Increased Expression of FAT10 is Correlated with Progression and Prognosis of Human Glioma

Abstract

FAT10, as a small ubiquitin-like modifier, plays an important role in various cellular processes, including mitosis, immune response, and apoptosis, the dys-regulation of which may arise tumorigenesis. Therefore, the aim of this study was to examine the expression of FAT10 at gene and protein levels in glioma samples with different WHO grades and its association with survival. One hundred and twenty-eight glioma specimens and 10 non-neoplastic brain tissues were collected. Immunohistochemistry assay, quantitative real-time PCR and Western blot analysis were carried out to investigate the expression of FAT10. Kaplan-Meier method and Cox's proportional hazards model were used in survival analysis. Immunohistochemistry showed that FAT10 protein was over-expressed in glioma tissues. FAT10 mRNA and protein levels were both higher in glioma compared to control on real-time PCR and Western blot analysis (both P < 0.001). Additionally, its expression levels increase from grade I to grade IV glioma according to the results of real-time PCR, immunohistochemistry analysis and Western blot. Moreover, the survival rate of FAT10-positive patients was significantly lower than that of FAT10-negative patients (P < 0.001). We further confirmed that the increased expression of FAT10 was a significant and independent prognostic indicator in glioma by multivariate analysis (P < 0.001). Our data provides convincing evidence for the first time that the increased expression of FAT10 at gene and protein levels is correlated with poor outcome in patients with glioma. FAT10 may promote the aggressiveness of glioma and may be a potential prognosis predictor of glioma.