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BACKGROUND: Supratentorial RELA fusion (ST-RELA) ependymomas (EPNs) are resistant tumors without an approved chemotherapeutic treatment. Unfortunately, the molecular mechanisms that lead to chemoresistance traits of ST-RELA remain elusive. The aim of this study was to assess RELA fusion-dependent signaling modules, specifically the role of the Hedgehog (Hh) pathway as a novel targetable vulnerability in ST-RELA. METHODS: Gene expression was analyzed in EPN from patient cohorts, by microarray, RNA-seq, qRT-PCR, and scRNA-seq. Inhibitors against Smoothened (SMO) (Sonidegib) and Aurora kinase A (AURKA) (Alisertib) were evaluated. Protein expression, primary cilia formation, and drug effects were assessed by immunoblot, immunofluorescence, and immunohistochemistry. RESULTS: Hh components were selectively overexpressed in EPNs induced by the RELA fusion. Single-cell analysis showed that the Hh signature was primarily confined to undifferentiated, stem-like cell subpopulations. Sonidegib exhibited potent growth-inhibitory effects on ST-RELA cells, suggesting a key role in active Hh signaling; importantly, the effect of Sonidegib was reversed by primary cilia loss. We, thus, tested the effect of AURKA inhibition by Alisertib, to induce cilia stabilization/reassembly. Strikingly, Alisertib rescued ciliogenesis and synergized with Sonidegib in killing ST-RELA cells. Using a xenograft model, we show that cilia loss is a mechanism for acquiring resistance to the inhibitory effect of Sonidegib. However, Alisertib fails to rescue cilia and highlights the need for other strategies to promote cilia reassembly, for treating ST-RELA tumors. CONCLUSION: Our study reveals a crucial role for the Hh pathway in ST-RELA tumor growth, and suggests that rescue of primary cilia represents a vulnerability of the ST-RELA EPNs.

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Replicative immortality is a key feature of cancer cells and it is maintained by the expression of telomerase, a promising target of novel therapies. Long-term telomerase inhibition can induce resistance, but the mechanisms underlying this process remain unclear. The Sonic hedgehog pathway (SHH) is an embryogenic pathway involved in tumorigenesis and modulates the transcription of telomerase. We evaluated the effects of long-term treatment of the telomerase inhibitor MST-312 in morphology, proliferation, resistance, and in the SHH pathway molecules expression levels in lung cancer cells. Cells treated for 12 weeks with MST-312 showed changes in morphology, such as spindle-shaped cells, and a shift in the distribution of F-ACTIN from cortical to diffuse. Treatment also significantly reduced cells' efficiency to form spheroids and their clonogenic potential, independently of the cell cycle and telomeric DNA content. Moreover, GLI-1 expression levels were significantly reduced after 12 weeks of MST-312 treatment, indicating a possible inhibition of this signaling axis in the SHH pathway, without hindering NANOG and OCT4 expression. Here, we described a novel implication of long-term treatment with MST-312 functionally and molecularly, shedding new light on the molecular mechanisms of this drug in vitro.

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Oral Squamous Cell Carcinoma (OSCC) presents an important challenge for the health systems worldwide. Thus, unraveling the biological mechanisms involved in OSCC pathogenesis is essential to the discovery of new drugs with anticancer potential. The Hedgehog (HH) pathway has shown promising results as a therapeutic target both in vitro and in vivo. This study aimed to investigate the effects of vismodegib and itraconazole on the expression of Hedgehog (HH) genes (PTCH1, SMO, and GLI1), cell cycle and cell death in OSCC cells. Alamar Blue assay was used to assess the cytotoxicity of vismodegib and itraconazole in a panel of oral cancer cell lines, including CAL27. The expression of HH signaling components after treatment with vismodegib and itraconazole, at concentrations of 25 or 50 µg/ml was evaluated by qPCR. Cell cycle and apoptosis were evaluated by flow cytometry after 72 h treatment with 50 µg/ml of vismodegib or itraconazole. HH signaling was activated in OSCC cell lines CAL27, SCC4, SCC9, and HSC3. Vismodegib and itraconazole significantly reduced CAL27 cell viability after 48 h of treatment. Gene expression of PTCH1, SMO, and GLI1 decreased in response to 24 h of treatment with vismodegib or itraconazole. Furthermore, CAL27 cells exhibited alterations in morphology, cell size, and cellular granularity. An increase in the DNA fragmentation was observed after treatment and both inhibitors induced apoptosis after 72 h. In conclusion, SMO inhibitors vismodegib and itraconazole demonstrably reduced the expression of HH genes in CAL27 OSCC cell line. In addition, treatment with vismodegib and itraconazole reduced cellular viability and altered the morphology of CAL27 cells, and also induced apoptosis.

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Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant disorder characterized by multiple basal cell carcinomas (BCC), mainly caused by PTCH1 gene mutations. Our current study aimed to establish (1) PTCH1 germinal and somatic mutational status, (2) component and Hedgehog (HH) pathway targets gene expression patterns, and (3) profile variations according to the genetic background in BCC and normal surrounding skin (NSS). We collected 23 blood and 20 BCC patient samples and analyzed the PTCH1 gene using bidirectional sequencing and multiplex ligation-dependent probe amplification. Quantitative PCR was used to determine the mRNA expression levels of PTCH1, SMO, GLI3, and CCND1 in paired samples of BCC and NSS from 20 patients and four non-NBCCS skin controls (C). Our analyses identified 12 germline and five somatic sequence variants in PTCH1. mRNA levels of PTCH1, SMO, and GLI3 were higher in NSS compared to C samples, reaching maximum values in BCC samples (p < 0.05). NSS with PTCH1 germline mutations had modified SMO,PTCH1, and GLI3 mRNA levels compared to samples without mutation (p < 0.01). Two PTCH1 mutations in BCC led to an increase in PTCH1, SMO, and GLI3, and a decrease in CCND1 mRNA levels (p < 0.01 vs. BCC with germline mutation only). These results indicate that besides PTCH1, other genes are responsible for NBCCS and BCC development in a population exposed to high UV radiation. Additionally, the mutational events caused increased expression of HH-related genes, even in phenotypically normal skin.

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Hedgehog (Hh) signaling pathway plays an essential role during vertebrate embryonic development and tumorigenesis. It is already known that Sonic hedgehog (Shh) pathway is important for the evolution of radio and chemo-resistance of several types of tumors. Most of the brain tumors are resistant to chemotherapeutic drugs, consequently, they have a poor prognosis. So, a better knowledge of the Shh pathway opens an opportunity for targeted therapies against brain tumors considering a multi-factorial molecular overview. Therefore, emerging studies are being conducted in order to find new inhibitors for Shh signaling pathway, which could be safely used in clinical trials. Shh can signal through a canonical and non-canonical way, and it also has important points of interaction with other pathways during brain tumorigenesis. So, a better knowledge of Shh signaling pathway opens an avenue of possibilities for the treatment of not only for brain tumors but also for other types of cancers. In this review, we will also highlight some clinical trials that use the Shh pathway as a target for treating brain cancer.

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INTRODUÇÃO/OBJETIVO: A esquistossomose mansonica é causa importante de fibrose hepática e hipertensão porta em regiões tropicais, e a patogênese da fibrose não está bem esclarecida. Como a via do hedgehog e um dos seus genes alvos,a osteopontina, estão envolvidos em fibroses hepáticas de outras etiologias o objetivo foi investigar a ativação destas vias na esquIsitossomose humana e murina experimental, no intuito de verificar o seu envolvimento no desenvolvimento da forma hepatoesplênica da esquistossomose mansonica (FHE). MATERIAL E MÉTODOS: 87 biópsias em cunha de fígados de pacientes com FHE submetidos a cirurgia e fragmentos de fígado de camundongos suiços infectados com Schistosoma mansoni foram submetidos a métodos imunohistoquímicos e de biologia molecular para avaliar a expressão de ligantes hedgehog (Ihh, Shh), receptor Patched, fatores de transcrição Gli 1 e 2 e osteopontina. Osteopontina sérica e ligante Shh do hedgehog foram avaliados em camundongos suíços infectados e os de osteopontina em camundongos CBA/J infectados e em pacientes com FHE e forma hepatointestinal da esquistossomose. In vitro foi avaliado o efeito de antígeno solúvel do ovo (SEA) em células de Kuppfer, células estreladas, macrófagos, colangiócitos e células endoteliais sinusoidais hepáticas. A relação com a via da IL-13 foi avaliada em camundongos geneticamente deficientes ou hiperexpressando a citocina. Foi avaliado in vitro se a IL-13 induz ligantes hedghog ou ativação da via em células de Kuppfer. RESULTADOS: Os resultados mostraram: (a) aumento expressão de ligantes Ihh, de fatores de transcrição Gli2 e de osteopontina no fígado de camundongos suíços infectados com Schistosoma mansoni, aumento de shh e osteopontina no plasma de camundongos suíços e de osteopontina no plasma de camundongos CBA/J infectados com S. mansoni; (b) aumento na expressão de Ihh, Shh, Gli1 e 2, receptor Patched e de osteopontina no fígado de pacientes com esquistossomose e aumento da osteopontina sérica em pacientes com a FHE; (c) A expressão de ligantes hedgehog e de Gli2 foi observada em macrófagos, células estreladas, ductos biliares e células endoteliais, e a de osteoponina em ductos biliares,macrófagos e células estreladas/miofibroblastos; (d) correlação positiva entre ativação do hedgehog (Gli2 e osteopontina) e fibrose, no modelo murino experimental e nos pacientes; nestes a correlação também foi observada com o grau de fibrose classificada pelo ultrassom e com a hipertensão porta; (e) Inibição in vitro do hedgehog com ciclopamina e vismodegib ou por nocauteamento condicional de receptor Smoothened bloqueou a ativação alternativa de macrófagos e inibiu a angiogênese a partir de células endoteliais sinusoidais hepáticas; (f) que o bloqueio da via da IL-13 reduziu e a hiperexpressão aumentou a ativação da via do hedgehog e IL-13 diretamente induziu, in vitro,produção de ihh em células de Kupffer de camundongos e de humanos, demonstrando a inter-relação das duas vias...

BACKGROUND AND AIMS: Schistosomiasis is a major cause of liver fibrosis and portal hypertension in tropical regions, and the pathogenesis of fibrosis is not well established. As hedgehog pathway and one of its target genes, osteopontin, are involved in liver fibrosis of other etiologies our aims were to investigate the activation of these pathways in human and experimental murine schistosomiasis, in an attempt to verify their involvement in the development of hepatosplenic schistosomiasis mansoni (HS). METHODS: 87 wedge liver biopsies of patients with HS submitted to surgery and liver fragments Swiss mice infected with Schistosoma mansoni were submitted to immunohistochemistry and molecular biology methods to evaluate the expression of hedgehog ligands (Ihh, Shh), patched receptor , Gli transcription factors and osteopontin. Serum osteopontin and Shh were evaluated in infected Swiss mice and osteopontin was evaluated in serum of infected CBA/J mice and plasma from patients with hepatointestinal and HS forms of schistosomiasis. The effect of soluble egg antigen (SEA) on Kuppfer cells, stellate cells, macrophages, cholangiocytes and liver sinusoidal endothelial cells was evaluated in vitro. Relationship with IL-13 pathway was evaluated in mice genetically deficient or with hyperexpression of this cytokine. Whether IL-13 induces production of ligands and/or activation of the hedgehog pathway in Kuppfer cells was evaluated in vitro. RESULTS: Results demonstrated: (a) increased expression of Ihh, transcription factor Gli2 and osteopontin in the livers of Swiss mice infected with S. mansoni, increased plasma levels of shh and osteopontin in infected Swiss mice and increased osteopontin in plasma of S. mansoni infected CBA/J mice; (b) increased expression of ihh, shh, Gli1 and 2, patched and osteopontin receptor in the liver of patients with schistosomiasis and increased serum osteopontin in patients with HS; (c) expression of hedgehog ligands and Gli2 was observed in macrophages, stellate cells, endothelial cells and bile duct and expression of osteopontin was detected in macrophages and stellate/myofibroblast cells; (d) positive correlation between activation of the hedgehog (Gli2 and osteopontin) and fibrosis in experimental murine model and in patients; these correlation was also observed with the degree of fibrosis classified by ultrasound and with portal hypertension; (e) in vitro inhibition of hedgehog pathway with cyclopamine or vismogedib or by conditional knockout of Smoothened co-receptor blocked the alternative activation of macrophage and inhibited angiogenesis in liver sinusoidal endothelial cells; (f) reduction of IL-13 pathway or IL-13 over-expression respectively reduced or increased the activation of the hedgehog pathway and IL-13 directly induced in vitro ihh production in Kupffer cells from mice and human, demonstrating a cross-talk between the two pathways...

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INTRODUÇÃO/OBJETIVO: A esquistossomose mansonica é causa importante de fibrose hepática e hipertensão porta em regiões tropicais, e a patogênese da fibrose não está bem esclarecida. Como a via do hedgehog e um dos seus genes alvos, a osteopontina, estão envolvidos em fibroses hepáticas de outras etiologias o objetivo foi investigar a ativação destas vias na esquIsitossomose humana e murina experimental, no intuito de verificar o seu envolvimento no desenvolvimento da forma hepatoesplênica da esquistossomose mansonica (FHE). MATERIAL E MÉTODOS: 87 biópsias em cunha de fígados de pacientes com FHE submetidos a cirurgia e fragmentos de fígado de camundongos suiços infectados com Schistosoma mansoni foram submetidos a métodos imunohistoquímicos e de biologia molecular para avaliar a expressão de ligantes hedgehog (Ihh, Shh), receptor Patched, fatores de transcrição Gli 1 e 2...

inglês: BACKGROUND AND AIMS: Schistosomiasis is a major cause of liver fibrosis and portal hypertension in tropical regions, and the pathogenesis of fibrosis is not well established. As hedgehog pathway and one of its target genes, osteopontin, are involved in liver fibrosis of other etiologies our aims were to investigate the activation of these pathways in human and experimental murine schistosomiasis, in an attempt to verify their involvement in the development of hepatosplenic schistosomiasis mansoni (HS). METHODS: 87 wedge liver biopsies of patients with HS submitted to surgery and liver fragments Swiss mice infected with Schistosoma mansoni were submitted to immunohistochemistry and molecular biology methods to evaluate the expression of hedgehog ligands (Ihh, Shh), patched receptor , Gli transcription factors and osteopontin...

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