Association of Glioblastoma Multiforme Stem Cell Characteristics, Differentiation, and Microglia Marker Genes with Patient Survival

Figure 4

Protein expression of candidate differentiation marker GFAP and microglia markers Iba1 and Sparc in glioblastoma tissue. (a) Protein expression in glioblastoma (GBM) in comparison to nonmalignant brain tissue (NB) determined by Western blot with densitometric analysis. The relative optical densities of the specific bands were calculated and normalized to GAPDH as a loading control in relation to the median of NB. Data are shown as box plots representing the median as horizontal bars as well as the 5th and 95th percentiles. Mann–Whitney U test, . (b) Investigation of an impact of protein expression on patients’ survival by subdividing our patient cohort into two groups in dependence of their survival time (≤median versus >median). Data are shown as box plots representing the median as horizontal bars as well as the 5th and 95th percentiles. Mann–Whitney U test; no significant differences. (c) Kaplan-Meier survival curves for patients with GBM based on their GFAP, Iba1, or Sparc protein expression. Patients were divided into two subgroups depending on the respective median gene expression as determined by quantitative RT-PCR. Calculation of hazard ratios (≤median versus >median expression); Gehan-Breslow-Wilcoxon test and log-rank Mantel-Cox test, no significant differences.

(a)

(b)

(c)