in FA by aromatic groups, directly connected to the scaffold or separated by a linker, leads to compounds with better affinity to TEAD. Co-crystallization studies show that these compounds bind similarly to FA, but deeper within the PA pocket. Our studies identified LM-41 and AF-2112 as two TEAD binders that strongly reduce the expression of CTGF, Cyr61, Axl and NF2. LM-41 gave the strongest reduction of migration of human MDA-MB-231 breast cancer cells.

4-Cyanamido-substituted benzenesulfonamides act as dual carbonic anhydrase and cathepsin inhibitors

A set of novel N-cyano-N-substituted 4-aminobenzenesulfonamide derivatives were synthesized and investigated for their inhibitory activity against four cytosolic carbonic anhydrase (CA, EC 4.2.1.1) isoforms (hCA I, II, VII and XIII) and two cathepsins (S and B). N-alkyl/benzyl-substituted derivatives were revealed to be very potent inhibitors against brain-associated hCA VII, but inactive against both cathepsins. On the other hand, N-acyl-substituted derivatives displayed significant inhibitory activities against cathepsin S, but only moderate to poor inhibitory potency against hCA VII. Both hCA VII and cathepsin S have recently been validated as therapeutic targets in neuropathic pain. This study provided an excellent starting point for further structural optimization of this class of bifunctional compounds to enhance their inhibitory activity and selectivity against hCA VII and cathepsin S and to achieve new compounds with an attractive dual mechanism of action as anti-neuropathic agents.

Chloroacetamide fragment library screening identifies new scaffolds for covalent inhibition of the TEAD·YAP1 interaction

Transcriptional enhanced associate domain (TEAD) binding to co-activator yes-associated protein (YAP1) leads to a transcription factor of the Hippo pathway. TEADs are regulated by S-palmitoylation of a conserved cysteine located in a deep well-defined hydrophobic pocket outside the TEAD·YAP1 interaction interface. Previously, we reported the discovery of a small molecule based on the structure of flufenamic acid that binds to the palmitate pocket, forms a covalent bond with the conserved cysteine, and inhibits TEAD4 binding to YAP1. Here, we screen a fragment library of chloroacetamide electrophiles to identify new scaffolds that bind to the palmitate pocket of TEADs and disrupt their interaction with YAP1. Time- and concentration-dependent studies with wild-type and mutant TEAD1-4 provided insight into their reaction rates and binding constants and established the compounds as covalent inhibitors of TEAD binding to YAP1. Binding pose hypotheses were generated by covalent docking revealing that the fragments and compounds engage lower, middle, and upper sub-sites of the palmitate pocket. Our fragments and compounds provide new scaffolds and starting points for the design of derivatives with improved inhibition potency of TEAD palmitoylation and binding to YAP1.

Pharmacotherapeutic strategies for epithelioid sarcoma: are we any closer to a non-surgical cure?

INTRODUCTION

Epithelioid sarcoma (ES) is a rare soft tissue sarcoma subtype, predominantly occurring in children and young adults. Despite optimal management of localized disease, approximately 50% of patients develop advanced disease. The management of advanced ES remains challenging due to limited response to conventional chemotherapy and despite novel oral EZH2 inhibitors that have better tolerability but similar efficacy to chemotherapy.

AREAS COVERED

We performed a literature review using the PubMed (MEDLINE) and Web of Science databases. We have focused on the role of chemotherapy, targeted agents such as EZH2 inhibitors, potential new targets and immune checkpoint inhibitors and combinations of therapies currently undergoing clinical investigation.

EXPERT OPINION

ES is a soft tissue sarcoma with a heterogeneous pathological, clinical, and molecular presentation. In the current era of precision medicine, more trials with targeted therapies and a combination of chemotherapy or immunotherapy with targeted therapies are required to establish optimal treatment for ES.