Inhibition Of YAP Research Articles

Transient proliferation by reversible YAP-mediated increase of the cyclin D1/p27 ratio.

YAP signaling controls cell cycle entry and exit by up- and down-regulating the cyclin D1/p27 ratio above and below a conserved thresholdYAP-induced proliferation is intrinsically transient since contact inhibition of YAP suppresses EGFR signaling after a delay to reduce this cyclin D1/p27 ratioYAP can still be robustly inhibited after Merlin/NF2 ablation but only at higher local cell densityThe YAP-regulated cyclin D1/p27 ratio is primarily controlled by MEK-ERK rather than mTOR activity.

The RNA helicase DDX21 activates YAP to promote tumorigenesis and is transcriptionally upregulated by β-catenin in colorectal cancer

The RNA helicase DDX21 is vital for ribosome biogenesis and is upregulated in CRC, but the mechanism by which DDX21 is dysregulated and by which DDX21 promotes tumorigenesis in CRC remains poorly understood. Here, we showed that DDX21 is a direct transcriptional target gene of β-catenin and mediates the protumorigenic function of β-catenin in CRC. DDX21 expression is correlated with the expression and activity of β-catenin, and high DDX21 expression is associated with a poor prognosis in CRC patients. Loss of DDX21 leads to cytoplasmic translocation and decreased transcriptional activity of YAP and suppresses the proliferation and migration of CRC cells, which can be partially rescued by YAP reactivation. Importantly, by using translation elongation inhibitors and DNA intercalators, we showed that ribosomal stress upregulates DDX21 expression and induces the downregulation of LATS and the activation of YAP, probably through the ZAKα-MKK4/7-JNK axis. Overall, our study revealed the transcriptional activation mechanism of DDX21 in CRC and the activation of YAP in the ribosomal stress response, indicating the potential of combination therapy involving the induction of ribosomal stress and YAP inhibition.

Genetic Screen in a Pre-Clinical Model of Sarcoma Development Defines Drivers and Therapeutic Vulnerabilities.

High-grade complex karyotype sarcomas are a heterogeneous group of tumors with a uniformly poor prognosis. Within complex karyotype sarcomas, there are innumerable genetic changes but identifying those that are clinically relevant has been challenging. To address this, we utilized a pooled genetic screening approach, informed by TCGA data, to identify key drivers and modifiers of sarcoma development that were validated in vivo. YAP1 and wildtype KRAS were validated as drivers and transformed human mesenchymal stem cells into two distinct sarcoma subtypes, undifferentiated pleomorphic sarcoma (UPS) and myxofibrosarcoma (MFS), respectively. A subset of tumors driven by CDK4 and PIK3CA reflected leiomyosarcoma (LMS) and osteosarcoma (OS) demonstrating the plasticity of this approach and the potential to investigate sarcoma subtype heterogeneity. All generated tumors histologically reflected human sarcomas and had increased aneuploidy as compared to simple karyotype sarcomas. Comparing differential gene expression of TCGA samples to model data identified increased oxidative phosphorylation signaling in YAP1 tumors. Treatment of a panel of soft tissue sarcomas with a combination of YAP1 and oxidative phosphorylation inhibitors led to significantly decreased viability. Transcriptional co-analysis of TCGA patient samples to YAP1 and KRAS model tumors support that these sarcoma subtypes lie along a spectrum of disease and adds guidance for further transcriptome-based refinement of sarcoma subtyping. This approach can be used to begin to understand pathways and mechanisms driving human sarcoma development, the relationship between sarcoma subtypes and to identify and validate new therapeutic vulnerabilities for this aggressive and heterogeneous disease.

YAP O-GlcNAcylation contributes to corneal epithelial cell ferroptosis under cigarette smoke exposure

Cigarette smoke (CS) is an important indoor air pollutant associated with an increased risk of ocular surface disease. As the eye's outermost layer, the cornea is highly sensitive to air pollutants like CS. However, the specific mechanisms linking CS exposure to corneal dysfunction have not been fully elucidated. In the present study, we found that CS exposure damages corneal epithelial cells, accompanied by increased iron (Fe2+) levels and lipid peroxidation, both hallmarks of ferroptosis. Ferroptosis inhibitors, including Ferrostatin-1 (Fer-1) and Deferoxamine mesylate (DFO), protect against CS-induced cell damage. To understand the underlying mechanisms, we investigated how CS affects iron and lipid metabolism. Our results showed that CS could upregulate intracellular iron levels by increasing TFRC expression and promote lipid peroxidation by increasing ACSL4 expression. Silencing ACSL4 or TFRC expression prevented CS-induced ferroptosis. Furthermore, we found that the upregulation of TFRC and ACSL4 was driven by increased YAP transcription. Pharmacological or genetic inhibition of YAP effectively prevented corneal epithelial cell ferroptosis under CS stimulation. Additionally, our results suggest that CS exposure could increase O-GlcNAc transferase activity, leading to YAP O-GlcNAcylation. This glycosylation of YAP interfered with its K48-linked ubiquitination, resulting in YAP stabilization. Collectively, we found that CS exposure induces corneal epithelial cell ferroptosis via the YAP O-GlcNAcylation, and provide evidence that CS exposure is a strong risk factor for ocular surface disease.

YAP1 Inhibition Induces Phenotype Switching of Cancer-Associated Fibroblasts to Tumor Suppressive in Prostate Cancer.

Prostate cancer (PCa) rarely responds to immune-checkpoint blockade (ICB) therapies. Cancer-associated fibroblasts (CAFs) are critical components of the immunologically "cold" tumor microenvironment and are considered a promising target to enhance the immunotherapy response. In this study, we aimed to reveal the mechanisms regulating CAF plasticity to identify potential strategies to switch CAFs from pro-tumorigenic to anti-tumor phenotypes and enhance ICB efficacy in PCa. Integration of four PCa single-cell RNA-sequencing datasets defined pro-tumorigenic and anti-tumor CAFs, and RNA-seq, flow cytometry, and a PCa organoid model demonstrated the functions of two CAF subtypes. Extracellular matrix-associated CAFs (ECM-CAF) promoted collagen deposition and cancer cell progression, and lymphocyte-associated CAFs (Lym-CAF) exhibited an anti-tumor phenotype and induced the infiltration and activation of CD8+ T cells. YAP1 activity regulated the ECM-CAF phenotype, and YAP1 silencing promoted switching to Lym-CAFs. NF-κB p65 was the core transcription factor in the Lym-CAF subset, and YAP1 inhibited nuclear translocation of p65. Selective depletion of YAP1 in ECM-CAFs in vivo promoted CD8+ T-cell infiltration and activation and enhanced the therapeutic effects of anti- PD-1 treatment in PCa. Overall, this study revealed a mechanism regulating CAF identity in PCa and highlighted a therapeutic strategy for altering the CAF subtype to suppress tumor growth and increase sensitivity to ICB.

Disrupting YAP1-mediated glutamine metabolism induces synthetic lethality alongside ODC1 inhibition in osteosarcoma.

Osteosarcoma, a highly malignant primary bone tumor primarily affecting adolescents, frequently develops resistance to initial chemotherapy, leading to metastasis and limited treatment options. Our study aims to uncover novel therapeutic targets for metastatic and recurrent osteosarcoma. In this study, we proved the potential of modulating the YAP1-regulated glutamine metabolic pathway to augment the response of OS to DFMO. We initially employed single-cell transcriptomic data to gauge the activation level of polyamine metabolism in MTAP-deleted OS patients. This was further substantiated by transcriptome sequencing data from recurrent and non-recurrent patient tissues, confirming the activation of polyamine metabolism in progressive OS. Through high-throughput drug screening, we pinpointed CIL56, a YAP1 inhibitor, as a promising candidate for a combined therapeutic strategy with DFMO. In vivo, we utilized PDX and CDX models to validate the therapeutic efficacy of this drug combination. In vitro, we conducted western blot analysis, qPCR analysis, immunofluorescence staining, and PuMA experiments to monitor alterations in molecular expression, distribution, and tumor metastasis capability. We employed CCK-8 and colony formation assays to assess the proliferative capacity of cells in the experimental group. We used flow cytometry and reactive oxygen probes to observe changes in ROS and glutamine metabolism within the cells. Finally, we applied RNA-seq in tandem with metabolomics to identify metabolic alterations in OS cells treated with a DFMO and CIL56 combination. This enabled us to intervene and validate the role of the YAP1-mediated glutamine metabolic pathway in DFMO resistance. Through single-cell RNA-seq data analysis, we pinpointed a subset of late-stage OS cells with significantly upregulated polyamine metabolism. This upregulation was further substantiated by transcriptomic profiling of recurrent and non-recurrent OS tissues. High-throughput drug screening revealed a promising combination strategy involving DFMO and CIL56. DFMO treatment curbs the phosphorylation of YAP1 protein in OS cells, promoting nuclear entry and initiating the YAP1-mediated glutamine metabolic pathway. This reduces intracellular ROS levels, countering DFMO's anticancer effect. The therapeutic efficacy of DFMO can be amplified both in vivo and in vitro by combining it with the YAP1 inhibitor CIL56 or the glutaminase inhibitor CB-839. This underscores the significant potential of targeting the YAP1-mediated glutamine metabolic pathway to enhance efficacy of DFMO. Our findings elucidate YAP1-mediated glutamine metabolism as a crucial bypass mechanism against DFMO, following the inhibition of polyamine metabolism. Our study provides valuable insights into the potential role of DFMO in an "One-two Punch" therapy of metastatic and recurrent osteosarcoma.

Shikonin Suppresses Cell Tumorigenesis in Gastric Cancer Associated with the Inhibition of c-Myc and Yap-1.

The study aimed to study the potential roles and mechanisms of shikonin in gastric cancer by network pharmacology and biological experiments. The key genes and targets of shikonin in gastric cancer were predicted by network pharmacology and molecular docking study. The effect of shikonin on the proliferation, migration, and invasion of gastric cancer cells was detected by the CCK8 method, and wound healing and transwell assays. The expression levels of c-Myc and Yap-1 were detected via western blotting in gastric cancer cells after shikonin intervention. The results of network pharmacology revealed the key target genes of shikonin on gastric cancer cells to be c-Myc, Yap-1, AKT1, etc. GO and KEGG analysis showed regulation of cell migration, proliferation, adhesion, and other biological processes, including the PI3K-Akt signaling pathway, HIF-1 signaling pathway, necroptosis, and other cancer pathways. Molecular docking showed shikonin to be most closely combined with protooncogenes c-Myc and Yap-1. In vitro experiments showed that the proliferation rate, migration, and invasion ability of the gastric cancer cell group decreased significantly after shikonin intervention for 24h. The expression levels of c-Myc and Yap-1 in gastric cancer cells were found to be significantly decreased after shikonin intervention. This study showed protooncogenes c-Myc and Yap-1 to be the core target genes of shikonin on gastric cancer cells. Shikonin may suppress gastric cancer cells by inhibiting the protooncogenes c-Myc and Yap-1. This suggests that shikonin may be a good candidate for the treatment of gastric cancer.

High Hydrostatic Pressure Exacerbates Bladder Fibrosis through Activating Piezo1.

Bladder outlet obstruction (BOO) results in significant fibrosis in the chronic stage and elevated bladder pressure. Piezo1 is a type of mechanosensitive (MS) channel that directly responds to mechanical stimuli. To identify new targets for intervention in the treatment of BOO-induced fibrosis, this study investigated the impact of high hydrostatic pressure (HHP) on Piezo1 activity and the progression of bladder fibrosis. Immunofluorescence staining was conducted to assess the protein abundance of Piezo1 in fibroblasts from obstructed rat bladders. Bladder fibroblasts were cultured under normal atmospheric conditions (0 cmH2O) or exposed to HHP (50 cmH2O or 100 cmH2O). Agonists or inhibitors of Piezo1, YAP1, and ROCK1 were used to determine the underlying mechanism. The Piezo1 protein levels in fibroblasts from the obstructed bladder exhibited an elevation compared to the control group. HHP significantly promoted the expression of various pro-fibrotic factors and induced proliferation of fibroblasts. Additionally, the protein expression levels of Piezo1, YAP1, ROCK1 were elevated, and calcium influx was increased as the pressure increased. These effects were attenuated by the Piezo1 inhibitor Dooku1. The Piezo1 activator Yoda1 induced the expression of pro-fibrotic factors and the proliferation of fibroblasts, and elevated the protein levels of YAP1 and ROCK1 under normal atmospheric conditions in vitro. However, these effects could be partially inhibited by YAP1 or ROCK inhibitors. The study suggests that HHP may exacerbate bladder fibrosis through activating Piezo1.

ACSL3 regulates breast cancer progression via lipid metabolism reprogramming and the YES1/YAP axis.

Mitochondrial fatty acid oxidation is a metabolic pathway whose dysregulation is recognized as a critical factor in various cancers, because it sustains cancer cell survival, proliferation, and metastasis. The acyl-CoA synthetase long-chain (ACSL) family is known to activate long-chain fatty acids, yet the specific role of ACSL3 in breast cancer has not been determined. We assessed the prognostic value of ACSL3 in breast cancer by using data from tumor samples. Gain-of-function and loss-of-function assays were also conducted to determine the roles and downstream regulatory mechanisms of ACSL3 in vitro and in vivo. ACSL3 expression was notably downregulated in breast cancer tissues compared with normal tissues, and this phenotype correlated with improved survival outcomes. Functional experiments revealed that ACSL3 knockdown in breast cancer cells promoted cell proliferation, migration, and epithelial-mesenchymal transition. Mechanistically, ACSL3 was found to inhibit β-oxidation and the formation of associated byproducts, thereby suppressing malignant behavior in breast cancer. Importantly, ACSL3 was found to interact with YES proto-oncogene 1, a member of the Src family of tyrosine kinases, and to suppress its activation through phosphorylation at Tyr419. The decrease in activated YES1 consequently inhibited YAP1 nuclear colocalization and transcriptional complex formation, and the expression of its downstream genes in breast cancer cell nuclei. ACSL3 suppresses breast cancer progression by impeding lipid metabolism reprogramming, and inhibiting malignant behaviors through phospho-YES1 mediated inhibition of YAP1 and its downstream pathways. These findings suggest that ACSL3 may serve as a potential biomarker and target for comprehensive therapeutic strategies for breast cancer.

Hernandonine-mediated autophagic cell death in hepatocellular carcinoma: Interplay of p53 and YAP signaling pathways

Hepatocellular carcinoma (HCC), the primary form of liver cancer, is the third leading cause of cancer-related death globally. Hernandonine is a natural alkaloid derived from Hernandia nymphaeifolia that has been shown to exert various biological functions. In a previous study, hernandonine was shown to suppress the proliferation of several solid tumor cell lines without affecting normal human cell lines. However, little is known about the effect of hernandonine on HCC. Therefore, this study aimed to investigate the effect and mechanism of hernandonine on HCC in relation to autophagy. We found that hernandonine inhibited HCC cell growth in vitro and in vivo. In addition, hernandonine elicited autophagic cell death and DNA damage in HCC cells. RNA-seq analysis revealed that hernandonine upregulated p53 and Hippo signaling pathway-related genes in HCC cells. Small RNA interference of p53 resulted in hernandonine-induced autophagic cell death attenuation. However, inhibition of YAP sensitized HCC cells to hernandonine by increasing the autophagy induction. This is the first study to illustrate the complex involvement of p53 and YAP in the hernandonine-induced autophagic cell death in human HCC cells. Our findings provide novel evidence for the potential of hernandonine as a therapeutic agent for HCC treatment.

YAP promotes the early development of temporomandibular joint bony ankylosis by regulating mesenchymal stem cell function

To explore the role of YAP, a key effector of the Hippo pathway, in temporomandibular joint (TMJ) ankylosis. The temporal and spatial expression of YAP was detected via immunohistochemistry and multiplex immunohistochemistry on postoperative Days 1, 4, 7, 9, 11, 14 and 28 in a sheep model. Isolated mesenchymal stem cells (MSCs) from samples of the Day 14. The relative mRNA expression of YAP was examined before and after the osteogenic induction of MSCs. A YAP-silenced MSC model was constructed, and the effect of YAP knockdown on MSC function was examined. YAP is expressed in the nucleus of the key sites that determine the ankylosis formation, indicating that YAP is activated in a physiological state. The expression of YAP increased gradually over time. Moreover, the number of cells coexpressing of RUNX2 and YAP—with the osteogenic active zone labelled by RUNX2—tended to increase after Day 9. After the osteogenic induction of MSCs, the expression of YAP increased. After silencing YAP, the osteogenic, proliferative and migratory abilities of the MSCs were inhibited. YAP is involved in the early development of TMJ bony ankylosis. Inhibition of YAP using shRNA might be a promising way to prevent or treat TMJ ankylosis.

Bcl-2 dependent modulation of Hippo pathway in cancer cells

IntroductionBcl-2 and Bcl-xL are the most studied anti-apoptotic members of Bcl-2 family proteins. We previously characterized both of them, not only for their role in regulating apoptosis and resistance to therapy in cancer cells, but also for their non-canonical functions, mainly including promotion of cancer progression, metastatization, angiogenesis, and involvement in the crosstalk among cancer cells and components of the tumor microenvironment. Our goal was to identify transcriptional signature and novel cellular pathways specifically modulated by Bcl-2.MethodsWe performed RNAseq analysis of siRNA-mediated transient knockdown of Bcl-2 or Bcl-xL in human melanoma cells and gene ontology analysis to identify a specific Bcl-2 transcriptional signature. Expression of genes modulated by Bcl-2 and associated to Hippo pathway were validated in human melanoma, breast adenocarcinoma and non-small cell lung cancer cell lines by qRT-PCR. Western blotting analysis were performed to analyse protein expression of upstream regulators of YAP and in relation to different level of Bcl-2 protein. The effects of YAP silencing in Bcl-2 overexpressing cancer cells were evaluated in migration and cell viability assays in relation to different stiffness conditions. In vitro wound healing assays and co-cultures were used to evaluate cancer-specific Bcl-2 ability to activate fibroblasts.ResultsWe demonstrated the Bcl-2-dependent modulation of Hippo Pathway in cancer cell lines from different tumor types by acting on upstream YAP regulators. YAP inhibition abolished the ability of Bcl-2 to increase tumor cell migration and proliferation on high stiffness condition of culture, to stimulate in vitro fibroblasts migration and to induce fibroblasts activation.ConclusionsWe discovered that Bcl-2 regulates the Hippo pathway in different tumor types, promoting cell migration, adaptation to higher stiffness culture condition and fibroblast activation. Our data indicate that Bcl-2 inhibitors should be further investigated to counteract cancer-promoting mechanisms.

Abstract 3142: Pik3c3 Safeguards Smooth Muscle Identity By Promoting Lysosome-mediated Yap1 Degradation

Background: Mature vascular smooth muscle cells (VSMCs) are quiescent and geared for maintaining vascular homeostasis by expressing a unique repertoire of contractile genes. However, key factors in controlling the contractile phenotype of VSMCs are poorly defined. Class III PI3K, PIK3C3 (Phosphatidylinositol 3-Kinase Catalytic Subunit Type 3) is a critical regulator of vesicular trafficking. Although PIK3C3 is known to play an essential role in cardiac homeostasis, its role in VSMCs remains elusive. Methods: To elucidate the role of Pik3c3 in regulating SMC fate and plasticity, we generated smooth muscle-specific Pik3c3 inducible knock out (KO) mice with SMC-lineage tracing. Proteomic mass spectrometry, next-generation RNA sequencing, SMC fate mapping coupled with single-cell RNA sequencing were applied to determine the phenotype and trajectories of SMCs after Pik3c3 ablation. Results: Specific ablation of Pik3c3 in SMCs results in severe gastrointestinal pseudo-obstruction and premature death. Analysis of aorta from the KO mice revealed dramatic vascular remodeling including dilatation, thickening of the vascular wall, spontaneous neointimal formation that was largely contributed by cells of SMC origin, and complete loss of contractility. Proteomics, bulk RNA-seq, and scRNA-seq studies of SMC-restricted Pik3c3 KO mouse aorta showed near complete loss of smooth muscle identity and the acquisition of an intermediate smooth muscle progenitor-like cell phenotype that underwent re-programming into multiple cell types including macrophages, T cells and osteoblasts. Mechanistically, we found that Pik3c3 deletion in VSMCs induces the accumulation of YAP1 (Yes associated protein 1) and its downstream target genes; this elevated YAP1 program appears to result from a blockade of autophagic lysosome-mediated degradation of YAP1, leading to phenotypic modulation of SMCs. Importantly, pharmacological inhibition of YAP by Verteporfin or genetic deletion of Yap1 rescues the vascular phenotype of Pik3c3 SM-specific KO mice. Conclusion: Our study reveals PIK3C3 as a master regulator safeguarding VSMC identity, and perturbation of the PIK3C3-YAP axis may be a novel mechanism underlying VSMC-driven vascular diseases in humans.

Novel Personalized Cancer Vaccine Using Tumor Extracellular Vesicles with Attenuated Tumorigenicity and Enhanced Immunogenicity.

Cancer vaccines offer a promising avenue in cancer immunotherapy by inducing systemic, tumor-specific immune responses. Tumor extracellular vesicles (TEVs) are nanoparticles naturally laden with tumor antigens, making them appealing for vaccine development. However, their inherent malignant properties from the original tumor cells limit their direct therapeutic use. This study introduces a novel approach to repurpose TEVs as potent personalized cancer vaccines. The study shows that inhibition of both YAP and autophagy not only diminishes the malignancy-associated traits of TEVs but also enhances their immunogenic attributes by enriching their load of tumor antigens and adjuvants. These revamped TEVs, termed attenuated yet immunogenically potentiated TEVs (AI-TEVs), showcase potential in inhibiting tumor growth, both as a preventive measure and a possible treatment for recurrent cancers. They prompt a tumor-specific and enduring immune memory. In addition, by showing that AI-TEVs can counteract cancer growth in a personalized vaccine approach, a potential strategy is presented for developing postoperative cancer immunotherapy that's enduring and tailored to individual patients.

Abstract 7207: Targeting hippo signaling pathway to overcome chemoresistance in glioblastoma

Abstract The study aims to investigate whether the Hippo signaling pathway contributes to temozolomide chemoresistance in glioblastoma, and to validate whether the combinational treatment of temozolomide and YAP inhibitor is effective against glioblastoma. Temozolomide-sensitive and temozolomide-resistant U87 and U251 GBM human cell lines were previously established. Temozolomide-resistant cells were maintained in low-dose temozolomide. Here, we investigate whether Hippo signaling contributes to temozolomide chemoresistance. By modulating the Hippo signaling pathway through YAP gene knockdown, the outcome on cell proliferation was studied by cell viability assay (in vitro) and mouse orthotopic xenograft (in vivo). Finally, the therapeutic effect of YAP inhibitor is studied in vitro and in vivo respectively. Our data showed that YAP is overexpressed in temozolomide-resistant glioblastoma cells. Nuclear translocation of YAP (which becomes its active state) is increased in temozolomide-resistant cells. In fact, YAP inhibition show decreased cell viability and higher susceptibility to temozolomide. In addition, mice with tumor injection of the YAP knockdown cells reduced tumor size with temozolomide treatment. Similarly, YAP inhibitor resensitizes temozolomide-resistant cells to temozolomide. Combinational treatment of YAP inhibitor and temozolomide is effective in shrinking tumor size in mouse xenograft models. In conclusion, our data suggest dysregulated Hippo signaling pathway contributes to temozolomide chemoresistance, thus targeting the Hippo signaling pathway resensitizes GBM cells to temozolomide. This research provides pre-clinical evidence on using YAP inhibitor for combinational therapy with temozolomide for the treatment of glioblastoma. Citation Format: Cheuk Lun Ethan Wong, Mei Yee Karrie Kiang, Ka Kit Gilberto Leung. Targeting hippo signaling pathway to overcome chemoresistance in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7207.

Abstract 4268: Engineered hydrogel elucidates contributions of matrix mechanics to pathobiology of adenocarcinoma and identify matrix-activated therapeutic targets

Abstract Dysregulation of the extracellular matrix (ECM) properties disturbs tissue homeostasis and contributes to pathological conditions, such as cancer. Recent studies have demonstrated that ECM stiffening is associated with metaplasia-dysplasia-adenocarcinoma sequence in the esophagus. This underscores a compelling need to develop a physiologically-relevant 3D culture model to enable the study of the independent contribution of matrix stiffness to the initiation and progression of esophageal adenocarcinoma (EAC). Such a model will then serve as a platform for pre-clinical drug screening in the context of matrix properties. In this context, we have engineered a hyaluronic acid-based 3D hydrogel platform that supports the growth and differentiation of patient-derived Barrett’s esophagus (BE) organoids, a precursor to EAC, as well as patient-derived EAC organoids. The engineered biomaterial 3D platform allows control over matrix stiffness to better recapitulate the mechanically dynamic esophageal cancer microenvironment and help identify therapeutic targets in EAC.Our data demonstrates that BE and EAC organoid density, growth and proliferation can be controlled by matrix stiffness. RNA sequencing data show that increased matrix stiffness promotes changes in the transcriptional profiles of BE and EAC organoids, revealing enrichment of pathways associated with tumorigenesis and disease progression. Furthermore, we demonstrate through molecular and functional assays that increased matrix stiffness endows stem-like properties to the EAC organoids via Yap-Sox9 mechano-activation. Finally, targeted therapy studies in our in vitro and in vivo engineered environments revealed that Yap inhibition regressed the effects of increased matrix stiffness in EAC organoids. In summary, our data suggest that matrix mechanics have a significant role in activation of EAC-associated signaling pathways in patient-derived BE and EAC organoids. We also demonstrate that the engineered hydrogel serves as a platform to identify potential therapeutic targets to disrupt the contribution of pro-tumorigenic matrix mechanics in EAC. Together, these studies establish an engineered patient-derived organoid culture platform that can be used to elucidate underlying matrix-mediated mechanisms of the metaplasia-dysplasia-adenocarcinoma sequence and inform the development of novel therapeutics that target ECM stiffness in EAC. FUNDING SOURCES: NCI P01CA098101, U54 CA163004 and NIDDK K01 DK133620. Citation Format: Ricardo Cruz-Acuna, Secunda W. Kariuki, Kensuke Sugiura, Spyros Karaiskos, Eleanor M. Plaster, Claudia Loebel, Gizem Efe, Tatiana Karakasheva, Joel T. Gabre, Jianhua Hu, Jason A. Burdick, Anil K. Rustgi. Engineered hydrogel elucidates contributions of matrix mechanics to pathobiology of adenocarcinoma and identify matrix-activated therapeutic targets [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4268.

Abstract 3037: Sex-specific differences in Yap1 and Cd276 function and expression regulate medulloblastoma progression and immune evasion

Abstract Unveiling the molecular mechanisms underlying sex-specific differences in cancer initiation, progression and treatment outcomes will provide novel insights that will advance cancer research and clinical care. This study highlights an unexpected, sex-biased role of the oncogene Yap1 in SHH medulloblastoma (MB). We discovered that Yap1 deletion in SmoM2-driven SHH MB significantly prolongs survival in male but not female mice. Using an integrated multi-omics approach, we show that YAP1 promotes cancer stem cell maintenance through concurrent transcriptional activation of stemness genes, such as Sox2, and repression of differentiation genes such as NeuroD1 and Zic1/2. Interestingly, while Yap1 is essential for maintaining cancer stem cells in both sexes, it plays a more critical role in immune evasion in males. Specifically, YAP1 regulates the expression of an immune checkpoint molecule Cd276 to suppress T cell function. Blocking CD276 or deleting Yap1 is sufficient to significantly reverse T cell suppression in males but not females. Furthermore, YAP1 direct targets of transcriptional regulation, including CD276, predicts survival in male but not female patients across multiple human cancers, suggesting that our findings have broader implications beyond medulloblastomas and is conserved across species. This study provides compelling evidence for male-biased susceptibility to Yap1 inhibition and uncovers the YAP1-CD276 axis as a sexually diverse pathway in T cell suppression in tumors. Citation Format: Nourhan Abdelfattah, Sivaraman Natarajan, Han Nhat Tran, Jose Maldonado, Rachael McMinimy, Hannah Borland, Shu-hsia Chen, Fernando Camargo, James Olson, Joshy George, Kyuson Yun. Sex-specific differences in Yap1 and Cd276 function and expression regulate medulloblastoma progression and immune evasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3037.

17β-Estradiol, through activating the G protein-coupled estrogen receptor, exacerbates the complication of benign prostatic hyperplasia in type 2 diabetes mellitus patients by inducing prostate proliferation

Benign prostatic hyperplasia (BPH) is one of the major chronic complications of type 2 diabetes mellitus (T2DM), and sex steroid hormones are common risk factors for the occurrence of T2DM and BPH. The profiles of sex steroid hormones are simultaneously quantified by LC–MS/MS in the clinical serum of patients, including simple BPH patients, newly diagnosed T2DM patients, T2DM complicated with BPH patients and matched healthy individuals. The G protein-coupled estrogen receptor (GPER) inhibitor G15, GPER knockdown lentivirus, the YAP1 inhibitor verteporfin, YAP1 knockdown/overexpression lentivirus, targeted metabolomics analysis, and Co-IP assays are used to investigate the molecular mechanisms of the disrupted sex steroid hormones homeostasis in the pathological process of T2DM complicated with BPH. The homeostasis of sex steroid hormone is disrupted in the serum of patients, accompanying with the proliferated prostatic epithelial cells (PECs). The sex steroid hormone metabolic profiles of T2DM patients complicated with BPH have the greatest degrees of separation from those of healthy individuals. Elevated 17β-estradiol (E2) is the key contributor to the disrupted sex steroid hormone homeostasis, and is significantly positively related to the clinical characteristics of T2DM patients complicated with BPH. Activating GPER by E2 via Hippo-YAP1 signaling exacerbates high glucose (HG)-induced PECs proliferation through the formation of the YAP1-TEAD4 heterodimer. Knockdown or inhibition of GPER-mediated Hippo-YAP1 signaling suppresses PECs proliferation in HG and E2 co-treated BPH-1 cells. The anti-proliferative effects of verteporfin, an inhibitor of YAP1, are blocked by YAP1 overexpression in HG and E2 co-treated BPH-1 cells. Inactivating E2/GPER/Hippo/YAP1 signaling may be effective at delaying the progression of T2DM complicated with BPH by inhibiting PECs proliferation.

Elevated levels of alcohol dehydrogenase aggravate ethanol-evoked cardiac remodeling and contractile anomalies through FKBP5-yap-mediated regulation of ferroptosis and ER stress

Alcohol intake provokes severe organ injuries including alcoholic cardiomyopathy with hallmarks of cardiac remodeling and contractile defects. This study examined the toxicity of facilitated ethanol metabolism in alcoholism-evoked changes in myocardial morphology and contractile function, insulin signaling and various cell death domains using cardiac-selective overexpression of alcohol dehydrogenase (ADH). WT and ADH mice were offered an alcohol liquid diet for 12 weeks prior to assessment of cardiac geometry, function, ER stress, apoptosis and ferroptosis. Alcohol intake provoked pronounced glucose intolerance, cardiac remodeling and contractile anomalies with apoptosis, ER stress, and ferroptosis, the effects were accentuated by ADH with the exception of global glucose intolerance. Hearts from alcohol ingesting mice displayed dampened insulin-stimulated phosphorylation of insulin receptor (tyr1146) and IRS-1 (tyrosine) along with elevated IRS-1 serine phosphorylation, the effect was augmented by ADH. Alcohol challenge dampened phosphorylation of Akt and GSK-3β, and increased phosphorylation of c-Jun and JNK, the effects were accentuated by ADH. Alcohol challenge promoted ER stress, FK506 binding protein 5 (FKBP5), YAP, apoptosis and ferroptosis, the effects were exaggerated by ADH. Using a short-term ethanol challenge model (3 g/kg, i.p., twice in three days), we found that inhibition of FKBP5-YAP signaling or facilitated ethanol detoxification by Alda-1 alleviated ethanol cardiotoxicity. In vitro study revealed that the ethanol metabolite acetaldehyde evoked cardiac contractile anomalies, lipid peroxidation, and apoptosis, the effects of which were mitigated by Alda-1, inhibition of ER stress, FKBP5 and YAP. These data suggest that facilitated ethanol metabolism via ADH exacerbates alcohol-evoked myocardial remodeling, functional defects, and insulin insensitivity possibly through a FKBP5-YAP-associated regulation of ER stress and ferroptosis.

Cell softness renders cytotoxic T lymphocytes and T leukemic cells resistant to perforin-mediated killing

Mechanical force contributes to perforin pore formation at immune synapses, thus facilitating the cytotoxic T lymphocytes (CTL)-mediated killing of tumor cells in a unidirectional fashion. How such mechanical cues affect CTL evasion of perforin-mediated autolysis remains unclear. Here we show that activated CTLs use their softness to evade perforin-mediated autolysis, which, however, is shared by T leukemic cells to evade CTL killing. Downregulation of filamin A is identified to induce softness via ZAP70-mediated YAP Y357 phosphorylation and activation. Despite the requirements of YAP in both cell types for softness induction, CTLs are more resistant to YAP inhibitors than malignant T cells, potentially due to the higher expression of the drug-resistant transporter, MDR1, in CTLs. As a result, moderate inhibition of YAP stiffens malignant T cells but spares CTLs, thus allowing CTLs to cytolyze malignant cells without autolysis. Our findings thus hint a mechanical force-based immunotherapeutic strategy against T cell leukemia.