RT Journal Article
SR Electronic
T1 Arsenite-induced Radiosensitization of Glioma Cells Is Dependent on p53 Deficiency
JF Anticancer Research
JO Anticancer Res
FD International Institute of Anticancer Research
SP 2551
OP 2559
DO 10.21873/anticanres.16422
VO 43
IS 6
A1 NINOMIYA, YASUHARU
A1 IMAOKA, TATSUHIKO
A1 DAINO, KAZUHIRO
A1 KAKINUMA, SHIZUKO
A1 NAKAJIMA, TETSUO
YR 2023
UL http://ar.iiarjournals.org/content/43/6/2551.abstract
AB Background/Aim: Arsenite is a radiosensitizer of glioma cells both in vitro and in vivo; however, the underlying mechanism of action is unclear. Radiosensitizers specific for p53-deficient tumors are a promising adjunct to radiotherapy because, unlike normal cells, many tumor cells lack p53. Previously, we demonstrated that arsenite sensitizes the p53-deficient glioma cell line U87MG-E6 to X-rays. Materials and Methods: Using flowcytometry, we expand these findings to p53-proficient U87MG cells exposed to heavy ion beams, including carbon and iron ions. Results: Arsenite sensitized U87MG-E6, but not U87MG, cells to heavy ion beams and X-rays. Cell cycle analysis indicated that sensitization of U87MG-E6 was related to an increase in the percentage of cells in the late S/G2/M phases after combined treatment with arsenite, especially when carbon ion beams were used. Induction of γH2AX was significant in U87MG-E6, but not in U87MG, cells after irradiation with carbon ion beams plus arsenite. Conclusion: Arsenite sensitizes cells by increasing the percentage of cells in the late S/G2/M phases after irradiation, possibly via inhibition of DNA repair in the context of p53 deficiency. The findings provide information that may be useful for the development of advanced radiotherapy protocols.