Figures & data
Table 1. Patient demographic and tumor* characteristics
Table 2. Final 35 DNA methylation/gene expression pairs that are significantly associated with survival
Figure 1. Significant expression-based and alternative associations of DNA methylation on gene expression and survival. The 35 unique DNA methylation/gene expression pairs were subjected to an Accelerated Failure Time (AFT) survival model and applied to alternative and expression-based equations (2–5 in methods). This yielded a total of 27 significant methylation/expression pairs, 10 had significant expression-based associations (A), 13 had significant alternative associations (B), and 4 had both significant expression-based and alternative associations (C). Grey lines indicate alternative associations, black lines indicate expression-based associations, gray circles indicate that the methylation locus for that gene pair was found in a CpG island, and black circles indicate that the methylation locus for that gene pair was not found in a CpG island. The y-axis indicates the change in survival time per 5% increase in methylation; therefore, effects that fall above the line are associated with an increase in survival, and effects that fall below the line are associated with a decrease in survival.
Figure 2. Model for mediation analysis. First a linear model adjusted for study was used to determine significantly correlated methylation/expression pairs. Next, a Cox proportional hazards model was used to find significant association between survival and expression, methylation, and their interaction term (adjusting for age, gender, and study phase). An Accelerated failure time model (AFT) was used to estimate the association between survival and expression, methylation, and their interaction term (adjusting for age, gender, and study phase), and a mediation analysis was performed to estimate the alternative and expression-based associations on glioma survival.
