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Updated: Jan 2, 2026
A Unified Methodological Framework for Vestibular Schwannoma Research
Published on: June 20, 2017
CPI-17 Overexpression and Its Correlation With the NF2 Mutation Spectrum in Sporadic Vestibular Schwannomas
Jianhui Xu1,2, Yang Zhang1,2, Yuxuan Shi1,2
1ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University.
Hypothesis:
We hypothesized that CPI-17 expression and NF2 mutations are correlated with merlin phosphorylation in the etiology of sporadic vestibular schwannoma (VS).
Background:
NF2 gene mutations have been identified in the majority of sporadic and NF2-associated schwannomas and NF2 gene mutations have been shown to result in merlin protein phosphorylation. CPI-17 can drive Ras activity and promote tumorigenic transformation by inhibiting the tumor suppressor merlin. The aim of this study was to determine the correlation between CPI-17 overexpression and the NF2 mutation spectrum in sporadic VS.
Methods:
In this study, we measured CPI-17 expression and identified NF2 gene alterations in a series of sporadic VS samples. Freshly frozen tumor and matched peripheral blood leukocytes from 44 individuals with sporadic VS were analyzed using next-generation sequencing and Sanger sequencing. Western blotting was used to determine the level of merlin phosphorylation, and immunohistochemistry and Western blotting were used to measure CPI-17 expression in the sporadic VS samples. CCK-8 and wound-healing assays were used to determine the influence of CPI-17 overexpression on cell proliferation.
Results:
NF2 mutations were identified in 79.5% of sporadic vestibular schwannomas, with all mutations being exclusively somatic. IHC and WB showed the expression of CPI-17 is upregulated in the sporadic VS. NF2 mutation and CPI-17 are positively correlated with merlin phosphorylation. CPI-17 overexpression induces the proliferation of HEI193 cells.
Conclusion:
NF2 mutations and CPI-17 expression together induce merlin phosphorylation, which is correlated with the tumorigenesis of sporadic VSs.
