Canadian Journal of Medicine

Abstract

The prognosis of patients with malignant glioma is poor. Identification of novel and effective
biomarkers for this purpose has long been an important target. In this study, we investigated the role
and expression of GFAP, YKL-40 and RBP4 in glioma patients. We evaluated the expression of
markers above on glioma by ELISA, qRT-PCR, Western blot, Kaplan-Meier method, log-rank test
and Cox proportional-hazard analysis. The median RBP4 level in serum sample of patients was
53.61 ± 21.23 ng/ml, while it was 13.07 ± 10.31 ng/ml in control group. Moreover, the result
revealed raised serum concentrations of YKL-40 and GFAP in patients as compared to controls.
(The median level: 293.51± 105.41 versus 86.4 ± 51.2 ng/ml; 187.51± 91.06 versus 24.27 ±
12.64 ng/ml, respectively).And also, the transcriptional levels of RBP4 were determined to be
increased in tumor tissue samples compared with control samples (mean ± SD: 2.82 ± 1.23 vs. 0.75
± 0.21, P <0.001), as well as transcriptional levels YKL-40 and GFAP were notably strong in glioma
patients, comparable to that seen in control tissues (mean ± SD: 5.33± 1.13 vs. 1.21 ± 0.86; 3.05±
1.37 vs. 0.68 ± 0.34; all P <0.001). Consistent with the transcriptional levels, western blotting
analysis also indicated that the RBP4, YKL-40 and GFAP proteins were increased in glioma tissues.
Furthermore, the serum RBP4 level was not linked to advanced tumor grade, age, location or gender
or with Karnofsky performance Status (KPS) (all P >0.05). The serum YKL-40 and GFAP levels
were significantly higher in glioma patients with high tumor grades (P= 0.001). The Kaplan-Meier
analysis and the Log-rank test showed that high expression of YKL-40 and GFAP were associated
with shorter survival (All p <0.001), while RBP4 expression was not related to shorter survival (P
>0.05). Our results showed that high serum expression of YKL-40 and GFAP were independent
prognostic molecule biomarkers for poor prognosis prediction in glioma patients