PHF3-specific antibody responses in over 60% of patients with glioblastomamultiforme

Glioblastoma multiforme (GBM), a malignant astrocytic tumour, represents th e most frequent tumour of the human brain. Nevertheless, its molecular path ology is not well understood. We utilized the immune system, which contribu tes to cancer protection, to help identify new GEM-related genes. By screen ing a human GEM cDNA library with autologous patient serum (SEREX-approach) , we isolated a gene termed PHF3 (PHD finger protein 3), The gene product o f PHF3 is immunogenic in GEM as tested in an allogenic patient serum screen ing demonstrating antibodies in 24 of 39 (61.53%) sera, whereas none of the 14 healthy persons had antibodies against PHF3, While previous SEREX studi es revealed allogenic antibody responses up to 40%, our results for PHF3 re present the highest reported rate for a specific antibody response. We show that GEM patients with an antibody response against PHF3 show significant better survival than patients without PHF3-specific antibodies. Because the amino acid sequence of PHF3 contains a PHD finger (also termed LAP motif), a TFIIS homology, a proline rich region and nuclear localization signals, it supposedly functions as a transcription factor. A polyclonal antibody ge nerated against PHF3 shows nuclear expression in most investigated formalin -fixed, paraffin embedded tissues. In GEM, PHF3 expression is concentrated in cells surrounding necroses.