Abstract: Objective To investigate pathological characteristics of adult H3K27-altered diffuse midline glioma (DMG) and differential protein expression in tumor brain tissue, for providing more comprehensive diagnostic clues. Methods Clinical and pathological data from eight adult patients with H3K27-altered DMG were collected. Proteomics analysis of tumor tissue was performed using laser microdissection combined with mass spectrometry. Differentially expressed proteins were screened for functional analysis, and four key proteins among these proteins were selected for immuno-histochemical validation. Results A total of 6 171 proteins were identified in these tissue samples. Compared with the non-tumor control group, 867 proteins were significantly expressed in the tumor group; compared with the para-neoplastic group, 277 proteins were significantly expressed tumor group. It was mainly related to mRNA synthesis and protein synthesis. CTBP2, YBX1, SRSF1, and SRSF2, which were significantly up-regulated in tumor tissues, were verified by immuno-histochemistry(P＜0.05). Conclusions The tumor tissue exhibits significant proteomic characteristic differences. Differential protein expression analysis can provide more comprehensive information to support diagnosis.

Key words: H3K27-altered diffuse midline glioma, adult, pathological characteristic, differential proteins