SUFU

Gene Summary

Gene:SUFU; SUFU negative regulator of hedgehog signaling
Aliases: SUFUH, SUFUXL, PRO1280
Location:10q24.32
Summary:The Hedgehog signaling pathway plays an important role in early human development. The pathway is a signaling cascade that plays a role in pattern formation and cellular proliferation during development. This gene encodes a negative regulator of the hedgehog signaling pathway. Defects in this gene are a cause of medulloblastoma. Alternative splicing results in multiple transcript variants.[provided by RefSeq, May 2010]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:suppressor of fused homolog
Source:NCBIAccessed: 14 March, 2017

Ontology:

What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 14 March 2017 using data from PubMed using criteria.

Literature Analysis

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Tag cloud generated 14 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (7)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: SUFU (cancer-related)

Shanley S, McCormack C
Diagnosis and Management of Hereditary Basal Cell Skin Cancer.
Recent Results Cancer Res. 2016; 205:191-212 [PubMed] Related Publications
Basal cell carcinoma (BCC) is the most common cancer in Caucasians worldwide and its incidence is rising. It is generally considered a sporadic tumour, most likely to affect fair-skinned individuals exposed to ultraviolet (UV) radiation. This chapter focusses on the approach to recognising the relatively few individuals in whom a high-risk hereditary susceptibility may be present. Gorlin syndrome is the main consideration and the gene most commonly mutated is PTCH1, a key regulator of the Hedgehog developmental pathway. Recently, loss of function of another gene in the same pathway, SUFU, has been found to explain a subset of families. Understanding the pathogenesis of familial BCCs has advanced the understanding of the biology of sporadic tumours and led to targeted therapy trials. The management of familial BCCs remains a challenge due to significant unmet needs for non-surgical treatments and a high burden of disease for the individual. Together with the prospect of advances in gene discovery and translation, these challenges highlight the need for ongoing review of at-risk and affected individuals by a multidisciplinary team.

Garcia N, Bozzini N, Baiocchi G, et al.
May Sonic Hedgehog proteins be markers for malignancy in uterine smooth muscle tumors?
Hum Pathol. 2016; 50:43-50 [PubMed] Related Publications
Several studies have demonstrated that the Sonic Hedgehog signaling pathway (SHH) plays an important role in tumorigenesis and cellular differentiation. We analyzed the protein expression of SHH pathway components and evaluated whether their profile could be useful for the diagnosis, prognosis, or prediction of the risk of malignancy for uterine smooth muscle tumors (USMTs). A total of 176 samples (20 myometrium, 119 variants of leiomyoma, and 37 leiomyosarcoma) were evaluated for the protein expression of the SHH signaling components, HHIP1 (SHH inhibitor), and BMP4 (SHH target) by immunohistochemistry. Western blot analysis was performed to verify the specificity of the antibodies. We grouped leiomyoma samples into conventional leiomyomas and unusual leiomyomas that comprise atypical, cellular, mitotically active leiomyomas and uterine smooth muscle tumors of uncertain malignant potential. Immunohistochemical analysis showed that SMO, SUFU, GLI1, GLI3, and BMP4 expression gradually increased depending on to the histologic tissue type. The protein expression of SMO, SUFU, and GLI1 was increased in unusual leiomyoma and leiomyosarcoma samples compared to normal myometrium. The inhibitor HHIP1 showed higher expression in myometrium, whereas only negative or basal expression of SMO, SUFU, GLI1, and GLI3 was detected in these samples. Strong expression of SHH was associated with poorer overall survival. Our data suggest that the expression of SHH proteins can be useful for evaluating the potential risk of malignancy for USMTs. Moreover, GLI1 and SMO may serve as future therapeutic targets for women with USMTs.

Bresler SC, Padwa BL, Granter SR
Nevoid Basal Cell Carcinoma Syndrome (Gorlin Syndrome).
Head Neck Pathol. 2016; 10(2):119-24 [PubMed] Free Access to Full Article Related Publications
Nevoid basal cell carcinoma syndrome, or basal cell nevus syndrome (Gorlin syndrome), is a rare autosomal dominantly inherited disorder that is characterized by development of basal cell carcinomas from a young age. Other distinguishing clinical features are seen in a majority of patients, and include keratocystic odontogenic tumors (formerly odontogenic keratocysts) as well as dyskeratotic palmar and plantar pitting. A range of skeletal and other developmental abnormalities are also often seen. The disorder is caused by defects in hedgehog signaling which result in constitutive pathway activity and tumor cell proliferation. As sporadic basal cell carcinomas also commonly harbor hedgehog pathway aberrations, therapeutic agents targeting key signaling constituents have been developed and tested against advanced sporadically occurring tumors or syndromic disease, leading in 2013 to FDA approval of the first hedgehog pathway-targeted small molecule, vismodegib. The elucidation of the molecular pathogenesis of nevoid basal cell carcinoma syndrome has resulted in further understanding of the most common human malignancy.

Bonilla X, Parmentier L, King B, et al.
Genomic analysis identifies new drivers and progression pathways in skin basal cell carcinoma.
Nat Genet. 2016; 48(4):398-406 [PubMed] Related Publications
Basal cell carcinoma (BCC) of the skin is the most common malignant neoplasm in humans. BCC is primarily driven by the Sonic Hedgehog (Hh) pathway. However, its phenotypic variation remains unexplained. Our genetic profiling of 293 BCCs found the highest mutation rate in cancer (65 mutations/Mb). Eighty-five percent of the BCCs harbored mutations in Hh pathway genes (PTCH1, 73% or SMO, 20% (P = 6.6 × 10(-8)) and SUFU, 8%) and in TP53 (61%). However, 85% of the BCCs also harbored additional driver mutations in other cancer-related genes. We observed recurrent mutations in MYCN (30%), PPP6C (15%), STK19 (10%), LATS1 (8%), ERBB2 (4%), PIK3CA (2%), and NRAS, KRAS or HRAS (2%), and loss-of-function and deleterious missense mutations were present in PTPN14 (23%), RB1 (8%) and FBXW7 (5%). Consistent with the mutational profiles, N-Myc and Hippo-YAP pathway target genes were upregulated. Functional analysis of the mutations in MYCN, PTPN14 and LATS1 suggested their potential relevance in BCC tumorigenesis.

Vidal MT, Lourenço SV, Soares FA, et al.
The sonic hedgehog signaling pathway contributes to the development of salivary gland neoplasms regardless of perineural infiltration.
Tumour Biol. 2016; 37(7):9587-601 [PubMed] Related Publications
The pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (ACC) are common tumors arising from salivary glands whose histopathology is heterogeneous. The sonic hedgehog signaling pathway (Hh) and signal transducer and activator of transcription 3 (STAT3) play important roles in cell proliferation, favoring tumor growth. The aim of this investigation was to study components of the Hh pathway, as well as STAT3 in salivary gland neoplasms in an attempt to add information about the biological characteristics of these neoplasms. We used 9 cases of PA, 17 cases of ACC, and 20 cases of MEC. Using immunohistochemistry, SHH, GLI1, SUFU, HHIP, and STAT3 were investigated. For comparative purposes, MCM3 (cellular proliferation marker) was also included. In PA, there was high expression of cytoplasmic SHH and SUFU and low expression of STAT3 and MCM3. In the ACC, there was high expression of GLI1, HHIP, and STAT3 and low expression of SHH, SUFU, and MCM3. In the MEC, we observed high expression of SHH, GLI1, SUFU, and HHIP and low expression of STAT3 and MCM3. There was a statistically significant difference between SHH (p = 0.0064), STAT3 (p = 0.0003), and MCM3 (p = 0.0257) when all tumors were compared and a higher expression in parenchyma for all tumors when stroma and parenchyma were compared (p < 0.05). These findings suggests a possible role of Hh pathway in the development and maintenance of the cytoarchitectural pattern of PA, ACC, and MEC, as well as the participation of STAT3 in the development of ACC, irrespective perineural infiltration.

Arnhold V, Boos J, Lanvers-Kaminsky C
Targeting hedgehog signaling pathway in pediatric tumors: in vitro evaluation of SMO and GLI inhibitors.
Cancer Chemother Pharmacol. 2016; 77(3):495-505 [PubMed] Related Publications
PURPOSE: The successful use of SMO inhibitors in tumors with activating mutations in hedgehog signaling raised interests in their exploitation against other malignancies. The role of hedgehog signaling in pediatric malignancies remains unclear.
METHODS: We investigated the hedgehog signaling and its inhibition in a panel of 18 tumor cell lines derived from six of the most common and highly aggressive pediatric tumor types. None of the cell lines was known to stem from tumors with activating hedgehog mutations. Tetrazolium-based assays (MTT and MTS) and BrdU assays were used to analyze cell viability and proliferation after exposure to SANT1 and GANT61. Expression analysis of hedgehog signaling members and cyclins was performed by quantitative real-time PCR and Western blot.
RESULTS: Key members of hedgehog signaling (SHH, PTCH1, SMO, GLI1, GLI2 and SUFU) were expressed in all cell lines. In 50% of the cell lines viability was significantly increased by SHH exposure. Stimulation was not restricted to distinct tumor types, but related to cell lines with higher mRNA levels of PTCH1, SMO, GLI1 and GLI2. SMO inhibition by SANT1 moderately decreased cell viability with GI50s between 28 and 93 µmol/l. Sensitivity to SANT1 was not related to distinct tumor types. The GLI inhibitor GANT61 inhibited cell viability and proliferation more effectively than SANT1.
CONCLUSIONS: Our preclinical data provide evidence that hedgehog signaling is active and can be stimulated by PTCH1 ligands in various pediatric tumors. We suggest further evaluation of GLI inhibitors as inhibitors of hedgehog signaling for the treatment of the investigated tumor types.

Šoukalová J, Vejmělková K, Cermanová T, et al.
[Identification of a Family with SUFU Germline Deletion Based on a Case of Desmoplastic Medulloblastoma in an Infant].
Klin Onkol. 2016; 29 Suppl 1:S83-8 [PubMed] Related Publications
BACKGROUND: Medulloblastoma, an embryonal neuroectodermal tumor of the cerebellum, is the most common malignant brain tumor in children. There are approximately 15 cases diagnosed in the Czech Republic each year. The recent World Health Organization classification recognizes several histopathological subtypes of medulloblastoma: classical, desmoplastic/ nodular with its extensive-nodularity variant, and anaplastic/ large-cell variant. Further molecular analysis identified four basic subgroups of medulloblastoma: WNT, SHH, Group 3, and Group 4. The subgroup of SHH meduloblastoma is associated with somatic mutations of SHH, PTCH1, SUFU, SMO and TP53, while the most common mutations found in infants up to three years of age were PTCH1 and SUFU. The majority of medulloblastomas are sporadic diseases, whereas only about 5- 10% of all cases occur in connection with hereditary genetic syndromes.
CASE: We present a case of a 21-months old girl diagnosed with a localized posterior fossa tumor. The histopathological examination revealed a desmoplastic/ nodular medulloblastoma. The treatment comprised a radical exstirpation of the tumor followed by adjuvant chemotherapy. With the use of array-CGH, a partial biallelic deletion of the SUFU gene (locus 10q24.32) was detected in the tumor DNA, whereas a monoallelic deletion was found in the peripheral lymphocyte DNA of the patient. These findings were confirmed by an independent qPCR method. Monoallelic germline deletion of SUFU was also identified in the patients mother, who was a healthy carrier. Pedigree of the family suggested a transition of the germline deletion of SUFU, since another brain tumors (including one case diagnosed before the age of three years) were identified in previous generations.
CONCLUSION: Germline mutations in SUFU gene are believed to predispose to infant desmoplastic/ nodular medulloblastomas, basal cell carcinomas and meningiomas. The susceptibility gene shows autosomal dominant inheritance with an incomplete penetrance. There is no evidence-based surveillance strategy suggested for the carriers of germline SUFU mutations/ deletions so far. Our recommendation is based both on a family history of our patient and similar cases described in the literature. Since the germinal mutations in SUFU are responsible for up to 50% of all desmoplastic medulloblastomas in children under three years of age, genetic testing of SUFU should be encouraged in this population of patients.

Ock CY, Son B, Keam B, et al.
Identification of genomic mutations associated with clinical outcomes of induction chemotherapy in patients with head and neck squamous cell carcinoma.
J Cancer Res Clin Oncol. 2016; 142(4):873-83 [PubMed] Related Publications
PURPOSE: We performed deep sequencing of target genes in head and neck squamous cell carcinoma (HNSCC) tumors to identify somatic mutations that are associated with induction chemotherapy (IC) response.
METHODS: Patients who were diagnosed with HNSCC were retrospectively identified. Patients who were treated with IC were divided into two groups: good responders and poor responders by tumor response and progression-free survival. Targeted gene sequencing for 2404 somatic mutations of 44 genes was performed on HNSCC tissues. Mutations with total coverage of <500 were excluded, and the cutoff for altered allele frequency was >10 %.
RESULTS: Of the 71 patients, 45 were treated upfront with IC. Mean total coverage was 1941 per locus, and 42.2 % of tumors had TP53 mutations. Thirty-three mutations in TP53, NOTCH3, FGFR2, FGFR3, ATM, EGFR, MET, PTEN, FBXW7, SYNE1, and SUFU were frequently altered in poor responders. Among the patients who were treated with IC, those with unfavorable genomic profiles had significantly poorer overall survival than those without unfavorable genomic profiles (hazard ratio 6.45, 95 % confidence interval 2.07-20.10, P < 0.001).
CONCLUSIONS: Comprehensive analysis of mutation frequencies identified unfavorable genomic profiles, and the patients without unfavorable genomic profiles can obtain clinical benefits from IC in patients with HNSCC.

Schulman JM, Oh DH, Sanborn JZ, et al.
Multiple Hereditary Infundibulocystic Basal Cell Carcinoma Syndrome Associated With a Germline SUFU Mutation.
JAMA Dermatol. 2016; 152(3):323-7 [PubMed] Related Publications
IMPORTANCE: Multiple hereditary infundibulocystic basal cell carcinoma syndrome (MHIBCC) is a rare genodermatosis in which numerous indolent, well-differentiated basal cell carcinomas develop primarily on the face and genitals, without other features characteristic of basal cell nevus syndrome. The cause is unknown. The purpose of the study was to identify a genetic basis for the syndrome and a mechanism by which the associated tumors develop.
OBSERVATIONS: Whole-exome sequencing of 5 tumors and a normal buccal mucosal sample from a patient with MHIBCC was performed. A conserved splice-site mutation in 1 copy of the suppressor of fused gene (SUFU) was identified in all tumor and normal tissue samples. Additional distinct deletions of the trans SUFU allele were identified in all tumor samples, none of which were present in the normal sample.
CONCLUSIONS AND RELEVANCE: A germline SUFU mutation was present in a patient with MHIBCC, and additional acquired SUFU mutations underlie the development of infundibulocystic basal cell carcinomas. The downstream location of the SUFU gene within the sonic hedgehog pathway may explain why its loss is associated with relatively well-differentiated tumors and suggests that MHIBCC will not respond to therapeutic strategies, such as smoothened inhibitors, that target upstream components of this pathway.

Farahani M, Rubbi C, Liu L, et al.
CLL Exosomes Modulate the Transcriptome and Behaviour of Recipient Stromal Cells and Are Selectively Enriched in miR-202-3p.
PLoS One. 2015; 10(10):e0141429 [PubMed] Free Access to Full Article Related Publications
Bi-directional communication with the microenvironment is essential for homing and survival of cancer cells with implications for disease biology and behaviour. In chronic lymphocytic leukemia (CLL), the role of the microenvironment on malignant cell behaviour is well described. However, how CLL cells engage and recruit nurturing cells is poorly characterised. Here we demonstrate that CLL cells secrete exosomes that are nanovesicles originating from the fusion of multivesicular bodies with the plasma membrane, to shuttle proteins, lipids, microRNAs (miR) and mRNAs to recipient cells. We characterise and confirm the size (50-100 nm) and identity of the CLL-derived exosomes by Electron microscopy (EM), Atomic force microscopy (AFM), flow cytometry and western blotting using both exosome- and CLL-specific markers. Incubation of CLL-exosomes, derived either from cell culture supernatants or from patient plasma, with human stromal cells shows that they are readily taken up into endosomes, and induce expression of genes such as c-fos and ATM as well as enhance proliferation of recipient HS-5 cells. Furthermore, we show that CLL exosomes encapsulate abundant small RNAs and are enriched in certain miRs and specifically hsa-miR-202-3p. We suggest that such specific packaging of miR-202-3p into exosomes results in enhanced expression of 'suppressor of fused' (Sufu), a Hedgehog (Hh) signalling intermediate, in the parental CLL cells. Thus, our data show that CLL cells secrete exosomes that alter the transcriptome and behaviour of recipient cells. Such communication with microenvironment is likely to have an important role in CLL disease biology.

Long H, Wang Z, Chen J, et al.
microRNA-214 promotes epithelial-mesenchymal transition and metastasis in lung adenocarcinoma by targeting the suppressor-of-fused protein (Sufu).
Oncotarget. 2015; 6(36):38705-18 [PubMed] Free Access to Full Article Related Publications
Distant metastasis is the major cause of cancer-related deaths in patients with lung adenocarcinoma (LAD). Emerging evidence reveals that miRNA is critical for tumor metastasis. miR-214 expression has been associated with LAD progression. However, whether and how miR-214 is involved in the development and metastasis of LAD remain unaddressed. Here, we found that the expression of miR-214 was elevated in LAD and correlated positively with LAD metastasis and epithelial-mesenchymal transition (EMT). In addition, we found that miR-214 enhanced the molecular program controlling the EMT of LAD cells and promoted LAD cell metastasis both in vitro and in vivo. This study thus provides the first evidence to show that the miR-214 expression by LAD cells contributes to the EMT and metastasis of LAD. Mechanistically, Sufu was identified as an important miR-214 functional target for the EMT and metastasis of LAD, ectopic expression of Sufu alleviated miR-214 promoted EMT and metastasis. Importantly, the expression of Sufu inversely correlated with the expression of miR-214 and vimentin and positively associated with the expression of E-cadherin in the tumor cells from human LAD patients. Collectively, this study uncovers a previously unappreciated miR-214-Sufu pathway in controlling EMT and metastasis of LAD and suggests that interfering with miR-214 and Sufu could be a viable approach to treat late stage metastatic LAD patients.

D'Amico D, Antonucci L, Di Magno L, et al.
Non-canonical Hedgehog/AMPK-Mediated Control of Polyamine Metabolism Supports Neuronal and Medulloblastoma Cell Growth.
Dev Cell. 2015; 35(1):21-35 [PubMed] Free Access to Full Article Related Publications
Developmental Hedgehog signaling controls proliferation of cerebellar granule cell precursors (GCPs), and its aberrant activation is a leading cause of medulloblastoma. We show here that Hedgehog promotes polyamine biosynthesis in GCPs by engaging a non-canonical axis leading to the translation of ornithine decarboxylase (ODC). This process is governed by AMPK, which phosphorylates threonine 173 of the zinc finger protein CNBP in response to Hedgehog activation. Phosphorylated CNBP increases its association with Sufu, followed by CNBP stabilization, ODC translation, and polyamine biosynthesis. Notably, CNBP, ODC, and polyamines are elevated in Hedgehog-dependent medulloblastoma, and genetic or pharmacological inhibition of this axis efficiently blocks Hedgehog-dependent proliferation of medulloblastoma cells in vitro and in vivo. Together, these data illustrate an auxiliary mechanism of metabolic control by a morphogenic pathway with relevant implications in development and cancer.

Wu D, Zhang J, Wang J, et al.
Hesperetin induces apoptosis of esophageal cancer cells via mitochondrial pathway mediated by the increased intracellular reactive oxygen species.
Tumour Biol. 2016; 37(3):3451-9 [PubMed] Related Publications
Esophageal cancer is of high prevalence and poor prognosis. Hesperetin has been reported to exert antitumor ability by inducing apoptosis in many cancers in vitro and in vivo without obvious toxicity. However, there is no study concerning about the effect of hesperetin on esophageal cancer. In this study, we aimed to investigate whether hesperetin could induce apoptosis in esophageal cancer cells and explore its potential mechanism. We found that hesperetin induced esophageal cancer cells apoptosis in a concentration-dependent and time-dependent manner compared with the untreated cells. Hoechst 33258 staining and flow cytometry analysis showed more apoptotic cells in the hesperetin-treated group (p < 0.05, respectively). The intracellular reactive oxygen species (ROS) increased significantly, and glutathione (GSH) was depleted. The loss of △Ψ m was more tremendous in the hesperetin-treated cells. N-acetylcysteine (NAC) reduced the proapoptotic ability of hesperetin, while DL-buthionine-S, R-sulfoximine (BSO) enhanced the anticancer effect. Western blotting showed that the expression levels of cytochrome C (Cyt C) and apoptosis-inducing factor (AIF) decreased in mitochondria and increased in cytoplasm (p < 0.05). The levels of intracellular cleaved caspase-9, cleaved caspase-3, Apaf-1, Bcl-2-associated X protein (Bax), and suppressor of fused (SuFu) increased, while B cell lymphoma 2 (Bcl-2) and Survivin decreased. What is more, in xenograft tumor model, hesperetin inhibited the tumor growth significantly via induction of cell apoptosis which was detected by TUNEL assay (p < 0.05). Taken together, our study demonstrated that hesperetin could induce cell apoptosis in esophageal cancer cells via mitochondrial-mediated intrinsic pathway by accumulation of ROS.

Cherepanov SA, Baklaushev VP, Gabashvili AN, et al.
[Hedgehog signaling in the pathogenesis of neuro-oncology diseases].
Biomed Khim. 2015 May-Jun; 61(3):332-42 [PubMed] Related Publications
The review summarizes current knowledge on the Hedgehog signaling pathway, its role in normal embryogenesis and/or initiation and progression of neuro-oncological diseases, especially of high-grade gliomas, the most malignant neuroepithelial tumors. The main proteins forming the Hedgehog signaling pathway include Shh, PTCH1, SMO, HHIP, SUFU and GLI1 isoforms. Effects of other signaling pathways on the family of transcription factors GLI and other proteins are described. The review summarizes modern data about the impact of the Hedgehog signaling pathway on proliferation, migration activity and invasiveness, and also on tumor neoangiogenesis and tumor cell chemoresistance. The role of the Hedgehog signaling pathway in origin of cancer stem cells and epithelial-mesenchymal transition is also analyzed. Some prospects for new anticancer drugs acting on components of the Hedgehog signaling pathway inhibitors are demonstrated.

Hoelzl MA, Heby-Henricson K, Bilousova G, et al.
Suppressor of Fused Plays an Important Role in Regulating Mesodermal Differentiation of Murine Embryonic Stem Cells In Vivo.
Stem Cells Dev. 2015; 24(21):2547-60 [PubMed] Related Publications
The hedgehog (Hh) signaling pathway plays fundamental roles during embryonic development and tumorigenesis. Previously, we have shown that ablation of the tumor suppressor and negative regulator, Suppressor of fused (Sufu), within this pathway causes embryonic lethality around E9.5 in the mouse. In this study, we examine how lack of Sufu influences early cell fate determination processes. We established embryonic stem cell (ESC) lines from preimplantation Sufu(-/-) and wild-type mouse embryos and show that these ESCs express the typical pluripotency markers, alkaline phosphatase, SSEA-1, Oct4, Sox2, and Nanog. We demonstrate that these ESCs express all core Hh pathway components and that glioma-associated protein (Gli)1 mRNA levels are increased in Sufu(-/-) ESCs. Upon spontaneous differentiation of Sufu(-/-) ESCs into embryoid bodies (EBs) in vitro, the Hh pathway is strongly upregulated as indicated by an increase in both Gli1 and patched1 (Ptch1) gene expression. Interestingly, developing Sufu(-/-) EBs were smaller than their wild-type counterparts and showed decreased expression of the ectodermal markers, Fgf5 and Sox1. In vivo teratoma formation revealed that Sufu(-/-) ESCs have a limited capacity for differentiation as the resulting tumors lacked the mesodermal derivatives, cartilage and bone. However, Sufu(-/-) ESCs were able to develop into chondrocytes and osteocytes in vitro, which suggests a differential response of ESCs compared with in vivo conditions. Our findings suggest a regulatory function of the Hh signaling pathway in early mesodermal cell fate determination and emphasize the role of Sufu as a key molecule in this process.

Zhao X, Ponomaryov T, Ornell KJ, et al.
RAS/MAPK Activation Drives Resistance to Smo Inhibition, Metastasis, and Tumor Evolution in Shh Pathway-Dependent Tumors.
Cancer Res. 2015; 75(17):3623-35 [PubMed] Free Access to Full Article Related Publications
Aberrant Shh signaling promotes tumor growth in diverse cancers. The importance of Shh signaling is particularly evident in medulloblastoma and basal cell carcinoma (BCC), where inhibitors targeting the Shh pathway component Smoothened (Smo) show great therapeutic promise. However, the emergence of drug resistance limits long-term efficacy, and the mechanisms of resistance remain poorly understood. Using new medulloblastoma models, we identify two distinct paradigms of resistance to Smo inhibition. Sufu mutations lead to maintenance of the Shh pathway in the presence of Smo inhibitors. Alternatively activation of the RAS-MAPK pathway circumvents Shh pathway dependency, drives tumor growth, and enhances metastatic behavior. Strikingly, in BCC patients treated with Smo inhibitor, squamous cell cancers with RAS/MAPK activation emerged from the antecedent BCC tumors. Together, these findings reveal a critical role of the RAS-MAPK pathway in drug resistance and tumor evolution of Shh pathway-dependent tumors.

Smith MJ
Germline and somatic mutations in meningiomas.
Cancer Genet. 2015; 208(4):107-14 [PubMed] Related Publications
Meningiomas arise from the arachnoid layer of the meninges that surround the brain and spine. They account for over one third of all primary central nervous system tumors in adults and confer a significant risk of location-dependent morbidity due to compression or displacement. A significant increase in risk of meningiomas is associated with neurofibromatosis type 2 (NF2) disease through mutation of the NF2 gene. In addition, approximately 5% of individuals with schwannomatosis disease develop meningiomas, through mutation of the SWI/SNF chromatin remodeling complex subunit, SMARCB1. Recently, a second SWI/SNF complex subunit, SMARCE1, was identified as a cause of clear cell meningiomas, indicating a wider role for this complex in meningioma disease. The sonic hedgehog (SHH)-GLI1 signaling pathway gene, SUFU, has also been identified as the cause of hereditary multiple meningiomas in a large Finnish family. The recent identification of somatic mutations in components of the SHH-GLI1 and AKT1-MTOR signaling pathways indicates the potential for cross talk of these pathways in the development of meningiomas. This review describes the known meningioma predisposition genes and their links to the recently identified somatic mutations.

Sharpe HJ, Pau G, Dijkgraaf GJ, et al.
Genomic analysis of smoothened inhibitor resistance in basal cell carcinoma.
Cancer Cell. 2015; 27(3):327-41 [PubMed] Related Publications
Smoothened (SMO) inhibitors are under clinical investigation for the treatment of several cancers. Vismodegib is approved for the treatment of locally advanced and metastatic basal cell carcinoma (BCC). Most BCC patients experience significant clinical benefit on vismodegib, but some develop resistance. Genomic analysis of tumor biopsies revealed that vismodegib resistance is associated with Hedgehog (Hh) pathway reactivation, predominantly through mutation of the drug target SMO and to a lesser extent through concurrent copy number changes in SUFU and GLI2. SMO mutations either directly impaired drug binding or activated SMO to varying levels. Furthermore, we found evidence for intra-tumor heterogeneity, suggesting that a combination of therapies targeting components at multiple levels of the Hh pathway is required to overcome resistance.

Dereure O
[Gorlin syndrome and SUFU germline mutations].
Ann Dermatol Venereol. 2015; 142(3):231-2 [PubMed] Related Publications

Gomes DC, Jamra SA, Leal LF, et al.
Sonic Hedgehog pathway is upregulated in adamantinomatous craniopharyngiomas.
Eur J Endocrinol. 2015; 172(5):603-8 [PubMed] Related Publications
OBJECTIVES: Pituitary stem cells play a role in the oncogenesis of human adamantinomatous craniopharyngiomas (aCPs). We hypothesized that crosstalk between the Wnt/β-catenin and Sonic Hedgehog (SHH) pathways, both of which are important in normal pituitary development, would contribute to the pathogenesis of aCPs.
DESIGN: To explore the mRNA and protein expression of components of the SHH signaling pathway in aCPs and their relationship with the identification of CTNNB1/β-catenin mutations and patients outcomes.
PATIENTS AND METHODS: In 18 aCP samples, CTNNB1 was sequenced, and the mRNA expression levels of SHH pathway members (SHH, PTCH1, SMO, GLI1, GLI2, GLI3, and SUFU) and SMO, GLI1, GLI3, SUFU, β-catenin, and Ki67 proteins were evaluated by quantitative real-time PCR and immunohistochemistry respectively. Anterior normal pituitaries were used as controls. Associations between molecular findings and clinical data were analyzed.
RESULTS: The aCPs presented higher mRNA expression of SHH (+400-fold change (FC); P<0.01), GLI1 (+102-FC; P<0.001), and GLI3 (+5.1-FC; P<0.01) than normal anterior pituitaries. Longer disease-free survival was associated with low SMO and SUFU mRNA expression (P<0.01 and P=0.02 respectively). CTNNB1/β-catenin mutations were found in 47% of the samples. aCPs with identified mutations presented with higher mRNA expression of SMO and GLI1 (+4.3-FC; P=0.02 and +10.2-FC; P=0.03 respectively). SMO, GLI1, GLI3, and SUFU staining was found in 85, 67, 93, and 64% of the samples respectively. Strong GLI1 and GLI3 staining was detected in palisade cells, which also labeled Ki67, a marker of cell proliferation.
CONCLUSIONS: The upregulation of SHH signaling occurs in aCPs. Thus, activation of Wnt/β-catenin and SHH pathways, both of which are important in pituitary embryogenesis, appears to contribute to the pathogenesis of aCP.

Di Magno L, Manzi D, D'Amico D, et al.
Druggable glycolytic requirement for Hedgehog-dependent neuronal and medulloblastoma growth.
Cell Cycle. 2014; 13(21):3404-13 [PubMed] Free Access to Full Article Related Publications
Aberrant activation of SHH pathway is a major cause of medulloblastoma (MB), the most frequent brain malignancy of the childhood. A few Hedgehog inhibitors, all antagonizing the membrane transducer Smo, have been approved or are under clinical trials for the treatment of human MB. However, the efficacy of these drugs is limited by the occurrence of novel mutations or by activation of downstream or non-canonical Hedgehog components. Thus, the identification of novel druggable downstream pathways represents a critical step to overcome this problem. In the present work we demonstrate that aerobic glycolysis is a valuable HH-dependent downstream target, since its inhibition significantly counteracts the HH-mediated growth of normal and tumor cells. Hedgehog activation induces transcription of hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2), two key gatekeepers of glycolysis. The process is mediated by the canonical activation of the Gli transcription factors and causes a robust increase of extracellular lactate concentration. We show that inhibition of glycolysis at different levels blocks the Hedgehog-induced proliferation of granule cell progenitors (GCPs), the cells from which medulloblastoma arises. Remarkably, we demonstrate that this glycolytic transcriptional program is also upregulated in SHH-dependent tumors and that pharmacological targeting with the pyruvate kinase inhibitor dichloroacetate (DCA) efficiently represses MB growth in vitro and in vivo. Together, these data illustrate a previously uncharacterized pharmacological strategy to target Hedgehog dependent growth, which can be exploited for the treatment of medulloblastoma patients.

Smith MJ, Beetz C, Williams SG, et al.
Germline mutations in SUFU cause Gorlin syndrome-associated childhood medulloblastoma and redefine the risk associated with PTCH1 mutations.
J Clin Oncol. 2014; 32(36):4155-61 [PubMed] Related Publications
PURPOSE: Heterozygous germline PTCH1 mutations are causative of Gorlin syndrome (naevoid basal cell carcinoma), but detection rates > 70% have rarely been reported. We aimed to define the causative mutations in individuals with Gorlin syndrome without PTCH1 mutations.
METHODS: We undertook exome sequencing on lymphocyte DNA from four unrelated individuals from families with Gorlin syndrome with no PTCH1 mutations found by Sanger sequencing, multiplex ligation-dependent probe amplification (MLPA), or RNA analysis.
RESULTS: A germline heterozygous nonsense mutation in SUFU was identified in one of four exomes. Sanger sequencing of SUFU in 23 additional PTCH1-negative Gorlin syndrome families identified a SUFU mutation in a second family. Copy-number analysis of SUFU by MLPA revealed a large heterozygous deletion in a third family. All three SUFU-positive families fulfilled diagnostic criteria for Gorlin syndrome, although none had odontogenic jaw keratocysts. Each SUFU-positive family included a single case of medulloblastoma, whereas only two (1.7%) of 115 individuals with Gorlin syndrome and a PTCH1 mutation developed medulloblastoma.
CONCLUSION: We demonstrate convincing evidence that SUFU mutations can cause classical Gorlin syndrome. Our study redefines the risk of medulloblastoma in Gorlin syndrome, dependent on the underlying causative gene. Previous reports have found a 5% risk of medulloblastoma in Gorlin syndrome. We found a < 2% risk in PTCH1 mutation-positive individuals, with a risk up to 20× higher in SUFU mutation-positive individuals. Our data suggest childhood brain magnetic resonance imaging surveillance is justified in SUFU-related, but not PTCH1-related, Gorlin syndrome.

Song J, Zhang J, Wang J, et al.
β1 integrin mediates colorectal cancer cell proliferation and migration through regulation of the Hedgehog pathway.
Tumour Biol. 2015; 36(3):2013-21 [PubMed] Related Publications
β1 integrin (ITGB1) is the major expressed integrin protein of normal cells and tumor-associated cells. It is often up-regulated in human malignancies and is involved in many developmental processes, such as tumor progression and metastasis. However, little is known about the function of ITGB1 in colorectal cancer. We constructed lentiviral vectors expressing ITGB1 or ITGB1-specific RNA interference (RNAi) and an unrelated control vector. After infecting HT29 cells in vitro, proliferation and migration were evaluated by Cell Counting Kit 8 (CCK-8) assays, transwell invasion assays, and Western blots. The influence of lentivirus infection on the tumor development capacity of HT29 cells in vivo was examined by xenografting the tumor cells. The expression of ITGB1 in the xenografted tumor cells was analyzed by immunohistochemistry. The up-regulation of ITGB1 significantly increased the proliferation in HT29 cells in vitro. Moreover, we found that the overexpression of ITGB1 up-regulated sonic hedgehog (Shh) while down-regulating Gli1 and SuFu in HT29-ITGB1 cells compared to controls. Moreover, the levels of c-myc and cyclin D1 proteins were up-regulated. Transwell assays showed that the number of migrating HT29-RNAi cells was lower than that in the other cell groups, indicating that ITGB1 significantly enhances the invasive ability of HT29 cells. In addition to these in vitro results, ITGB1 was found to be a significantly effective growth factor in a xenografted tumor mouse model. These results suggest that ITGB1 induces growth and invasion in a human colorectal cancer cell line through the hedgehog (Hh) signaling pathway in vitro and in vivo.

Liu X, Wang X, Du W, et al.
Suppressor of fused (Sufu) represses Gli1 transcription and nuclear accumulation, inhibits glioma cell proliferation, invasion and vasculogenic mimicry, improving glioma chemo-sensitivity and prognosis.
Oncotarget. 2014; 5(22):11681-94 [PubMed] Free Access to Full Article Related Publications
Glioblastoma are highly aggressive brain tumors with poor prognosis. While various dysregulation of signaling pathways in gliomas have been described, the identification of biomarkers and therapy targets remains an important task for novel diagnostic and therapeutic approaches. Here we described that the Suppressor of fused (also known as Sufu) is significantly down-regulated in high-grade gliomas, correlating with a poor prognosis. We demonstrated that ectopic expression of Sufu inhibited cell proliferation, invasion and vasculogenic mimicry. In addition, overexpression of Sufu reduced Gli reporter gene transcription activity and prevented Gli1 nuclear accumulation, whereas knockdown of Sufu reversed these effects. Furthermore, overexpressed Sufu sensitized glioblastoma to Temozolomide and Cyclopamine. Thus, Sufu is potential tumor suppressor and therapeutic target in glioblastoma.

Long J, Li B, Rodriguez-Blanco J, et al.
The BET bromodomain inhibitor I-BET151 acts downstream of smoothened protein to abrogate the growth of hedgehog protein-driven cancers.
J Biol Chem. 2014; 289(51):35494-502 [PubMed] Free Access to Full Article Related Publications
Epigenetic enzymes modulate signal transduction pathways in different biological contexts. We reasoned that epigenetic regulators might modulate the Hedgehog (HH) signaling pathway, a main driver of cell proliferation in various cancers including medulloblastoma. To test this hypothesis, we performed an unbiased small-molecule screen utilizing an HH-dependent reporter cell line (Light2 cells). We incubated Light2 cells with small molecules targeting different epigenetic modulators and identified four histone deacetylase inhibitors and a bromodomain and extra terminal domain (BET) protein inhibitor (I-BET151) that attenuate HH activity. I-BET151 was also able to inhibit the expression of HH target genes in Sufu(-/-) mouse embryonic fibroblasts, in which constitutive Gli activity is activated in a Smoothened (Smo)-independent fashion, consistent with it acting downstream of Smo. Knockdown of Brd4 (which encodes one of the BET proteins) phenocopies I-BET151 treatment, suggesting that Brd4 is a regulator of the HH signaling pathway. Consistent with this suggestion, Brd4 associates with the proximal promoter region of the Gli1 locus, and does so in a manner that can be reversed by I-BET151. Importantly, I-BET151 also suppressed the HH activity-dependent growth of medulloblastoma cells, in vitro and in vivo. These studies suggest that BET protein modulation may be an attractive therapeutic strategy for attenuating the growth of HH-dependent cancers, such as medulloblastoma.

Mann K, Magee J, Guillaud-Bataille M, et al.
Multiple skin hamartomata: a possible novel clinical presentation of SUFU neoplasia syndrome.
Fam Cancer. 2015; 14(1):151-5 [PubMed] Related Publications
Medulloblastoma tumours may arise sporadically or as part of an inherited syndrome. A subset of children with medulloblastoma carry germline and somatic mutations in the SUFU tumour suppressor gene located at 10q24. We report a 55 year old woman referred for investigation on the basis of skin lesions and a family history of two children from different unions with medulloblastoma. Examination of our patient revealed facial papules (classified as benign folliculosebaceous hamartomatous lesions) and dysmorphology (macrocephaly, hypertelorism and prognathism). She reported her father and her son share the same dermatological features; photographs of the son display hypertelorism. Sequencing in our patient revealed a splice-site mutation in intron 6 of SUFU (c. 756+1G>A), predicted to lead to skipping of exon 6. We suggest that the emerging phenotype in SUFU associated with familial medulloblastoma may include hamartomatous skin lesions. Consideration of these features, along with macrocephaly will alert clinicians to the likely genetic basis of the syndrome, affording the opportunity for genetic counselling, prenatal or pre-implantation genetic diagnosis in at-risk families.

Tang Y, Gholamin S, Schubert S, et al.
Epigenetic targeting of Hedgehog pathway transcriptional output through BET bromodomain inhibition.
Nat Med. 2014; 20(7):732-40 [PubMed] Free Access to Full Article Related Publications
Hedgehog signaling drives oncogenesis in several cancers, and strategies targeting this pathway have been developed, most notably through inhibition of Smoothened (SMO). However, resistance to Smoothened inhibitors occurs by genetic changes of Smoothened or other downstream Hedgehog components. Here we overcome these resistance mechanisms by modulating GLI transcription through inhibition of bromo and extra C-terminal (BET) bromodomain proteins. We show that BRD4 and other BET bromodomain proteins regulate GLI transcription downstream of SMO and suppressor of fused (SUFU), and chromatin immunoprecipitation studies reveal that BRD4 directly occupies GLI1 and GLI2 promoters, with a substantial decrease in engagement of these sites after treatment with JQ1, a small-molecule inhibitor targeting BRD4. Globally, genes associated with medulloblastoma-specific GLI1 binding sites are downregulated in response to JQ1 treatment, supporting direct regulation of GLI activity by BRD4. Notably, patient- and GEMM (genetically engineered mouse model)-derived Hedgehog-driven tumors (basal cell carcinoma, medulloblastoma and atypical teratoid rhabdoid tumor) respond to JQ1 even when harboring genetic lesions rendering them resistant to Smoothened antagonists. Altogether, our results reveal BET proteins as critical regulators of Hedgehog pathway transcriptional output and nominate BET bromodomain inhibitors as a strategy for treating Hedgehog-driven tumors with emerged or a priori resistance to Smoothened antagonists.

Gurgel CA, Buim ME, Carvalho KC, et al.
Transcriptional profiles of SHH pathway genes in keratocystic odontogenic tumor and ameloblastoma.
J Oral Pathol Med. 2014; 43(8):619-26 [PubMed] Related Publications
BACKGROUND: Sonic hedgehog (SHH) pathway activation has been identified as a key factor in the development of many types of tumors, including odontogenic tumors. Our study examined the expression of genes in the SHH pathway to characterize their roles in the pathogenesis of keratocystic odontogenic tumors (KOT) and ameloblastomas (AB).
METHODS: We quantified the expression of SHH, SMO, PTCH1, SUFU, GLI1, CCND1, and BCL2 genes by qPCR in a total of 23 KOT, 11 AB, and three non-neoplastic oral mucosa (NNM). We also measured the expression of proteins related to this pathway (CCND1 and BCL2) by immunohistochemistry.
RESULTS: We observed overexpression of SMO, PTCH1, GLI1, and CCND1 genes in both KOT (23/23) and AB (11/11). However, we did not detect expression of the SHH gene in 21/23 KOT and 10/11 AB tumors. Low levels of the SUFU gene were expressed in KOT (P = 0.0199) and AB (P = 0.0127) relative to the NNM. Recurrent KOT exhibited high levels of SMO (P = 0.035), PTCH1 (P = 0.048), CCND1 (P = 0.048), and BCL2 (P = 0.045) transcripts. Using immunolabeling of CCND1, we observed no statistical difference between primary and recurrent KOT (P = 0.8815), sporadic and NBCCS-KOT (P = 0.7688), and unicystic and solid AB (P = 0.7521).
CONCLUSIONS: Overexpression of upstream (PTCH1 and SMO) and downstream (GLI1, CCND1 and BCL2) genes in the SHH pathway leads to the constitutive activation of this pathway in KOT and AB and may suggest a mechanism for the development of these types of tumors.

Szczepny A, Wagstaff KM, Dias M, et al.
Overlapping binding sites for importin β1 and suppressor of fused (SuFu) on glioma-associated oncogene homologue 1 (Gli1) regulate its nuclear localization.
Biochem J. 2014; 461(3):469-76 [PubMed] Related Publications
A key factor in oncogenesis is the transport into the nucleus of oncogenic signalling molecules, such as Gli1 (glioma-associated oncogene homologue 1), the central transcriptional activator in the Hedgehog signalling pathway. Little is known, however, how factors such as Gli are transported into the nucleus and how this may be regulated by interaction with other cellular factors, such as the negative regulator suppressor of fused (SuFu). In the present study we show for the first time that nuclear entry of Gli1 is regulated by a unique mechanism through mutually exclusive binding by its nuclear import factor Impβ1 (importin β1) and SuFu. Using quantitative live mammalian cell imaging, we show that nuclear accumulation of GFP-Gli1 fusion proteins, but not of a control protein, is specifically inhibited by co-expression of SuFu. Using a direct binding assay, we show that Impβ1 exhibits a high nanomolar affinity to Gli1, with specific knockdown of Impβ1 expression being able to inhibit Gli1 nuclear accumulation, thus implicating Impβ1 as the nuclear transporter for Gli1 for the first time. SuFu also binds to Gli1 with a high nanomolar affinity, intriguingly being able to compete with Impβ1 for binding to Gli1, through the fact that the sites for SuFu and Impβ1 binding overlap at the Gli1 N-terminus. The results indicate for the first time that the relative intracellular concentrations of SuFu and Impβ1 are likely to determine the localization of Gli1, with implications for its action in cancer, as well as in developmental systems.

Gomes DC, Leal LF, Mermejo LM, et al.
Sonic hedgehog signaling is active in human adrenal cortex development and deregulated in adrenocortical tumors.
J Clin Endocrinol Metab. 2014; 99(7):E1209-16 [PubMed] Related Publications
BACKGROUND: The sonic hedgehog (SHH) pathway plays a key role in rodent adrenal cortex development and is involved in tumorigenesis in several human tissues, but data in human adrenal glands are limited.
OBJECTIVES: The objectives of the study were to analyze the involvement of the SHH pathway in human adrenal development and tumorigenesis and the effects of SHH inhibition on an adrenocortical tumor (ACT) cell line.
PATIENTS AND METHODS: Expression of SHH pathway components was evaluated by immunohistochemistry in 51 normal adrenals (33 fetal) and 34 ACTs (23 pediatric) and by quantitative PCR in 81 ACTs (61 pediatric) and 19 controls (10 pediatric). The effects of SHH pathway inhibition on gene expression and cell viability in the NCI-H295A adrenocortical tumor cell line after cyclopamine treatment were analyzed.
RESULTS: SHH pathway proteins were present in fetal and postnatal normal adrenals and showed distinct patterns of spatiotemporal expression throughout development. Adult adrenocortical carcinomas presented with higher expression of PTCH1, SMO, GLI3, and SUFU compared with normal adult adrenal cortices. Conversely, pediatric ACTs showed lower mRNA expression of SHH, PTCH1, SMO, GLI1, and GLI3 compared with normal pediatric adrenal cortices. In vitro treatment with cyclopamine resulted in decreased GLI3, SFRP1, and CTNNB1 mRNA expression and β-catenin staining as well as decreased cell viability.
CONCLUSIONS: The SHH pathway is active in human fetal and postnatal adrenals, up-regulated in adult adrenocortical carcinomas, and down-regulated in pediatric ACTs. SHH pathway antagonism impaired cell viability. The SHH pathway is deregulated in ACTs and might provide a new target therapy to be explored.

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