Merlin; NF2 Tumor Suppressor and Regulator of Receptor Distribution/Signaling

Abstract

Received March 23, 2011 Accepted March 30, 2011 Address for correspondence Ju Hyoung Lee, MD Department of OtolaryngologyHead and Neck Surgery, Gil Medical Center, Gachon University of Medicine & Science, 1198 Guwol-dong, Namdong-gu, Incheon 405-760, Korea Tel +82-32-460-3763 Fax +82-32-467-9044 E-mail febent@gilhospital.com Acoustic tumor is the most common tumor originating from cerebellopontine angle. Acoustic tumor is benign and main origin of this tumor is vestibular nerve. This tumor arises in Schwann cell (SC) and is encapsulated. Recently, the tumor is called vestibular schwannoma (VS). VS is classified to two type by epidemiology, sporadic form and neurofibromatosis type 2 (NF2). NF2 is autosomal dominant inherent disorder. This tumor is characterized bilateral VS, brain tumors such as meningioma and ependymoma, and spinal or cranial nerve schwannoma. Genetic studies suggested that NF2 is caused by abnormality or mutation of NF2 gene in chromosome 22q12. Both of them are known to develop the tumor by mutation of NF2 gene. Merlin is the cytoskeletal protein product of the NF2 tumor suppressor gene that mediates cell to cell contact information to regulate SC proliferation and survival. And merlin is highly homologous to ERM proteins. Merlin function is regulated by its conformation, adopting an inactive, growth permissive state following serine 518 (S518) phosphorylation. In NF2 patients, the precise mechanisms of developing the VS are unclear. But, the abnormalities of merlin are confirmed by many studies. And now, a lot of research about merlin function is progressing. In this study, the author would introduce about merlin (structure, function, molecular pathway, tumorigenesis and regulation) which leads to VS and molecular studies about merlin, and suggest the future direction of research. Korean J Otorhinolaryngol-Head Neck Surg 2011;54:379-85