TRPS1 shapes YAP/TEAD-dependent transcription in breast cancer cells

Analysis of the function, mechanism and clinical application prospect of TRPS1, a new marker for breast cancer

It has been discovered that Trichorhinophalangeal Syndrome-1 (TRPS1), a novel member of the GATA transcription factor family, participates in both normal physiological processes and the development of numerous diseases. Recently, TRPS1 has been identified as a new biomarker to aid in cancer diagnosis and is very common in breast cancer (BC), especially in triple-negative breast cancer (TNBC). In this review, we discussed the structure and function of TRPS1 in various normal cells, focused on its role in tumorigenesis and tumor development, and summarize the research status of TRPS1 in the occurrence and development of BC. We also analyzed the potential use of TRPS1 in guiding clinically personalized precision treatment and the development of targeted drugs.

Spatial transcriptomics reveals unique metabolic profile and key oncogenic regulators of cervical squamous cell carcinoma

BACKGROUND

As a prevalent and deadly malignant tumor, the treatment outcomes for late-stage patients with cervical squamous cell carcinoma (CSCC) are often suboptimal. Previous studies have shown that tumor progression is closely related with tumor metabolism and microenvironment reshaping, with disruptions in energy metabolism playing a critical role in this process. To delve deeper into the understanding of CSCC development, our research focused on analyzing the tumor microenvironment and metabolic characteristics across different regions of tumor tissue.

METHODS

Utilizing spatial transcriptomics (ST) sequencing technology, we conducted a study on FFPE (formalin-fixed paraffin-embedded) tumor samples from CSCC patients. Coupled with single-cell RNA sequencing (scRNA-seq) data after deconvolution, we described spatial distribution maps of tumor leading edge and core regions in detail. Tumor tissues were classified into hypermetabolic and hypometabolic regions to analyze the metabolism profiles and tumor differentiation degree across different spatial areas. We also employed The Cancer Genome Atlas (TCGA) database to examine the analysis results of ST data.

RESULTS

Our findings indicated a more complex tumor microenvironment in hypermetabolic regions. Cell-cell communication analysis showed that various cells in tumor microenvironment were influenced by the signalling molecule APP released by cancer cells and higher expression of APP was observed in hypermetabolic regions. Furthermore, our results revealed the correlation between APP and the transcription factor TRPS1. Both APP and TRPS1 demonstrated significant effects on cancer cell proliferation, migration, and invasion, potentially contributing to tumor progression.

CONCLUSIONS

Utilizing ST, scRNA-seq, and TCGA database, we examined the spatial metabolic profiles of CSCC tissues, including metabolism distribution, metabolic variations, and the relationship between metabolism and tumor differentiation degree. Additionally, potential cancer-promoting factors were proposed, offering a valuable foundation for the development of more effective treatment strategies for CSCC.

Down-regulation of miR-138-5p in PP2A KO mice promoted apoptosis of spermatocytes

BACKGROUND

Protein phosphatase 2 A (PP2A) is known to have a pivotal and diverse functions in various physiological processes. In the previous study, we utilized the cre-loxp system to generate germ cell-specific knockout mice for the PP2A catalytic subunit alpha subunit (Ppp2cacKO).

METHODS AND RESULTS

Using high-throughput miRNA sequencing of testis tissues and real‑time PCR, we have identified a notable decrease in the expression of miR-138-5p in the testes of Ppp2cacKO mice. Our findings indicate that miR-138-5p plays a role in the regulation of apoptosis and proliferation of GC2 cells. Furthermore, bioinformatics analyses suggested that miR-138- 5p may target the transcriptional repressor Trps1. Consistent with these predictions, we observed a significant upregulation of Trps1 in the testes of Ppp2cacKO mice. Through transfection experiments, we have validated the negative regulation of Trps1 expression by miR-138-5p in GC2 cells.

CONCLUSION

Our study indicates that the down-regulation of miR-138-5p in PP2A KO mice, which targets Trps1 to promote spermatocyte apoptosis.

Active enhancers: recent research advances and insights into disease

Precise regulation of gene expression is crucial to development. Enhancers, the core of gene regulation, determine the spatiotemporal pattern of gene transcription. Since many disease-associated mutations are characterized in enhancers, the research on enhancer will provide clues to precise medicine. Rapid advances in high-throughput sequencing technology facilitate the characterization of enhancers at genome wide, but understanding the functional mechanisms of enhancers remains challenging. Herein, we provide a panorama of enhancer characteristics, including epigenetic modifications, enhancer transcripts, and enhancer-promoter interaction patterns. Furthermore, we outline the applications of high-throughput sequencing technology and functional genomics methods in enhancer research. Finally, we discuss the role of enhancers in human disease and their potential as targets for disease prevention and treatment strategies.

Differential chromatin accessibility and transcriptional dynamics define breast cancer subtypes and their lineages

Breast cancer (BC) is defined by distinct molecular subtypes with different cells of origin. The transcriptional networks that characterize the subtype-specific tumor-normal lineages are not established. In this work, we applied bulk, single-cell and single-nucleus multi-omic techniques as well as spatial transcriptomics and multiplex imaging on 61 samples from 37 patients with BC to show characteristic links in gene expression and chromatin accessibility between BC subtypes and their putative cells of origin. Regulatory network analysis of transcription factors underscored the importance of BHLHE40 in luminal BC and luminal mature cells and KLF5 in basal-like tumors and luminal progenitor cells. Furthermore, we identify key genes defining the basal-like (SOX6 and KCNQ3) and luminal A/B (FAM155A and LRP1B) lineages. Exhausted CTLA4-expressing CD8+ T cells were enriched in basal-like BC, suggesting an altered means of immune dysfunction. These findings demonstrate analysis of paired transcription and chromatin accessibility at the single-cell level is a powerful tool for investigating cancer lineage and highlight transcriptional networks that define basal and luminal BC lineages.

Multiomics profiling of mouse polycystic kidney disease progression at a single-cell resolution

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease and causes significant morbidity, ultimately leading to kidney failure. PKD pathogenesis is characterized by complex and dynamic alterations in multiple cell types during disease progression, hampering a deeper understanding of disease mechanism and the development of therapeutic approaches. Here, we generate a single-nucleus multimodal atlas of an orthologous mouse PKD model at early, mid, and late timepoints, consisting of 125,434 single-nucleus transcriptomic and epigenetic multiomes. We catalog differentially expressed genes and activated epigenetic regions in each cell type during PKD progression, characterizing cell-type-specific responses to Pkd1 deletion. We describe heterogeneous, atypical collecting duct cells as well as proximal tubular cells that constitute cyst epithelia in PKD. The transcriptional regulation of the cyst lining cell marker GPRC5A is conserved between mouse and human PKD cystic epithelia, suggesting shared gene regulatory pathways. Our single-nucleus multiomic analysis of mouse PKD provides a foundation to understand the earliest changes molecular deregulation in a mouse model of PKD at a single-cell resolution.

GATA factor TRPS1, a new DNA repair protein, cooperates with reversible PARylation to promote chemoresistance in patients with breast cancer

Resistance to DNA-damaging agents is a major unsolved challenge for breast cancer patients undergoing chemotherapy. Here, we show that elevated expression of transcriptional repressor GATA binding 1 (TRPS1) is associated with lower drug sensitivity, reduced response rate, and poor prognosis in chemotherapy-treated breast cancer patients. Mechanistically, elevated TRPS1 expression promotes hyperactivity of DNA damage repair (DDR) in breast cancer cells. We provide evidence that TRPS1 dynamically localizes to DNA breaks in a Ku70-and Ku80-dependent manner and that TRPS1 is a new member of the DDR protein family. We also discover that the dynamics of TRPS1 assembly at DNA breaks is regulated by its reversible PARylation in the DDR, and that mutations of the PARylation sites on TRPS1 lead to increased sensitivity to chemotherapeutic drugs. Taken together, our findings provide new mechanistic insights into the DDR and chemoresistance in breast cancer patients and identify TRPS1 as a critical DDR protein. TRPS1 may also be considered as a target to improve chemo-sensitization strategies and, consequently, clinical outcomes for breast cancer patients.

UVB-induced TRPS1 regulates MITF transcription activity to promote skin pigmentation

Hyperpigmented dermatoses are characterized by increased skin pigmentation caused by genetic, environmental factors and inflammation, which lasts a long time and is difficult to treat. Ultraviolet (UV), especially ultraviolet B (UVB), is the primary external factor inducing skin pigmentation. However, the specific regulatory mechanisms are not fully understood. Through analysis of GEO datasets from four UV-exposed skin cell/tissue samples, we found that TRPS1 is the only gene differentially expressed in multiple datasets (GSE22083, GSE67098 and GSE70280) and highly positively correlated with the expression of key melanogenesis genes. Consistently, we observed that TRPS1 is highly expressed in sun-exposed skin tissues compared to non-exposed skin. Additionally, the expression of TRPS1 was also significantly upregulated after UVB irradiation in isolated skin tissues and melanocytes, while knockdown of TRPS1 expression inhibited the UVB-induced melanogenesis. Further research revealed that overexpression of TRPS1 increased melanin content and tyrosinase activity in MNT1 cells, as well as upregulated the expression levels of key melanogenesis genes (MITF, TYR, TYRP1, DCT). In contrast, inhibition of TRPS1 expression showed the opposite effect. Moreover, we found that TRPS1 can bind to the promoter region of MITF, inhibiting the expression of MITF can antagonize the melanogenesis induced by TRPS1. In conclusion, UVB-induced TRPS1 promotes melanogenesis by activating the transcriptional activity of MITF.

Single-cell exome sequencing reveals polyclonal seeding and TRPS1 mutations in colon cancer metastasis

Liver metastasis remains the primary cause of mortality in patients with colon cancer. Identifying specific driver gene mutations that contribute to metastasis may offer viable therapeutic targets. To explore clonal evolution and genetic heterogeneity within the metastasis, we conducted single-cell exome sequencing on 150 single cells isolated from the primary tumor, liver metastasis, and lymphatic metastasis from a stage IV colon cancer patient. The genetic landscape of the tumor samples revealed that both lymphatic and liver metastases originated from the same region of the primary tumor. Notably, the liver metastasis was derived directly from the primary tumor, bypassing the lymph nodes. Comparative analysis of the sequencing data for individual cell pairs within different tumors demonstrated that the genetic heterogeneity of both liver and lymphatic metastases was also greater than that of the primary tumor. This finding indicates that liver and lymphatic metastases arose from clusters of circulating tumor cell (CTC) of a polyclonal origin, rather than from a single cell from the primary tumor. Single-cell transcriptome analysis suggested that higher EMT score and CNV scores were associated with more polyclonal metastasis. Additionally, a mutation in the TRPS1 (Transcriptional repressor GATA binding 1) gene, TRPS1 R544Q, was enriched in the single cells from the liver metastasis. The mutation significantly increased CRC invasion and migration both in vitro and in vivo through the TRPS1R544Q/ZEB1 axis. Further TRPS1 mutations were detected in additional colon cancer cases, correlating with advanced-stage disease and inferior prognosis. These results reveal polyclonal seeding and TRPS1 mutation as potential mechanisms driving the development of liver metastases in colon cancer.

Multi-omics profiling of mouse polycystic kidney disease progression at a single cell resolution

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease and causes significant morbidity, ultimately leading to end-stage kidney disease. PKD pathogenesis is characterized by complex and dynamic alterations in multiple cell types during disease progression, hampering a deeper understanding of disease mechanism and the development of therapeutic approaches. Here, we generate a single nucleus multimodal atlas of an orthologous mouse PKD model at early, mid and late timepoints, consisting of 125,434 single-nucleus transcriptomic and epigenetic multiomes. We catalogue differentially expressed genes and activated epigenetic regions in each cell type during PKD progression, characterizing cell-type-specific responses to Pkd1 deletion. We describe heterogeneous, atypical collecting duct cells as well as proximal tubular cells that constitute cyst epithelia in PKD. The transcriptional regulation of the cyst lining cell marker GPRC5A is conserved between mouse and human PKD cystic epithelia, suggesting shared gene regulatory pathways. Our single nucleus multiomic analysis of mouse PKD provides a foundation to understand the earliest changes molecular deregulation in a mouse model of PKD at a single-cell resolution.

TRPS1 maintains luminal progenitors in the mammary gland by repressing SRF/MRTF activity

The transcription factor TRPS1 is a context-dependent oncogene in breast cancer. In the mammary gland, TRPS1 activity is restricted to the luminal population and is critical during puberty and pregnancy. Its function in the resting state remains however unclear. To evaluate whether it could be a target for cancer therapy, we investigated TRPS1 function in the healthy adult mammary gland using a conditional ubiquitous depletion mouse model where long-term depletion does not affect fitness. Using transcriptomic approaches, flow cytometry and functional assays, we show that TRPS1 activity is essential to maintain a functional luminal progenitor compartment. This requires the repression of both YAP/TAZ and SRF/MRTF activities. TRPS1 represses SRF/MRTF activity indirectly by modulating RhoA activity. Our work uncovers a hitherto undisclosed function of TRPS1 in luminal progenitors intrinsically linked to mechanotransduction in the mammary gland. It may also provide new insights into the oncogenic functions of TRPS1 as luminal progenitors are likely the cells of origin of many breast cancers.

Identification of a Gene Signature That Predicts Dependence upon YAP/TAZ-TEAD

Targeted therapies are effective cancer treatments when accompanied by accurate diagnostic tests that can help identify patients that will respond to those therapies. The YAP/TAZ-TEAD axis is activated and plays a causal role in several cancer types, and TEAD inhibitors are currently in early-phase clinical trials in cancer patients. However, a lack of a reliable way to identify tumors with YAP/TAZ-TEAD activation for most cancer types makes it difficult to determine which tumors will be susceptible to TEAD inhibitors. Here, we used a combination of RNA-seq and bioinformatic analysis of metastatic melanoma cells to develop a YAP/TAZ gene signature. We found that the genes in this signature are TEAD-dependent in several melanoma cell lines, and that their expression strongly correlates with YAP/TAZ activation in human melanomas. Using DepMap dependency data, we found that this YAP/TAZ signature was predictive of melanoma cell dependence upon YAP/TAZ or TEADs. Importantly, this was not limited to melanoma because this signature was also predictive when tested on a panel of over 1000 cancer cell lines representing numerous distinct cancer types. Our results suggest that YAP/TAZ gene signatures like ours may be effective tools to predict tumor cell dependence upon YAP/TAZ-TEAD, and thus potentially provide a means to identify patients likely to benefit from TEAD inhibitors.

Inhibition of the YAP-MMB interaction and targeting NEK2 as potential therapeutic strategies for YAP-driven cancers

YAP activation in cancer is linked to poor outcomes, making it an attractive therapeutic target. Previous research focused on blocking the interaction of YAP with TEAD transcription factors. Here, we took a different approach by disrupting YAP's binding to the transcription factor B-MYB using MY-COMP, a fragment of B-MYB containing the YAP binding domain fused to a nuclear localization signal. MY-COMP induced cell cycle defects, nuclear abnormalities, and polyploidization. In an AKT and YAP-driven liver cancer model, MY-COMP significantly reduced liver tumorigenesis, highlighting the importance of the YAP-B-MYB interaction in tumor development. MY-COMP also perturbed the cell cycle progression of YAP-dependent uveal melanoma cells but not of YAP-independent cutaneous melanoma cell lines. It counteracted YAP-dependent expression of MMB-regulated cell cycle genes, explaining the observed effects. We also identified NIMA-related kinase (NEK2) as a downstream target of YAP and B-MYB, promoting YAP-driven transformation by facilitating centrosome clustering and inhibiting multipolar mitosis.

TRPS1 modulates chromatin accessibility to regulate estrogen receptor alpha (ER) binding and ER target gene expression in luminal breast cancer cells

Common genetic variants in the repressive GATA-family transcription factor (TF) TRPS1 locus are associated with breast cancer risk, and luminal breast cancer cell lines are particularly sensitive to TRPS1 knockout. We introduced an inducible degron tag into the native TRPS1 locus within a luminal breast cancer cell line to identify the direct targets of TRPS1 and determine how TRPS1 mechanistically regulates gene expression. We acutely deplete over 80 percent of TRPS1 from chromatin within 30 minutes of inducing degradation. We find that TRPS1 regulates transcription of hundreds of genes, including those related to estrogen signaling. TRPS1 directly regulates chromatin structure, which causes estrogen receptor alpha (ER) to redistribute in the genome. ER redistribution leads to both repression and activation of dozens of ER target genes. Downstream from these primary effects, TRPS1 depletion represses cell cycle-related gene sets and reduces cell doubling rate. Finally, we show that high TRPS1 activity, calculated using a gene expression signature defined by primary TRPS1-regulated genes, is associated with worse breast cancer patient prognosis. Taken together, these data suggest a model in which TRPS1 modulates the genomic distribution of ER, both activating and repressing transcription of genes related to cancer cell fitness.

Trps1 acts as a regulator of Sf-1 transcription and testosterone synthesis in mouse Leydig cells

Infertility has attracted global concern, and disruption of testosterone is a common cause of male infertility. Exploring the critical factors in testosterone biosynthesis may provide new insights for disease research and clinical therapy. Research on trichorhinophalangeal syndrome-1 (Trps1) gene has recently been focus on cancers; it is yet unknown whether Trps1 produces a marked effect in the male reproductive system. In the current study, single-cell RNA sequencing analysis of trichorhinophalangeal syndrome-1 gene (Trps1) expression in mouse testes and cleavage under targets and tagmentation and RNA sequencing were utilized to investigate the functionality of Trps1 in mouse Leydig cells. Knockdown of Trps1 increased testosterone synthesis in vitro and vivo using adeno-associated viral delivery and conditional knockout models. The results showed that Trps1 was abundantly expressed in Leydig cells. The expression levels of both steroidogenic factor-1 (Sf-1) and steroidogenic enzymes (Cyp11a1, Hsd3b, Cyp17a1, and Hsd17b3) as well as testosterone secretion were increased after Trps1 deficiency in vivo and vitro. Furthermore, disruption of Trps1 reduced histone deacetylase 1/2 activity and increased histone H3 acetylation in the Sf-1 promoter, thereby promoting testosterone secretion. Interestingly, Sf-1 also regulated the transcription of Trps1 through activating transcription factor 2. These results indicate that Trps1 targets Sf-1 to affect steroidogenesis through histone acetylation and shed light on the critical role of Trps1 functioning in the mouse Leydig cells.

New Insights into YAP/TAZ-TEAD-Mediated Gene Regulation and Biological Processes in Cancer

The Hippo pathway is conserved across species. Key mammalian Hippo pathway kinases, including MST1/2 and LATS1/2, inhibit cellular growth by inactivating the TEAD coactivators, YAP, and TAZ. Extensive research has illuminated the roles of Hippo signaling in cancer, development, and regeneration. Notably, dysregulation of Hippo pathway components not only contributes to tumor growth and metastasis, but also renders tumors resistant to therapies. This review delves into recent research on YAP/TAZ-TEAD-mediated gene regulation and biological processes in cancer. We focus on several key areas: newly identified molecular patterns of YAP/TAZ activation, emerging mechanisms that contribute to metastasis and cancer therapy resistance, unexpected roles in tumor suppression, and advances in therapeutic strategies targeting this pathway. Moreover, we provide an updated view of YAP/TAZ's biological functions, discuss ongoing controversies, and offer perspectives on specific debated topics in this rapidly evolving field.

Differential chromatin accessibility and transcriptional dynamics define breast cancer subtypes and their lineages

Breast cancer is a heterogeneous disease, and treatment is guided by biomarker profiles representing distinct molecular subtypes. Breast cancer arises from the breast ductal epithelium, and experimental data suggests breast cancer subtypes have different cells of origin within that lineage. The precise cells of origin for each subtype and the transcriptional networks that characterize these tumor-normal lineages are not established. In this work, we applied bulk, single-cell (sc), and single-nucleus (sn) multi-omic techniques as well as spatial transcriptomics and multiplex imaging on 61 samples from 37 breast cancer patients to show characteristic links in gene expression and chromatin accessibility between breast cancer subtypes and their putative cells of origin. We applied the PAM50 subtyping algorithm in tandem with bulk RNA-seq and snRNA-seq to reliably subtype even low-purity tumor samples and confirm promoter accessibility using snATAC. Trajectory analysis of chromatin accessibility and differentially accessible motifs clearly connected progenitor populations with breast cancer subtypes supporting the cell of origin for basal-like and luminal A and B tumors. Regulatory network analysis of transcription factors underscored the importance of BHLHE40 in luminal breast cancer and luminal mature cells, and KLF5 in basal-like tumors and luminal progenitor cells. Furthermore, we identify key genes defining the basal-like ( PRKCA , SOX6 , RGS6 , KCNQ3 ) and luminal A/B ( FAM155A , LRP1B ) lineages, with expression in both precursor and cancer cells and further upregulation in tumors. Exhausted CTLA4-expressing CD8+ T cells were enriched in basal-like breast cancer, suggesting altered means of immune dysfunction among breast cancer subtypes. We used spatial transcriptomics and multiplex imaging to provide spatial detail for key markers of benign and malignant cell types and immune cell colocation. These findings demonstrate analysis of paired transcription and chromatin accessibility at the single cell level is a powerful tool for investigating breast cancer lineage development and highlight transcriptional networks that define basal and luminal breast cancer lineages.

A dysfunctional miR-1-TRPS1-MYOG axis drives ERMS by suppressing terminal myogenic differentiation

Rhabdomyosarcoma is the most common pediatric soft tissue tumor, comprising two major subtypes: the PAX3/7-FOXO1 fusion-negative embryonal and the PAX3/7-FOXO1 fusion-positive alveolar subtype. Here, we demonstrate that the expression levels of the transcriptional repressor TRPS1 are specifically enhanced in the embryonal subtype, resulting in impaired terminal myogenic differentiation and tumor growth. During normal myogenesis, expression levels of TRPS1 have to decrease to allow myogenic progression, as demonstrated by overexpression of TRPS1 in myoblasts impairing myotube formation. Consequentially, myogenic differentiation in embryonal rhabdomyosarcoma in vitro as well as in vivo can be achieved by reducing TRPS1 levels. Furthermore, we show that TRPS1 levels in RD cells, the bona fide model cell line for embryonal rhabdomyosarcoma, are regulated by miR-1 and that TRPS1 and MYOD1 share common genomic binding sites. The myogenin (MYOG) promoter is one of the critical targets of TRPS1 and MYOD1; we demonstrate that TRPS1 restricts MYOG expression and thereby inhibits terminal myogenic differentiation. Therefore, reduction of TRPS1 levels in embryonal rhabdomyosarcoma might be a therapeutic approach to drive embryonal rhabdomyosarcoma cells into myogenic differentiation, thereby generating postmitotic myotubes.

TRPS1 modulates chromatin accessibility to regulate estrogen receptor (ER) binding and ER target gene expression in luminal breast cancer cells

Breast cancer is the most frequently diagnosed cancer in women. The most common subtype is luminal breast cancer, which is typically driven by the estrogen receptor α (ER), a transcription factor (TF) that activates many genes required for proliferation. Multiple effective therapies target this pathway, but individuals often develop resistance. Thus, there is a need to identify additional targets that regulate ER activity and contribute to breast tumor progression. TRPS1 is a repressive GATA-family TF that is overexpressed in breast tumors. Common genetic variants in the TRPS1 locus are associated with breast cancer risk, and luminal breast cancer cell lines are particularly sensitive to TRPS1 knockout. However, we do not know how TRPS1 regulates target genes to mediate these breast cancer patient and cellular outcomes. We introduced an inducible degron tag into the native TRPS1 locus within a luminal breast cancer cell line to identify the direct targets of TRPS1 and determine how TRPS1 mechanistically regulates gene expression. We acutely deplete over eighty percent of TRPS1 from chromatin within 30 minutes of inducing degradation. We find that TRPS1 regulates transcription of hundreds of genes, including those related to estrogen signaling. TRPS1 directly regulates chromatin structure, which causes ER to redistribute in the genome. ER redistribution leads to both repression and activation of dozens of ER target genes. Downstream from these primary effects, TRPS1 depletion represses cell cycle-related gene sets and reduces cell doubling rate. Finally, we show that high TRPS1 activity, calculated using a gene expression signature defined by primary TRPS1-regulated genes, is associated with worse breast cancer patient prognosis. Taken together, these data suggest a model in which TRPS1 modulates the activity of other TFs, both activating and repressing transcription of genes related to cancer cell fitness.

MicroRNA PC-3p-2869 Regulates Antler Growth and Inhibits Proliferation and Migration of Human Osteosarcoma and Chondrosarcoma Cells by Targeting CDK8, EEF1A1, and NTN1

MicroRNAs (miRNAs) play a crucial role in maintaining the balance between the rapid growth and suppression of tumorigenesis during antler regeneration. This study investigated the role of a novel miRNA, PC-3p-2869 (miR-PC-2869), in antler growth and its therapeutic potential in human osteosarcoma and chondrosarcoma. Stem-loop RT-qPCR showed that miR-PC-2869 was expressed extensively in diverse layers of antler tissues. Overexpression of miR-PC-2869 suppressed the proliferation and migration of antler cartilage cells. Similarly, heterologous expression of miR-PC-2869 reduced the proliferation, colony formation, and migration of osteosarcoma cell line MG63 and U2OS and chondrosarcoma cell line SW1353. Moreover, 18 functional target genes of miR-PC-2869 in humans were identified based on the screening of the reporter library. Among them, 15 target genes, including CDK8, EEF1A1, and NTN1, possess conserved miR-PC-2869-binding sites between humans and red deer (Cervus elaphus). In line with this, miR-PC-2869 overexpression decreased the expression levels of CDK8, EEF1A1, and NTN1 in MG63, SW1353, and antler cartilage cells. As expected, the knockdown of CDK8, EEF1A1, or NTN1 inhibited the proliferation and migration of MG63, SW1353, and antler cartilage cells, demonstrating similar suppressive effects as miR-PC-2869 overexpression. Furthermore, we observed that CDK8, EEF1A1, and NTN1 mediated the regulation of c-myc and cyclin D1 by miR-PC-2869 in MG63, SW1353, and antler cartilage cells. Overall, our work uncovered the cellular functions and underlying molecular mechanism of antler-derived miR-PC-2869, highlighting its potential as a therapeutic candidate for bone cancer.

TRPS1 regulates the opposite effect of progesterone via RANKL in endometrial carcinoma and breast carcinoma

Medroxyprogesterone (MPA) has therapeutic effect on endometrial carcinoma (EC), while it could promote the carcinogenesis of breast cancer (BC) by activating receptor activator of NF-kB ligand (RANKL). However, the selective mechanism of MPA in endometrium and breast tissue remains obscure. Multiomics analysis of chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) were performed in cell lines derived from endometrial cancer and mammary tumor to screen the differential co-regulatory factors of progesterone receptor (PR). Dual-luciferase assays and ChIP-PCR assays were used to validate the transcriptional regulation. Co-immunoprecipitation (Co-IP) and immunofluorescence assays were carried out to explore molecular interactions between PR, the cofactor transcriptional repressor GATA binding 1 (TRPS1), and histone deacetylase 2 (HDAC2). Subsequently, human endometrial cancer/breast cancer xenograft models were established to investigate the regulation effect of cofactor TRPS1 in vivo. In the current study, we found that MPA downregulated RANKL expression in a time- and dose-dependent manner in EC, while had the opposite effect on BC. Then PR could recruit cofactor TRPS1 to the promoter of RANKL, leading to histone deacetylation of RANKL to repress its transcription in EC, whereas MPA disassociated the PR/TRPS1/HDAC2 complex to enhance RANKL histone acetylation in BC. Therefore, TRPS1, the coregulator recruited by PR played a critical role in the selective mechanism of progesterone in EC and BC and could become a potential candidate for targeted therapy to improve the anticancer effect of MPA on EC and avoid its carcinogenic effect on BC.

New insights into the ambivalent role of YAP/TAZ in human cancers

Hippo signaling was first identified in Drosophila as a key controller of organ size by regulating cell proliferation and anti-apoptosis. Subsequent studies have shown that this pathway is highly conserved in mammals, and its dysregulation is implicated in multiple events of cancer development and progression. Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) (hereafter YAP/TAZ) are the downstream effectors of the Hippo pathway. YAP/TAZ overexpression or activation is sufficient to induce tumor initiation and progression, as well as recurrence and therapeutic resistance. However, there is growing evidence that YAP/TAZ also exert a tumor-suppressive function in a context-dependent manner. Therefore, caution should be taken when targeting Hippo signaling in clinical trials in the future. In this review article, we will first give an overview of YAP/TAZ and their oncogenic roles in various cancers and then systematically summarize the tumor-suppressive functions of YAP/TAZ in different contexts. Based on these findings, we will further discuss the clinical implications of YAP/TAZ-based tumor targeted therapy and potential future directions.

LncRNA modulates Hippo-YAP signaling to reprogram iron metabolism

Iron metabolism dysregulation is tightly associated with cancer development. But the underlying mechanisms remain poorly understood. Increasing evidence has shown that long noncoding RNAs (lncRNAs) participate in various metabolic processes via integrating signaling pathway. In this study, we revealed one iron-triggered lncRNA, one target of YAP, LncRIM (LncRNA Related to Iron Metabolism, also named ZBED5-AS1 and Loc729013), which effectively links the Hippo pathway to iron metabolism and is largely independent on IRP2. Mechanically, LncRIM directly binds NF2 to inhibit NF2-LATS1 interaction, which causes YAP activation and increases intracellular iron level via DMT1 and TFR1. Additionally, LncRIM-NF2 axis mediates cellular iron metabolism dependent on the Hippo pathway. Clinically, high expression of LncRIM correlates with poor patient survival, suggesting its potential use as a biomarker and therapeutic target. Taken together, our study demonstrated a novel mechanism in which LncRIM-NF2 axis facilitates iron-mediated feedback loop to hyperactivate YAP and promote breast cancer development.

Taz protects hematopoietic stem cells from an aging-dependent decrease in PU.1 activity

Specific functions of the immune system are essential to protect us from infections caused by pathogens such as viruses and bacteria. However, as we age, the immune system shows a functional decline that can be attributed in large part to age-associated defects in hematopoietic stem cells (HSCs)—the cells at the apex of the immune cell hierarchy. Here, we find that the Hippo pathway coactivator TAZ is potently induced in old HSCs and protects these cells from functional decline. We identify Clca3a1 as a TAZ-induced gene that allows us to trace TAZ activity in vivo. Using CLCA3A1 as a marker, we can isolate “young-like” HSCs from old mice. Mechanistically, Taz acts as coactivator of PU.1 and to some extent counteracts the gradual loss of PU.1 expression during HSC aging. Our work thus uncovers an essential role for Taz in a previously undescribed fail-safe mechanism in aging HSCs.

Immune system function declines with age, a consequence of defects in hematopoietic stem cells (HSCs). Here the authors show that TAZ buffers age-related loss of PU.1 activity to maintain HSC functionality and identify the surface protein Clca3a1 as a marker of “young-like” HSCs, even in old mice.

Functional mechanisms of TRPS1 in disease progression and its potential role in personalized medicine

The gene of transcriptional repressor GATA binding 1 (TRPS1), as an atypical GATA transcription factor, has received considerable attention in a plethora of physiological and pathological processes, and may become a promising biomarker for targeted therapies in diseases and tumors. However, there still lacks a comprehensive exploration of its functions and promising clinical applications. Herein, relevant researches published in English from 2000 to 2022 were retrieved from PubMed, Google Scholar and MEDLINE, concerning the roles of TRPS1 in organ differentiation and tumorigenesis. This systematic review predominantly focused on summarizing the structural characteristics and biological mechanisms of TRPS1, its involvement in tricho-rhino-phalangeal syndrome (TRPS), its participation in the development of multiple tissues, the recent advances of its vital features in metabolic disorders as well as malignant tumors, in order to prospect its potential applications in disease detection and cancer targeted therapy. From the clinical perspective, the deeply and thoroughly understanding of the complicated context-dependent and cell-lineage-specific mechanisms of TRPS1 would not only gain novel insights into the complex etiology of diseases, but also provide the fundamental basis for the development of therapeutic drugs targeting both TRPS1 and its critical cofactors, which would facilitate individualized treatment.

Loss of PRMT7 reprograms glycine metabolism to selectively eradicate leukemia stem cells in CML

Our group has reported previously on the role of various members of the protein arginine methyltransferase (PRMT) family, which are involved in epigenetic regulation, in the progression of leukemia. Here, we explored the role of PRMT7, given its unique function within the PRMT family, in the maintenance of leukemia stem cells (LSCs) in chronic myeloid leukemia (CML). Genetic loss of Prmt7, and the development and testing of a small-molecule specific inhibitor of PRMT7, showed that targeting PRMT7 delayed leukemia development and impaired self-renewal of LSCs in a CML mouse model and in primary CML CD34⁺ cells from humans without affecting normal hematopoiesis. Mechanistically, loss of PRMT7 resulted in reduced expressions of glycine decarboxylase, leading to the reprograming of glycine metabolism to generate methylglyoxal, which is detrimental to LSCs. These findings link histone arginine methylation with glycine metabolism, while suggesting PRMT7 as a potential therapeutic target for the eradication of LSCs in CML.

YAP inhibits ERα and ER+ breast cancer growth by disrupting a TEAD-ERα signaling axis

Hippo signaling restricts tissue growth by inhibiting the transcriptional effector YAP. Here we uncover a role of Hippo signaling and a tumor suppressor function of YAP in estrogen receptor positive (ER⁺) breast cancer. We find that inhibition of Hippo/MST1/2 or activation of YAP blocks the ERα transcriptional program and ER⁺ breast cancer growth. Mechanistically, the Hippo pathway transcription factor TEAD physically interacts with ERα to increase its promoter/enhancer occupancy whereas YAP inhibits ERα/TEAD interaction, decreases ERα occupancy on its target promoters/enhancers, and promotes ERα degradation by the proteasome. Furthermore, YAP inhibits hormone-independent transcription of ERα gene (ESR1). Consistently, high levels of YAP correlate with good prognosis of ER⁺ breast cancer patients. Finally, we find that pharmacological inhibition of Hippo/MST1/2 impeded tumor growth driven by hormone therapy resistant ERα mutants, suggesting that targeting the Hippo-YAP-TEAD signaling axis could be a potential therapeutical strategy to overcome endocrine therapy resistance conferred by ERα mutants.

The biology of YAP in programmed cell death

In the last few decades, YAP has been shown to be critical in regulating tumor progression. YAP activity can be regulated by many kinase cascade pathways and proteins through phosphorylation and promotion of cytoplasmic localization. Other factors can also affect YAP activity by modulating its binding to different transcription factors (TFs). Programmed cell death (PCD) is a genetically controlled suicide process present with the scope of eliminating cells unnecessary or detrimental for the proper development of the organism. In some specific states, PCD is activated and facilitates the selective elimination of certain types of tumor cells. As a candidate oncogene correlates with many regulatory factors, YAP can inhibit or induce different forms of PCD, including apoptosis, autophagy, ferroptosis and pyroptosis. Furthermore, YAP may act as a bridge between different forms of PCD, eventually leading to different outcomes regarding tumor development. Researches on YAP and PCD may benefit the future development of novel treatment strategies for some diseases. Therefore, in this review, we provide a general overview of the cellular functions of YAP and the relationship between YAP and PCD.

A high level of the long non-coding RNA MCF2L-AS1 is associated with poor prognosis in breast cancer and MCF2L-AS1 activates YAP transcriptional activity to enhance breast cancer proliferation and metastasis

Breast cancer (BC) is one of the most prevalent gynecologic malignant tumors with a poor prognosis and the second leading cause of cancer-related deaths in women worldwide. In recent years, it has been shown that long non-coding RNA (lncRNA) plays an important role in the development of breast cancer (BC). An antisense lncRNA from the MCF2 cell line (MCF2L-AS1) has been discovered recently and has been shown to function in a variety of malignancies. However, its function as a regulator of BC development has yet to be determined. Herein, the bioinformatics study analysis showed that MCF2L-AS1 was frequently highly expressed in BC tumors, and this overexpression was associated with worse patient outcomes. BC cells' proliferation, migration, and invasion are inhibited when MCF2L-AS1 is silenced, whereas the inverse is evident when MCF2L-AS1 is overexpressed. It was also observed that MCF2L-AS1 knockdown decreased carcinogenesis in xenograft tumor models. Furthermore, we discovered that MCF2L-AS1 could bind to and improve the transcription activity of the yes-associated protein (YAP). However, following YAP knockdown, this lncRNA's ability to drive BC malignancy was considerably reduced. In conclusion, MCF2L-AS1 may represent a potential predictive biomarker in BC patients, as well as a key regulator of BC cell proliferation. It works through positive feedback processes involving direct YAP binding and subsequent modulation of intracellular gene expression. Our findings add to our understanding of MCF2L-AS1 regulation and its potential as a therapeutic target in patients with this fatal cancer type.

Paclitaxel Resistance Modulated by the Interaction between TRPS1 and AF178030.2 in Triple-Negative Breast Cancer

Paclitaxel is a chemotherapeutic agent that acts as an inhibitor of cellular mitosis and has been widely used in the treatment of triple-negative breast cancer (TNBC). However, paclitaxel resistance is one of the major reasons that contribute to the high failure rates of chemotherapy and the relapse of TNBC. Accumulating studies have demonstrated that long noncoding RNA (lncRNA) plays a role in the paclitaxel resistance and positively correlated with progression and metastasis of breast cancers. In the present study, microarray expression profile analysis of lncRNA was performed between paclitaxel-resistant TNBC cell line MDA-MB-231 and their parental cells. After verification with quantitative PCR, we identified that AF178030.2, an orphan lncRNA, was significantly upregulated in paclitaxel-resistant TNBC cells. Overexpression of AF178030.2 greatly attenuated the sensitivity of TNBC to paclitaxel, whereas knockdown of AF178030.2 enhanced the sensitivity of TNBC cells to paclitaxel. Furthermore, bioinformatic analysis and RNA binding protein immunoprecipitation assay reveal that AF178030.2 can directly bind with trichorhinophalangeal syndrome-1 (TRPS1), an oncogene in breast cancer, and downregulate its expression in paclitaxel-resistant TNBC cells. TRPS1 overexpression effectively increased the sensitivity of paclitaxel-resistant TNBC cells to paclitaxel. Taking together, high AF178030.2 expression contributed to paclitaxel resistance in TNBC through TRPS1 and poor clinical outcomes, which may provide a new treatment strategy for paclitaxel-resistant TNBC patients.

Tumor immunology CRISPR screening: present, past, and future

Recent advances in immunotherapy have fundamentally changed the landscape of cancer treatment by leveraging the specificity and selectivity of the adaptive immune system to kill cancer cells. These successes have ushered in a new wave of research aimed at understanding immune recognition with the hope of developing newer immunotherapies. The advent of clustered regularly interspaced short palindromic repeats (CRISPR) technologies and advancement of multiomics modalities have greatly accelerated the discovery process. Here, we review the current literature surrounding CRISPR screens within the context of tumor immunology, provide essential components needed to conduct immune-specific CRISPR screens, and present avenues for future research.

Context-dependent transcriptional regulations of YAP/TAZ in cancer

As the downstream effectors of Hippo pathway, YAP/TAZ are identified to participate in organ growth, regeneration and tumorigenesis. However, owing to lack of a DNA-binding domain, YAP/TAZ usually act as coactivators and cooperate with other transcription factors or partners to mediate their transcriptional outputs. In this article, we first present an overview of the core components and the upstream regulators of Hippo-YAP/TAZ signaling in mammals, and then systematically summarize the identified transcription factors or partners that are responsible for the downstream transcriptional output of YAP/TAZ in various cancers.

Emerging Principles in the Transcriptional Control by YAP and TAZ

Simple Summary

YAP and TAZ are transcriptional cofactors that integrate several upstream signals to generate context-dependent transcriptional responses. This requires extensive integration with epigenetic regulators and other transcription factors. The molecular and genomic characterization of YAP and TAZ nuclear function has broad implications both in physiological and pathological settings.

Abstract

Yes-associated protein (YAP) and TAZ are transcriptional cofactors that sit at the crossroad of several signaling pathways involved in cell growth and differentiation. As such, they play essential functions during embryonic development, regeneration, and, once deregulated, in cancer progression. In this review, we will revise the current literature and provide an overview of how YAP/TAZ control transcription. We will focus on data concerning the modulation of the basal transcriptional machinery, their ability to epigenetically remodel the enhancer–promoter landscape, and the mechanisms used to integrate transcriptional cues from multiple pathways. This reveals how YAP/TAZ activation in cancer cells leads to extensive transcriptional control that spans several hallmarks of cancer. The definition of the molecular mechanism of transcriptional control and the identification of the pathways regulated by YAP/TAZ may provide therapeutic opportunities for the effective treatment of YAP/TAZ-driven tumors.

Trps1 targets Ccnd1 to regulate mouse Leydig cell proliferation

BACKGROUND

The tricho-rhino-phalangeal syndrome-1 gene (Trps1) is an atypical GATA family member. Although current studies of Trps1 mainly focus on tumors, whether Trps1 plays a role in the male reproductive system remains unknown.

OBJECTIVES

The purpose of this study was to elucidate the function of Trps1 in Leydig cells, indicating its regulatory mechanism on the cell cycle.

METHODS

Gene-silencing technology, RNA-seq, RT-qPCR, and western blotting were used to evaluate the function of Trps1 in mouse primary Leydig cells and MLTC-1 cells. In addition, ChIP-base sets and ChIP-qPCR were employed to further assess the regulatory mechanism of Trps1 in MLTC-1 cells.

RESULTS

Knockdown of Trps1 in Leydig cells significantly suppressed phosphorylation of Src and Akt and expression of Ccnd1, which was accompanied by impairment of cell proliferative ability. Trps1 may affect the cell cycle through the Src/Akt/Ccnd1 signaling pathway. In addition, Trps1 may bind to the promoter of Srcin1 to regulate its transcription, thus influencing Src phosphorylation levels and the proliferation of Leydig cells.

DISCUSSION AND CONCLUSION

Src increases in Leydig cells during pubertal development, suggesting its functional involvement in differentiated adult Leydig cells. Inhibition of the Src/Akt pathway would reduce Ccnd1 expression. In the present study, we found that Trps1 may regulate the phosphorylation level of Src and Akt through Srcin1, targeting Ccnd1 to influence mouse Leydig cell proliferation. These findings shed light on the regulation of Trps1 on cell proliferation and differentiation of mouse Leydig cells.

YAP1 is a Prognostic Biomarker and Correlated with Immune Cell Infiltration in Pancreatic Cancer

Yes-associated protein-1 (YAP1) is an important effector of the Hippo pathway and has crosstalk with other cancer signaling pathways. It induces an immunosuppressive tumor microenvironment by activating pathways in several cellular components. However, the mechanisms by which it drives immune infiltration in pancreatic cancer remain poorly understood. We analyzed the expression of YAP1 as well as its prognostic value and correlations with immune infiltrates in various cancers, with a focus on pancreatic cancer. In particular, using the Oncomine database and Gene Expression Profiling Interactive Analysis (GEPIA) database, we found that YAP1 is differentially expressed between tumor tissues and control tissues in a number of cancers and in particular, is elevated in pancreatic cancer. Using the Kaplan–Meier plotter, GEPIA, and Long-term Outcome and Gene Expression Profiling database of pan-cancers (LOGpc), we further established the prognostic value of YAP1. We found that YAP1 expression was significantly related to outcomes in multiple types of cancer based on data from The Cancer Genome Atlas, particularly in pancreatic cancer. Correlations between YAP1 and immune cell infiltration and immune cell marker expression were examined using Tumor Immune Estimation Resource and GEPIA. High expression levels of YAP1 were significantly associated with a variety of immune markers and immune cell subsets in pancreatic cancer. These results suggest that YAP1 is correlated with patient outcomes and tumor immune cell infiltration in multiple cancer types and is a valuable prognostic biomarker in pancreatic cancer.

Hippo pathway: Regulation, deregulation and potential therapeutic targets in cancer

Hippo pathway is a master regulator of development, cell proliferation, stem cell function, tissue regeneration, homeostasis, and organ size control. Hippo pathway relays signals from different extracellular and intracellular events to regulate cell behavior and functions. Hippo pathway is conserved from Protista to eukaryotes. Deregulation of the Hippo pathway is associated with numerous cancers. Alteration of the Hippo pathway results in cell invasion, migration, disease progression, and therapy resistance in cancers. However, the function of the various components of the mammalian Hippo pathway is yet to be elucidated in detail especially concerning tumor biology. In the present review, we focused on the Hippo pathway in different model organisms, its regulation and deregulation, and possible therapeutic targets for cancer treatment.

CRISPR screen in cancer: status quo and future perspectives

Clustered regularly interspaced short palindromic repeats (CRISPR) system offers a powerful platform for genome manipulation, including protein-coding genes, noncoding RNAs and regulatory elements. The development of CRISPR screen enables high-throughput interrogation of gene functions in diverse tumor biologies, such as tumor growth, metastasis, synthetic lethal interactions, therapeutic resistance and immunotherapy response, which are mostly performed in vitro or in transplant models. Recently, direct in vivo CRISPR screens have been developed to identify drivers of tumorigenesis in native microenvironment. Key parameters of CRISPR screen are constantly being optimized to achieve higher targeting efficiency and lower off-target effect. Here, we review the recent advances of CRISPR screen in cancer studies both in vitro and in vivo, with a particular focus on identifying cancer immunotherapy targets, and propose optimizing strategies and future perspectives for CRISPR screen.

YAP and β-Catenin Cooperate to Drive Oncogenesis in Basal Breast Cancer

Targeting cancer stem cells (CSC) can serve as an effective approach toward limiting resistance to therapies. While basal-like (triple-negative) breast cancers encompass cells with CSC features, rational therapies remain poorly established. We show here that the receptor tyrosine kinase Met promotes YAP activity in basal-like breast cancer and find enhanced YAP activity within the CSC population. Interfering with YAP activity delayed basal-like cancer formation, prevented luminal to basal transdifferentiation, and reduced CSC. YAP knockout mammary glands revealed a decrease in β-catenin target genes, suggesting that YAP is required for nuclear β-catenin activity. Mechanistically, nuclear YAP interacted with β-catenin and TEAD4 at gene regulatory elements. Proteomic patient data revealed an upregulation of the YAP signature in basal-like breast cancers. Our findings demonstrate that in basal-like breast cancers, β-catenin activity is dependent on YAP signaling and controls the CSC program. These findings suggest that targeting the YAP/TEAD4/β-catenin complex offers a potential therapeutic strategy for eradicating CSCs in basal-like breast cancers. SIGNIFICANCE: These findings show that YAP cooperates with β-catenin in basal-like breast cancer to regulate CSCs and that targeting this interaction may be a novel CSC therapy for patients with basal-like breast cancer. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/8/2116/F1.large.jpg.

YAP-TEAD up-regulates IRS2 expression to induce and deteriorate oesophageal cancer

Oesophageal cancer (EC) represents a significant cause of cancer worldwide. Yes‐associated protein (YAP) is reported to correlate with the initiation of multiple cancers including EC, but the underlying mechanism remains elusive. The current study aimed to investigate the molecular mechanism of YAP‐TEAD in the occurrence and progression of EC. EC tissues and cells were obtained, followed by determination of the expression of YAP, c‐Jun, pc‐Jun and IRS2. The effect of YAP‐TEAD on the biological EC cell processes was explored through gain‐ and loss‐of‐function approaches. The interaction between YAP and TEAD was detected by co‐immunoprecipitation. The binding of TEAD to the c‐Jun promoter was determined using chromatin immunoprecipitation. Tumour formation in the nude mice was detected in order to ascertain the effect of YAP and IRS2 in vivo. We found elevated YAP in the EC tissues and cells. YAP silencing led to a decrease in EC cell proliferation, invasion and sphere formation. YAP‐TEAD complex bound to the promotor of c‐Jun, and c‐Jun led to an increase in the expression of IRS2 through the JNK/c‐Jun pathway. Additionally, pc‐Jun and phosphorylated JNK were localized in the nuclear in addition to displaying enhanced expression in the EC tissues. IRS2 overexpression negated the inhibition of cell proliferation, invasion and sphere formation triggering YAP silencing. YAP up‐regulated IRS2 and aggravated EC in vivo. Taken together, YAP‐TEAD activates the JNK/c‐Jun pathway to up‐regulate IRS2, ultimately promoting EC progression. Therefore, YAP‐TEAD inhibition could be a promising therapeutic approach for EC treatment.

Endothelial YAP/TAZ Signaling in Angiogenesis and Tumor Vasculature

Solid tumors are dependent on vascularization for their growth. The hypoxic, stiff, and pro-angiogenic tumor microenvironment induces angiogenesis, giving rise to an immature, proliferative, and permeable vasculature. The tumor vessels promote tumor metastasis and complicate delivery of anti-cancer therapies. In many types of tumors, YAP/TAZ activation is correlated with increased levels of angiogenesis. In addition, endothelial YAP/TAZ activation is important for the formation of new blood and lymphatic vessels during development. Oncogenic activation of YAP/TAZ in tumor cell growth and invasion has been studied in great detail, however the role of YAP/TAZ within the tumor endothelium remains insufficiently understood, which complicates therapeutic strategies aimed at targeting YAP/TAZ in cancer. Here, we overview the upstream signals from the tumor microenvironment that control endothelial YAP/TAZ activation and explore the role of their downstream targets in driving tumor angiogenesis. We further discuss the potential for anti-cancer treatments and vascular normalization strategies to improve tumor therapies.

Genome-Wide Estrogen Receptor Activity in Breast Cancer

The largest subtype of breast cancer is characterized by the expression and activity of the estrogen receptor alpha (ERalpha/ER). Although several effective therapies have significantly improved survival, the adaptability of cancer cells means that patients frequently stop responding or develop resistance to endocrine treatment. ER does not function in isolation and multiple associating factors have been reported to play a role in regulating the estrogen-driven transcriptional program. This review focuses on the dynamic interplay between some of these factors which co-occupy ER-bound regulatory elements, their contribution to estrogen signaling, and their possible therapeutic applications. Furthermore, the review illustrates how some ER association partners can influence and reprogram the genomic distribution of the estrogen receptor. As this dynamic ER activity enables cancer cell adaptability and impacts the clinical outcome, defining how this plasticity is determined is fundamental to our understanding of the mechanisms of disease progression.

TRPS1 and YAP1 Regulate Cell Proliferation and Drug Resistance of Osteosarcoma via Competitively Binding to the Target of circTADA2A - miR-129-5p

Introduction

The yes-associated protein (YAP) and trichorhinophalangeal syndrome 1 (TRPS1) have been reported to account for the pathogenesis of cancers and may play an important role in osteosarcoma (OS). This study intended to investigate the modulatory effect and relationship of TRPS1 and YAP1 in OS cells.

Methods

The expression difference of YAP1 and TRPS1 in OS cells was measured. Then, the effect of circTADA2A silence on YAP1 and TRPS1 expression as well as OS proliferation and drug resistance was estimated.

Results

TRPS1 and YAP1 were upregulated in OS cell lines, and TRPS1 and YAP1 were highly expressed in MG63 and U2OS cells, respectively. The cell proliferation of MG63 was lower than that of U2OS, but the opposite result was observed in the presence of cisplatin (DDP). CircTADA2A was upregulated while miR-129-5p was downregulated in MG63 and U2OS cells compared. Besides, circTADA2A knockdown inhibited cell proliferation and reduced DDP resistance in both MG63 and U2OS. MiR-129-5p was increased but TRPS1 and YAP1 were decreased by circTADA2A knockdown. Meanwhile, circTADA2A knockdown reduced TRPS1 protein expression but enhanced phosphorylated (p)-YAP1. In xenograft OS tumor mice, circTADA2A knockdown inhibited tumor growth in the absence or presence of DDP. Finally, miR-129-5p could bind to circTADA2A, TRPS1 and YAPS.

Discussion

CircRNA TADA2A could target miR-129-5p, which was competitively bound by TRPS1 and YAP1, thereby regulating OS cell proliferation and drug resistance.

YAP Triggers Bladder Cancer Proliferation by Affecting the MAPK Pathway

Background

The transcriptional regulator YAP is frequently overexpressed in human cancers, such as breast and pancreatic cancers, plays an important role in tumorigenesis and can regulate many factors affecting cancer progression. These observations encouraged us to investigate the effect of YAP expression on bladder cancer.

Methods

The changes in multiple cellular functions associated with tumor progression including cell proliferation, cell migration, cell cycle, and cell apoptosis were assessed after YAP knockdown/overexpression in bladder cancer cell lines. Additionally, Western blot was developed to verify the change of proteins caused by YAP knockdown/overexpression.

Results

YAP had relatively higher expression in bladder cancer tissues than in normal tissues. The proliferation and migration of bladder cancer cells were inhibited by YAP knockdown but were promoted by its overexpression. This promoting effect was accompanied by the increased activity of MAPK/ERK pathway.

Conclusion

Our data established that YAP is an oncogene involved in bladder cancer and thus can be a potential target for treatment.

TRPS1 Confers Multidrug Resistance of Breast Cancer Cells by Regulating BCRP Expression

Multidrug resistance (MDR) is the major obstruction in the successful treatment of breast cancer (BCa). The elucidation of molecular events that confer chemoresistance of BCa is of major therapeutic importance. Several studies have elucidated the correlation of TRPS1 and BCa. Here we focused on the role of TRPS1 in acquisition of chemoresistance, and reported a unique role of TRPS1 renders BCa cells resistant to chemotherapeutic drugs via the regulation of BCRP expression. Bioinformation analysis based on publicly available BCa data suggested that TRPS1 overexpression linked to chemoresistance. Mechanistically, TRPS1 regulated BCRP expression and efflux transportation. Overexpression of TRPS1 led to upregulation of BCRP while its inhibition resulted in repression of BCRP. The correlation of TRPS1 and BCRP was further confirmed by immunohistochemistry in 180 BCa samples. MTT assay demonstrated that manipulation of TRPS1 expression affects the chemosensitivity of BCa cells. In total, high expression of TRPS1 confers MDR of BCa which is mediated by BCRP. Our data demonstrated a new insight into mechanisms and strategies to overcome chemoresistance in BCa.

YAP/TAZ functions and their regulation at a glance

YAP and TAZ proteins are transcriptional coactivators encoded by paralogous genes, which shuttle between the cytoplasm and the nucleus in response to multiple inputs, including the Hippo pathway. In the nucleus, they pair with DNA-binding factors of the TEAD family to regulate gene expression. Nuclear YAP/TAZ promote cell proliferation, organ overgrowth, survival to stress and dedifferentiation of post-mitotic cells into their respective tissue progenitors. YAP/TAZ are required for growth of embryonic tissues, wound healing and organ regeneration, where they are activated by cell-intrinsic and extrinsic cues. Surprisingly, this activity is dispensable in many adult self-renewing tissues, where YAP/TAZ are constantly kept in check. YAP/TAZ lay at the center of a complex regulatory network including cell-autonomous factors but also cell- and tissue-level structural features such as the mechanical properties of the cell microenvironment, the establishment of cell-cell junctions and of basolateral tissue polarity. Enhanced levels and activity of YAP/TAZ are observed in many cancers, where they sustain tumor growth, drug resistance and malignancy. In this Cell Science at a Glance article and the accompanying poster, we review the biological functions of YAP/TAZ and their regulatory mechanisms, and highlight their position at the center of a complex signaling network.

TRPS1 acts as a context-dependent regulator of mammary epithelial cell growth/differentiation and breast cancer development

In this study, Cornelissen et al. set out to elucidate the role of the GATA-type zinc finger transcription factor TRPS1 in breast cancer. Using in vitro and in vivo loss-of-function approaches, the authors demonstrate that TRPS1 can function as a context-dependent tumor suppressor in breast cancer, while being essential for growth and differentiation of normal mammary epithelial cells.

The GATA-type zinc finger transcription factor TRPS1 has been implicated in breast cancer. However, its precise role remains unclear, as both amplifications and inactivating mutations in TRPS1 have been reported. Here, we used in vitro and in vivo loss-of-function approaches to dissect the role of TRPS1 in mammary gland development and invasive lobular breast carcinoma, which is hallmarked by functional loss of E-cadherin. We show that TRPS1 is essential in mammary epithelial cells, since TRPS1-mediated suppression of interferon signaling promotes in vitro proliferation and lactogenic differentiation. Similarly, TRPS1 expression is indispensable for proliferation of mammary organoids and in vivo survival of luminal epithelial cells during mammary gland development. However, the consequences of TRPS1 loss are dependent on E-cadherin status, as combined inactivation of E-cadherin and TRPS1 causes persistent proliferation of mammary organoids and accelerated mammary tumor formation in mice. Together, our results demonstrate that TRPS1 can function as a context-dependent tumor suppressor in breast cancer, while being essential for growth and differentiation of normal mammary epithelial cells.

TRPS1 Is a Lineage-Specific Transcriptional Dependency in Breast Cancer

Perturbed epigenomic programs play key roles in tumorigenesis, and chromatin modulators are candidate therapeutic targets in various human cancer types. To define singular and shared dependencies on DNA and histone modifiers and transcription factors in poorly differentiated adult and pediatric cancers, we conducted a targeted shRNA screen across 59 cell lines of 6 cancer types. Here, we describe the TRPS1 transcription factor as a strong breast cancer-specific hit, owing largely to lineage-restricted expression. Knockdown of TRPS1 resulted in perturbed mitosis, apoptosis, and reduced tumor growth. Integrated analysis of TRPS1 transcriptional targets, chromatin binding, and protein interactions revealed that TRPS1 is associated with the NuRD repressor complex. These findings uncover a transcriptional network that is essential for breast cancer cell survival and propagation.

Witwicki et al. use a targeted shRNA screening strategy to identify transcriptional and epigenomic dependencies in poorly differentiated human cancers. TRPS1 is a lineage-specific transcription factor that is required for mitosis in breast cancer cells. TRPS1 is associated with the NuRD complex, and it regulates cell adhesion, cytoskeleton, and G2-M phase-related genes.