COMP-10. ANTI-CORRELATED TGFβ AND ALTERNATIVE END-JOINING DNA REPAIR SIGNATURES ASSOCIATE WITH OUTCOME IN PRIMARY GBM

Abstract Transforming growth factor β (TGFβ), which is distinctively overexpressed in glioblastoma (GBM) while undetectable in normal brain tissue, could underlie GBM intrinsic radioresistance by endorsing effective DNA damage responses. We showed that most (5/7) primary GBM explants respond to TGFβ and are radiosensitized by TGFβ inhibition, but a few were unresponsive in both assays (Neoplasia 18:795–805). To further examine the link between TGFβ and the DNA damage response we used microarray transcriptomes from 369 IDH wild-type GBM patients from The Cancer Genome Atlas Consortium (TCGA). Surprisingly, our study unveiled a very strong inverse correlation (Pearson’s correlation coefficient, PCC=-0.80; p