Proteomics of glioblastoma based on microdissection

Objective To analyze differentially expressed proteins in glioblastoma(GBM) tissues and to provide potential clews for early diagnosis of glioblastoma. Methods A total of 27 formalin fixed paraffin embedded(FFPE) specimens of glioblastoma tumor tissues,glioblastoma paired para-neoplastic tissues and non-tumor brain tissues were collected. The tissue samples were obtained using laser capture microdissection(LCM),followed by liquid chromatography-mass spectrometry for quantitative proteomic analysis. The screened differentially expressed proteins were subjected to functional analysis and three of them were selected for immunohistochemical validation. Results A total of 6 205 proteins were identified in these tissue samples. Compared with the non-tumor group,142 proteins were significantly expressed abnormally in the paraneoplastic group and 1 273 proteins in the tumor group; Compared with the paraneoplastic group,743 proteins were significantly expressed abnormally in the tumor group. PTBP1,AK2 and SHMT2 were studied and immunohistochemically verified, the results showed that all three proteins were significantly up-regulated in the tumor group(P＜0.05) as compared with the non-tumor group and paraneoplastic group. Conclusions Significant proteomic differences between tumor,para-neoplastic and non-tumor tissues of glioblastoma provide important clues for in-depth study of early diagnosis of glioblastoma.