TEADs serve as potential prognostic biomarkers and targets for human gastric cancer

Hippo Signaling at the Hallmarks of Cancer and Drug Resistance

Originally identified in Drosophila melanogaster in 1995, the Hippo signaling pathway plays a pivotal role in organ size control and tumor suppression by inhibiting proliferation and promoting apoptosis. Large tumor suppressors 1 and 2 (LATS1/2) directly phosphorylate the Yki orthologs YAP (yes-associated protein) and its paralog TAZ (also known as WW domain-containing transcription regulator 1 [WWTR1]), thereby inhibiting their nuclear localization and pairing with transcriptional coactivators TEAD1-4. Earnest efforts from many research laboratories have established the role of mis-regulated Hippo signaling in tumorigenesis, epithelial mesenchymal transition (EMT), oncogenic stemness, and, more recently, development of drug resistances. Hippo signaling components at the heart of oncogenic adaptations fuel the development of drug resistance in many cancers for targeted therapies including KRAS and EGFR mutants. The first U.S. food and drug administration (US FDA) approval of the imatinib tyrosine kinase inhibitor in 2001 paved the way for nearly 100 small-molecule anti-cancer drugs approved by the US FDA and the national medical products administration (NMPA). However, the low response rate and development of drug resistance have posed a major hurdle to improving the progression-free survival (PFS) and overall survival (OS) of cancer patients. Accumulating evidence has enabled scientists and clinicians to strategize the therapeutic approaches of targeting cancer cells and to navigate the development of drug resistance through the continuous monitoring of tumor evolution and oncogenic adaptations. In this review, we highlight the emerging aspects of Hippo signaling in cross-talk with other oncogenic drivers and how this information can be translated into combination therapy to target a broad range of aggressive tumors and the development of drug resistance.

TEAD4: A key regulator of tumor metastasis and chemoresistance - Mechanisms and therapeutic implications

Cancer metastasis is a complex process influenced by various factors, including epithelial-mesenchymal transition (EMT), tumor cell proliferation, tumor microenvironment, and cellular metabolic status, which remains a significant challenge in clinical oncology, accounting for a majority of cancer-related deaths. TEAD4, a key mediator of the Hippo signaling pathway, has been implicated in regulating these factors that are all critical in the metastatic cascade. TEAD4 drives tumor metastasis and chemoresistance, and its upregulation is associated with poor prognosis in many types of cancers, making it an attractive target for therapeutic intervention. TEAD4 promotes EMT by interacting with coactivators and activating the transcription of genes involved in mesenchymal cell characteristics and extracellular matrix remodeling. Additionally, TEAD4 enhances the stemness of cancer stem cells (CSCs) by regulating the expression of genes associated with CSC maintenance. TEAD4 contributes to metastasis by modulating the secretion of paracrine factors and promoting heterotypic cellular communication. In this paper, we highlight the central role of TEAD4 in cancer metastasis and chemoresistance and its impact on various aspects of tumor biology. Understanding the mechanistic basis of TEAD4-mediated processes can facilitate the development of targeted therapies and combination approaches to combat cancer metastasis and improve treatment outcomes.

Novel KDM2B/SAV1 Signaling Pathway Promotes the Progression of Gastric Cancer

Salvador homologue 1 (SAV1), which is reported to act as a tumor suppressor in different types of cancer, is one of the key components of the Hippo pathway. However, the expression and mechanisms of SAV1 in the development and progression of gastric cancer (GC) remain to be elucidated. Immunohistochemistry (IHC) was performed in the present study to assess the expression levels of SAV1 and lysine-specific demethylase 2B (KDM2B) in GC tissues. The biological effects of SAV1 on GC cell proliferation, migration, and invasion were studied in vitro. KDM2B transcriptionally regulates SAV1 expression in several GC cell lines, and molecular experiments were performed to investigate underlying mechanisms. The expression level of SAV1 was significantly decreased in GC tissues and cell lines, negatively associated with tumor invasion depth, lymph node metastasis, and TNM stage, and positively associated with the overall survival of patients with GC. SAV1 overexpression inhibited the proliferation, migration, and invasion of GC cells. Further mechanistic studies revealed that KDM2B transcriptionally regulated SAV1 expression and further regulated the Hippo signaling pathway. To conclude, the present study demonstrated that KDM2B transcriptionally regulated SAV1 expression and promoted GC progression.

The Hippo signaling pathway in gastric cancer

Gastric cancer (GC) is an aggressive malignant disease which still lacks effective early diagnosis markers and targeted therapies, representing the fourth-leading cause of cancer-associated death worldwide. The Hippo signaling pathway plays crucial roles in organ size control and tissue homeostasis under physiological conditions, yet its aberrations have been closely associated with several hallmarks of cancer. The last decade witnessed a burst of investigations dissecting how Hippo dysregulation contributes to tumorigenesis, highlighting the therapeutic potential of targeting this pathway for tumor intervention. In this review, we systemically document studies on the Hippo pathway in the contexts of gastric tumor initiation, progression, metastasis, acquired drug resistance, and the emerging development of Hippo-targeting strategies. By summarizing major open questions in this field, we aim to inspire further in-depth understanding of Hippo signaling in GC development, as well as the translational implications of targeting Hippo for GC treatment.

Therapeutic targeting of TEAD transcription factors in cancer

The Hippo signaling pathway inhibits the activity of the oncogenic YAP (Yes-associated protein)/TAZ (transcriptional co-activator with PDZ-binding motif)-TEAD (TEA/ATTS domain) transcriptional complex. In cancers, inactivating mutations in upstream Hippo components and/or enhanced activity of YAP/TAZ and TEAD have been observed. The activity of this transcriptional complex can be effectively inhibited by targeting the TEAD family of transcription factors. The development of TEAD inhibitors has been driven by the discovery that TEAD has druggable hydrophobic pockets, and is currently at the clinical development stage. Three small molecule TEAD inhibitors are currently being tested in Phase I clinical trials. In this review, we highlight the role of TEADs in cancer, discuss various avenues through which TEAD activity can be inhibited, and outline the opportunities for the administration of TEAD inhibitors.