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Azamat S, Buz-Yalug B, Dindar SS, Yilmaz Tan K, Ozcan A, Can O, Ersen Danyeli A, Pamir MN, Dincer A, Ozduman K, Ozturk-Isik E. Susceptibility-Weighted MRI for Predicting NF-2 Mutations and S100 Protein Expression in Meningiomas. Diagnostics (Basel) 2024; 14:748. [PMID: 38611661 PMCID: PMC11012050 DOI: 10.3390/diagnostics14070748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
S100 protein expression levels and neurofibromatosis type 2 (NF-2) mutations result in different disease courses in meningiomas. This study aimed to investigate non-invasive biomarkers of NF-2 copy number loss and S100 protein expression in meningiomas using morphological, radiomics, and deep learning-based features of susceptibility-weighted MRI (SWI). This retrospective study included 99 patients with S100 protein expression data and 92 patients with NF-2 copy number loss information. Preoperative cranial MRI was conducted using a 3T clinical MR scanner. Tumor volumes were segmented on fluid-attenuated inversion recovery (FLAIR) and subsequent registration of FLAIR to high-resolution SWI was performed. First-order textural features of SWI were extracted and assessed using Pyradiomics. Morphological features, including the tumor growth pattern, peritumoral edema, sinus invasion, hyperostosis, bone destruction, and intratumoral calcification, were semi-quantitatively assessed. Mann-Whitney U tests were utilized to assess the differences in the SWI features of meningiomas with and without S100 protein expression or NF-2 copy number loss. A logistic regression analysis was used to examine the relationship between these features and the respective subgroups. Additionally, a convolutional neural network (CNN) was used to extract hierarchical features of SWI, which were subsequently employed in a light gradient boosting machine classifier to predict the NF-2 copy number loss and S100 protein expression. NF-2 copy number loss was associated with a higher risk of developing high-grade tumors. Additionally, elevated signal intensity and a decrease in entropy within the tumoral region on SWI were observed in meningiomas with S100 protein expression. On the other hand, NF-2 copy number loss was associated with lower SWI signal intensity, a growth pattern described as "en plaque", and the presence of calcification within the tumor. The logistic regression model achieved an accuracy of 0.59 for predicting NF-2 copy number loss and an accuracy of 0.70 for identifying S100 protein expression. Deep learning features demonstrated a strong predictive capability for S100 protein expression (AUC = 0.85 ± 0.06) and had reasonable success in identifying NF-2 copy number loss (AUC = 0.74 ± 0.05). In conclusion, SWI showed promise in identifying NF-2 copy number loss and S100 protein expression by revealing neovascularization and microcalcification characteristics in meningiomas.
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Affiliation(s)
- Sena Azamat
- Institute of Biomedical Engineering, Bogazici University, Istanbul 34342, Turkey
- Basaksehir Cam and Sakura City Hospital, Istanbul 34480, Turkey
| | - Buse Buz-Yalug
- Institute of Biomedical Engineering, Bogazici University, Istanbul 34342, Turkey
| | - Sukru Samet Dindar
- Electrical and Electronics Engineering Department, Bogazici University, Istanbul 34342, Turkey
| | - Kubra Yilmaz Tan
- Department of Medical Biotechnology, Acibadem University, Istanbul 34752, Turkey
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, The Sahlgrenska Academy, University of Gothenburg, 42130 Mölndal, Sweden
| | - Alpay Ozcan
- Electrical and Electronics Engineering Department, Bogazici University, Istanbul 34342, Turkey
| | - Ozge Can
- Department of Biomedical Engineering, Acibadem University, Istanbul 34752, Turkey
| | - Ayca Ersen Danyeli
- Department of Medical Pathology, Acibadem University, Istanbul 34752, Turkey
- Center for Neuroradiological Applications and Research, Acibadem University, Istanbul 34752, Turkey
- Brain Tumor Research Group, Acibadem University, Istanbul 34752, Turkey
| | - M. Necmettin Pamir
- Center for Neuroradiological Applications and Research, Acibadem University, Istanbul 34752, Turkey
- Department of Neurosurgery, Acibadem University, Istanbul 34752, Turkey
| | - Alp Dincer
- Center for Neuroradiological Applications and Research, Acibadem University, Istanbul 34752, Turkey
- Brain Tumor Research Group, Acibadem University, Istanbul 34752, Turkey
- Department of Radiology, Acibadem University, Istanbul 34752, Turkey
| | - Koray Ozduman
- Center for Neuroradiological Applications and Research, Acibadem University, Istanbul 34752, Turkey
- Brain Tumor Research Group, Acibadem University, Istanbul 34752, Turkey
- Department of Neurosurgery, Acibadem University, Istanbul 34752, Turkey
| | - Esin Ozturk-Isik
- Institute of Biomedical Engineering, Bogazici University, Istanbul 34342, Turkey
- Brain Tumor Research Group, Acibadem University, Istanbul 34752, Turkey
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2
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Suspitsin EN, Imyanitov EN. Hereditary Conditions Associated with Elevated Cancer Risk in Childhood. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:880-891. [PMID: 37751861 DOI: 10.1134/s0006297923070039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/16/2023] [Accepted: 03/18/2023] [Indexed: 09/28/2023]
Abstract
Received January, 31, 2023 Revised March, 16, 2023 Accepted March, 18, 2023 Widespread use of the next-generation sequencing (NGS) technologies revealed that a significant percentage of tumors in children develop as a part of monogenic hereditary diseases. Predisposition to the development of pediatric neoplasms is characteristic of a wide range of conditions including hereditary tumor syndromes, primary immunodeficiencies, RASopathies, and phakomatoses. The mechanisms of tumor molecular pathogenesis are diverse and include disturbances in signaling cascades, defects in DNA repair, chromatin remodeling, and microRNA processing. Timely diagnosis of tumor-associated syndromes is important for the proper choice of cancer treatment, genetic counseling of families, and development of the surveillance programs. The review describes the spectrum of neoplasms characteristic of the most common syndromes and molecular pathogenesis of these diseases.
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Affiliation(s)
- Evgeny N Suspitsin
- N. N. Petrov National Medical Research Center of Oncology, Ministry of Health of the Russian Federation, Saint Petersburg, 197758, Russia.
- St.-Petersburg State Pediatric Medical University, Saint Petersburg, 194100, Russia
| | - Evgeny N Imyanitov
- N. N. Petrov National Medical Research Center of Oncology, Ministry of Health of the Russian Federation, Saint Petersburg, 197758, Russia
- St.-Petersburg State Pediatric Medical University, Saint Petersburg, 194100, Russia
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3
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Dougherty MC, Shibata SB, Clark JJ, Canady FJ, Yates CW, Hansen MR. Reduction of sporadic and neurofibromatosis type 2-associated vestibular schwannoma growth in vitro and in vivo after treatment with the c-Jun N-terminal kinase inhibitor AS602801. J Neurosurg 2022; 138:962-971. [PMID: 36087315 DOI: 10.3171/2022.7.jns22934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 07/12/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Vestibular schwannomas (VSs) are benign nerve sheath tumors that result from mutation in the tumor suppressor gene NF2, with functional loss of the protein merlin. The authors have previously shown that c-Jun N-terminal kinase (JNK) is constitutively active in human VS cells and plays a central role in their survival by suppressing accumulation of mitochondrial superoxides, implicating JNK inhibitors as a potential systemic treatment for VS. Thus, the authors hypothesized that the adenosine 5'-triphosphate-competitive JNK inhibitor AS602801 would demonstrate antitumor activity in multiple VS models. METHODS Treatment with AS602801 was tested in primary human VS cultures, human VS xenografts, and a genetic mouse model of schwannoma (Postn-Cre;Nf2flox/flox). Primary human VS cell cultures were established from freshly obtained surgical tumor specimens; treatment group media was enriched with AS602801. VS xenograft tumors were established in male athymic nude mice from freshly collected human tumor. Four weeks postimplantation, a pretreatment MRI scan was obtained, followed by 65 days of AS602801 (n = 18) or vehicle control (n = 19) treatment. Posttreatment MRI scans were used to measure final tumor volume. Tumors were then harvested. Finally, Postn-Cre;Nf2flox/flox mice were treated with AS602801 (n = 10) or a vehicle (n = 13) for 65 days. Posttreatment auditory brainstem responses were obtained. Dorsal root ganglia from Postn-Cre;Nf2flox/flox mice were then harvested. In all models, schwannoma identity was confirmed with anti-S100 staining, cell proliferation was measured with the EdU assay, and cell death was measured with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining. All protocols were approved by the local institutional review board and Institutional Animal Care and Use Committees. RESULTS Treatment with AS602801 decreased cell proliferation and increased apoptosis in primary human VS cultures. The systemic administration of AS602801 in mice with human VS xenografts reduced tumor volume and cell proliferation. Last, the AS602801-treated Postn-Cre;Nf2flox/flox mice demonstrated decreased cell proliferation in glial cells in the dorsal root ganglia. However, AS602801 did not significantly delay hearing loss in Postn-Cre;Nf2flox/flox mice up to 3 months posttreatment. CONCLUSIONS The data suggest that JNK inhibition with AS602801 suppresses growth of sporadic and neurofibromatosis type 2-associated VSs. As such, AS602801 is a potential systemic therapy for VS and warrants further investigation.
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Affiliation(s)
| | - Seiji B Shibata
- 2Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, Iowa; and
| | - J Jason Clark
- 2Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, Iowa; and
| | - Franklin J Canady
- 2Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, Iowa; and
| | - Charles W Yates
- 3Department of Otolaryngology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Marlan R Hansen
- 2Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, Iowa; and
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Ishan M, Chen G, Yu W, Wang Z, Giovannini M, Cao X, Liu HX. Deletion of Nf2 in neural crest-derived tongue mesenchyme alters tongue shape and size, Hippo signalling and cell proliferation in a region- and stage-specific manner. Cell Prolif 2021; 54:e13144. [PMID: 34697858 PMCID: PMC8666282 DOI: 10.1111/cpr.13144] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 12/02/2022] Open
Abstract
Objectives The mammalian tongue develops from the branchial arches (1–4) and comprises highly organized tissues compartmentalized by mesenchyme/connective tissue that is largely derived from neural crest (NC). This study aimed to understand the roles of tumour suppressor Neurofibromin 2 (Nf2) in NC‐derived tongue mesenchyme in regulating Hippo signalling and cell proliferation for the proper development of tongue shape and size. Materials and methods Conditional knockout (cKO) of Nf2 in NC cell lineage was generated using Wnt1‐Cre (Wnt1‐Cre/Nf2cKO). Nf2 expression, Hippo signalling activities, cell proliferation and tongue shape and size were thoroughly analysed in different tongue regions and tissue types of Wnt1‐Cre/Nf2cKO and Cre‐/Nf2fx/fx littermates at various stages (E10.5–E18.5). Results In contrast to many other organs in which the Nf2/Hippo pathway activity restrains growth and cell proliferation and as a result, loss of Nf2 decreases Hippo pathway activity and promotes an enlarged organ development, here we report our observations of distinct, tongue region‐ and stage‐specific alterations of Hippo signalling activity and cell proliferation in Nf2cKO in NC‐derived tongue mesenchyme. Compared to Cre−/Nf2fx/fx littermates, Wnt1‐Cre/Nf2cKO depicted a non‐proportionally enlarged tongue (macroglossia) at E12.5–E13.5 and microglossia at later stages (E15.5–E18.5). Specifically, at E12.5 Nf2cKO mutants had a decreased level of Hippo signalling transcription factor Yes‐associated protein (Yap), Yap target genes and cell proliferation anteriorly, while having an increased Yap, Yap target genes and cell proliferation posteriorly, which lead to a tip‐pointed and posteriorly widened tongue. At E15.5, loss of Nf2 in the NC lineage resulted in distinct changes in cell proliferation in different regions, that is, high in epithelium and mesenchyme subjacent to the epithelium, and lower in deeper layers of the mesenchyme. At E18.5, cell proliferation was reduced throughout the Nf2cKO tongue.
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Affiliation(s)
- Mohamed Ishan
- Regenerative Bioscience Center, University of Georgia, Athens, GA, USA.,Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA
| | - Guiqian Chen
- Regenerative Bioscience Center, University of Georgia, Athens, GA, USA.,Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA
| | - Wenxin Yu
- Regenerative Bioscience Center, University of Georgia, Athens, GA, USA.,Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA
| | - Zhonghou Wang
- Regenerative Bioscience Center, University of Georgia, Athens, GA, USA.,Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA
| | - Marco Giovannini
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Xinwei Cao
- Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Hong-Xiang Liu
- Regenerative Bioscience Center, University of Georgia, Athens, GA, USA.,Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, USA
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Dougherty MC, Shibata SB, Hansen MR. The biological underpinnings of radiation therapy for vestibular schwannomas: Review of the literature. Laryngoscope Investig Otolaryngol 2021; 6:458-468. [PMID: 34195368 PMCID: PMC8223465 DOI: 10.1002/lio2.553] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/05/2021] [Accepted: 03/12/2021] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE Radiation therapy is a mainstay in the treatment of numerous neoplasms. Numerous publications have reported good clinical outcomes for primary radiation therapy for Vestibular Schwannomas (VS). However, there are relatively few pathologic specimens of VSs available to evaluate post-radiation, which has led to a relative dearth in research on the cellular mechanisms underlying the effects of radiation therapy on VSs. METHODS Here we review the latest literature on the complex biological effects of radiation therapy on these benign tumors-including resistance to oxidative stress, mechanisms of DNA damage repair, alterations in normal growth factor pathways, changes in surrounding vasculature, and alterations in immune responses following radiation. RESULTS Although VSs are highly radioresistant, radiotherapy is often successful in arresting their growth. CONCLUSION By better understanding the mechanisms underlying these effects, we could potentially harness such mechanisms in the future to potentiate the clinical effects of radiotherapy on VSs. LEVEL OF EVIDENCE N/A.
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Affiliation(s)
- Mark C. Dougherty
- Department of NeurosurgeryUniversity of Iowa Hospitals & ClinicsIowa CityIowaUSA
| | - Seiji B. Shibata
- Department of Otolaryngology, Keck School of Medicine of USCUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Marlan R. Hansen
- Department of Otolaryngology—Head & Neck SurgeryUniversity of Iowa Hospitals & ClinicsIowa CityIowaUSA
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Neurofibromatosis Type 2 (NF2) and the Implications for Vestibular Schwannoma and Meningioma Pathogenesis. Int J Mol Sci 2021; 22:ijms22020690. [PMID: 33445724 PMCID: PMC7828193 DOI: 10.3390/ijms22020690] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 12/14/2022] Open
Abstract
Patients diagnosed with neurofibromatosis type 2 (NF2) are extremely likely to develop meningiomas, in addition to vestibular schwannomas. Meningiomas are a common primary brain tumor; many NF2 patients suffer from multiple meningiomas. In NF2, patients have mutations in the NF2 gene, specifically with loss of function in a tumor-suppressor protein that has a number of synonymous names, including: Merlin, Neurofibromin 2, and schwannomin. Merlin is a 70 kDa protein that has 10 different isoforms. The Hippo Tumor Suppressor pathway is regulated upstream by Merlin. This pathway is critical in regulating cell proliferation and apoptosis, characteristics that are important for tumor progression. Mutations of the NF2 gene are strongly associated with NF2 diagnosis, leading to benign proliferative conditions such as vestibular schwannomas and meningiomas. Unfortunately, even though these tumors are benign, they are associated with significant morbidity and the potential for early mortality. In this review, we aim to encompass meningiomas and vestibular schwannomas as they pertain to NF2 by assessing molecular genetics, common tumor types, and tumor pathogenesis.
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7
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SHANK2 is a frequently amplified oncogene with evolutionarily conserved roles in regulating Hippo signaling. Protein Cell 2020; 12:174-193. [PMID: 32661924 PMCID: PMC7895894 DOI: 10.1007/s13238-020-00742-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 05/11/2020] [Indexed: 12/22/2022] Open
Abstract
Dysfunction of the Hippo pathway enables cells to evade contact inhibition and provides advantages for cancerous overgrowth. However, for a significant portion of human cancer, how Hippo signaling is perturbed remains unknown. To answer this question, we performed a genome-wide screening for genes that affect the Hippo pathway in Drosophila and cross-referenced the hit genes with human cancer genome. In our screen, Prosap was identified as a novel regulator of the Hippo pathway that potently affects tissue growth. Interestingly, a mammalian homolog of Prosap, SHANK2, is the most frequently amplified gene on 11q13, a major tumor amplicon in human cancer. Gene amplification profile in this 11q13 amplicon clearly indicates selective pressure for SHANK2 amplification. More importantly, across the human cancer genome, SHANK2 is the most frequently amplified gene that is not located within the Myc amplicon. Further studies in multiple human cell lines confirmed that SHANK2 overexpression causes deregulation of Hippo signaling through competitive binding for a LATS1 activator, and as a potential oncogene, SHANK2 promotes cellular transformation and tumor formation in vivo. In cancer cell lines with deregulated Hippo pathway, depletion of SHANK2 restores Hippo signaling and ceases cellular proliferation. Taken together, these results suggest that SHANK2 is an evolutionarily conserved Hippo pathway regulator, commonly amplified in human cancer and potently promotes cancer. Our study for the first time illustrated oncogenic function of SHANK2, one of the most frequently amplified gene in human cancer. Furthermore, given that in normal adult tissues, SHANK2’s expression is largely restricted to the nervous system, SHANK2 may represent an interesting target for anticancer therapy.
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8
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Hong AW, Meng Z, Plouffe SW, Lin Z, Zhang M, Guan KL. Critical roles of phosphoinositides and NF2 in Hippo pathway regulation. Genes Dev 2020; 34:511-525. [PMID: 32115406 PMCID: PMC7111263 DOI: 10.1101/gad.333435.119] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 01/27/2020] [Indexed: 12/29/2022]
Abstract
In this study, Hong et al. provide new insights into how NF2 mediates upstream signals to regulate the Hippo pathway. They show that NF2's lipid-binding ability is critical for its function in activating the Hippo pathway in response to osmotic stress in mammalian cells, and identify the PIP5K family as novel regulators upstream of Hippo signaling. The Hippo pathway is a master regulator of tissue homeostasis and organ size. NF2 is a well-established tumor suppressor, and loss of NF2 severely compromises Hippo pathway activity. However, the precise mechanism of how NF2 mediates upstream signals to regulate the Hippo pathway is not clear. Here we report that, in mammalian cells, NF2's lipid-binding ability is critical for its function in activating the Hippo pathway in response to osmotic stress. Mechanistically, osmotic stress induces PI(4,5)P2 plasma membrane enrichment by activating the PIP5K family, allowing for NF2 plasma membrane recruitment and subsequent downstream Hippo pathway activation. An NF2 mutant deficient in lipid binding is unable to activate the Hippo pathway in response to osmotic stress, as measured by LATS and YAP phosphorylation. Our findings identify the PIP5K family as novel regulators upstream of Hippo signaling, and uncover the importance of phosphoinositide dynamics, specifically PI(4,5)P2, in Hippo pathway regulation.
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Affiliation(s)
- Audrey W Hong
- Department of Pharmacology and Moores Cancer Center, University of California at San Diego, La Jolla, California 92093, USA
| | - Zhipeng Meng
- Department of Pharmacology and Moores Cancer Center, University of California at San Diego, La Jolla, California 92093, USA
| | - Steven W Plouffe
- Department of Pharmacology and Moores Cancer Center, University of California at San Diego, La Jolla, California 92093, USA
| | - Zhijie Lin
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Mingjie Zhang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China.,Center of Systems Biology and Human Health, Hong Kong University of Science and Technology, Kowloon, China
| | - Kun-Liang Guan
- Department of Pharmacology and Moores Cancer Center, University of California at San Diego, La Jolla, California 92093, USA
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Yu C, Zhang L, Luo D, Yan F, Liu J, Shao S, Zhao L, Jin T, Zhao J, Gao L. MicroRNA-146b-3p Promotes Cell Metastasis by Directly Targeting NF2 in Human Papillary Thyroid Cancer. Thyroid 2018; 28:1627-1641. [PMID: 30244634 PMCID: PMC6308293 DOI: 10.1089/thy.2017.0626] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background: MiR-146b has been reported to be overexpressed in papillary thyroid cancer (PTC) tissues and associated with aggressive PTC. MiR-146b is regarded as a relevant diagnostic marker for this type of cancer. MiR-146b-5p has been confirmed to increase cell proliferation by repressing SMAD4. However, detailed functional analysis of another mature form of miR-146b, miR-146b-3p, has not been carried out. This study aimed to identify the differential expression of miR-146b-5p and miR-146b-3p in more aggressive PTC associated with lymph node metastasis, and further elucidate the contribution and mechanism of miR-146b-3p in the process of PTC metastasis. Methods: Expression of miR-146b-5p and miR-146b-3p was assessed in formalin-fixed paraffin-embedded tissue samples from PTC patients, and the relationship with lymph node metastasis was analyzed. A variety of PTC cells, including BHP10-3, BHP10-3SCmice, and K1 cells, were cultured and treated with miR-146b-5p or miR-146b-3p mimics/inhibitors. The cell migration and invasion abilities were characterized by the real-time cell analyzer assay and Transwell™ assay. PTC xenograft models were used to examine the effect of miR-146b-3p on PTC metastatic ability in vivo. Direct downstream targets of miR-146b-3p were analyzed by luciferase reporter assay and Western blotting. The mechanism by which miR-146b-3p affects cell metastasis was further characterized by co-transfection with merlin, the protein product of the NF2 gene. Results: MiR-146b-5p and miR-146b-3p expression was significantly higher in thyroid cancer tissues and cell lines than in normal thyroid tissue and cells. Moreover, expression of miR-146b-5p and miR-146b-3p was further increased in thyroid metastatic nodes than in thyroid cancer. After overexpression of miR-146b-5p or miR-146b-3p in BHP10-3 or K1 cells, PTC migration and invasion were increased. Notably, miR-146b-3p increased cell migration and invasion more obviously than did miR-146b-5p. Overexpression of miR-146b-3p also significantly promoted PTC tumor metastasis in vivo. Luciferase reporter assay results revealed that NF2 is a downstream target of miR-146b-3p in PTC cells, as miR-146b-3p bound directly to the 3' untranslated region of NF2, thus reducing protein levels of NF2. Overexpression of merlin reversed the enhanced aggressive effects of miR-146b-3p. Conclusions: Overexpression of miR-146b-5p and miR-146b-3p is associated with PTC metastasis. MiR-146b-3p enhances cell invasion and metastasis more obviously than miR-146b-5p through the suppression of the NF2 gene. These findings suggest a potential diagnostic and therapeutic value of these miRNAs in PTC metastasis.
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Affiliation(s)
- Chunxiao Yu
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Shandong, P.R. China
- Address correspondence to: Chunxiao Yu, PhD, Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, 324 Jing 5 Road, Jinan, Shandong 2500021, China
| | - Li Zhang
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Shandong, P.R. China
- Department of Endocrinology, Shandong Provincial Third Hospital, Shandong, P.R. China
| | - Dandan Luo
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Shandong, P.R. China
- School of Medicine, Shandong University, Shandong, P.R. China
| | - Fang Yan
- Department of Pain Management, Shandong Provincial Hospital affiliated to Shandong University, Shandong, P.R. China
| | - Jia Liu
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Shandong, P.R. China
| | - Shanshan Shao
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Shandong, P.R. China
| | - Lifang Zhao
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Shandong, P.R. China
| | - Tong Jin
- Department of Otorhinolaryngology, Qilu Hospital, Shandong University, Shandong, P.R. China
| | - Jiajun Zhao
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Shandong, P.R. China
| | - Ling Gao
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Shandong, P.R. China
- Scientific Center, Shandong Provincial Hospital affiliated to Shandong University, Shandong, P.R. China
- Ling Gao, PhD, MD, Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, 324 Jing 5 Road, Jinan, Shandong 2500021, China
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10
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Voltan R. p53 and merlin tumor suppressors: Two of a kind. EBioMedicine 2018; 37:23-24. [PMID: 30385232 PMCID: PMC6286265 DOI: 10.1016/j.ebiom.2018.10.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 10/24/2018] [Indexed: 12/02/2022] Open
Affiliation(s)
- Rebecca Voltan
- Department of Morphology, Surgery, Experimental Medicine and LTTA Centre, University of Ferrara, Via Fossato di Mortara 70, 44121 Ferrara, Italy.
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11
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Olshan M, Srinivasan VM, Landrum T, Sataloff RT. Acoustic neuroma: An investigation of associations between tumor size and diagnostic delays, facial weakness, and surgical complications. EAR, NOSE & THROAT JOURNAL 2016; 93:304-16. [PMID: 25181660 DOI: 10.1177/014556131409300808] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We conducted a retrospective case review to ascertain the clinical characteristics associated with acoustic neuromas and their treatment. Our study population was made up of 96 patients-41 men and 55 women, aged 17 to 84 years (mean: 54)-who had undergone treatment for acoustic neuromas and for whom necessary data were available. We compiled data on presenting symptoms, the interval from symptom onset to diagnosis, tumor size at diagnosis, facial weakness, the interval from diagnosis to surgery, the type of surgical approach, and surgical complications. Our primary goals were to determine if tumor size was correlated to (1) the interval from symptom onset to diagnosis, (2) the degree of preoperative facial weakness, and (3) surgical complications. We also sought to document various other clinical characteristics of these cases. The mean interval from the first symptom to diagnosis was 4.5 years; the time to diagnosis did not correlate with tumor size. Nor was tumor size correlated with the degree of preoperative facial weakness as determined by facial electroneurography. Surgical complications occurred in 15 of the 67 patients who underwent surgery (22.4%), and they did correlate with tumor size. The most common complications were postoperative facial weakness (13.4% of operated patients), cerebrospinal fluid leak (6.0%), and infection (3.0%). Since tumors typically grow about 2 mm per year and since larger tumors are associated with more severe symptoms and surgical complications, we expected that the time to diagnosis would correlate with tumor size, but we found no significant association.
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Affiliation(s)
- Marc Olshan
- Department of Internal Medicine, University of Miami-Jackson Memorial Hospital, Miami, FL, USA
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Troilo A, Benson EK, Esposito D, Garibsingh RAA, Reddy EP, Mungamuri SK, Aaronson SA. Angiomotin stabilization by tankyrase inhibitors antagonizes constitutive TEAD-dependent transcription and proliferation of human tumor cells with Hippo pathway core component mutations. Oncotarget 2016; 7:28765-82. [PMID: 27144834 PMCID: PMC5045355 DOI: 10.18632/oncotarget.9117] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 03/26/2016] [Indexed: 12/29/2022] Open
Abstract
The evolutionarily conserved Hippo inhibitory pathway plays critical roles in tissue homeostasis and organ size control, while mutations affecting certain core components contribute to tumorigenesis. Here we demonstrate that proliferation of Hippo pathway mutant human tumor cells exhibiting high constitutive TEAD transcriptional activity was markedly inhibited by dominant negative TEAD4, which did not inhibit the growth of Hippo wild-type cells with low levels of regulatable TEAD-mediated transcription. The tankyrase inhibitor, XAV939, identified in a screen for inhibitors of TEAD transcriptional activity, phenocopied these effects independently of its other known functions by stabilizing angiomotin and sequestering YAP in the cytosol. We also identified one intrinsically XAV939 resistant Hippo mutant tumor line exhibiting lower and less durable angiomotin stabilization. Thus, angiomotin stabilization provides a new mechanism for targeting tumors with mutations in Hippo pathway core components as well as a biomarker for sensitivity to such therapy.
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Affiliation(s)
- Albino Troilo
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Erica K. Benson
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Davide Esposito
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - E. Premkumar Reddy
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Sathish Kumar Mungamuri
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Stuart A. Aaronson
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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13
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Yu FX, Zhao B, Guan KL. Hippo Pathway in Organ Size Control, Tissue Homeostasis, and Cancer. Cell 2016; 163:811-28. [PMID: 26544935 DOI: 10.1016/j.cell.2015.10.044] [Citation(s) in RCA: 1552] [Impact Index Per Article: 194.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Indexed: 12/16/2022]
Abstract
Two decades of studies in multiple model organisms have established the Hippo pathway as a key regulator of organ size and tissue homeostasis. By inhibiting YAP and TAZ transcription co-activators, the Hippo pathway regulates cell proliferation, apoptosis, and stemness in response to a wide range of extracellular and intracellular signals, including cell-cell contact, cell polarity, mechanical cues, ligands of G-protein-coupled receptors, and cellular energy status. Dysregulation of the Hippo pathway exerts a significant impact on cancer development. Further investigation of the functions and regulatory mechanisms of this pathway will help uncovering the mystery of organ size control and identify new targets for cancer treatment.
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Affiliation(s)
- Fa-Xing Yu
- Children's Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China.
| | - Bin Zhao
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Kun-Liang Guan
- Department of Pharmacology and Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA.
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14
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Role of cyclins D1 and D3 in vestibular schwannoma. The Journal of Laryngology & Otology 2015; 130 Suppl 1:S2-10. [PMID: 26165351 DOI: 10.1017/s0022215115001735] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Vestibular schwannomas in younger patients have been observed to be larger in size and grow more quickly. OBJECTIVE This study aimed to evaluate the expression of three important cell cycle proteins, cyclin D1, cyclin D3 and Ki-67, in vestibular schwannoma patients separated into two age groups: ≤ 40 years or > 40 years. METHOD Immunohistochemical detection of cyclin D1, cyclin D3 and Ki-67 was undertaken in 180 surgically resected vestibular schwannomas. RESULTS The proliferation index of vestibular schwannomas was statistically higher in the ≤ 40 years age group compared to that in the > 40 years age group (mean of 4.52 vs 3.27, respectively; p = 0.01). Overexpression of cyclin D1 and cyclin D3 was found in 68 per cent and 44 per cent of tumours, respectively. CONCLUSION There was an increased Ki-67 proliferation index in the younger age group that appears to correlate with clinical behaviour. Vestibular schwannomas in both age groups show increased expression of cyclin D1 and cyclin D3.
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15
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Ahmad I, Yue WY, Fernando A, Clark JJ, Woodson EA, Hansen MR. p75NTR is highly expressed in vestibular schwannomas and promotes cell survival by activating nuclear transcription factor κB. Glia 2014; 62:1699-712. [PMID: 24976126 PMCID: PMC4150679 DOI: 10.1002/glia.22709] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 06/03/2014] [Accepted: 06/06/2014] [Indexed: 01/08/2023]
Abstract
Vestibular schwannomas (VSs) arise from Schwann cells (SCs) and result from the loss of function of merlin, the protein product of the NF2 tumor suppressor gene. In contrast to non-neoplastic SCs, VS cells survive long-term in the absence of axons. We find that p75(NTR) is overexpressed in VSs compared with normal nerves, both at the transcript and protein level, similar to the response of non-neoplastic SCs following axotomy. Despite elevated p75(NTR) expression, VS cells are resistant to apoptosis due to treatment with proNGF, a high affinity ligand for p75(NTR) . Furthermore, treatment with proNGF protects VS cells from apoptosis due to c-Jun N-terminal kinase (JNK) inhibition indicating that p75(NTR) promotes VS cell survival. Treatment of VS cells with proNGF activated NF-κB while inhibition of JNK with SP600125 or siRNA-mediated knockdown reduced NF-κB activity. Significantly, proNGF also activated NF-κB in cultures treated with JNK inhibitors. Thus, JNK activity appears to be required for basal levels of NF-κB activity but not for proNGF-induced NF-κB activity. To confirm that the increase in NF-κB activity contributes to the prosurvival effect of proNGF, we infected VS cultures with Ad.IκB.SerS32/36A virus, which inhibits NF-κB activation. Compared with control virus, Ad.IκB.SerS32/36A significantly increased apoptosis including in VS cells treated with proNGF. Thus, in contrast to non-neoplastic SCs, p75(NTR) signaling provides a prosurvival response in VS cells by activating NF-κB independent of JNK. Such differences may contribute to the ability of VS cells to survive long-term in the absence of axons.
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Affiliation(s)
- Iram Ahmad
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, Iowa 52242
| | - Wei Ying Yue
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, Iowa 52242
- Department of Otolaryngology-HNS, Mayo Clinic, Rochester, MN
| | - Augusta Fernando
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, Iowa 52242
- Department of Otolaryngology-HNS, Northwestern University, Chicago, IL
| | - J. Jason Clark
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, Iowa 52242
| | - Erika A. Woodson
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, Iowa 52242
- Department of Otolaryngology-HNS, Cleveland Clinic, Cleveland, OH
| | - Marlan R. Hansen
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa, Iowa City, Iowa 52242
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16
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A hypothesis about the potential role of statin administration as adjuvant treatment in the management of Merlin-deficient tumors. INTERDISCIPLINARY NEUROSURGERY-ADVANCED TECHNIQUES AND CASE MANAGEMENT 2014. [DOI: 10.1016/j.inat.2014.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Koutsimpelas D, Ruerup G, Mann WJ, Brieger J. Lack of neurofibromatosis type 2 gene promoter methylation in sporadic vestibular schwannomas. ORL J Otorhinolaryngol Relat Spec 2012; 74:33-7. [PMID: 22249120 DOI: 10.1159/000334968] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 10/27/2011] [Indexed: 11/19/2022]
Abstract
BACKGROUND Vestibular schwannomas (VS) are benign tumors of the nervous system that are usually sporadic but also occur in the inherited disorder neurofibromatosis type 2 (NF2). In VS, losses of chromosomal material and mutations of the NF2 gene have been established to be causative. For a subset of VS without detectable gene alterations, promoter inactivation by hypermethylation has been suggested. However, published data are very limited and contradictory. METHODS We analyzed NF2 gene promoter methylation in 35 sporadic VS by methylation-specific PCR. RESULTS Twenty-three of the tumors were informative, showing no promoter methylation. In the remaining 12 tumors, promoter methylation could neither be verified nor excluded. CONCLUSIONS Our study suggests that NF2 gene inactivation by promoter hypermethylation is a rare or very uncommon mechanism of NF2 gene inactivation in sporadic VS. Other mechanisms destabilizing the NF2 gene product, yet to be identified, might play a role in the genesis of VS apart from the loss or mutation of the NF2 gene.
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Affiliation(s)
- D Koutsimpelas
- Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, Mainz, Germany.
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18
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Kullar PJ, Pearson DM, Malley DS, Collins VP, Ichimura K. CpG island hypermethylation of the neurofibromatosis type 2 (NF2) gene is rare in sporadic vestibular schwannomas. Neuropathol Appl Neurobiol 2011; 36:505-14. [PMID: 20831745 DOI: 10.1111/j.1365-2990.2010.01090.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS Loss of both wild-type copies of the neurofibromatosis type 2 (NF2) gene is found in both sporadic and neurofibromatosis type 2-associated vestibular schwannomas (VS). Previous studies have identified a subset of VS with no loss or mutation of NF2. We hypothesized that methylation of NF2 resulting in gene silencing may play a role in such tumours. METHODS Forty sporadic VS were analysed by array comparative genomic hybridization using 1 Mb whole genome and chromosome 22 tile path arrays. The NF2 genes were sequenced and methylation of NF2 examined by pyrosequencing. RESULTS Monosomy 22 was the only recurrent change found. Twelve tumours had NF2 mutations. Eight tumours had complete loss of wild-type NF2, four had one mutated and one wild-type allele, 11 had only one wild-type allele and 17 showed no abnormalities. Methylation analysis showed low-level methylation in four tumours at a limited number of CpGs. No high-level methylation was found. CONCLUSIONS This study shows that a significant proportion of sporadic VS (>40%) have unmethylated wild-type NF2 genes. This indicates that other mechanisms, yet to be identified, are operative in the oncogenesis of these VSs.
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Affiliation(s)
- P J Kullar
- Division of Molecular Histopathology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
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19
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Sughrue ME, Kane AJ, Shangari G, Parsa AT, Berger MS, McDermott MW. Prevalence of previous extracranial malignancies in a series of 1228 patients presenting with meningioma. J Neurosurg 2010; 113:1115-21. [PMID: 20433279 DOI: 10.3171/2010.3.jns091975] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECT The study of patients with multiple neoplasms can yield valuable insight into the common pathogenesis of both diseases, as well as identify more subtle risk factors that might not be as readily apparent otherwise. The authors present an analysis of the prevalence of previously diagnosed extracranial malignancies at the time of meningioma diagnosis in 1228 patients evaluated at a single institution. METHODS All patients who underwent evaluation and/or treatment for meningioma between 1991 and 2007 at the authors' institution were identified. The intake history and physical were assessed for any history of extracranial malignancy. Using the National Cancer Institute data, the authors calculated an expected cancer prevalence for their meningioma patient population, and compared this derived value to the observed rate of these cancers in this population. RESULTS There were 1228 patients included in this study. A total of 50 patients (4.1%) with newly diagnosed meningioma had a history of an extracranial malignant tumor at the time of their initial meningioma diagnosis. In general, most malignancies did not differ in prevalence from their expected frequency in the population in the present study. Notable exceptions were acute leukemia (p < 0.0001), and papillary thyroid carcinoma, which had a prevalence 2.5 times that expected in this population (p < 0.05). CONCLUSIONS The data support a growing body of evidence suggesting an epidemiological link between papillary carcinoma of the thyroid and meningioma. Although the link between these tumors is not immediately apparent, it is possible that further exploration will yield interesting insight into the pathogenesis of both diseases.
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Affiliation(s)
- Michael E Sughrue
- Brain Tumor Research Center, Department of Neurological Surgery, University of California, San Francisco, California 94143, USA
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20
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Hernandez P, Tirnauer JS. Tumor suppressor interactions with microtubules: keeping cell polarity and cell division on track. Dis Model Mech 2010; 3:304-15. [DOI: 10.1242/dmm.004507] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Tumor suppressor proteins protect cells and tissues from malignant transformation. Among their diverse actions, many of these proteins interact with the microtubule cytoskeleton. This review focuses on the interactions of several tumor suppressors with microtubules and speculates on how disruption of microtubule-dependent processes may contribute to cancer development and spread. We conclude that several tumor suppressors stabilize microtubules and organize microtubule arrays, functions that are likely to be important in preventing tumorigenesis. How tumor suppressors link microtubule stability with cell fate, and how their mutation affects the response of cancer cells to anti-microtubule chemotherapy drugs, remains unclear; these should prove fertile areas for future research.
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Affiliation(s)
- Paula Hernandez
- Center for Molecular Medicine and Neag Comprehensive Cancer Center, University of Connecticut Health Center, Farmington, CT 06030-3101, USA
| | - Jennifer S. Tirnauer
- Center for Molecular Medicine and Neag Comprehensive Cancer Center, University of Connecticut Health Center, Farmington, CT 06030-3101, USA
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21
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Pytel P, Karrison T, Can Gong, Tonsgard JH, Krausz T, Montag AG. Neoplasms with schwannian differentiation express transcription factors known to regulate normal schwann cell development. Int J Surg Pathol 2009; 18:449-57. [PMID: 20034979 DOI: 10.1177/1066896909351698] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A number of transcription factors have been identified as important in guiding normal Schwann cell development. This study used immunohistochemistry on tissue arrays to assess the expression of some of these transcription factors (Sox5, Sox9, Sox10, AP-2α, Pax7, and FoxD3) on 76 schwannomas, 105 neurofibromas, and 34 malignant peripheral nerve sheath tumors (MPNSTs). Sox9 and Sox10 were found to be widely expressed in all tumor types. FoxD3 reactivity was stronger and more frequently found in schwannomas and MPNSTs than neurofibromas. AP-2α was positive in 31% to 49% of all tumors, but strong reactivity was limited to MPNSTs and schwannomas. Pax7 and Sox5 expression was restricted to subsets of MPNSTs. Statistical analysis showed significant differences between the 3 tumor types in the expression of these markers. No differences were found in the analyzed tumor subgroups, including schwannomas of different sites, schwannomas with or without NF2 association, neurofibromas of different types, or sporadic versus NF1-associated MPNSTs. These results suggest that the transcription factors that guide normal Schwann cell development also play a role in the biology of neoplastic cells with Schwannian differentiation. FoxD3, AP-2α, Pax7, and Sox5 are upregulated in MPNSTs compared with neurofibromas and may be markers of malignant transformation. Screening the expression of FoxD3, Sox9, and Sox10 on 23 cases of other spindle-cell proliferations that may be considered in the differential diagnosis of MPNST, including synovial sarcoma and spindle cell melanoma, suggests that these 3 are helpful markers of Schwannian differentiation in the context of diagnosing MPNSTs.
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Affiliation(s)
- Peter Pytel
- University of Chicago Medical Center, Chicago, IL, USA.
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22
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Yeung AH, Sughrue ME, Kane AJ, Tihan T, Cheung SW, Parsa AT. Radiobiology of vestibular schwannomas: mechanisms of radioresistance and potential targets for therapeutic sensitization. Neurosurg Focus 2009; 27:E2. [PMID: 19951055 DOI: 10.3171/2009.9.focus09185] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Vestibular schwannomas (VS) are benign tumors arising from the Schwann cells of cranial nerve VIII. Historically the prevailing therapy for patients with VS has been microsurgical resection. More recently, stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy have gained acceptance as effective alternatives. Although the side effect profile and rates of tumor control appear to be favorable for SRS, there is a subset of radioresistant tumors that continue to progress despite properly administered radiation treatment. In this review, the authors summarize what is known about the mechanism of radioresistance in VS at the clinical and molecular level. An improved understanding of the radiobiological behavior of VS may help guide appropriate patient selection for SRS and potentially aid in the design of novel therapies to treat radioresistant tumors.
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Affiliation(s)
- Andrea H Yeung
- Departments of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, San Francisco, California, USA
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23
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Sughrue ME, Yeung AH, Rutkowski MJ, Cheung SW, Parsa AT. Molecular biology of familial and sporadic vestibular schwannomas: implications for novel therapeutics. J Neurosurg 2009; 114:359-66. [PMID: 19943731 DOI: 10.3171/2009.10.jns091135] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Vestibular schwannomas (VSs) are benign tumors arising from the sheath of cranial nerve VIII. The pathogenesis underlying most familial and sporadic VSs has been linked to a mutation in a single gene, the neurofibromin 2 (NF2) gene located on chromosome 22, band q11-13.1. In this review, the authors summarized what is known about the epidemiology of NF2 mutations and patients with VSs. The authors also discuss the function of the NF2 gene product, merlin, and describe the known and hypothetical effects of genetic mutations that lead to merlin dysfunction on a broad variety of cellular and histological end points. A better understanding of the molecular pathobiology of VSs may lead to novel therapeutics to augment current modalities of treatment while minimizing morbidity.
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Affiliation(s)
- Michael E Sughrue
- Department of Otolaryngology-Head and Neck Surgery, University of California at San Francisco, 94143-0350, USA
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24
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Gerber PA, Antal AS, Neumann NJ, Homey B, Matuschek C, Peiper M, Budach W, Bölke E. Neurofibromatosis. Eur J Med Res 2009; 14:102-5. [PMID: 19380279 PMCID: PMC3352057 DOI: 10.1186/2047-783x-14-3-102] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Neurofibromatosis (NF) is one of the most common genetic disorders. Inherited in an autosomal dominant fashion, this phacomatosis is classified into two genetically distinct subtypes characterized by multiple cutaneous lesions and tumors of the peripheral and central nervous system. Neurofibromatosis type 1 (NF1), also referred to as Recklinghausen's disease, affects about 1 in 3500 individuals and presents with a variety of characteristic abnormalities of the skin and the peripheral nervous system. Neurofibromatosis type 2 (NF2), previously termed central neurofibromatosis, is much more rare occurring in less than 1 in 25 000 individuals. Often first clinical signs of NF2 become apparent in the late teens with a sudden loss of hearing due to the development of bi-or unilateral vestibular schwannomas. In addition NF2 patients may suffer from further nervous tissue tumors such as meningiomas or gliomas. This review summarizes the characteristic features of the two forms of NF and outlines commonalities and distinctions between NF1 and NF2.
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Affiliation(s)
- P A Gerber
- Department of Dermatology, Heinrich-Heine-Universität Düsseldorf, Germany
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25
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Radiosurgical treatment of vestibular schwannomas in patients with neurofibromatosis type 2. Cancer 2008; 115:390-8. [DOI: 10.1002/cncr.24036] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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26
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Yang E, Maguire T, Yarmush M, Androulakis I. Informative gene selection and design of regulatory networks using integer optimization. Comput Chem Eng 2008. [DOI: 10.1016/j.compchemeng.2007.01.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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27
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Cousins VC. Lateral skull base surgery: a complicated pursuit? The Journal of Laryngology & Otology 2007; 122:221-9. [PMID: 17727737 DOI: 10.1017/s0022215107000436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The management of lesions of the lateral skull base is a highly sophisticated branch of surgery generally performed by otolaryngology-head and neck surgeons as part of a multi-disciplinary team. Assessment of patients with diseases affecting the lateral skull base can be complex, as can the application of the various treatment modalities and the management of the expected and unexpected side effects of that treatment. A wide range of pathological conditions occur in the lateral skull base. Many operations and procedures have been described for dealing with them. There is not necessarily one correct solution to the management of any particular problem in the skull base, with multiple factors to be considered in planning and intervention. As surgeons, we need to know how our own results and outcomes compare with pooled, published data concerning the implications and complications occurring as a result of intervention, in order to better advise our patients on their management.
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Affiliation(s)
- V C Cousins
- Department of Surgery, Monash University, The Alfred Hospital, Melbourne, Victoria, Australia
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28
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Lee H, Kim D, Dan HC, Wu EL, Gritsko TM, Cao C, Nicosia SV, Golemis EA, Liu W, Coppola D, Brem SS, Testa JR, Cheng JQ. Identification and characterization of putative tumor suppressor NGB, a GTP-binding protein that interacts with the neurofibromatosis 2 protein. Mol Cell Biol 2007; 27:2103-19. [PMID: 17210637 PMCID: PMC1820506 DOI: 10.1128/mcb.00572-06] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Mutations of the neurofibromatosis 2 (NF2) tumor suppressor gene have frequently been detected not only in schwannomas and other central nervous system tumors of NF2 patients but also in their sporadic counterparts and malignant tumors unrelated to the NF2 syndrome such as malignant mesothelioma, indicating a broader role for the NF2 gene in human tumorigenesis. However, the mechanisms by which the NF2 product, merlin or schwannomin, is regulated and controls cell proliferation remain elusive. Here, we identify a novel GTP-binding protein, dubbed NGB (referring to NF2-associated GTP binding protein), which binds to merlin. NGB is highly conserved between Saccharomyces cerevisiae, Caenorhabditis elegans, and human cells, and its GTP-binding region is very similar to those found in R-ras and Rap2. However, ectopic expression of NGB inhibits cell growth, cell aggregation, and tumorigenicity in tumorigenic schwanomma cells. Down-regulation and infrequent mutation of NGB were detected in human glioma cell lines and primary tumors. The interaction of NGB with merlin impairs the turnover of merlin, yet merlin does not affect the GTPase nor GTP-binding activity of NGB. Finally, the tumor suppressor functions of NGB require merlin and are linked to its ability to suppress cyclin D1 expression. Collectively, these findings indicate that NGB is a tumor suppressor that regulates and requires merlin to suppress cell proliferation.
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Affiliation(s)
- Hansoo Lee
- Department of Pathology, H. Lee Moffitt Cancer Center, University of South Florida, Tampa, FL 33612, USA
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Pellock BJ, Buff E, White K, Hariharan IK. The Drosophila tumor suppressors Expanded and Merlin differentially regulate cell cycle exit, apoptosis, and Wingless signaling. Dev Biol 2006; 304:102-15. [PMID: 17258190 PMCID: PMC1924969 DOI: 10.1016/j.ydbio.2006.12.021] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 12/05/2006] [Accepted: 12/10/2006] [Indexed: 12/19/2022]
Abstract
Mutations that inactivate either merlin (mer) or expanded (ex) result in increased cell growth and proliferation in Drosophila. Both Mer and Ex are members of the Band 4.1 protein superfamily, and, based on analyses of mer ex double mutants, they are proposed to function together in at least a partially redundant manner upstream of the Hippo (Hpo) and Warts (Wts) proteins to regulate cell growth and division. By individually analyzing ex and mer mutant phenotypes, we have found important qualitative and quantitative differences in the ways Mer and Ex function to regulate cell proliferation and cell survival. Though both mer and ex restrict cell and tissue growth, ex clones exhibit delayed cell cycle exit in the developing eye, while mer clones do not. Conversely, loss of mer substantially compromises normal developmental apoptosis in the pupal retina, while loss of ex has only mild effects. Finally, ex has a role in regulating Wingless protein levels in the eye that is not obviously shared by either mer or hpo. Taken together, our data suggest that Mer and Ex differentially regulate multiple downstream pathways.
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Affiliation(s)
- Brett J. Pellock
- Massachusetts General Hospital Cutaneous Biology Research Center
- Massachusetts General Hospital Cancer Center
| | - Eugene Buff
- Massachusetts General Hospital Cancer Center
| | - Kristin White
- Massachusetts General Hospital Cutaneous Biology Research Center
| | - Iswar K. Hariharan
- Massachusetts General Hospital Cancer Center
- University of California, Berkeley Department of Molecular and Cell Biology
- *Corresponding author: Iswar K. Hariharan, University of California, Berkeley, Department of Molecular and Cell Biology, 361 LSA, Berkeley, CA 94720, , phone: 510 643 7438, fax: 510 643 7448
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Musti M, Kettunen E, Dragonieri S, Lindholm P, Cavone D, Serio G, Knuutila S. Cytogenetic and molecular genetic changes in malignant mesothelioma. ACTA ACUST UNITED AC 2006; 170:9-15. [PMID: 16965949 DOI: 10.1016/j.cancergencyto.2006.04.011] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 03/28/2006] [Accepted: 04/04/2006] [Indexed: 11/29/2022]
Abstract
Malignant mesothelioma (MM) results from the accumulation of a number of acquired genetic events, especially deletions, which lead to the inactivation of multiple onco-suppressor genes in a multistep cascade mechanism. Past asbestos exposure represents the major risk factor for MM, and the link between asbestos fibers and MM has been largely proved by several epidemiologic and experimental studies. Asbestos fibers induce DNA and chromosomal damage. Most MM cases have shown multiple chromosomal abnormalities. Chromosomal losses are more common than gains. The most common cytogenetic abnormality in MM is a deletion in 9p21, the locus of CDKN2A, a tumor suppressor gene (TSG). The deletion of CDKN2A is a negative prognostic factor in MM. Loss of TSG CDKN2A/p14(ARF) is also common in MM and mutations in NF2 occur in approximately half of the cases. Despite the ban on asbestos use in Western countries, the incidence of MM is increasing, and asbestos is still used in developing countries. This epidemiologic situation calls for further research. Ongoing studies are already applying high-throughput genomic profiling methods in MM. Genetic alterations observed in MM may be useful in differential diagnosis between lung cancer and MM, as diagnostic markers or therapeutic targets, and as indicators of premalignancy for primary prevention and health surveillance.
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Affiliation(s)
- Marina Musti
- Preventive Medicine of Workers and Psychotechnology, Department of Internal Medicine and Public Medicine, Section of Occupational Medicine, University of Bari, and National Register of Mesothelioma, Regional Operative Centre Apulia, Bari, Italy
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Jin H, Sperka T, Herrlich P, Morrison H. Tumorigenic transformation by CPI-17 through inhibition of a merlin phosphatase. Nature 2006; 442:576-9. [PMID: 16885985 DOI: 10.1038/nature04856] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2005] [Accepted: 05/02/2006] [Indexed: 11/08/2022]
Abstract
The tumour suppressor protein merlin (encoded by the neurofibromatosis type 2 gene NF2) is an important regulator of proliferation in many cell and tissue types. Merlin is activated by dephosphorylation at serine 518 (S518), which occurs on serum withdrawal or on cell-cell or cell-matrix contact. However, the relevant phosphatase that activates merlin's tumour suppressor function is unknown. Here we identify this enzyme as the myosin phosphatase (MYPT-1-PP1delta). The cellular MYPT-1-PP1delta-specific inhibitor CPI-17 causes a loss of merlin function characterized by merlin phosphorylation, Ras activation and transformation. Constitutively active merlin (S518A) reverses CPI-17-induced transformation, showing that merlin is the decisive substrate of MYPT-1-PP1delta in tumour suppression. In addition we show that CPI-17 levels are raised in several human tumour cell lines and that the downregulation of CPI-17 induces merlin dephosphorylation, inhibits Ras activation and abolishes the transformed phenotype. MYPT-1-PP1delta and its substrate merlin are part of a previously undescribed tumour suppressor cascade that can be hindered in two ways, by mutation of the NF2 gene and by upregulation of the oncoprotein CPI-17.
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Affiliation(s)
- Hongchuan Jin
- Leibniz Institute of Age Research-Fritz-Lipmann-Institute, Beutenbergstrasse 11, 07745 Jena, Germany
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Hansen MR, Roehm PC, Chatterjee P, Green SH. Constitutive neuregulin-1/ErbB signaling contributes to human vestibular schwannoma proliferation. Glia 2006; 53:593-600. [PMID: 16432850 DOI: 10.1002/glia.20316] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vestibular schwannomas (VSs) are benign tumors that arise from the Schwann cells (SCs) lining the vestibular nerve. VS cells survive and proliferate far from neurons and axonally derived growth factors. We have previously shown that VSs produce the glial growth factor, neuregulin-1 (NRG1), and its receptors, ErbB2 and ErbB3. In the present work, we explore the contribution of constitutive NRG1:ErbB signaling to human VS cell proliferation. We confirm that human VSs, which express markers of immature and denervated SCs, also express endogenous NRG1 and activated ErbB2. We find that a blocking anti-NRG1 antibody and trastuzumab (Herceptin, HCN), a humanized anti-ErbB2 inhibitory monoclonal antibody, effectively inhibit NRG1 induced SC proliferation. Treatment of primary VS cultures with anti-NRG1 or HCN reduces cell proliferation in the absence of exogenous NRG1. Furthermore, conditioned medium from VS cell cultures contains NRG1 and stimulates SC proliferation in SC cultures, an effect that is inhibited by anti-NRG1 and HCN. These data suggest an autocrine pathway of VS growth stimulation involving NRG and ErbB receptors. Inhibition of constitutive NRG:ErbB signaling reduces VS cell proliferation in vitro and may have therapeutic potential for patients with VSs.
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MESH Headings
- Animals
- Animals, Newborn
- Antibodies/pharmacology
- Autocrine Communication/drug effects
- Autocrine Communication/physiology
- Biomarkers/metabolism
- Cell Differentiation/drug effects
- Cell Differentiation/physiology
- Cell Division/drug effects
- Cell Division/physiology
- Cell Proliferation/drug effects
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cells, Cultured
- Culture Media, Conditioned/pharmacology
- Down-Regulation/drug effects
- Down-Regulation/physiology
- Gene Expression Regulation, Neoplastic/physiology
- Glycoproteins/metabolism
- Humans
- Neuregulin-1/antagonists & inhibitors
- Neuregulin-1/genetics
- Neuregulin-1/metabolism
- Neuroma, Acoustic/genetics
- Neuroma, Acoustic/metabolism
- Neuroma, Acoustic/pathology
- Oncogene Proteins v-erbB/genetics
- Oncogene Proteins v-erbB/metabolism
- Rats
- Receptor, ErbB-2
- Schwann Cells/drug effects
- Schwann Cells/metabolism
- Signal Transduction/physiology
- Stem Cells/drug effects
- Stem Cells/metabolism
- Vestibular Nerve/metabolism
- Vestibular Nerve/pathology
- Vestibular Nerve/physiopathology
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Affiliation(s)
- Marlan R Hansen
- Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, 52242, USA.
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Stonecypher MS, Chaudhury AR, Byer SJ, Carroll SL. Neuregulin growth factors and their ErbB receptors form a potential signaling network for schwannoma tumorigenesis. J Neuropathol Exp Neurol 2006; 65:162-75. [PMID: 16462207 DOI: 10.1097/01.jnen.0000199575.93794.2f] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Sporadic and neurofibromatosis type 2-associated schwannomas contain a glial growth factor (GGF)-like activity that has been hypothesized to promote neoplastic Schwann cell mitogenesis. It is not known whether this GGF-like activity is neuregulin-1 (NRG-1), an epidermal growth factor (EGF)-related molecule that regulates the proliferation, survival, and differentiation of developing Schwann cells, the related factor NRG-2, or another NRG/EGF ligand. We report that neoplastic Schwann cells within schwannomas overexpress multiple alpha and beta transmembrane precursors from the class II and class III NRG-1 subfamilies. NRG-2 alpha and beta transcripts are similarly overexpressed in some tumors. Of the other 8 known NRG/EGF ligands, only heparin-binding EGF, epiregulin, and TGFalpha are detectable in schwannomas. Neoplastic Schwann cells almost uniformly express erbB2 and erbB3, 2 membrane receptor tyrosine kinases mediating NRG-1 and NRG-2 action. Expression of the NRG receptor erbB4 and EGF receptor is also evident in schwannomas, but is more limited, occurring in only a subset of these tumors. ErbB2, the preferred dimerization partner for all erbB kinases, is constitutively phosphorylated in schwannomas. These observations suggest that autocrine, paracrine, and/or juxtacrine NRG-1/NRG-2 signaling promotes schwannoma pathogenesis and that this signaling pathway may be an important therapeutic target in schwannomas.
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Affiliation(s)
- Mark S Stonecypher
- Department of Cell Biology, The University of Alabama at Birmingham, 1720 Seventh Avenue South, Birmingham, AL 35294, USA
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Abstract
Neurofibromatosis types 1 and 2 (NF1 and NF2) are autosomal dominant phakomatoses. The NF1 and NF2 genes encode for neurofibromin and merlin, respectively. These 2 functionally unrelated proteins both act as tumor suppressor genes, possibly through modulation of the RAS/RAC oncogenic pathways. Improved understanding of the mechanisms by which these tumor suppressors act may allow for medical therapies for neurofibromatosis and may offer insights for cancer therapeutics.
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Affiliation(s)
- Kaleb H Yohay
- Division of Child Neurology and Pediatrics, Johns Hopkins University, Baltimore, MD 21287, USA.
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Wei BL, Arora VK, Raney A, Kuo LS, Xiao GH, O'Neill E, Testa JR, Foster JL, Garcia JV. Activation of p21-activated kinase 2 by human immunodeficiency virus type 1 Nef induces merlin phosphorylation. J Virol 2006; 79:14976-80. [PMID: 16282498 PMCID: PMC1287594 DOI: 10.1128/jvi.79.23.14976-14980.2005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The accessory human immunodeficiency virus type 1 (HIV-1) protein Nef activates the autophosphorylation activity of p21-activated kinase 2 (PAK2). Merlin, a cellular substrate of PAK2, is homologous to the ezrin-radixin-moesin family and plays a critical role in Rac signaling. To assess the possible impact on host cell metabolism of Nef-induced PAK2 activation, we investigated the phosphorylation of merlin in Nef expressing cells. Here we report that Nef induces merlin phosphorylation in multiple cell lines independently of protein kinase A. This intracellular phosphorylation of merlin directly correlates with in vitro assay of the autophosphorylation activity of Nef-activated PAK2. Importantly, merlin phosphorylation induced by Nef was also observed in human primary T cells. The finding that Nef induces phosphorylation of the key signaling molecule merlin suggests several possible roles for PAK2 activation in HIV pathogenesis.
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Affiliation(s)
- Bangdong L Wei
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
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Hamaratoglu F, Willecke M, Kango-Singh M, Nolo R, Hyun E, Tao C, Jafar-Nejad H, Halder G. The tumour-suppressor genes NF2/Merlin and Expanded act through Hippo signalling to regulate cell proliferation and apoptosis. Nat Cell Biol 2005; 8:27-36. [PMID: 16341207 DOI: 10.1038/ncb1339] [Citation(s) in RCA: 611] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Accepted: 11/17/2005] [Indexed: 11/09/2022]
Abstract
Merlin, the protein product of the Neurofibromatosis type-2 gene, acts as a tumour suppressor in mice and humans. Merlin is an adaptor protein with a FERM domain and it is thought to transduce a growth-regulatory signal. However, the pathway through which Merlin acts as a tumour suppressor is poorly understood. Merlin, and its function as a negative regulator of growth, is conserved in Drosophila, where it functions with Expanded, a related FERM domain protein. Here, we show that Drosophila Merlin and Expanded are components of the Hippo signalling pathway, an emerging tumour-suppressor pathway. We find that Merlin and Expanded, similar to other components of the Hippo pathway, are required for proliferation arrest and apoptosis in developing imaginal discs. Our genetic and biochemical data place Merlin and Expanded upstream of Hippo and identify a pathway through which they act as tumour-suppressor genes.
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Affiliation(s)
- Fisun Hamaratoglu
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
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Abstract
Motor proteins link concepts of impaired axonal transport with concepts of impaired energy metabolism in motor neuron disease. Thus it is not surprising that in recent years several reports on the relevance of motor protein function in mice models for motor neuron disease as well as motor neuron patients have appeared. This article summarizes the broad spectrum of neurological phenotypes, which are caused by alterations of motor protein function. This is likely to add to the understanding of motor neuron disease and may be relevant in terms of future therapeutic approaches.
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Bian LG, Tirakotai W, Sun QF, Zhao WG, Shen JK, Luo QZ. Molecular genetics alterations and tumor behavior of sporadic vestibular schwannoma from the People's Republic of China. J Neurooncol 2005; 73:253-60. [PMID: 15980976 DOI: 10.1007/s11060-004-5176-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2004] [Indexed: 10/25/2022]
Abstract
OBJECTIVES To analyze the molecular genetic alteration of sporadic vestibular schwannomas from the People's Republic of China and to correlate these alterations with the tumor behaviors. METHODS Four highly polymorphic microsatellite DNA markers were used to observe the frequency of loss of heterozygosity (LOH) in chromosome 22. The NF2 gene mutations were detected by Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing. The schwannomin/merlin (S/M) expression was examined using anti-NF2 (A-19) IgG under immunohistochemistry and western blot. The proliferative index (LI) of vestibular schwannoma was evaluated by proliferative cell nuclear antigen investigation. RESULTS Sixteen vestibular schwannomas (44.4%) showed allele loss. We found 22 mutations in 36 schwannomas. The LI and the growth rate of schwannomas with LOH or mutation were significantly higher than those without LOH or mutation. All of these vestibular schwannomas showed no immunoreaction to anti-NF2(A-19) IgG by immunohistochemistry. By immunoblotting technique, reduced expression of S/M was found in 31 cases (86%). The growth index of schwannomas with severely reduced expression of S/M was significantly higher than those with moderately reduced or normal expression. CONCLUSION The molecular genetic changes in sporadic vestibular schwannomas from Chinese patients were similar to the previous reports. We demonstrate the relationship between tumor behaviors and genetic alteration (including LOH and mutation of NF2 gene). We propose that inactivation of S/M, may be an important step in tumorigenesis of sporadic vestibular schwannoma.
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Affiliation(s)
- Liu-Guan Bian
- Department of Neurosurgery, Rui-Jin Hospital, Shanghai Second Medical University, Shanghai, The People's Republic of China.
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Abstract
The percentage of childhood cancers that are caused by a clearly inherited predisposition varies significantly from only a few percent to more than 50% with individual tumor types. Recent advances in genetic testing and studies of cohorts of cancer patients have demonstrated the likelihood of identifying a cancer susceptibility mutation for numerous childhood cancers. Inherited predisposition to cancer is frequently the result of dominant constitutional mutations in tumor suppressor genes, which can be inherited from an affected parent or occur de novo during gametogenesis. In this article, we review the childhood malignancies that are associated with at least a 10% likelihood of being caused by a genetic susceptibility to cancer and therefore warrant consideration for a genetic evaluation; these malignancies include retinoblastoma, adrenocortical carcinoma, atypical teratoid and malignant rhabdoid tumors, optic pathway tumors, juvenile myelomonocytic leukemia, malignant peripheral nerve sheath tumors, vestibular schwannomas, endolymphatic sac tumors, hemangioblastomas, medullary thyroid cancer, pheochromocytomas, and paragangliomas. Children with other malignancies may also warrant genetic evaluation if there is the co-occurrence of malignancy and two or more congenital anomalies, or malignancy and a significant family history of related cancers. We also review the importance of the correct genetic diagnosis in order to ensure appropriate treatment and ongoing cancer surveillance for the child with cancer and closely related family members (e.g., parents and siblings).
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Affiliation(s)
- Sharon E Plon
- Texas Children's Cancer Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA.
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40
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Bignold LP. The cell-type-specificity of inherited predispositions to tumours: review and hypothesis. Cancer Lett 2005; 216:127-46. [PMID: 15533589 DOI: 10.1016/j.canlet.2004.07.037] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Revised: 07/28/2004] [Accepted: 07/29/2004] [Indexed: 12/19/2022]
Abstract
Most hereditary predispositions to tumours affect only one particular cell type of the body but the genes bearing the relevant germ-line mutation are not cell-type-specific. Some predisposition syndromes include increased risks of lesions (developmental or tumourous) of unrelated cell types, in any individual predisposed to the main lesion (e.g. osteosarcoma in patients predisposed to retinoblastoma). Other predispositions to additional lesions occur only in members of some families with the predisposition to the basic lesion (e.g. Gardner's syndrome in some families suffering familial adenomatous polyposis). In yet other predisposition syndromes, different mutations of the same gene are associated with markedly differing family-specific clinical syndromes. In particular, identical germline mutations (e.g. in APC, RET and PTEN genes), have been found associated with differing clinical syndromes in different families. This paper reviews previously suggested mechanisms of the cell-type specificity of inherited predispositions to tumour. Models of tumour formation in predisposition syndromes are discussed, especially those involving a germline mutation (the first 'hit') of a tumour suppressor gene (TSG) and a second (somatic) hit on the second allele of the same TSG. A modified model is suggested, such that the second hit is a co-mutation of the second allele of the TSG and a regulator which is specific for growth and/or differentiation of the cell type which is susceptible to the tumour predisposition. In some cases of tumour, the second hit may be large enough to be associated with a cytogenetically-demonstrable abnormality of the part of the chromosome carrying the TSG, but in other cases, the co-mutation may be of 'sub-cytogenetic' size (i.e. 10(2)-10(5) bases). For the latter, mutational mechanisms of frameshift and impaired fidelity of replication of DNA by DNA polyerases may sometimes be involved. Candidate cell-type-specific regulators may include microRNAs and perhaps transcription factors. It is suggested that searching the introns within 10(5)-10(6) bases either side of known of exonic mutations of TSGs associated with inherited tumour predisposition might reveal microRNA cell-type-specific regulators. Additional investigations may involve fluorescent in situ hybridisations on interphase tumour nuclei.
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Affiliation(s)
- Leon P Bignold
- Division of Tissue Pathology, Institute of Medical and Veterinary Science, PO Box 14, Rundle Mall, Adelaide, SA 5001, Australia.
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Abstract
Peripheral nerve tumors show an interesting histologic variety despite being composed ofa limited array of cellular constituents. As we learn more about the interplay between the Schwann cells, perineurial cells, and ganglion cells that comprise these tumors, it is likely that we will better understand the biologic behavior of these important tumors. Key issues for the pathologist include distinguishing schwannomas from neurofibromas, ganglioneuromas from neurofibromas involving ganglia, and MPNSTs from cellular schwannomas or neurofibromas. The association of each of these tumors with genetic tumor disorders provides a unique window into discovering basic mechanisms of cell regulation and tumorigenesis that may ultimately shed light on the biology of a much wider array of human disease.
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Affiliation(s)
- Daniel M Skovronsky
- Division of Neuropathology, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, 613 Stellar Chance, 422 Curie Boulevard, Philadelphia, PA 19104, USA.
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Affiliation(s)
- Zahara M Jaffer
- Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA
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