Fibroblast growth factor receptor expression investibular schwannoma

INTRODUCTION: The family of fibroblast growth factor (FGF) and their receptors (FGFRs) play a critical role in nervous system development. Aberrant expression or a change in the pattern of their expression may contribute to neural tumour formation. The FGFR expression status in vestibular schwannoma is unknown. AIM: To characterize the pattern of FGFR-1, FGFR-3 and FGFR-4 expression in resection vestibular schwannoma. METHOD: Fifty paraffin-embedded archival specimens of vestibular schwannomas were immunostained fro FGFR-1, FGFR-3 and FGFR-4 using specific rabbit polyclonal antibodies. signals were graded as weak, moderate or strong by two independent observers. Normal tissues and appropriate positive and negative controls were included. RESULTS: FGFR-1 and FGFR-3 appeared to have similar patterns of immunoreactivity with predominantly membrane and cytoplasmic signals in control tissues. In contrast, in vestibular schwannomas, FGFR-1 and FGFR-3, preferentially localize to the nucleau, with moderate to strong signals in 80% and 76% of the specimens, respectively. FGFR-4 expression was upregulated in 70% of vestibular schwannomas to a moderate level, localizing to the perinuclear and cytoplasmic area. Differential cellular localization of receptor proteins has been demonstrated in vestibular schwannomas. CONCLUSION: This is the first comprehensive study characterizing FGFR expression in vestibular schwannoma. The development of vestibular schwannomas is associated with an altered pattern and level of FGFR expression. Our ongoing work aims to examine their significance in the pathogenesis of vestibular schwannomas.