Activation Of Hedgehog Signaling Research Articles

Generation of striatal neurons from human induced pluripotent stem cells by controlling extrinsic signals with small molecules

Human induced pluripotent stem cells (hiPSCs) are powerful tools for modeling human brain development and treating neurodegenerative diseases. Here we established a robust protocol with high scalability for generating striatal medium spiny neurons (MSNs) from hiPSCs using small molecules under two- and three-dimensional culture conditions. Using this protocol, GSH2+ lateral ganglionic eminence (LGE) progenitors were generated in two-dimensional culture by Sonic hedgehog signaling activation using purmorphamine, WNT signaling inhibition using XAV939, and dual-SMAD inhibition using LDN193189 and A83-01. Quantitative PCR analysis revealed sequential expression of LGE and striatal genes during differentiation. These LGE progenitors subsequently gave rise to DARPP32+ MSNs exhibiting spontaneous and evoked monophasic spiking activity. Applying this protocol in three-dimensional culture, we generated striatal neurospheres with gene expression profiles and cell layer organization resembling that of the developing striatum, including distinct ventricular and subventricular zones and DARPP32+ neurons at the surface. This protocol provides a useful experimental model for studying striatal development and yields cells potentially applicable for regenerative medicine to treat striatum-related disorders such as Huntington’s disease.

Meningitic Escherichia coli \u03b1-hemolysin aggravates blood\u2013brain barrier disruption via targeting TGF\u03b21-triggered hedgehog signaling

Bacterial meningitis is a life-threatening infectious disease with severe neurological sequelae and a high mortality rate, in which Escherichia coli is one of the primary Gram-negative etiological bacteria. Meningitic E. coli infection is often accompanied by an elevated blood–brain barrier (BBB) permeability. BBB is the structural and functional barrier composed of brain microvascular endothelial cells (BMECs), astrocytes, and pericytes, and we have previously shown that astrocytes-derived TGFβ1 physiologically maintained the BBB permeability by triggering a non-canonical hedgehog signaling in brain microvascular endothelial cells (BMECs). Here, we subsequently demonstrated that meningitic E. coli infection could subvert this intercellular communication within BBB by attenuating TGFBRII/Gli2-mediated such signaling. By high-throughput screening, we identified E. coli α-hemolysin as the critical determinant responsible for this attenuation through Sp1-dependent TGFBRII reduction and triggering Ca2+ influx and protein kinase A activation, thus leading to Gli2 suppression. Additionally, the exogenous hedgehog agonist SAG exhibited promising protection against the infection-caused BBB dysfunction. Our work revealed a hedgehog-targeted pathogenic mechanism during meningitic E. coli-caused BBB disruption and suggested that activating hedgehog signaling within BBB could be a potential protective strategy for future therapy of bacterial meningitis.

PHF19 activates hedgehog signaling and promotes tumorigenesis in hepatocellular carcinoma

Aberrant activation of Hedgehog-Gli1 signaling and accumulation of Gli1 in hepatocellular carcinoma (HCC) are frequently observed. However, the mechanisms leading to the overactivation of this signaling pathway are not fully understood. In this study, we show that the short isoform of PHD finger protein 19 (PHF19) interacts with β-TrCP, the E3 ligase of Gli1, and that knocking down PHF19 promotes the ubiquitination of Gli1. In a biological function study, PHF19 was found to promote the growth of HCC cells both in liquid culture and in soft agar. Moreover, knocking out PHF19 in a HCC mouse model (MycF/F) using the hydrodynamic method inhibited tumorigenesis and improved survival. Taken together, these results demonstrate that PHF19 promotes the growth of HCC cells by activating the Hedgehog signaling pathway.

PH-Sensitive, Cerebral Vasculature-Targeting Hydroxyethyl Starch Functionalized Nanoparticles for Improved Angiogenesis and Neurological Function Recovery in Ischemic Stroke.

Angiogenesis, an essential restorative process following ischemia, is a promising therapeutic approach to improve neurological deficits. However, overcoming the blood-brain barrier (BBB) and effective drug enrichment are challenges for conventional drug delivery methods, which has limited the development of treatment strategies. Herein, a dual-targeted therapeutic strategy is reported to enable pH-sensitive drug release and allow cerebral ischemia targeting to improve stroke therapeutic efficacy. Targeted delivery is achieved by surface conjugation of Pro-His-Ser-Arg-Asn (PHSRN) peptides, which binds to integrin α5 β1 enriched in the cerebral vasculature of ischemic tissue. Subsequently, smoothened agonist (SAG), an activator of sonic hedgehog (Shh) signaling, is coupled to PHSRN-HES by pH-dependent electrostatic adsorption. SAG@PHSRN-HES nanoparticles can sensitively release more SAG in the acidic environment of ischemic brain tissue. More importantly, SAG@PHSRN-HES exerts the synergistic mechanisms of PHSRN and SAG to promote angiogenesis and BBB integrity, thus improving neuroplasticity and neurological function recovery. This study proposes a new approach to improve the delivery of medications in the ischemic brain. Dual-targeted therapeutic strategies have excellent potential to treat patients suffering from cerebral infarction.

Predictive and prognostic biomarker identification in a large cohort of androgen receptor-positive salivary duct carcinoma patients scheduled for combined androgen blockade.

6071 Background: Patients suffering from recurrent or metastatic (R/M) salivary duct carcinoma (SDC) are often treated with combined androgen blockade (CAB). This treatment however frequently fails (response rates: 18-53%), resulting in a worse prognosis. Therefore, biomarkers that have prognostic value and can predict treatment response are urgently needed. Methods: mRNA from 77 R/M androgen receptor (AR) positive SDC patients treated with leuprorelin acetate combined with bicalutamide was extracted from pre-treatment tumor specimens. AR, Notch, Mitogen-Activated Protein Kinase (MAPK), Transforming Growth Factor beta (TGFβ), Estrogen Receptor (ER), Hedgehog (HH) and the Phosphoinositide 3-Kinase (PI3K) signaling pathway activities were calculated based on expression levels of relevant target genes. Besides this, 5-alpha reductase type 1 ( SRD5A1) expression and Human Epidermal growth factor Receptor 2 (HER2) status were determined. Clinical benefit was defined as complete or partial response or stable disease ≥6 months. Results: Of the 7 signaling pathways, AR pathway activity was the best predictor of clinical benefit (AUC 0.67, 95%-CI 0.54-0.80). At a threshold of 47.8, 21% of the patients tested negative, with a negative predictive value of 93%. SRD5A1 expression outperformed the signaling pathways regarding predictive value (AUC 0.78, 95%-CI 0.67-0.88). Fitting of a multivariable model led to the identification of SRD5A1, Notch and TGFβ as most predictive combination (AUC 0.82, 95%-CI 0.72-0.91). AR, Notch, HH and SRD5A1 were also of prognostic importance regarding progression free survival and SRD5A1 expression levels also for overall survival (median of 175.0 weeks for high versus 96.7 weeks for low expression). Conclusions: Our study revealed predictive and/or prognostic value of AR, HH, Notch and TGFβ signaling activities and SRD5A1 expression in SDC patients treated with CAB. AR pathway activity can be used for identifying non-responders. Further clinical validation is required before implementation of these biomarkers in clinical practice. The observed role of SRD5A1 expression in CAB response forms a rational basis for including SRD5A1-inhibitors in the treatment of SDC patients.[Table: see text]

Expression of Hedgehog signalling molecules inmicrocystic adnexal carcinoma.

Microcystic adnexal carcinoma (MAC) is a rare skin neoplasm that has not been characterized on a molecular basis. To assess expression profiles of Hedgehog (HH) signalling molecules in MAC and control tumours. Immunohistochemistry was performed for Sonic Hedgehog (SHH), Indian Hedgehog (IHH), Patched 1 (PTCH1) and Smoothened (SMO) on patient MAC tissue (n=26) and control tumour tissue, including syringoma (SyG; n=11), trichoepithelioma (TE; n=11) and basal cell carcinoma (BCC; n=12) tissues. Patched 1 and SMO immunoreactivity was significantly higher in BCC than in SyG, TE or MAC (P<0.001 and P<0.03, respectively). The highest IHH expression was observed in BCC and TE compared with SyG and MAC (P<0.04). Notably, the highest SHH protein expression was observed in SyG compared with MAC, TE and even BCC (P<0.001). In patients with MAC, SMO immunoreactivity significantly (r=0.51; P<0.01) correlated with PTCH1 expression. Further correlation studies did not show significant associations between the HH expression markers assessed (P>0.05). Our results indicate that alterations of the HH signalling are unlikely to play a major role in the pathogenesis of MAC, which is in contrast to the morphologically similar BCC and TE. Our observation provides additional information to the limited molecular pathology knowledge on this rare tumour.

Dual activation of Hedgehog and Wnt/β-catenin signaling pathway caused by downregulation of SUFU targeted by miRNA-150 in human gastric cancer.

Mounting evidence has shown that miRNA-150 expression is upregulated in gastric cancer (GC) and is associated with gastric carcinogenesis, but the underlying oncogenic mechanism remains elusive. Here, we discovered that miRNA-150 targets the tumor suppressor SUFU to promote cell proliferation, migration, and the epithelial–mesenchymal transition (EMT) via the dual activation of Hedgehog (Hh) and Wnt signaling. MiRNA-150 was highly expressed in GC tissues and cell lines, and the level of this miRNA was negatively related to that of SUFU. In addition, both the miRNA-150 and SUFU levels were associated with tumor differentiation. Furthermore, miRNA-150 activated GC cell proliferation and migration in vitro. We found that miRNA-150 inhibitors repressed not only Wnt signaling by promoting cytoplasmic β-catenin localization, but also repressed Hh signaling and EMT. MiRNA-150 inhibition also resulted in significant tumor volume reductions in vivo, suggesting the potential application of miRNA-150 inhibitors in GC therapy. The expression of genes downstream of Hh and Wnt signaling was also reduced in tumors treated with miRNA-150 inhibitors. Notably, anti-SUFU siRNAs rescued the inhibitory effects of miRNA-150 inhibitors on Wnt signaling, Hh activation, EMT, cell proliferation, cell migration, and colony formation. Taken together, these findings indicate that miRNA-150 is oncogenic and promotes GC cell proliferation, migration, and EMT by activating Wnt and Hh signaling via the suppression of SUFU expression.

Ubiquitin-protein ligase Ubr5 cooperates with hedgehog signalling to promote skeletal tissue homeostasis.

Mammalian Hedgehog (HH) signalling pathway plays an essential role in tissue homeostasis and its deregulation is linked to rheumatological disorders. UBR5 is the mammalian homologue of the E3 ubiquitin-protein ligase Hyd, a negative regulator of the Hh-pathway in Drosophila. To investigate a possible role of UBR5 in regulation of the musculoskeletal system through modulation of mammalian HH signaling, we created a mouse model for specific loss of Ubr5 function in limb bud mesenchyme. Our findings revealed a role for UBR5 in maintaining cartilage homeostasis and suppressing metaplasia. Ubr5 loss of function resulted in progressive and dramatic articular cartilage degradation, enlarged, abnormally shaped sesamoid bones and extensive heterotopic tissue metaplasia linked to calcification of tendons and ossification of synovium. Genetic suppression of smoothened (Smo), a key mediator of HH signalling, dramatically enhanced the Ubr5 mutant phenotype. Analysis of HH signalling in both mouse and cell model systems revealed that loss of Ubr5 stimulated canonical HH-signalling while also increasing PKA activity. In addition, human osteoarthritic samples revealed similar correlations between UBR5 expression, canonical HH signalling and PKA activity markers. Our studies identified a crucial function for the Ubr5 gene in the maintenance of skeletal tissue homeostasis and an unexpected mode of regulation of the HH signalling pathway.

Cholesterol Contributes to Male Sex Differentiation Through Its Developmental Role in Androgen Synthesis and Hedgehog Signaling.

Two specialized functions of cholesterol during fetal development include serving as a precursor to androgen synthesis and supporting hedgehog (HH) signaling activity. Androgens are produced by the testes to facilitate masculinization of the fetus. Recent evidence shows that intricate interactions between the HH and androgen signaling pathways are required for optimal male sex differentiation and defects of either can cause birth anomalies indicative of 46,XY male variations of sex development (VSD). Further, perturbations in cholesterol synthesis can cause developmental defects, including VSD, that phenocopy those caused by disrupted androgen or HH signaling, highlighting the functional role of cholesterol in promoting male sex differentiation. In this review, we focus on the role of cholesterol in systemic androgen and local HH signaling events during fetal masculinization and their collective contributions to pediatric VSD.

Adipocyte Fatty Acid Binding Protein Promotes the Onset and Progression of Liver Fibrosis via Mediating the Crosstalk between Liver Sinusoidal Endothelial Cells and Hepatic Stellate Cells.

Development of liver fibrosis results in drastic changes in the liver microenvironment, which in turn accelerates disease progression. Although the pathological function of various hepatic cells in fibrogenesis is identified, the crosstalk between them remains obscure. The present study demonstrates that hepatic expression of adipocyte fatty acid binding protein (A‐FABP) is induced especially in the liver sinusoidal endothelial cells (LSECs) in mice after bile duct ligation (BDL). Genetic ablation and pharmacological inhibition of A‐FABP attenuate BDL‐ or carbon tetrachloride‐induced liver fibrosis in mice associating with reduced collagen accumulation, LSEC capillarization, and hepatic stellate cell (HSC) activation. Mechanistically, elevated A‐FABP promotes LSEC capillarization by activating Hedgehog signaling, thus impairs the gatekeeper function of LSEC on HSC activation. LSEC‐derived A‐FABP also acts on HSCs in paracrine manner to potentiate the transactivation of transforming growth factor β1 (TGFβ1) by activating c‐Jun N‐terminal kinase (JNK)/c‐Jun signaling. Elevated TGFβ1 subsequently exaggerates liver fibrosis. These findings uncover a novel pathological mechanism of liver fibrosis in which LSEC‐derived A‐FABP is a key regulator modulating the onset and progression of the disease. Targeting A‐FABP may represent a potential approach against liver fibrosis.

Heterozygous truncating variants in SUFU cause congenital ocular motor apraxia

PurposeThis study aimed to delineate the genetic basis of congenital ocular motor apraxia (COMA) in patients not otherwise classifiable. MethodsWe compiled clinical and neuroimaging data of individuals from six unrelated families with distinct clinical features of COMA who do not share common diagnostic characteristics of Joubert syndrome or other known genetic conditions associated with COMA. We used exome sequencing to identify pathogenic variants and functional studies in patient-derived fibroblasts. ResultsIn 15 individuals, we detected familial as well as de novo heterozygous truncating causative variants in the Suppressor of Fused (SUFU) gene, a negative regulator of the Hedgehog (HH) signaling pathway. Functional studies showed no differences in cilia occurrence, morphology, or localization of ciliary proteins, such as smoothened. However, analysis of expression of HH signaling target genes detected a significant increase in the general signaling activity in COMA patient–derived fibroblasts compared with control cells. We observed higher basal HH signaling activity resulting in increased basal expression levels of GLI1, GLI2, GLI3, and Patched1. Neuroimaging revealed subtle cerebellar changes, but no full-blown molar tooth sign. ConclusionTaken together, our data imply that the clinical phenotype associated with heterozygous truncating germline variants in SUFU is a forme fruste of Joubert syndrome.

Functional cooperation of the hedgehog and androgen signaling pathways during developmental and repairing myelination.

Hedgehog morphogens control fundamental cellular processes during tissue development and regeneration. In the central nervous system (CNS), Hedgehog signaling has been implicated in oligodendrocyte and myelin production, where it functions in a concerted manner with other pathways. Since androgen receptor (AR) plays a key role in establishing the sexual phenotype of myelin during development and is required for spontaneous myelin regeneration in the adult CNS, we hypothesized the existence of a possible coordination between Hedgehog and androgen signals in oligodendrocyte and myelin production. Here, we report complementary activities of both pathways during early postnatal oligodendrogenesis further revealing that persistent Hedgehog signaling activation impedes myelin production. The data also uncover prominent pro-myelinating activity of testosterone and involvement of AR in the control of neural stem cell commitment toward the oligodendroglial lineage. In the context of CNS demyelination, we provide evidence for the functional cooperation of the pathways leading to acceleration of myelin regeneration that might be related to their respective role on microglial and astroglial responses, higher preservation of axonal integrity, lower neuroinflammation, and functional improvement of animals in an immune model of CNS demyelination. Strong decreases of deleterious cytokines in the CNS (GM-CSF, TNF-α, IL-17A) and spleen (IL-2, IFN-γ) stand as unique features of the combined drugs while the potent therapeutic activity of testosterone on peripheral immune cells contributes to increase tolerogenic CD11c+ dendritic cells, reduce the clonal expansion of conventional CD4+ T cells and increase CD4+ Foxp3+ regulatory T cells. Altogether, these data might open promising perspectives for demyelinating diseases.

Hedgehog signaling in endocrine and folliculo-stellate cells of the adult pituitary.

Ubiquitous overactivation of Hedgehog signaling in adult pituitaries results in increased expression of proopiomelanocortin (Pomc), growth hormone (Gh) and prolactin (Prl), elevated adrenocorticotropic hormone (Acth) production and proliferation of Sox2+ cells. Moreover, ACTH, GH and PRL-expressing human pituitary adenomas strongly express the Hedgehog target GLI1. Accordingly, Hedgehog signaling seems to play an important role in pathology and probably also in homeostasis of the adult hypophysis. However, the specific Hedgehog-responsive pituitary cell type has not yet been identified. We here investigated the Hedgehog pathway activation status and the effects of deregulated Hedgehog signaling cell-specifically in endocrine and non-endocrine pituitary cells. We demonstrate that Hedgehog signaling is unimportant for the homeostasis of corticotrophs, whereas it is active in subpopulations of somatotrophs and folliculo-stellate cells in vivo. Reinforcement of Hedgehog signaling activity in folliculo-stellate cells stimulates growth hormone production/release from somatotrophs in a paracrine manner, which most likely is mediated by the neuropeptide vasoactive intestinal peptide. Overall, our data show that Hedgehog signaling affects the homeostasis of pituitary hormone production via folliculo-stellate cell-mediated regulation of growth hormone production/secretion.

A novel protein encoded by circular SMO RNA is essential for Hedgehog signaling activation and glioblastoma tumorigenicity

BackgroundAberrant activation of the Hedgehog pathway drives tumorigenesis of many cancers, including glioblastoma. However, the sensitization mechanism of the G protein-coupled-like receptor smoothened (SMO), a key component of Hedgehog signaling, remains largely unknown.ResultsIn this study, we describe a novel protein SMO-193a.a. that is essential for Hedgehog signaling activation in glioblastoma. Encoded by circular SMO (circ-SMO), SMO-193a.a. is required for sonic hedgehog (Shh) induced SMO activation, via interacting with SMO, enhancing SMO cholesterol modification, and releasing SMO from the inhibition of patched transmembrane receptors. Deprivation of SMO-193a.a. in brain cancer stem cells attenuates Hedgehog signaling intensity and suppresses self-renewal, proliferation in vitro, and tumorigenicity in vivo. Moreover, circ-SMO/SMO-193a.a. is positively regulated by FUS, a direct transcriptional target of Gli1. Shh/Gli1/FUS/SMO-193a.a. form a positive feedback loop to sustain Hedgehog signaling activation in glioblastoma. Clinically, SMO-193a.a. is more specifically expressed in glioblastoma than SMO and is relevant to Gli1 expression. Higher expression of SMO-193a.a. predicts worse overall survival of glioblastoma patients, indicating its prognostic value.ConclusionsOur study reveals that SMO-193a.a., a novel protein encoded by circular SMO, is critical for Hedgehog signaling, drives glioblastoma tumorigenesis and is a novel target for glioblastoma treatment.

MicroRNA miR-19b-3p mediated G protein γ subunit 7 (GNG7) loss contributes lung adenocarcinoma progression through activating Hedgehog signaling

ABSTRACT G protein γ subunit 7 (GNG7) is a subunit of heterotrimeric G protein. It has been demonstrated low expressed GNG7 in various cancers. Nevertheless, the role of GNG7 in lung adenocarcinoma (LUAD) remains unclear. In the present study, GNG7 expression in LUAD tissues and cell lines was analyzed by RT-qPCR, western blot and immunohistochemical. Kaplan–Meier analysis was performed for determining the prognostic value of GNG7 expression. Then, the function of GNG7 in LUAD progression was examined by cell proliferation, invasion and mouse xenograft assays. In addition, the underlying biological mechanisms of GNG7 in LUAD progression were explored via the bioinformatics analysis and experimental validation. We found GNG7 was markedly down-regulated in LUAD tissues and cell lines. Clinically, low expression of GNG7 was associated with the dismal prognosis of LUAD patients. Gain-of-function analysis showed that GNG7 overexpression inhibited proliferation and invasion of LUAD cell in vitro, and compromised tumor formation ability in vivo. Besides, mechanistic study revealed that overexpression of GNG7 affected the progression of LUAD via inhibiting activation of Hedgehog signaling. Moreover, bioinformatics prediction and experimental verification confirmed that GNG7 was targeted by miR-19b-3p, which was elevated expression in LUAD and promoting the progression of LUAD. Furthermore, rescue experiments demonstrated that GNG7 reintroduction weakened miR-19b-3p-mediated aggressive tumor phenotypes of LUAD cells. These findings suggested miR-19b-3p/GNG7 axis contributed to the progression of LUAD through Hedgehog signaling, which might be a potential therapeutic target for LUAD treatment.

Transient Activation of the Hedgehog-Gli Pathway Rescues Radiotherapy-Induced Dry Mouth via Recovering Salivary Gland Resident Macrophages.

Irreversible hypofunction of salivary glands is a common side effect of radiotherapy for head and neck cancer and is difficult to remedy. Recent studies indicate that transient activation of Hedgehog signaling rescues irradiation-impaired salivary function in animal models, but the underlying mechanisms are largely unclear. Here, we show in mice that activation of canonical Gli-dependent Hedgehog signaling by Gli1 gene transfer is sufficient to recover salivary function impaired by irradiation. Salivary gland cells responsive to Hedgehog/Gli signaling comprised small subsets of macrophages, epithelial cells, and endothelial cells, and their progeny remained relatively rare long after irradiation and transient Hedgehog activation. Quantities and activities of salivary gland resident macrophages were substantially and rapidly impaired by irradiation and restored by Hedgehog activation. Conversely, depletion of salivary gland macrophages by clodronate liposomes compromised the restoration of irradiation-impaired salivary function by transient Hedgehog activation. Single-cell RNA sequencing and qRT-PCR of sorted cells indicated that Hedgehog activation greatly enhances paracrine interactions between salivary gland resident macrophages, epithelial progenitors, and endothelial cells through Csf1, Hgf, and C1q signaling pathways. Consistently, expression of these paracrine factors and their receptors in salivary glands decreased following irradiation but were restored by transient Hedgehog activation. These findings reveal that resident macrophages and their prorepair paracrine factors are essential for the rescue of irradiation-impaired salivary function by transient Hedgehog activation and are promising therapeutic targets of radiotherapy-induced irreversible dry mouth. SIGNIFICANCE: These findings illuminate a novel direction for developing effective treatment of irreversible dry mouth, which is common after radiotherapy for head and neck cancer and for which no effective treatments are available. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/24/5531/F1.large.jpg.See related commentary by Coppes, p. 5462.

Macrophages Come To The Rescue.

The study by Zhao and colleagues, in this issue of Cancer Research, builds on previous work where they showed that transient activation of Hedgehog signaling within the murine submandibular gland rescued radiation-induced salivary gland dysfunction. The current study provides mechanistic insight into this phenomenon by showing that restoration of radiation-depleted resident macrophages through prorepair paracrine interactions with endothelial cells and epithelial progenitors rescued salivary function.See related article by Zhao et al., p. 5531.

VEGF-C mediates tumor growth and metastasis through promoting EMT-epithelial breast cancer cell crosstalk.

It is well established that a subset of cells within primary breast cancers can undergo an epithelial to mesenchymal transition (EMT), although the role of EMT in metastasis remains controversial. We previously demonstrated that breast cancer cells that had undergone an oncogenic EMT could increase metastasis of neighboring cancer cells via non-canonical paracrine-mediated activation of GLI activity that is dependent on SIX1 expression in the EMT cancer cells. However, the mechanism by which these SIX1-expressing EMT cells activate GLI signaling remained unclear. In this study, we demonstrate a novel mechanism for activation of GLI-mediated signaling in epithelial breast tumor cells via EMT cell-induced production and secretion of VEGF-C. We show that VEGF-C, secreted by breast cancer cells that have undergone an EMT, promotes paracrine-mediated increases in proliferation, migration and invasion of epithelial breast cancer cells, via non-canonical activation of GLI-signaling. We further show that the aggressive phenotypes, including metastasis, imparted by EMT cells on adjacent epithelial cancer cells can be disrupted by either inhibiting VEGF-C in EMT cells or by knocking down NRP2, a receptor which interacts with VEGF-C, in neighboring epithelial cancer cells. Interrogation of TCGA and GEO public datasets supports the relevance of this pathway in human breast cancer, demonstrating that VEGF-C strongly correlates with activation of Hedgehog signaling and EMT in the human disease. Our study suggests that the VEGF-C/NRP2/GLI axis is a novel and conserved paracrine means by which EMT cells enhance metastasis, and provides potential targets for therapeutic intervention in this heterogeneous disease.

MODL-30. DISSECTING THE ROLE OF MULTI-CILIOGENESIS NETWORK IN CHOROID PLEXUS TUMOR

The choroid plexus (CP) in brain ventricles consists of a fibro-vascular core encapsulated by epithelial cells that possess clusters of primary cilia on cell surface. CP tumors are rare primary brain neoplasms that most commonly occur in young children. Compared to the benign CP papilloma, choroid plexus carcinoma (CPC) is poorly understood and highly lethal with few treatments available. Molecular, cytogenetics and genomics studies uncovered complex alterations in CPC including frequent chromosomal loss and recurrent focal aberrations, whereas abnormal NOTCH signaling is observed in many CP tumors. We showed that activation of both NOTCH and Sonic Hedgehog (SHH) signaling in mice drives the formation of aggressive CP tumor. Molecular and histology analyses demonstrated that these murine CP tumors closely resemble their human counterparts, which also display aberrant SHH and NOTCH signaling, suggesting they may represent potential therapeutic avenues. Indeed, treatment with vismodegib, an FDA-approved SHH pathway inhibitor, suppresses CP tumor growth. Unlike multi-ciliated CP epithelial cells, tumor cells in these animal models are characterized by a solitary primary cilium. Though key genes of the multi-ciliogenesis circuit driven by Geminin coiled-coil domain-containing protein 1 (GEMC1) are expressed in CP epithelium, GEMC1-dependent transcriptional program is suppressed in NOTCH-driven CP tumors. Importantly, CPCs in humans consist of tumor cells with a solitary primary cilium and exhibit profound defects multi-ciliogenesis program. Together, these results indicate that a solitary primary cilium is crucial for CPC development, whereas multi-ciliogenesis circuit possesses tumor suppressive functions and may represent a novel therapeutic target in CPC.

Protective effects of Phlomis umbrosa extract on a monosodium iodoacetate–induced osteoarthritis model and prediction of molecular mechanisms using transcriptomics

BackgroundPhlomis umbrosa Turczaninow root has been traditionally used to treat fractures, rheumatoid arthritis, and arthralgia. However, the effects and mechanisms of P. umbrosa on osteoarthritis (OA) remain poorly understood and a functional genomic approach has not been investigated. AimThe purpose of this study was to investigate the effects and mechanisms of P. umbrosa extract (PUE) on OA using transcriptomic analysis. MethodsWe performed joint diameter measurements, micro computed tomography, and histopathological analysis of monosodium iodoacetate (MIA)-induced OA rats treated with PUE (200 mg/kg) for 3 weeks. Gene expression profiling in articular cartilage tissue was then performed using RNA sequencing (RNA-seq) followed by signaling pathway analysis of regulatory genes. ResultsPUE treatment improved OA based on decreased joint diameter, increased joint morphological parameters, and histopathological features. Many genes involved in multiple signal transduction pathway and collagen activation in OA were differentially regulated by PUE. These included genes related to Wnt/β-catenin, OA pathway, and sonic hedgehog signaling activity. Furthermore, PUE treatment downregulated cartilage damage factors (MMP-9, MMP-13, ADAMTs4, and ADMATs5) and upregulated chondrogenesis (COL2A1 and SOX-9) by regulating the transcription factors SOX-9, Ctnnb1, and Epas1. ConclusionBased on the results of gene expression profiling, this study highlighted the molecular mechanisms underlying the effects of PUE in MIA-induced OA rats. The findings provide novel insight into the mechanisms by which PUE treatment-induced gene expression changes may influence OA disease progression. Taken together, the results suggest that PUE may be used as a source of therapeutic agents for OA.