Increased replication stress and R-loop accumulation in EGFRvIII-expressing glioblastoma present new therapeutic opportunities

• DOI: 10.1093/noajnl/vdab180
• Publication Date: 2021-12-05T10:26:25Z
• Authors: Nina Struve; Konstantin Hoffer; Anna-Sophie Weik; Britta Riepen; Leonie Krug; Meryem H Cetin; Jasmin Burmester; Leonie Ott; Jana Liebing; Fruzsina Gatzemeier; Justus Müller-Goebel; Mirja Gerbach; Lara Bußmann; Ann Christin Parplys; Kristian Unger; Wael Y Mansour; Ulrich Schüller; Thorsten Rieckmann; Cordula Petersen; Kai Rothkamm; Susan C Short; Malte Kriegs
• Keywords: Replication factor C

Abstract Background The oncogene epidermal growth factor receptor variant III (EGFRvIII) is expressed in approximately one-third of all glioblastomas (GBMs). So far it not clear if EGFRvIII expression induces replication stress GBM cells, which might serve as a therapeutical target. Methods Isogenetic EGFRvIII− and EGFRvIII+ cell lines with endogenous were used. Markers oncogenic such γH2AX, RPA, 53BP1, ATR, CHK1 analyzed using western blot, immunofluorescence, flow cytometry. DNA fiber assay was performed to analyze replication, transcription measured by incorporation EU, genomic instability investigated micronuclei CGH-Array analysis. Immunohistochemistry staining used detect markers R-loops human samples. Results cells exhibit an activated response, increased spontaneous damage, elevated levels single-stranded DNA, reduced velocity, are indicative characteristics stress. Furthermore, we show here that linked instability. EGFRvIII-expressing display RNA synthesis R-loop formation, could also be confirmed EGFRvIII-positive patient Targeting irinotecan resulted sensitivity cells. Conclusion This study demonstrates associated stress, accumulation, contribute intratumoral heterogeneity but may exploited for individualized therapy approaches.