Primary high-grade
gliomas possess invasive growth and lead to unfavorable survival outcome. The investigation of
biomarkers for prediction of survival outcome in patients with
gliomas is important for clinical assessment. The DEAD (
Asp-Glu-
Ala-Asp) box helicase 3, X-linked (DDX3X) controls
tumor migration, proliferation, and progression. However, the role of DDX3X in defining the pathological grading and survival outcome in patients with human
gliomas is not yet clarified. We analyzed the DDX3X gene expression, WHO pathological grading, and overall survival from de-linked data. Further validation was done using quantitative RT-PCR of
cDNA from normal brain and
glioma, and immunohistochemical (IHC) staining of tissue microarray. Statistical analysis of GEO datasets showed that DDX3X
mRNA expression demonstrated statistically higher in WHO grade IV (n = 81) than in non-
tumor controls (n = 23, p = 1.13 × 10(-10)). Moreover, DDX3X level was also higher in WHO grade III (n = 19) than in non-
tumor controls (p = 2.43 × 10(-5)). Kaplan-Meier survival analysis showed poor survival in patients with high DDX3X
mRNA levels (n = 24) than in those with low DDX3X expression (n = 53) (median survival, 115 vs. 58 weeks, p = 0.0009, by log-rank test, hazard ratio: 0.3507, 95% CI: 0.1893-0.6496). Furthermore, DDX3X
mRNA expression and
protein production significantly increased in
glioma cells compared with normal brain tissue examined by quantitative RT-PCR, and Western blot. IHC staining showed highly staining of high-grade
glioma in comparison with normal brain tissue. Taken together, DDX3X expression level positively correlates with WHO pathologic grading and poor survival outcome, indicating that DDX3X is a valuable
biomarker in human
gliomas.