Figure 4. Gene expression changes regulating oxidative stress response are associated with radiation resistance in several cancer lineages.

(a) Correlation of NQO1 and SQSTM1 expression with radiation resistance. Spearman's correlation coefficient was calculated between gene expression and integral survival values. Correlation was then plotted relative to correlation rank. (b) Relationship between NQO1 and SQSTM1 mRNA expression in CCLE. (c) ssGSEA association between NFE2L2 signature score and integral survival. (d) NFE2L2 is frequently activated in hepatocellular (HCC) and biliary tumours. A column scatter plot of NFE2L2 signature score for 967 cell lines in the CCLE organized by disease site and histology where appropriate. Solid bars represent the mean in each category. Dashed line represents the median across all CCLE lines. (e) NFE2L2 activity scores and (f) SQSTM1 mRNA levels from HCC and biliary cancer cell lines were plotted as a function of radiation integral survival. (g) Kaplan–Meier survival analysis curve calculated from 122 hepatocellular cancer patients from TCGA (https://tcga-data.nci.nih.gov/tcga/); cut-off=z>1.5. z=+0.8 or greater demonstrated a statistically significant difference in overall survival by the log-rank test.