The Hippo-YAP pathway in organ size control and tumorigenesis: an updated version

Hippo signaling modulation and its biological implications in urological malignancies

Although cancer diagnosis and treatment have rapidly advanced in recent decades, urological malignancies, which have high morbidity and mortality rates, are among the most difficult diseases to treat. The Hippo signaling is an evolutionarily conserved pathway in organ size control and tissue homeostasis maintenance. Its downstream effectors, Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), are key modulators of numerous physiological and pathological processes. Recent work clearly indicates that Hippo signaling is frequently altered in human urological malignancies. In this review, we discuss the disparate viewpoints on the upstream regulators of YAP/TAZ and their downstream targets and systematically summarize the biological implications. More importantly, we highlight the molecular mechanisms involved in Hippo-YAP signaling to improve our understanding of its role in every stage of prostate cancer, bladder cancer and kidney cancer progression. A better understanding of the biological outcomes of YAP/TAZ modulation will contribute to the establishment of future therapeutic approaches.

Numerical investigation on flow-induced wall shear stress variation of metastatic cancer cells in lymphatics with elastic valves

Hematogenous metastasis occurs when cancer cells detach from the extracellular matrix in the primary tumor into the bloodstream or lymphatic system. Elucidating the response of metastatic tumor cells in suspension to the flow conditions in lymphatics with valves from a mechanical/fluidic perspective is necessary. A physiologically relevant computational model of a lymphatic vessel with valves was constructed using fully coupled fluid-cell-vessel interactions to investigate the effects of lymphatic vessel contractility, valve properties, and cell size and stiffness on the variations in magnitude and gradient of the flow-induced wall shear stress (WSS) experienced by suspended tumor cells. Results indicated that the maximum WSSmax increased with the increments in cell diameter, vessel contraction amplitude, and valve stiffness. The decrease in vessel contraction period and valve aspect ratio also increased the maximum WSSmax. The influence of the properties of the valve on the WSS was more significant among the factors mentioned above. The maximum WSSmax acting on the cancer cell when the cell reversed the direction of its motion in the valve region increased by 0.5-1.4 times that before the cell entered the valve region. The maximum change in WSS was in the range of 0.004-0.028 Pa/µm depending on the factors studied. They slightly exceeded the values associated with breast cancer cell apoptosis. The results of this study provide biofluid mechanics-based support for mechanobiological research on the metastasis of metastatic cancer cells in suspension within the lymphatics.

Investigating underlying molecular mechanisms, signaling pathways, emerging therapeutic approaches in pancreatic cancer

Pancreatic adenocarcinoma, a clinically challenging malignancy constitutes a significant contributor to cancer-related mortality, characterized by an inherently poor prognosis. This review aims to provide a comprehensive understanding of pancreatic adenocarcinoma by examining its multifaceted etiologies, including genetic mutations and environmental factors. The review explains the complex molecular mechanisms underlying its pathogenesis and summarizes current therapeutic strategies, including surgery, chemotherapy, and emerging modalities such as immunotherapy. Critical molecular pathways driving pancreatic cancer development, including KRAS, Notch, and Hedgehog, are discussed. Current therapeutic strategies, including surgery, chemotherapy, and radiation, are discussed, with an emphasis on their limitations, particularly in terms of postoperative relapse. Promising research areas, including liquid biopsies, personalized medicine, and gene editing, are explored, demonstrating the significant potential for enhancing diagnosis and treatment. While immunotherapy presents promising prospects, it faces challenges related to immune evasion mechanisms. Emerging research directions, encompassing liquid biopsies, personalized medicine, CRISPR/Cas9 genome editing, and computational intelligence applications, hold promise for refining diagnostic approaches and therapeutic interventions. By integrating insights from genetic, molecular, and clinical research, innovative strategies that improve patient outcomes can be developed. Ongoing research in these emerging fields holds significant promise for advancing the diagnosis and treatment of this formidable malignancy.

Collagen modification remodels the sarcoma tumor microenvironment and promotes resistance to immune checkpoint inhibition

Molecular mechanisms underlying immune checkpoint inhibitor (ICI) response heterogeneity in solid tumors, including soft tissue sarcomas (STS), remain poorly understood. Herein, we demonstrate that the collagen-modifying enzyme, procollagen-lysine,2-oxoglutarate 5-dioxygenase 2 (Plod2), which is over-expressed in many tumors relative to normal tissues, promotes immune evasion in undifferentiated pleomorphic sarcoma (UPS), a relatively common and aggressive STS subtype. This finding is consistent with our earlier observation that Plod2 promotes tumor metastasis in UPS, and its enzymatic target, collagen type VI (ColVI), enhances CD8+ T cell dysfunction. We determined that genetic and pharmacologic inhibition of Plod2 with the pan-Plod transcriptional inhibitor minoxidil, reduces UPS growth in an immune competent syngeneic transplant system and enhances the efficacy of anti-Pd1 therapy. These findings suggest that PLOD2 is an actionable cancer target and its modulation could augment immunotherapy responses in patients with UPS, and potentially other sarcomas and carcinomas.

YAP inhibition overcomes adaptive resistance in HER2-positive gastric cancer treated with trastuzumab via the AKT/mTOR and ERK/mTOR axis

BACKGROUND

Human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC) is a heterogeneous GC subtype characterized by the overexpression of HER2. To date, few specific targeted therapies have demonstrated durable efficacy in HER2-positive GC patients, with resistance to trastuzumab typically emerging within 1 year. However, the mechanisms of resistance to trastuzumab remain incompletely understood, presenting a significant challenge to clinical practice.

METHODS

In this study, we integrated genetic screening and bulk transcriptome and epigenomic profiling to define the mechanisms mediating adaptive resistance to HER2 inhibitors and identify potential effective therapeutic strategies for treating HER2-positive GCs.

RESULTS

We revealed a potential association between adaptive resistance to trastuzumab in HER2-positive GC and the expression of YES-associated protein (YAP). Notably, our investigation revealed that long-term administration of trastuzumab triggers extensive chromatin remodeling and initiates YAP gene transcription in HER2-positive cells characterized by the initial inhibition and subsequent reactivation. Furthermore, treatment of HER2-positive GC cells and cell line-derived xenografts (CDX) models with YAP inhibitors in combination with trastuzumab was found to induce synergistic effects through the AKT/mTOR and ERK/mTOR pathways.

CONCLUSION

These findings underscore the pivotal role of reactivated YAP and mTOR signaling pathways in the development of adaptive resistance to trastuzumab and may serve as a promising joint target to overcome resistance to trastuzumab.

The basement membrane regulates the cellular localization and the cytoplasmic interactome of Yes-Associated Protein (YAP) in mammary epithelial cells

The Hippo pathway, a signaling cascade involved in the regulation of organ size and several other processes, acts as a conduit between extracellular matrix (ECM) cues and cellular responses. We asked whether the basement membrane (BM), a specialized ECM component known to induce quiescence and differentiation in mammary epithelial cells, would regulate the localization, activity, and interactome of YAP, a Hippo pathway effector. To address this question, we used a broad range of experimental approaches, including 2D and 3D cultures of both mouse and human mammary epithelial cells, as well as the developing mouse mammary gland. In contrast to malignant cells, nontumoral cells cultured with a reconstituted BM (rBM) displayed higher concentrations of YAP in the cytoplasm. Incidentally, when in the nucleus of rBM-treated cells, YAP resided preferentially at the nuclear periphery. In agreement with our cell culture experiments, YAP exhibited cytoplasmic predominance in ductal cells of developing mammary epithelia, where a denser BM is found. Conversely, terminal end bud (TEB) cells with a thinner BM displayed higher nucleus-to-cytoplasm ratios of YAP. Bioinformatic analysis revealed that genes regulated by YAP were overrepresented in the transcriptomes of microdissected TEBs. Consistently, mouse epithelial cells exposed to the rBM expressed lower levels of YAP-regulated genes, although the protein level of YAP and Hippo components were slightly altered by the treatment. Mass spectrometry analysis identified a differential set of proteins interacting with YAP in cytoplasmic fractions of mouse epithelial cells in the absence or presence of rBM. In untreated cells, YAP interactants were enriched in processes related to ubiquitin-mediated proteolysis, whereas in cells exposed to rBM YAP interactants were mainly key proteins related to amino acid, amino sugar, and carbohydrate metabolism. Collectively, we unraveled that the BM induces YAP translocation or retention in the cytoplasm of nontumoral epithelial cells and that in the cytoplasm YAP seems to undertake novel functions in metabolic pathways.

Targeting the Hippo Pathway in Cutaneous Melanoma

Melanoma is the most aggressive form of skin cancer. In the advanced stage of development, it is resistant to currently available therapeutic modalities. Increased invasiveness and metastatic potential depend on several proteins involved in various signal transduction pathways. Hippo signaling plays a vital role in malignant transformation. Dysfunctions of the Hippo pathway initiate the expression of tumor growth factors and are associated with tumor growth and metastasis formation. This review summarizes the recent achievements in studying the role of the Hippo pathway in melanoma pathogenesis and points to the potential specific targets for anti-melanoma therapy.

YAP dysregulation triggers hypertrophy by CCN2 secretion and TGFβ uptake in human pluripotent stem cell-derived cardiomyocytes

Hypertrophy Cardiomyopathy (HCM) is the most prevalent hereditary cardiovascular disease - affecting >1:500 individuals. Advanced forms of HCM clinically present with hypercontractility, hypertrophy and fibrosis. Several single-point mutations in b-myosin heavy chain (MYH7) have been associated with HCM and increased contractility at the organ level. Different MYH7 mutations have resulted in increased, decreased, or unchanged force production at the molecular level. Yet, how these molecular kinetics link to cell and tissue pathogenesis remains unclear. The Hippo Pathway, specifically its effector molecule YAP, has been demonstrated to be reactivated in pathological hypertrophic growth. We hypothesized that changes in force production (intrinsically or extrinsically) directly alter the homeostatic mechano-signaling of the Hippo pathway through changes in stresses on the nucleus. Using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), we asked whether homeostatic mechanical signaling through the canonical growth regulator, YAP, is altered 1) by changes in the biomechanics of HCM mutant cardiomyocytes and 2) by alterations in the mechanical environment. We use genetically edited hiPSC-CM with point mutations in MYH7 associated with HCM, and their matched controls, combined with micropatterned traction force microscopy substrates to confirm the hypercontractile phenotype in MYH7 mutants. We next modulate contractility in healthy and disease hiPSC-CMs by treatment with positive and negative inotropic drugs and demonstrate a correlative relationship between contractility and YAP activity. We further demonstrate the activation of YAP in both HCM mutants and healthy hiPSC-CMs treated with contractility modulators is through enhanced nuclear deformation. We conclude that the overactivation of YAP, possibly initiated and driven by hypercontractility, correlates with excessive CCN2 secretion (connective tissue growth factor), enhancing cardiac fibroblast/myofibroblast transition and production of known hypertrophic signaling molecule TGFβ. Our study suggests YAP being an indirect player in the initiation of hypertrophic growth and fibrosis in HCM. Our results provide new insights into HCM progression and bring forth a testbed for therapeutic options in treating HCM.

Loss of the lysosomal protein CLN3 modifies the lipid content of the nuclear envelope leading to DNA damage and activation of YAP1 pro-apoptotic signaling

Batten disease is characterized by early-onset blindness, juvenile dementia and death during the second decade of life. The most common genetic causes are mutations in the CLN3 gene encoding a lysosomal protein. There are currently no therapies targeting the progression of the disease, mostly due to the lack of knowledge about the disease mechanisms. To gain insight into the impact of CLN3 loss on cellular signaling and organelle function, we generated CLN3 knock-out cells in a human cell line (CLN3-KO), and performed RNA sequencing to obtain the cellular transcriptome. Following a multi-dimensional transcriptome analysis, we identified the transcriptional regulator YAP1 as a major driver of the transcriptional changes observed in CLN3-KO cells. We further observed that YAP1 pro-apoptotic signaling is hyperactive as a consequence of CLN3 functional loss in retinal pigment epithelia cells, and in the hippocampus and thalamus of CLN3exΔ7/8 mice, an established model of Batten disease. Loss of CLN3 activates YAP1 by a cascade of events that starts with the inability of releasing glycerophosphodiesthers from CLN3-KO lysosomes, which leads to perturbations in the lipid content of the nuclear envelope and nuclear dysmorphism. This results in increased number of DNA lesions, activating the kinase c-Abl, which phosphorylates YAP1, stimulating its pro-apoptotic signaling. Altogether, our results highlight a novel organelle crosstalk paradigm in which lysosomal metabolites regulate nuclear envelope content, nuclear shape and DNA homeostasis. This novel molecular mechanism underlying the loss of CLN3 in mammalian cells and tissues may open new c-Abl-centric therapeutic strategies to target Batten disease.

Blockade of a novel MAP4K4-LATS2-SASH1-YAP1 cascade inhibits tumorigenesis and metastasis in luminal breast cancer

Novel components in the noncanonical Hippo pathway that mediate the growth, metastasis, and drug resistance of breast cancer (BC) cells need to be identified. Here, we showed that expression of SAM and SH3 domain-containing protein 1 (SASH1) is negatively correlated with expression of mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) in a subpopulation of patients with luminal-subtype BC. Downregulated SASH1 and upregulated MAP4K4 synergistically regulated the proliferation, migration, and invasion of luminal-subtype BC cells. The expression of LATS2, SASH1, and YAP1 and the phosphorylation of YAP1 were negatively regulated by MAP4K4, and LATS2 then phosphorylated SASH1 to form a novel MAP4K4-LATS2-SASH1-YAP1 cascade. Dephosphorylation of Yes1 associated transcriptional regulator (YAP1), YAP1/TAZ nuclear translocation, and downstream transcriptional regulation of YAP1 were promoted by the combined effects of ectopic MAP4K4 expression and SASH1 silencing. Targeted inhibition of MAP4K4 blocked proliferation, cell migration, and ER signaling both in vitro and in vivo. Our findings reveal a novel MAP4K4-LATS2-SASH1-YAP1 phosphorylation cascade, a noncanonical Hippo pathway that mediates ER signaling, tumorigenesis, and metastasis in breast cancer. Targeted intervention with this noncanonical Hippo pathway may constitute a novel alternative therapeutic approach for endocrine-resistant BC.

Tead4 and Tfap2c generate bipotency and a bistable switch in totipotent embryos to promote robust lineage diversification

The mouse and human embryo gradually loses totipotency before diversifying into the inner cell mass (ICM, future organism) and trophectoderm (TE, future placenta). The transcription factors TFAP2C and TEAD4 with activated RHOA accelerate embryo polarization. Here we show that these factors also accelerate the loss of totipotency. TFAP2C and TEAD4 paradoxically promote and inhibit Hippo signaling before lineage diversification: they drive expression of multiple Hippo regulators while also promoting apical domain formation, which inactivates Hippo. Each factor activates TE specifiers in bipotent cells, while TFAP2C also activates specifiers of the ICM fate. Asymmetric segregation of the apical domain reconciles the opposing regulation of Hippo signaling into Hippo OFF and the TE fate, or Hippo ON and the ICM fate. We propose that the bistable switch established by TFAP2C and TEAD4 is exploited to trigger robust lineage diversification in the developing embryo.

Angiotensin II type-2 receptor signaling facilitates liver injury repair and regeneration via inactivation of Hippo pathway

The angiotensin II type 2 receptor (AT2R) is a well-established component of the renin-angiotensin system and is known to counteract classical activation of this system and protect against organ damage. Pharmacological activation of the AT2R has significant therapeutic benefits, including vasodilation, natriuresis, anti-inflammatory activity, and improved insulin sensitivity. However, the precise biological functions of the AT2R in maintaining homeostasis in liver tissue remain largely unexplored. In this study, we found that the AT2R facilitates liver repair and regeneration following acute injury by deactivating Hippo signaling and that interleukin-6 transcriptionally upregulates expression of the AT2R in hepatocytes through STAT3 acting as a transcription activator binding to promoter regions of the AT2R. Subsequently, elevated AT2R levels activate downstream signaling via heterotrimeric G protein Gα12/13-coupled signals to induce Yap activity, thereby contributing to repair and regeneration processes in the liver. Conversely, a deficiency in the AT2R attenuates regeneration of the liver while increasing susceptibility to acetaminophen-induced liver injury. Administration of an AT2R agonist significantly enhances the repair and regeneration capacity of injured liver tissue. Our findings suggest that the AT2R acts as an upstream regulator in the Hippo pathway and is a potential target in the treatment of liver damage.

Regulation mechanism of EBV-encoded EBER1 and LMP2A on YAP1 and the impact of YAP1 on the EBV infection status in EBV-associated gastric carcinoma

This study aims to explore the role and regulatory mechanism of Yes-associated protein 1 (YAP1) in the development of Epstein-Barr virus-associated gastric cancer (EBVaGC). Here we showed that EBV can upregulate the expression and activity of YAP1 protein through its encoded latent products EBV-encoded small RNA 1 (EBER1) and latent membrane protein 2A (LMP2A), enhancing the malignant characteristics of EBVaGC cells. In addition, we also showed that overexpression of YAP1 induced the expression of EBV encoding latent and lytic phase genes and proteins in the epithelial cell line AGS-EBV infected with EBV, and increased the copy number of the EBV genome, while loss of YAP1 expression reduced the aforementioned indicators. Moreover, we found that YAP1 enhanced EBV lytic reactivation induced by two known activators, 12-O-tetradecanoylhorbol-13-acetate (TPA) and sodium butyrate (NaB). These results indicated a bidirectional regulatory mechanism between EBV and YAP1 proteins, providing new experimental evidence for further understanding the regulation of EBV infection patterns and carcinogenic mechanisms in gastric cancer.

The tumor suppressor NF2 modulates TEAD4 stability and activity in Hippo signaling via direct interaction

As an output effector of the Hippo signaling pathway, the TEAD transcription factor and co-activator YAP play crucial functions in promoting cell proliferation and organ size. The tumor suppressor NF2 has been shown to activate LATS1/2 kinases and interplay with the Hippo pathway to suppress the YAP-TEAD complex. However, whether and how NF2 could directly regulate TEAD remains unknown. We identified a direct link and physical interaction between NF2 and TEAD4. NF2 interacted with TEAD4 through its FERM domain and C-terminal tail and decreased the protein stability of TEAD4 independently of LATS1/2 and YAP. Furthermore, NF2 inhibited TEAD4 palmitoylation and induced the cytoplasmic translocation of TEAD4, resulting in ubiquitination and dysfunction of TEAD4. Moreover, the interaction with TEAD4 is required for NF2 function to suppress cell proliferation. These findings reveal an unanticipated role of NF2 as a binding partner and inhibitor of the transcription factor TEAD, shedding light on an alternative mechanism of how NF2 functions as a tumor suppressor through the Hippo signaling cascade.

Chlorin Conjugates in Photodynamic Chemotherapy for Triple-Negative Breast Cancer

Breast cancer (BC) is the most common type of cancer in women and the number of new cases in the US is still increasing each year. Triple-negative breast cancer (TNBC), which comprises 15-20% of all breast cancer, is a heterogeneous disease and is considered the most aggressive type of breast cancer due to the lack of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expressions for treatments. Traditional chemotherapy is the standard protocol for the treatment of TNBC. Toxicity and multidrug resistance are major drawbacks to chemotherapy. The lack of molecular targets and poor prognosis for TNBC prompts an urgent need to discover novel therapeutic strategies to improve clinical outcomes and quality of life for patients. Photodynamic therapy (PDT) or light treatment is a binary anti-cancer procedure that uses a photosensitizer (PS) that, upon light activation, produces cytotoxic oxygen species, destroying tumor cells. PDT is minimally invasive and can be repeated a few times without accumulating significant toxicity in the surrounding tissues. The primary goal of this study was to investigate in vitro photodynamic chemotherapy as a ternary combination therapy using our synthesized photosensitizers (chlorin-vitamin conjugates and their corresponding indium complexes) co-treated with known chemotherapeutic agents (taxol, doxorubicin, cisplatin, fluorouracil, or methotrexate) in the presence of light and determine the optimum conditions as a pre-clinical study of an enhanced tumoricidal effect against TNBC. Our results indicated that the best combination for an effective chemophotodynamic effect involves a ternary treatment of the indium complex of the chlorin-lipoic acid conjugate (InCLA) co-treated with taxol, which exhibited strong synergism at the nanomolar concentration when combined in the presence of visible light irradiation. Other ternary combinations containing taxol with a synergistic anti-tumor effect against TNBC include chlorin-pantothenic acid (CPA) and chlorin-biotin (CBTN) conjugates. Several other ternary combinations containing InCLA, CBTN, and CPA with either cisplatin, fluorouracil, or methotrexate were identified to generate a synergistic or additive effect. The light dosage remained constant, but the dosages of photosensitizers and chemotherapy drugs were varied to obtain the lowest possible concentration for the desired effect. The synergistic, additive or antagonistic effects of the drug combinations were determined based on the Chou-Talalay method, with InCLA-taxol having the lowest combination index (CI) of 0.25. Fluorescence and transmission electron microscopy (TEM) images provided evidence of apoptosis as the preferred mode of cell death. Our study demonstrated the combination of PDT and chemotherapy as a potential treatment option for TNBC patients.

A LATS2 and ALKBH5 positive feedback loop supports their oncogenic roles

N(6)-methyladenosine (m6A) critically regulates RNA dynamics in various biological processes. The m6A demethylase ALKBH5 promotes tumorigenesis of glioblastoma, while the intricate web that orchestrates its regulation remains enigmatic. Here, we discover that cell density affects ALKBH5 subcellular localization and m6A dynamics. Mechanistically, ALKBH5 is phosphorylated by the large tumor suppressor kinase 2 (LATS2), preventing its nuclear export and enhancing protein stability. Furthermore, phosphorylated ALKBH5 reciprocally erases m6A from LATS2 mRNA, thereby stabilizing this transcript. Unexpectedly, LATS2 depletion suppresses glioblastoma stem cell self-renewal independent of yes-associated protein activation. Additionally, deficiency in either LATS2 or ALKBH5 phosphorylation impedes tumor progression in mouse xenograft models. Moreover, high levels of LATS2 expression and ALKBH5 phosphorylation are associated with tumor malignancy in patients with gliomas. Collectively, our study unveils an oncogenic positive feedback loop between LATS2 and ALKBH5, revealing a non-canonical branch of the Hippo pathway for RNA processing and suggesting potential anti-cancer interventions.

Cellular geometry and epithelial-mesenchymal plasticity intersect with PIEZO1 in breast cancer cells

Differences in shape can be a distinguishing feature between different cell types, but the shape of a cell can also be dynamic. Changes in cell shape are critical when cancer cells escape from the primary tumor and undergo major morphological changes that allow them to squeeze between endothelial cells, enter the vasculature, and metastasize to other areas of the body. A shift from rounded to spindly cellular geometry is a consequence of epithelial-mesenchymal plasticity, which is also associated with changes in gene expression, increased invasiveness, and therapeutic resistance. However, the consequences and functional impacts of cell shape changes and the mechanisms through which they occur are still poorly understood. Here, we demonstrate that altering the morphology of a cell produces a remodeling of calcium influx via the ion channel PIEZO1 and identify PIEZO1 as an inducer of features of epithelial-to-mesenchymal plasticity. Combining automated epifluorescence microscopy and a genetically encoded calcium indicator, we demonstrate that activation of the PIEZO1 force channel with the PIEZO1 agonist, YODA 1, induces features of epithelial-to-mesenchymal plasticity in breast cancer cells. These findings suggest that PIEZO1 is a critical point of convergence between shape-induced changes in cellular signaling and epithelial-mesenchymal plasticity in breast cancer cells.

Convergent gene losses and pseudogenizations in multiple lineages of stomachless fishes

The regressive evolution of independent lineages often results in convergent phenotypes. Several teleost groups display secondary loss of the stomach, and four gastric genes, atp4a, atp4b, pgc, and pga2 have been co-deleted in agastric (stomachless) fish. Analyses of genotypic convergence among agastric fishes showed that four genes, slc26a9, kcne2, cldn18a, and vsig1, were co-deleted or pseudogenized in most agastric fishes of the four major groups. kcne2 and vsig1 were also deleted or pseudogenized in the agastric monotreme echidna and platypus, respectively. In the stomachs of sticklebacks, these genes are expressed in gastric gland cells or surface epithelial cells. An ohnolog of cldn18 was retained in some agastric teleosts but exhibited an increased non-synonymous substitution when compared with gastric species. These results revealed novel convergent gene losses at multiple loci among the four major groups of agastric fish, as well as a single gene loss in the echidna and platypus.

Transcriptomic analysis of benign prostatic hyperplasia identifies critical pathways in prostatic overgrowth and 5-alpha reductase inhibitor resistance

BACKGROUND

The medical therapy of prostatic symptoms (MTOPS) trial randomized men with symptoms of benign prostatic hyperplasia (BPH) and followed response of treatment with a 5α-reductase inhibitor (5ARI), an alpha-adrenergic receptor antagonist (α-blocker), the combination of 5ARI and α-blocker or no medical therapy (none). Medical therapy reduced risk of clinical progression by 66% but the reasons for nonresponse or loss of therapeutic response in some patients remains unresolved. Our previous work showed that prostatic glucocorticoid levels are increased in 5ARI-treated patients and that glucocorticoids can increased branching of prostate epithelia in vitro. To understand the transcriptomic changes associated with 5ARI treatment, we performed bulk RNA sequencing of BPH and control samples from patients who received 5ARI versus those that did not. Deconvolution analysis was performed to estimate cellular composition. Bulk RNA sequencing was also performed on control versus glucocorticoid-treated prostate epithelia in 3D culture to determine underlying transcriptomic changes associated with branching morphogenesis.

METHOD

Surgical BPH (S-BPH) tissue was defined as benign prostatic tissue collected from the transition zone (TZ) of patients who failed medical therapy while control tissue termed Incidental BPH (I-BPH) was obtained from the TZ of men undergoing radical prostatectomy for low-volume/grade prostatic adenocarcinoma confined to the peripheral zone. S-BPH patients were divided into four subgroups: men on no medical therapy (none: n = 7), α-blocker alone (n = 10), 5ARI alone (n = 6) or combination therapy (α-blocker and 5ARI: n = 7). Control I-BPH tissue was from men on no medical therapy (none: n = 8) or on α-blocker (n = 6). A human prostatic cell line in 3D culture that buds and branches was used to identify genes involved in early prostatic growth. Snap-frozen prostatic tissue taken at the time of surgery and 3D organoids were used for RNA-seq analysis. Bulk RNAseq data were deconvoluted using CIBERSORTx. Differentially expressed genes (DEG) that were statistically significant among S-BPH, I-BPH, and during budding and branching of organoids were used for pathway analysis.

RESULTS

Transcriptomic analysis between S-BPH (n = 30) and I-BPH (n = 14) using a twofold cutoff (p < 0.05) identified 377 DEG (termed BPH377) and a cutoff < 0.05 identified 3377 DEG (termed BPH3377). Within the S-BPH, the subgroups none and α-blocker were compared to patients on 5ARI to reveal 361 DEG (termed 5ARI361) that were significantly changed. Deconvolution analysis of bulk RNA seq data with a human prostate single cell data set demonstrated increased levels of mast cells, NK cells, interstitial fibroblasts, and prostate luminal cells in S-BPH versus I-BPH. Glucocorticoid (GC)-induced budding and branching of benign prostatic cells in 3D culture was compared to control organoids to identify early events in prostatic morphogenesis. GC induced 369 DEG (termed GC359) in 3D culture. STRING analysis divided the large datasets into 20-80 genes centered around a hub. In general, biological processes induced in BPH supported growth and differentiation such as chromatin modification and DNA repair, transcription, cytoskeleton, mitochondrial electron transport, ubiquitination, protein folding, and cholesterol synthesis. Identified signaling pathways were pooled to create a list of DEG that fell into seven hubs/clusters. The hub gene centrality was used to name the network including AP-1, interleukin (IL)-6, NOTCH1 and NOTCH3, NEO1, IL-13, and HDAC/KDM. All hubs showed connections to inflammation, chromatin structure, and development. The same approach was applied to 5ARI361 giving multiple networks, but the EGF and sonic hedgehog (SHH) hub was of particular interest as a developmental pathway. The BPH3377, 5ARI363, and GC359 lists were compared and 67 significantly changed DEG were identified. Common genes to the 3D culture included an IL-6 hub that connected to genes identified in BPH hubs that defined AP1, IL-6, NOTCH, NEO1, IL-13, and HDAC/KDM.

CONCLUSIONS

Reduction analysis of BPH and 3D organoid culture uncovered networks previously identified in prostatic development as being reinitiated in BPH. Identification of these pathways provides insight into the failure of medical therapy for BPH and new therapeutic targets for BPH/LUTS.

Myoglobin modulates the Hippo pathway to promote cardiomyocyte differentiation

The endogenous mechanisms that propagate cardiomyocyte differentiation and prevent de-differentiation remain unclear. While the expression of the heme protein myoglobin increases by over 50% during cardiomyocyte differentiation, a role for myoglobin in regulating cardiomyocyte differentiation has not been tested. Here, we show that deletion of myoglobin in cardiomyocyte models decreases the gene expression of differentiation markers and stimulates cellular proliferation, consistent with cardiomyocyte de-differentiation. Mechanistically, the heme prosthetic group of myoglobin catalyzes the oxidation of the Hippo pathway kinase LATS1, resulting in phosphorylation and inactivation of yes-associated protein (YAP). In vivo, myoglobin-deficient zebrafish hearts show YAP dephosphorylation and accelerated cardiac regeneration after apical injury. Similarly, myoglobin knockdown in neonatal murine hearts shows increased YAP dephosphorylation and cardiomyocyte cycling. These data demonstrate a novel role for myoglobin as an endogenous driver of cardiomyocyte differentiation and highlight myoglobin as a potential target to enhance cardiac development and improve cardiac repair and regeneration.

Targeting YAP1 to improve the efficacy of immune checkpoint inhibitors in liver cancer: mechanism and strategy

Liver cancer is the third leading of tumor death, including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). Immune checkpoint inhibitors (ICIs) are yielding much for sufferers to hope for patients, but only some patients with advanced liver tumor respond. Recent research showed that tumor microenvironment (TME) is critical for the effectiveness of ICIs in advanced liver tumor. Meanwhile, metabolic reprogramming of liver tumor leads to immunosuppression in TME. These suggest that regulating the abnormal metabolism of liver tumor cells and firing up TME to turn "cold tumor" into "hot tumor" are potential strategies to improve the therapeutic effect of ICIs in liver tumor. Previous studies have found that YAP1 is a potential target to improve the efficacy of anti-PD-1 in HCC. Here, we review that YAP1 promotes immunosuppression of TME, mainly due to the overstimulation of cytokines in TME by YAP1. Subsequently, we studied the effects of YAP1 on metabolic reprogramming in liver tumor cells, including glycolysis, gluconeogenesis, lipid metabolism, arachidonic acid metabolism, and amino acid metabolism. Lastly, we summarized the existing drugs targeting YAP1 in the treatment of liver tumor, including some medicines from natural sources, which have the potential to improve the efficacy of ICIs in the treatment of liver tumor. This review contributed to the application of targeted YAP1 for combined therapy with ICIs in liver tumor patients.

Development of Selective Pyrido[2,3-d]pyrimidin-7(8H)-one-Based Mammalian STE20-Like (MST3/4) Kinase Inhibitors

Mammalian STE20-like (MST) kinases 1-4 play key roles in regulating the Hippo and autophagy pathways, and their dysregulation has been implicated in cancer development. In contrast to the well-studied MST1/2, the roles of MST3/4 are less clear, in part due to the lack of potent and selective inhibitors. Here, we re-evaluated literature compounds, and used structure-guided design to optimize the p21-activated kinase (PAK) inhibitor G-5555 (8) to selectively target MST3/4. These efforts resulted in the development of MR24 (24) and MR30 (27) with good kinome-wide selectivity and high cellular potency. The distinct cellular functions of closely related MST kinases can now be elucidated with subfamily-selective chemical tool compounds using a combination of the MST1/2 inhibitor PF-06447475 (2) and the two MST3/4 inhibitors developed. We found that MST3/4-selective inhibition caused a cell-cycle arrest in the G1 phase, whereas MST1/2 inhibition resulted in accumulation of cells in the G2/M phase.

The Wnt-dependent and Wnt-independent functions of BCL9 in development, tumorigenesis, and immunity: Implications in therapeutic opportunities

B-cell CLL/lymphoma 9 (BCL9) is considered a key developmental regulator and a well-established oncogenic driver in multiple cancer types, mainly through potentiating the Wnt/β-catenin signaling. However, increasing evidences indicate that BCL9 also plays multiple Wnt-independent roles. Herein, we summarized the updates of the canonical and non-canonical functions of BCL9 in cellular, physiological, or pathological processes. Moreover, we also concluded that the targeted inhibitors disrupt the interaction of β-catenin with BCL9 reported recently.

YAP/TEAD involvement in resistance to paclitaxel chemotherapy in lung cancer

The Yes-associated protein (YAP) oncoprotein has been linked to both metastases and resistance to targeted therapy of lung cancer cells. We aimed to investigate the effect of YAP pharmacological inhibition, using YAP/TEA domain (TEAD) transcription factor interaction inhibitors in chemo-resistant lung cancer cells. YAP subcellular localization, as a readout for YAP activation, cell migration, and TEAD transcription factor functional transcriptional activity were investigated in cancer cell lines with up-regulated YAP, with and without YAP/TEAD interaction inhibitors. Parental (A549) and paclitaxel-resistant (A549R) cell transcriptomes were analyzed. The half-maximal inhibitory concentration (IC50) of paclitaxel or trametinib, which are Mitogen-Activated protein kinase and Erk Kinase (MEK) inhibitors, combined with a YAP/TEAD inhibitor (IV#6), was determined. A three-dimensional (3D) microfluidic culture device enabled us to study the effect of IV#6/paclitaxel combination on cancer cells isolated from fresh resected lung cancer samples. YAP activity was significantly higher in paclitaxel-resistant cell lines. The YAP/TEAD inhibitor induced a decreased YAP activity in A549, PC9, and H2052 cells, with reduced YAP nuclear staining. Wound healing assays upon YAP inhibition revealed impaired cell motility of lung cancer A549 and mesothelioma H2052 cells. Combining YAP pharmacological inhibition with trametinib in K-Ras mutated A549 cells recapitulated synthetic lethality, thereby sensitizing these cells to MEK inhibition. The YAP/TEAD inhibitor lowered the IC50 of paclitaxel in A549R cells. Differential transcriptomic analysis of parental and A549R cells revealed an increased YAP/TEAD transcriptomic signature in resistant cells, downregulated upon YAP inhibition. The YAP/TEAD inhibitor restored paclitaxel sensitivity of A549R cells cultured in a 3D microfluidic system, with lung cancer cells from a fresh tumor efficiently killed by YAP/TEAD inhibitor/paclitaxel doublet. Evidence of the YAP/TEAD transcriptional program's role in chemotherapy resistance paves the way for YAP therapeutic targeting.

Verteporfin induces lipid peroxidation and ferroptosis in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) has extremely poor prognosis, with a 5-year survival rate of approximately 11 %. Yes-associated protein (YAP) is a major downstream effector of the Hippo-YAP pathway and plays a pivotal role in regulation of cell proliferation and organ regeneration and tumorigenesis. Activation of YAP signaling has been associated with PDAC progression and drug resistance. Verteporfin (VP) is a photosensitizer used for photodynamic therapy and previous work showed that it can function as a YAP inhibitor. The efficacy of VP on human cancer are being tested in several trials. In this study, we examined the effect of VP on reactive oxygen species (ROS) and lipid peroxidation in pancreatic cancer cells, by using fluorescent molecular probes and by measuring the levels of malondialdehyde, a metabolic byproduct and marker of lipid peroxidation. We found that VP causes rapid increase of both overall ROS and lipid peroxide levels, independent of light activation. These effects were not dependent on YAP, as knockdown of YAP did not cause ROS or lipid peroxidation or enhance VP-induced ROS production. Temoporfin, another photodynamic drug, did not show similar activities. In addition, VP treatment led to loss of cell membrane integrity and reduction of viability. Notably, the activity of VP to induce lipid peroxidation was neutralized by ferroptosis inhibitors ferrostatin-1 or liproxstatin-1. VP treatment also reduced the levels of glutathione peroxidase 4 (GPX4), an enzyme that protects against lipid peroxidation. These results indicate that VP can induce lipid peroxidation and ferroptosis in the absence of light activation. Our findings reveal a novel mechanism by which VP inhibits tumor growth and provide insights into development of new therapeutic strategies for the treatment of pancreatic cancer.

Environmental factor reversibly determines cellular identity through opposing Integrators that unify epigenetic and transcriptional pathways

Organisms must adapt to environmental stresses to ensure their survival and prosperity. Different types of stresses, including thermal, mechanical, and hypoxic stresses, can alter the cellular state that accompanies changes in gene expression but not the cellular identity determined by a chromatin state that remains stable throughout life. Some tissues, such as adipose tissue, demonstrate remarkable plasticity and adaptability in response to environmental cues, enabling reversible cellular identity changes; however, the mechanisms underlying these changes are not well understood. We hypothesized that positive and/or negative "Integrators" sense environmental cues and coordinate the epigenetic and transcriptional pathways required for changes in cellular identity. Adverse environmental factors such as pollution disrupt the coordinated control contributing to disease development. Further research based on this hypothesis will reveal how organisms adapt to fluctuating environmental conditions, such as temperature, extracellular matrix stiffness, oxygen, cytokines, and hormonal cues by changing their cellular identities.

Differential age-related transcriptomic analysis of ovarian granulosa cells in Kazakh horses

Introduction

The Kazakh horse, renowned for its excellence as a breed, exhibits distinctive reproductive traits characterized by early maturity and seasonal estrus. While normal reproductive function is crucial for ensuring the breeding and expansion of the Kazakh horse population, a noteworthy decline in reproductive capabilities is observed after reaching 14 years of age.

Methods

In this study, ovarian granulosa cells (GCs) were meticulously collected from Kazakh horses aged 1, 2, 7, and above 15 years old (excluding 15 years old) for whole transcriptome sequencing.

Results

The analysis identified and selected differentially expressed mRNAs, lncRNAs, miRNAs, and circRNAs for each age group, followed by a thorough examination through GO enrichment analysis. The study uncovered significant variations in the expression profiles of mRNAs, lncRNAs, miRNAs, and circRNAs within GCs at different stages of maturity. Notably, eca-miR-486-3p and miR-486-y exhibited the highest degree of connectivity. Subsequent GO, KEGG, PPI, and ceRNA network analyses elucidated that the differentially expressed target genes actively participate in signaling pathways associated with cell proliferation, apoptosis, and hormonal regulation. These pathways include but are not limited to the MAPK signaling pathway, Hippo signaling pathway, Wnt signaling pathway, Calcium signaling pathway, Aldosterone synthesis and secretion, Cellular senescence, and NF-kappa B signaling pathway-essentially encompassing signal transduction pathways crucial to reproductive processes.

Discussion

This research significantly contributes to unraveling the molecular mechanisms governing follicular development in Kazakh horses. It establishes and preliminarily validates a differential regulatory network involving lncRNA-miRNA-mRNA, intricately associated with processes such as cell proliferation, differentiation, and apoptosis and integral to the developmental intricacies of stromal follicles. The findings of this study provide a solid theoretical foundation for delving deeper into the realm of reproductive aging in Kazakh mares, presenting itself as a pivotal regulatory pathway in the context of horse ovarian development.

CYLD regulates cell ferroptosis through Hippo/YAP signaling in prostate cancer progression

Prostate cancer (PCa) is one of the most common malignancy in men. However, the molecular mechanism of its pathogenesis has not yet been elucidated. In this study, we demonstrated that CYLD, a novel deubiquitinating enzyme, impeded PCa development and progression via tumor suppression. First, we found that CYLD was downregulated in PCa tissues, and its expression was inversely correlated with pathological grade and clinical stage. Moreover, we discovered that CYLD inhibited tumor cell proliferation and enhanced the sensitivity to cell ferroptosis in PCa in vitro and in vivo, respectively. Mechanistically, we demonstrated that CYLD suppressed the ubiquitination of YAP protein, then promoted ACSL4 and TFRC mRNA transcription. Then, we demonstrated that CYLD could enhance the sensitivity of PCa xenografts to ferroptosis in vivo. Furthermore, we discovered for the first time that there was a positive correlation between CYLD expression and ACSL4 or TFRC expression in human PCa specimens. The results of this study suggested that CYLD acted as a tumor suppressor gene in PCa and promoted cell ferroptosis through Hippo/YAP signaling.

Tumor-derived small extracellular vesicles in cancer invasion and metastasis: molecular mechanisms, and clinical significance

The production and release of tumor-derived small extracellular vesicles (TDSEVs) from cancerous cells play a pivotal role in the propagation of cancer, through genetic and biological communication with healthy cells. TDSEVs are known to orchestrate the invasion-metastasis cascade via diverse pathways. Regulation of early metastasis processes, pre-metastatic niche formation, immune system regulation, angiogenesis initiation, extracellular matrix (ECM) remodeling, immune modulation, and epithelial-mesenchymal transition (EMT) are among the pathways regulated by TDSEVs. MicroRNAs (miRs) carried within TDSEVs play a pivotal role as a double-edged sword and can either promote metastasis or inhibit cancer progression. TDSEVs can serve as excellent markers for early detection of tumors, and tumor metastases. From a therapeutic point of view, the risk of cancer metastasis may be reduced by limiting the production of TDSEVs from tumor cells. On the other hand, TDSEVs represent a promising approach for in vivo delivery of therapeutic cargo to tumor cells. The present review article discusses the recent developments and the current views of TDSEVs in the field of cancer research and clinical applications.

The biological functions and related signaling pathways of SPON2

Spondin-2 (SPON2), also referred to as M-spondin or DIL-1, is a member of the extracellular matrix protein family known as Mindin-F-spondin (FS). SPON2 can be used as a broad-spectrum tumor marker for more than a dozen tumors, mainly prostate cancer. Meanwhile, SPON2 is also a potential biomarker for the diagnosis of certain non-tumor diseases. Additionally, SPON2 plays a pivotal role in regulating tumor metastasis and progression. In normal tissues, SPON2 has a variety of biological functions represented by promoting growth and development and cell proliferation. This paper presents a comprehensive overview of the regulatory mechanisms, diagnostic potential as a broad-spectrum biomarker, diverse biological functions, involvement in various signaling pathways, and clinical applications of SPON2.

Impact of De Novo Cholesterol Biosynthesis on the Initiation and Progression of Breast Cancer

Cholesterol (CHOL) is a multifaceted lipid molecule. It is an essential structural component of cell membranes, where it cooperates in regulating the intracellular trafficking and signaling pathways. Additionally, it serves as a precursor for vital biomolecules, including steroid hormones, isoprenoids, vitamin D, and bile acids. Although CHOL is normally uptaken from the bloodstream, cells can synthesize it de novo in response to an increased requirement due to physiological tissue remodeling or abnormal proliferation, such as in cancer. Cumulating evidence indicated that increased CHOL biosynthesis is a common feature of breast cancer and is associated with the neoplastic transformation of normal mammary epithelial cells. After an overview of the multiple biological activities of CHOL and its derivatives, this review will address the impact of de novo CHOL production on the promotion of breast cancer with a focus on mammary stem cells. The review will also discuss the effect of de novo CHOL production on in situ and invasive carcinoma and its impact on the response to adjuvant treatment. Finally, the review will discuss the present and future therapeutic strategies to normalize CHOL biosynthesis.

(S)-10-Hydroxycamptothecin Inhibits EMT-evoked Osteosarcoma Cell Growth and Metastasis by Activating the HIPPO Signaling Pathway

BACKGROUND

Osteosarcoma is the most common primary bone cancer in children and adolescents with high metastatic ability.

AIM

This study aimed to explore the inhibitory effects of (S)-10-hydroxycamptothecin (HCPT) on osteosarcoma cell growth and metastasis as well as the underlying mechanism.

METHODS

The osteosarcoma cells of 143B and U-2 OS (U-2), treated with HCPT (20, 100, or 300 nM), underwent detections, such as CCK-8, flow cytometry, Transwell, wound healing, and immunoblotting. EMT-related key proteins, like N-cadherin, Snail, and Vimentin, were found to be down-regulated, while E-cadherin was up-regulated dose-dependently in HCPT-exposed 143B and U-2 cells. Additionally, incubation of 143B and U-2 cells with HCPT for 3 hours dosedependently reduced the expression ratios of p-LATS1/LATS1, p-MST1/MST1, p-YAP/YAP, and p-TAZ/TAZ.

RESULTS

Taken together, our study has demonstrated HCPT to inhibit osteosarcoma growth and metastasis potentially by activating the HIPPO signaling pathway and reversing EMT.

CONCLUSION

HCPT might be a candidate agent for the prevention and treatment of osteosarcoma.

Activating transcriptional coactivator with PDZ-binding motif by (R)-PFI-2 attenuates osteoclastogenesis and prevents ovariectomized-induced osteoporosis

Excessive osteoclast activation is a leading cause of osteoporosis. Therefore, identifying molecular targets and relevant pharmaceuticals that inhibit osteoclastogenesis is of substantial clinical importance. Prior research has indicated that transcriptional coactivator with PDZ-binding motif (TAZ) impedes the process of osteoclastogenesis by engaging the nuclear factor (NF)-κB signaling pathway, thereby suggesting TAZ activation as a potential therapeutic approach to treat osteoporosis. (R)-PFI-2 is a novel selective inhibitor of SETD7 methyltransferase activity, which prevents the nuclear translocation of YAP, a homolog of TAZ. Therefore, we hypothesized that (R)-PFI-2 could be an effective therapeutic agent in the treatment of osteoporosis. To test this hypothesis and explore the underlying mechanism, we first examined the impact of (R)-PFI-2 on osteoclastogenesis in bone marrow macrophages (BMMs) in vitro. (R)-PFI-2 treatment inhibited TAZ phosphorylation induced by NF-κB, thereby enhancing its nuclear localization, protein expression, and activation in BMMs. Moreover, (R)-PFI-2-induced TAZ activation inhibited osteoclast formation in a dose-dependent manner, which involved inhibition of osteoclastogenesis through the TAZ and downstream NF-κB pathways. Furthermore, (R)-PFI-2 inhibited osteoclastogenesis and prevented ovariectomy-induced bone loss in vivo in a mouse model. Overall, our findings suggest that TAZ activation by (R)-PFI-2 inhibits osteoclastogenesis and prevents osteoporosis, indicating an effective strategy for treating osteoclast-induced osteoporosis.

VEPH1 suppresses the progression of gastric cancer by regulating the Hippo-YAP signalling pathway

BACKGROUND

Ventricular zone-expressed PH domain-containing protein homologue 1 (VEPH1) is a recently discovered intracellular adaptor protein that plays an important role in human development. It has been reported that VEPH1 is closely related to the process of cellular malignancy, but its role in gastric cancer has not been elucidated. This study investigated the expression and function of VEPH1 in human gastric cancer (GC).

METHODS

We performed qRT‒PCR, Western blotting, and immunostaining assays in GC tissue samples to evaluate VEPH1 expression. Functional experiments were used to measure the malignancy of GC cells. A subcutaneous tumorigenesis model and peritoneal graft tumour model were established in BALB/c mice to determine tumour growth and metastasis in vivo.

RESULTS

VEPH1 expression is decreased in GC and correlates with the overall survival rates of GC patients. VEPH1 inhibits GC cell proliferation, migration, and invasion in vitro and suppresses tumour growth and metastasis in vivo. VEPH1 regulates the function of GC cells by inhibiting the Hippo-YAP signalling pathway, and YAP/TAZ inhibitor-1 treatment reverses the VEPH1 knockdown-mediated increase in the proliferation, migration and invasion of GC cells in vitro. Loss of VEPH1 is associated with increased YAP activity and accelerated epithelial-mesenchymal transition (EMT) in GC.

CONCLUSION

VEPH1 inhibited GC cell proliferation, migration, and invasion in vitro and in vivo and exerted its antitumour effects by inhibiting the Hippo-YAP signalling pathway and EMT process in GC.

Nuclear deformation regulates YAP dynamics in cancer associated fibroblasts

Cells cultured on stiff 2D substrates exert high intracellular force, resulting in mechanical deformation of their nuclei. This nuclear deformation (ND) plays a crucial role in the transport of Yes Associated Protein (YAP) from the cytoplasm to the nucleus. However, cells in vivo are in soft 3D environment with potentially much lower intracellular forces. Whether and how cells may deform their nuclei in 3D for YAP localization remains unclear. Here, by culturing human colon cancer associated fibroblasts (CAFs) on 2D, 2.5D, and 3D substrates, we differentiated the effects of stiffness, force, and ND on YAP localization. We found that nuclear translocation of YAP depends on the degree of ND irrespective of dimensionality, stiffness and total force. ND induced by the perinuclear force, not the total force, and nuclear membrane curvature correlate strongly with YAP activation. Immunostained slices of human tumors further supported the association between ND and YAP nuclear localization, suggesting ND as a potential biomarker for YAP activation in tumors. Additionally, we conducted quantitative analysis of the force dynamics of CAFs on 2D substrates to construct a stochastic model of YAP kinetics. This model revealed that the probability of YAP nuclear translocation, as well as the residence time in the nucleus follow a power law. This study provides valuable insights into the regulatory mechanisms governing YAP dynamics and highlights the significance of threshold activation in YAP localization. STATEMENT OF SIGNIFICANCE: Yes Associated Protein (YAP), a transcription cofactor, has been identified as one of the drivers of cancer progression. High tumor stiffness is attributed to driving YAP to the nucleus, wherein it activates pro-metastatic genes. Here we show, using cancer associated fibroblasts, that YAP translocation to the nucleus depends on the degree of nuclear deformation, irrespective of stiffness. We also identified that perinuclear force induced membrane curvature correlates strongly with YAP nuclear transport. A novel stochastic model of YAP kinetics unveiled a power law relationship between the activation threshold and persistence time of YAP in the nucleus. Overall, this study provides novel insights into the regulatory mechanisms governing YAP dynamics and the probability of activation that is of immense clinical significance.

Gα12 signaling regulates transcriptional and phenotypic responses that promote glioblastoma tumor invasion

In silico interrogation of glioblastoma (GBM) in The Cancer Genome Atlas (TCGA) revealed upregulation of GNA12 (Gα12), encoding the alpha subunit of the heterotrimeric G-protein G12, concomitant with overexpression of multiple G-protein coupled receptors (GPCRs) that signal through Gα12. Glioma stem cell lines from patient-derived xenografts also showed elevated levels of Gα12. Knockdown (KD) of Gα12 was carried out in two different human GBM stem cell (GSC) lines. Tumors generated in vivo by orthotopic injection of Gα12KD GSC cells showed reduced invasiveness, without apparent changes in tumor size or survival relative to control GSC tumor-bearing mice. Transcriptional profiling of GSC-23 cell tumors revealed significant differences between WT and Gα12KD tumors including reduced expression of genes associated with the extracellular matrix, as well as decreased expression of stem cell genes and increased expression of several proneural genes. Thrombospondin-1 (THBS1), one of the genes most repressed by Gα12 knockdown, was shown to be required for Gα12-mediated cell migration in vitro and for in vivo tumor invasion. Chemogenetic activation of GSC-23 cells harboring a Gα12-coupled DREADD also increased THBS1 expression and in vitro invasion. Collectively, our findings implicate Gα12 signaling in regulation of transcriptional reprogramming that promotes invasiveness, highlighting this as a potential signaling node for therapeutic intervention.

Magnetic Aggregation-Induced Bone-Targeting Nanocarrier with Effects of Piezo1 Activation and Osteogenic-Angiogenic Coupling for Osteoporotic Bone Repair

Osteoporosis, characterized by an imbalance in bone homeostasis, is a global health concern. Bone defects are difficult to heal in patients with osteoporosis. Classical drug treatments for osteoporotic bone defects have unsatisfactory efficacy owing to side effects and imprecise delivery problems. In this study, a magnetic aggregation-induced bone-targeting poly(lactic-co-glycolic acid, PLGA)-based nanocarrier (ZOL-PLGA@Yoda1/SPIO) is synthesized to realize dual-targeted delivery and precise Piezo1-activated therapy for osteoporotic bone defects. Piezo1 is an important mechanotransducer that plays a key role in regulating bone homeostasis. To achieve dual-targeting properties, ZOL-PLGA@Yoda1/SPIO is fabricated using zoledronate (ZOL)-decorated PLGA, superparamagnetic iron oxide (SPIO), and Piezo1-activated molecule Yoda1 via the emulsion solvent diffusion method. Bone-targeting molecular mediation and magnetic aggregation-induced properties can jointly and effectively achieve precise delivery to localized bone defects. Moreover, Yoda1 loading enables targeted and efficient mimicking of mechanical signals and activation of Piezo1. Experiments in vivo and in vitro demonstrate that ZOL-PLGA@Yoda1/SPIO can activate Piezo1 in bone defect areas of osteoporotic mice, improve osteogenesis through YAP/β-catenin signaling axis, promote a well-coordinated osteogenesis-angiogenesis coupling, and significantly accelerate bone reconstruction within the defects without noticeable side effects. Overall, this novel dual-targeting nanocarrier provides a potentially effective strategy for the clinical treatment of osteoporotic bone defects.

YAP-mediated trophoblast dysfunction: the common pathway underlying pregnancy complications

Yes-associated protein (YAP) is a pivotal regulator in cellular proliferation, survival, differentiation, and migration, with significant roles in embryonic development, tissue repair, and tumorigenesis. At the maternal-fetal interface, emerging evidence underscores the importance of precisely regulated YAP activity in ensuring successful pregnancy initiation and progression. However, despite the established association between YAP dysregulation and adverse pregnancy outcomes, insights into the impact of aberrant YAP levels in fetal-derived, particularly trophoblast cells, and the ensuing dysfunction at the maternal-fetal interface remain limited. This review comprehensively examines YAP expression and its regulatory mechanisms in trophoblast cells throughout pregnancy. We emphasize its integral role in placental development and maternal-fetal interactions and delve into the correlations between YAP dysregulation and pregnancy complications. A nuanced understanding of YAP's functions during pregnancy could illuminate intricate molecular mechanisms and pave the way for innovative prevention and treatment strategies for pregnancy complications. Video Abstract.

The AMPK-Sirtuin 1-YAP axis is regulated by fluid flow intensity and controls autophagy flux in kidney epithelial cells

Shear stress generated by urinary fluid flow is an important regulator of renal function. Its dysregulation is observed in various chronic and acute kidney diseases. Previously, we demonstrated that primary cilium-dependent autophagy allows kidney epithelial cells to adapt their metabolism in response to fluid flow. Here, we show that nuclear YAP/TAZ negatively regulates autophagy flux in kidney epithelial cells subjected to fluid flow. This crosstalk is supported by a primary cilium-dependent activation of AMPK and SIRT1, independently of the Hippo pathway. We confirm the relevance of the YAP/TAZ-autophagy molecular dialog in vivo using a zebrafish model of kidney development and a unilateral ureteral obstruction mouse model. In addition, an in vitro assay simulating pathological accelerated flow observed at early stages of chronic kidney disease (CKD) activates YAP, leading to a primary cilium-dependent inhibition of autophagic flux. We confirm this YAP/autophagy relationship in renal biopsies from patients suffering from diabetic kidney disease (DKD), the leading cause of CKD. Our findings demonstrate the importance of YAP/TAZ and autophagy in the translation of fluid flow into cellular and physiological responses. Dysregulation of this pathway is associated with the early onset of CKD.

A Vaccine against Cancer: Can There Be a Possible Strategy to Face the Challenge? Possible Targets and Paradoxical Effects

Is it possible to have an available vaccine that eradicates cancer? Starting from this question, this article tries to verify the state of the art, proposing a different approach to the issue. The variety of cancers and different and often unknown causes of cancer impede, except in some cited cases, the creation of a classical vaccine directed at the causative agent. The efforts of the scientific community are oriented toward stimulating the immune systems of patients, thereby preventing immune evasion, and heightening chemotherapeutic agents effects against cancer. However, the results are not decisive, because without any warning signs, metastasis often occurs. The purpose of this paper is to elaborate on a vaccine that must be administered to a patient in order to prevent metastasis; metastasis is an event that leads to death, and thus, preventing it could transform cancer into a chronic disease. We underline the fact that the field has not been studied in depth, and that the complexity of metastatic processes should not be underestimated. Then, with the aim of identifying the target of a cancer vaccine, we draw attention to the presence of the paradoxical actions of different mechanisms, pathways, molecules, and immune and non-immune cells characteristic of the tumor microenvironment at the primary site and pre-metastatic niche in order to exclude possible vaccine candidates that have opposite effects/behaviors; after a meticulous evaluation, we propose possible targets to develop a metastasis-targeting vaccine. We conclude that a change in the current concept of a cancer vaccine is needed, and the efforts of the scientific community should be redirected toward a metastasis-targeting vaccine, with the increasing hope of eradicating cancer.

Transcriptional repression of beige fat innervation via a YAP/TAZ-S100B axis

Sympathetic innervation is essential for the development of functional beige fat that maintains body temperature and metabolic homeostasis, yet the molecular mechanisms controlling this innervation remain largely unknown. Here, we show that adipocyte YAP/TAZ inhibit sympathetic innervation of beige fat by transcriptional repression of neurotropic factor S100B. Adipocyte-specific loss of Yap/Taz induces S100b expression to stimulate sympathetic innervation and biogenesis of functional beige fat both in subcutaneous white adipose tissue (WAT) and browning-resistant visceral WAT. Mechanistically, YAP/TAZ compete with C/EBPβ for binding to the zinc finger-2 domain of PRDM16 to suppress S100b transcription, which is released by adrenergic-stimulated YAP/TAZ phosphorylation and inactivation. Importantly, Yap/Taz loss in adipocytes or AAV-S100B overexpression in visceral WAT restricts both age-associated and diet-induced obesity, and improves metabolic homeostasis by enhancing energy expenditure of mice. Together, our data reveal that YAP/TAZ act as a brake on the beige fat innervation by blocking PRDM16-C/EBPβ-mediated S100b expression.

Biological characteristics of pancreatic ductal adenocarcinoma: Initiation to malignancy, intracellular to extracellular

Pancreatic ductal adenocarcinoma (PDAC) is a highly life-threatening tumour with a low early-detection rate, rapid progression and a tendency to develop resistance to chemotherapy. Therefore, understanding the regulatory mechanisms underlying the initiation, development and metastasis of pancreatic cancer is necessary for enhancing therapeutic effectiveness. In this review, we summarised single-gene mutations (including KRAS, CDKN2A, TP53, SMAD4 and some other less prevalent mutations), epigenetic changes (including DNA methylation, histone modifications and RNA interference) and large chromosome alterations (such as copy number variations, chromosome rearrangements and chromothripsis) associated with PDAC. In addition, we discussed variations in signalling pathways that act as intermediate oncogenic factors in PDAC, including PI3K/AKT, MAPK/ERK, Hippo and TGF-β signalling pathways. The focus of this review was to investigate alterations in the microenvironment of PDAC, particularly the role of immunosuppressive cells, cancer-associated fibroblasts, lymphocytes, other para-cancerous cells and tumour extracellular matrix in tumour progression. Peripheral axons innervating the pancreas have been reported to play a crucial role in the development of cancer. In addition, tumour cells can influence the behaviour of neighbouring non-tumour cells by secreting certain factors, both locally and at a distance. In this review, we elucidated the alterations in intracellular molecules and the extracellular environment that occur during the progression of PDAC. Altogether, this review may enhance the understanding of the biological characteristics of PDAC and guide the development of more precise treatment strategies.

miR-3133 inhibits gastrointestinal cancer progression through activation of Hippo and p53 signalling pathways via multi-targets

BACKGROUND

Malignant cell growth and chemoresistance, the main obstacles in treating gastrointestinal cancer (GIC), rely on the Hippo and p53 signalling pathways. However, the upstream regulatory mechanisms of these pathways remain complex and poorly understood.

METHODS

Immunohistochemistry (IHC), western blot and RT-qPCR were used to analyse the expression of RNF146, miR-3133 and key components of Hippo and p53 pathway. CCK-8, colony formation, drug sensitivity assays and murine xenograft models were used to investigate the effect of RNF146 and miR-3133 in GIC. Further exploration of the upstream regulatory mechanism was performed using bioinformatics analysis, dual-luciferase reporter gene, immunoprecipitation assays and bisulfite sequencing PCR (BSP).

RESULTS

Clinical samples, in vitro and in vivo experiments demonstrated that RNF146 exerts oncogenic effects in GIC by regulating the Hippo pathway. Bioinformatics analysis identified a novel miRNA, miR-3133, as an upstream regulatory factor of RNF146. fluorescence in situ hybridization and RT-qPCR assays revealed that miR-3133 was less expressed in gastrointestinal tumour tissues and was associated with adverse pathological features. Functional assays and animal models showed that miR-3133 promoted the proliferation and chemotherapy sensitivity of GIC cells. miR-3133 affected YAP1 protein expression by targeting RNF146, AGK and CUL4A, thus activating the Hippo pathway. miR-3133 inhibited p53 protein degradation and extended p53's half-life by targeting USP15, SPIN1. BSP experiments confirmed that miR-3133 promoter methylation is an important reason for its low expression.

CONCLUSION

miR-3133 inhibits GIC progression by activating the Hippo and p53 signalling pathways via multi-targets, including RNF146, thereby providing prognostic factors and valuable potential therapeutic targets for GIC.

Prostaglandin E2 attenuates lung fibroblast differentiation via inactivation of yes-associated protein signaling

Prostaglandin E2 (PGE2 ) has been implicated in counteracting fibroblast differentiation by TGFβ1 during pulmonary fibrosis. However, the precise mechanism is not well understood. We show here that PGE2 via EP2 R and EP4 R inhibits the expression of mechanosensory molecules Lysyl Oxidase Like 2 (LOXL2), myocardin-related transcription factor A (MRTF-A), ECM proteins, plasminogen activation inhibitor 1 (PAI-1), fibronectin (FN), α-smooth muscle actin (α-SMA), and redox sensor (nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4)) required for TGFβ1-mediated fibroblast differentiation. We further demonstrate that PGE2 inhibits fibrotic signaling via Yes-associated protein (YAP) but does so independently from its actions on SMAD phosphorylation and conserved cylindromatosis (CYLD; deubiquitinase) expression. Mechanistically, PGE2 phosphorylates/inactivates YAP downstream of EP2 R/Gαs and restrains its translocation to the nucleus, thus inhibiting its interaction with TEA domain family members (TEADs) and transcription of fibrotic genes. Importantly, pharmacological or siRNA-mediated inhibition of YAP significantly downregulates TGFβ1-mediated fibrotic gene expression and myofibroblast formation. Notably, YAP expression is upregulated in the lungs of D. farinae-treated wild type (WT) mice relative to saline-treated WT mice. Our results unravel a unique role for PGE2 -YAP interactions in fibroblast differentiation, and that PGE2 /YAP inhibition can be used as a novel therapeutic target in the treatment of pathological conditions associated with myofibroblasts like asthma.

Regulatory Mechanisms That Guide the Fetal to Postnatal Transition of Cardiomyocytes

Heart disease remains a global leading cause of death and disability, necessitating a comprehensive understanding of the heart's development, repair, and dysfunction. This review surveys recent discoveries that explore the developmental transition of proliferative fetal cardiomyocytes into hypertrophic postnatal cardiomyocytes, a process yet to be well-defined. This transition is key to the heart's growth and has promising therapeutic potential, particularly for congenital or acquired heart damage, such as myocardial infarctions. Although significant progress has been made, much work is needed to unravel the complex interplay of signaling pathways that regulate cardiomyocyte proliferation and hypertrophy. This review provides a detailed perspective for future research directions aimed at the potential therapeutic harnessing of the perinatal heart transitions.

Targeting the mechanism of IRF3 in sepsis-associated acute kidney injury via the Hippo pathway

Sepsis-induced inflammatory damage and adaptive repair are critical in the pathophysiological mechanisms of acute kidney injury (AKI). Here, we investigated the role of interferon regulatory factor three (IRF3) and subsequent activation of the Hippo pathway in inflammatory damage and repair using an in vitro cell model of LPS-induced AKI. LPS caused the phosphorylation and activation of IRF3 in the early stages of sepsis, and activated IRF3 enhanced the production of type I interferon (IFN), resulting in an excessive inflammatory response. Furthermore, LPS generated considerably more inflammatory injury than intended cell death, and IRF3 activation triggered the Hippo pathway, causing a reduction in YAP, which eventually impaired proliferation and repair in surviving renal tubular epithelial cells and exacerbated the development of AKI. In conclusion, IRF3 promoted the development of sepsis-associated AKI (SAKI) by modulating the Hippo pathway.

SDCBP promotes pancreatic cancer progression by preventing YAP1 from β-TrCP-mediated proteasomal degradation

OBJECTIVE

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal tumour with limited treatment options. Here, we identified syndecan binding protein (SDCBP), also known as syntenin1, as a novel targetable factor in promoting PDAC tumour progression. We also explored a therapeutic strategy for suppressing SDCBP expression.

DESIGN

We used samples from patients with PDAC, human organoid models, LSL-KrasG12D/+mice, LSL-Trp53R172H/+ and Pdx1-Cre (KPC) mouse models, and PDX mouse models. Immunostaining, colony formation assay, ethynyl-2-deoxyuridine incorporation assay, real-time cell analysis, cell apoptosis assay, automated cell tracking, invadopodia detection and gelatin degradation assays, coimmunoprecipitation, and pull-down assays were performed in this study.

RESULTS

The median overall survival and recurrence-free survival rates in the high-SDCBP group were significantly shorter than those in the low-SDCBP group. In vitro and in vivo studies have demonstrated that SDCBP promotes PDAC proliferation and metastasis. Mechanically, SDCBP inhibits CK1δ/ε-mediated YAP-S384/S387 phosphorylation, which further suppresses β-TrCP-mediated YAP1 ubiquitination and proteasome degradation by directly interacting with YAP1. SDCBP interacts with the TAD domain of YAP1, mainly through its PDZ1 domain. Preclinical KPC mouse cohorts demonstrated that zinc pyrithione (ZnPT) suppresses PDAC tumour progression by suppressing SDCBP.

CONCLUSIONS

SDCBP promotes the proliferation and metastasis of PDAC by preventing YAP1 from β-TrCP-mediated proteasomal degradation. Therefore, ZnPT could be a promising therapeutic strategy to inhibit PDAC progression by suppressing SDCBP.

AXL activates YAP through the EGFR-LATS1/2 axis and confers resistance to EGFR-targeted drugs in head and neck squamous cell carcinoma

The Hippo signaling pathway and its downstream effector YAP play a central role in cell proliferation. Dysregulation of the Hippo pathway triggers YAP hyperactivation, thereby inducing head and neck squamous cell carcinoma (HNSCC). Recently, we reported that EGFR promotes tyrosine phosphorylation of MOB1 and subsequent LATS1/2 inactivation, which are core components of the Hippo pathway, resulting in YAP activation. However, EGFR-targeted monotherapy has shown a low response rate in HNSCC patients. Given that YAP is activated in patient samples refractory to EGFR-targeted therapy, EGFR inhibitors may temporarily inactivate YAP, but intrinsic hyperactivation or acquired reactivation of YAP may confer resistance to EGFR inhibitors in HNSCC cells. The mechanism by which YAP is activated in HNSCC resistant to EGFR inhibitors remains unclear. Comprehensive transcriptional analysis revealed that AXL activates YAP through a novel mechanism: AXL heterodimerizes with EGFR, thereby activating YAP via the EGFR-LATS1/2 axis. The combination of AXL and EGFR inhibitors synergistically inactivates YAP and suppresses the viability of HNSCC and lung adenocarcinoma cells. In turn, LATS1/2 knockout and YAP hyperactivation confer resistance to the synergistic effects of these inhibitors. Our findings suggest that co-targeting both AXL and EGFR represent a promising therapeutic approach in patients with EGFR-altered cancers.

The impact of interaction between verteporfin and yes-associated protein 1/transcriptional coactivator with PDZ-binding motif-TEA domain pathway on the progression of isocitrate dehydrogenase wild-type glioblastoma

Verteporfin and 5-ALA are used for visualizing malignant tissue components in different body tumors and as photodynamic therapy in treating isocitrate dehydrogenase (IDH) wild-type glioblastoma (GBM). Additionally, verteporfin interferes with Yes-associated protein 1 (YAP)/Transcriptional coactivator with PDZ-binding motif - TEA domain (TAZ-TEAD) pathway, thus inhibiting the downstream effect of these oncogenes and reducing the malignant properties of GBM. Animal studies have shown verteporfin to be successful in increasing survival rates, which have led to the conduction of phase 1 and 2 clinical trials to further investigate its efficacy in treating GBM. In this article, we aimed to review the novel mechanism of verteporfin's action, the impact of its interaction with YAP/TAZ-TEAD, its effect on glioblastoma stem cells, and its role in inducing ferroptosis.

Metformin accelerates bone fracture healing by promoting type H vessel formation through inhibition of YAP1/TAZ expression

Due to increasing morbidity worldwide, fractures are becoming an emerging public health concern. This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures. Type H vessels have recently been identified as a bone-specific vascular subtype that supports osteogenesis. Here, we show that metformin accelerated fracture healing in both osteoporotic and normal mice. Moreover, metformin promoted angiogenesis in vitro under hypoxia as well as type H vessel formation throughout fracture healing. Mechanistically, metformin increased the expression of HIF-1α, an important positive regulator of type H vessel formation, by inhibiting the expression of YAP1/TAZ in calluses and hypoxia-cultured human microvascular endothelial cells (HMECs). The results of HIF-1α or YAP1/TAZ interference in hypoxia-cultured HMECs using siRNA further suggested that the enhancement of HIF-1α and its target genes by metformin is primarily through YAP1/TAZ inhibition. Finally, overexpression of YAP1/TAZ partially counteracted the effect of metformin in promoting type H vessel-induced angiogenesis-osteogenesis coupling during fracture repair. In summary, our findings suggest that metformin has the potential to be a therapeutic agent for fractures by promoting type H vessel formation through YAP1/TAZ inhibition.