Merlin/NF2 Regulates Angiogenesis in Schwannomas through a Rac1/Semaphorin 3F-Dependent Mechanism
Neurofibromatosis type 2 (NF2) is an autosomal-dominant multiple neoplasia syndrome that results from mutations in the NF2 tumor suppressor gene. Patients with NF2 develop hallmark schwannomas that require surgery or radiation, both of which have significant adverse effects. Recent studies have indi...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2012-02-01
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| Series: | Neoplasia: An International Journal for Oncology Research |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1476558612800388 |
| _version_ | 1818957145255706624 |
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| author | Hon-Kit Wong Akio Shimizu Nathaniel D. Kirkpatrick Igor Garkavtsev Annie W. Chan Emmanuelle di Tomaso Michael Klagsbrun Rakesh K. Jain |
| author_facet | Hon-Kit Wong Akio Shimizu Nathaniel D. Kirkpatrick Igor Garkavtsev Annie W. Chan Emmanuelle di Tomaso Michael Klagsbrun Rakesh K. Jain |
| author_sort | Hon-Kit Wong |
| collection | DOAJ |
| description | Neurofibromatosis type 2 (NF2) is an autosomal-dominant multiple neoplasia syndrome that results from mutations in the NF2 tumor suppressor gene. Patients with NF2 develop hallmark schwannomas that require surgery or radiation, both of which have significant adverse effects. Recent studies have indicated that the tumor microenvironment—in particular, tumor blood vessels—of schwannomas may be an important therapeutic target. Furthermore, although much has been done to understand how merlin, the NF2 gene product, functions as a tumor suppressor gene in schwannoma cells, the functional role of merlin in the tumor microenvironment and the mechanism(s) by which merlin regulates angiogenesis to support schwannoma growth is largely unexplored. Here we report that the expression of semaphorin 3F (SEMA3F) was specifically downregulated in schwannoma cells lacking merlin/NF2. When we reintroduced SEMA3F in schwannoma cells, we observed normalized tumor blood vessels, reduced tumor burden, and extended survival in nude mice bearing merlin-deficient brain tumors. Next, using chemical inhibitors and gene knockdown with RNA interference, we found that merlin regulated expression of SEMA3F through Rho GTPase family member Rac1. This study shows that, in addition to the tumor-suppressing activity of merlin, it also functions to maintain physiological angiogenesis in the nervous system by regulating antiangiogenic factors such as SEMA3F. Restoring the relative balance of proangiogenic and antiangiogenic factors, such as increases in SEMA3F, in schwannoma microenvironment may represent a novel strategy to alleviate the clinical symptoms of NF2-related schwannomas. |
| first_indexed | 2024-12-20T11:05:12Z |
| format | Article |
| id | doaj.art-4ccaaa28b7c7460f8daef679b73ea95d |
| institution | Directory Open Access Journal |
| issn | 1476-5586 1522-8002 |
| language | English |
| last_indexed | 2024-12-20T11:05:12Z |
| publishDate | 2012-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Neoplasia: An International Journal for Oncology Research |
| spelling | doaj.art-4ccaaa28b7c7460f8daef679b73ea95d2022-12-21T19:42:52ZengElsevierNeoplasia: An International Journal for Oncology Research1476-55861522-80022012-02-01142849410.1593/neo.111600Merlin/NF2 Regulates Angiogenesis in Schwannomas through a Rac1/Semaphorin 3F-Dependent MechanismHon-Kit Wong0Akio Shimizu1Nathaniel D. Kirkpatrick2Igor Garkavtsev3Annie W. Chan4Emmanuelle di Tomaso5Michael Klagsbrun6Rakesh K. Jain7The Steele Lab of Tumor Biology, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USADepartments of Surgery and Pathology, Children's Hospital Boston and Harvard Medical School, Boston, MA, USAThe Steele Lab of Tumor Biology, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USAThe Steele Lab of Tumor Biology, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USADepartment of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USAThe Steele Lab of Tumor Biology, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USADepartments of Surgery and Pathology, Children's Hospital Boston and Harvard Medical School, Boston, MA, USAThe Steele Lab of Tumor Biology, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USANeurofibromatosis type 2 (NF2) is an autosomal-dominant multiple neoplasia syndrome that results from mutations in the NF2 tumor suppressor gene. Patients with NF2 develop hallmark schwannomas that require surgery or radiation, both of which have significant adverse effects. Recent studies have indicated that the tumor microenvironment—in particular, tumor blood vessels—of schwannomas may be an important therapeutic target. Furthermore, although much has been done to understand how merlin, the NF2 gene product, functions as a tumor suppressor gene in schwannoma cells, the functional role of merlin in the tumor microenvironment and the mechanism(s) by which merlin regulates angiogenesis to support schwannoma growth is largely unexplored. Here we report that the expression of semaphorin 3F (SEMA3F) was specifically downregulated in schwannoma cells lacking merlin/NF2. When we reintroduced SEMA3F in schwannoma cells, we observed normalized tumor blood vessels, reduced tumor burden, and extended survival in nude mice bearing merlin-deficient brain tumors. Next, using chemical inhibitors and gene knockdown with RNA interference, we found that merlin regulated expression of SEMA3F through Rho GTPase family member Rac1. This study shows that, in addition to the tumor-suppressing activity of merlin, it also functions to maintain physiological angiogenesis in the nervous system by regulating antiangiogenic factors such as SEMA3F. Restoring the relative balance of proangiogenic and antiangiogenic factors, such as increases in SEMA3F, in schwannoma microenvironment may represent a novel strategy to alleviate the clinical symptoms of NF2-related schwannomas.http://www.sciencedirect.com/science/article/pii/S1476558612800388 |
| spellingShingle | Hon-Kit Wong Akio Shimizu Nathaniel D. Kirkpatrick Igor Garkavtsev Annie W. Chan Emmanuelle di Tomaso Michael Klagsbrun Rakesh K. Jain Merlin/NF2 Regulates Angiogenesis in Schwannomas through a Rac1/Semaphorin 3F-Dependent Mechanism Neoplasia: An International Journal for Oncology Research |
| title | Merlin/NF2 Regulates Angiogenesis in Schwannomas through a Rac1/Semaphorin 3F-Dependent Mechanism |
| title_full | Merlin/NF2 Regulates Angiogenesis in Schwannomas through a Rac1/Semaphorin 3F-Dependent Mechanism |
| title_fullStr | Merlin/NF2 Regulates Angiogenesis in Schwannomas through a Rac1/Semaphorin 3F-Dependent Mechanism |
| title_full_unstemmed | Merlin/NF2 Regulates Angiogenesis in Schwannomas through a Rac1/Semaphorin 3F-Dependent Mechanism |
| title_short | Merlin/NF2 Regulates Angiogenesis in Schwannomas through a Rac1/Semaphorin 3F-Dependent Mechanism |
| title_sort | merlin nf2 regulates angiogenesis in schwannomas through a rac1 semaphorin 3f dependent mechanism |
| url | http://www.sciencedirect.com/science/article/pii/S1476558612800388 |
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