[Expression of S518 phosphorylated Merlin and its interaction with CD44 in vestibular schwannoma].
OBJECTIVE
To investigate the impact of S518 phosphorylation in Merlin on the interaction with CD44 in vestibular schwannoma and the tumor growth.


METHODS
Thirty-five samples of vestibular schwannoma were identified by pathology. Immunohistopathology and western blot were employed to analyze the expression and localization of S518 phosphorylated Merlin in the tumor tissues. Nerve tissues that were collected during other surgical operation were used as control. The expression level of S518 phosphorylated Merlin was compared with clinical stages, tumor size, clinical course and cystic degeneration. Immunoprecipitation was used to evaluate the impact of S518 phosphorylation in Merlin on the interaction with CD44.


RESULTS
In vestibular schwannoma, Merlin was phosphorylated at S518 and demonstrated perinuclear localization. The S518 phosphorylation level was much lower in the normal control nerve tissues than that in vestibular schwannoma tissues. There was no correlation between the phosphorylation level on Merlin and clinical stages, tumor size, clinical course and cystic degeneration. The S518 phosphorylated Merlin bound CD44 was higher than wild-type Merlin bound CD44 in vestibular schwannoma tissues.


CONCLUSIONS
The affinity of Merlin to CD44 was increased after phosphorylation at S518. Different cellular biological results might be triggered through binding to wild type Merlin and S518 phosphorylated Merlin.
Cai
Li-hui
LH
Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Jiaotong University, Shanghai 200092, China.
Wu
Hao
H
Lü
Jing-rong
JR
Wang
Zhao-yan
ZY
D000328:Adult; D000368:Aged; D005260:Female; D016515:Genes, Neurofibromatosis 2; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D025581:Neurofibromin 2 / Q000235:genetics / Q000378:metabolism*; D009464:Neuroma, Acoustic / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation
D018960:Hyaluronan Receptors; D025581:Neurofibromin 2