Expression of ErbB-1 and 2 in vestibular schwannomas.

ErbB-1 and 2 are receptor tyrosine kinases expressed in malignant tumours. Heterodimers of the ErbB family confer aggressive malignant behaviour, but homodimers are regarded as being less active. Using immunohistochemistry and Western blot techniques we have shown an increased expression of ErbB-2 and no expression of ErbB-1 in vestibular schwannomas (VS). Immunoprecipitation of the ErbB-2 in VS showed less activity when compared to glioblastoma multiforme. These findings implicate a functional role of ErbB-2 in the benign nature of VS and that a rationale for using ErbB targeted therapies in VS may be warranted.