RT Journal Article SR Electronic T1 Ro 90-7501 Is a Novel Radiosensitizer for Cervical Cancer Cells that Inhibits ATM Phosphorylation JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 4805 OP 4810 DO 10.21873/anticanres.13665 VO 39 IS 9 A1 KEISUKE TAMARI A1 KEISUKE SANO A1 ZHIHAO LI A1 YUJI SEO A1 KEISUKE OTANI A1 SHOTARO TATEKAWA A1 MASAYASU TORATANI A1 YUJI TAKAOKA A1 YUTAKA TAKAHASHI A1 KAZUMASA MINAMI A1 FUMIAKI ISOHASHI A1 MASAHIKO KOIZUMI A1 KAZUHIKO OGAWA YR 2019 UL http://ar.iiarjournals.org/content/39/9/4805.abstract AB Background/Aim: Ro 90-7501 has been reported as an inhibitor of the amyloid β42 fibril assembly that is associated with Alzheimer's disease. The present study aimed to elucidate the radiosensitizing effects of Ro 90-7501 and focused on ATM signaling after irradiation. Materials and Methods: Clonogenic survival, apoptosis, and cell-cycle assays as well as western blotting were performed in HeLa cells treated with irradiation and Ro 90-7501. Tumor growth delay assay was also performed using BALB/c-nu mice. Results: The combination of irradiation with Ro 90-7501 showed significant radiosensitizing effects in clonogenic survival and tumor growth delay assays. Ro 90-7501 significantly increased apoptosis and impaired cell cycle after irradiation. Western blotting showed that Ro 90-7501 suppressed the phosphorylation of ATM and its downstream proteins, such as H2AX, Chk1, and Chk2, after irradiation. Conclusion: Ro 90-7501 inhibits DNA damage response by inhibiting ATM and has significant radiosensitizing effects on cervical cancer cells.