RT Journal Article SR Electronic T1 Inhibiting Integrin β8 to Differentiate and Radiosensitize Glioblastoma-Initiating Cells JF Molecular Cancer Research JO Mol Cancer Res FD American Association for Cancer Research SP 384 OP 397 DO 10.1158/1541-7786.MCR-18-0386 VO 17 IS 2 A1 Malric, Laure A1 Monferran, Sylvie A1 Delmas, Caroline A1 Arnauduc, Florent A1 Dahan, Perrine A1 Boyrie, Sabrina A1 Deshors, Pauline A1 Lubrano, Vincent A1 Da Mota, Dina Ferreira A1 Gilhodes, Julia A1 Filleron, Thomas A1 Siegfried, Aurore A1 Evrard, Solène A1 Kowalski-Chauvel, Aline A1 Moyal, Elizabeth Cohen-Jonathan A1 Toulas, Christine A1 Lemarié, Anthony YR 2019 UL http://mcr.aacrjournals.org/content/17/2/384.abstract AB Glioblastomas (GB) are malignant brain tumors with poor prognosis despite treatment with surgery and radio/chemotherapy. These tumors are defined by an important cellular heterogeneity and notably contain a subpopulation of GB-initiating cells (GIC), which contribute to tumor aggressiveness, resistance, and recurrence. Some integrins are specifically expressed by GICs and could be actionable targets to improve GB treatment. Here, integrin β8 (ITGB8) was identified as a potential selective target in this highly tumorigenic GIC subpopulation. Using several patient-derived primocultures, it was demonstrated that ITGB8 is overexpressed in GICs compared with their differentiated progeny. Furthermore, ITGB8 is also overexpressed in GB, and its overexpression is correlated with poor prognosis and with the expression of several other classic stem cell markers. Moreover, inhibiting ITGB8 diminished several main GIC characteristics and features, including self-renewal ability, stemness, migration potential, and tumor formation capacity. Blockade of ITGB8 significantly impaired GIC cell viability via apoptosis induction. Finally, the combination of radiotherapy and ITGB8 targeting radiosensitized GICs through postmitotic cell death.Implications: This study identifies ITGB8 as a new selective marker for GICs and as a promising therapeutic target in combination with chemo/radiotherapy for the treatment of highly aggressive brain tumors.