Reference - Detail
|Author||Jiaranuchart S, Kaida A, Onozato Y, Harada H, Miura M.|
|Title||DNA damage response following X-irradiation in oral cancer cell lines HSC3 and HSC4.|
|Journal||Arch Oral Biol|
OBJECTIVE:The objective of this study was to characterize the DNA damage response in two human oral cancer cell lines following X-irradiation.
DESIGN:To visualize radiation-induced cell cycle alterations, two human oral cancer cell lines, HSC3 and HSC4, expressing fluorescent ubiquitination-based cell cycle indicator (Fucci) were established in this study. G2 arrest kinetics following irradiation were obtained from two-color flow cytometric analysis and pedigrees of Fucci fluorescence. DNA double strand break repair kinetics were obtained from immunofluorescence staining for phosphorylated histone H2AX, p53-binding protein 1, phosphorylated DNA-dependent protein kinase catalytic subunit, and breast cancer susceptibility gene 1.
RESULTS:Both cell lines showed apparent G2 arrest after 10 Gy of irradiation, but it was more enhanced in the HSC3-Fucci cells. Radiosensitivity was higher in the HSC3-Fucci cells than in HSC4-Fucci cells. Pedigree analysis of Fucci fluorescence revealed that the HSC3-Fucci cells exhibited a significantly longer green phase (normally indicating S/G2/M phases, but here reflective of G2 arrest) when irradiated in the red phase (G1 phase) than HSC4-Fucci cells irradiated in either red or green phases. Non-homologous end joining was marginally suppressed during the G1 phase and markedly more likely to be impaired during the S/G2 phases in HSC3-Fucci cells. When G2 arrest was abrogated by checkpoint kinase 1 or Wee1 inhibitors, only HSC4-Fucci cells exhibited radiosensitization.
CONCLUSIONS:We characterized DNA damage response in HSC3-Fucci and HSC4-Fucci cells following irradiation and the former demonstrated inefficient non-homologous end joining, especially during the S/G2 phases, resulting in enhanced G2 arrest. These findings may have clinical implications for oral cancer.
|MeSH||Carcinoma, Squamous Cell / radiotherapy Cell Cycle / physiology* Cell Cycle / radiation effects* Cell Cycle Checkpoints / radiation effects Cell Cycle Proteins / metabolism Cell Division / radiation effects Cell Line, Tumor / physiology Cell Line, Tumor / radiation effects Checkpoint Kinase 1 / metabolism DNA Breaks, Double-Stranded / radiation effects DNA Damage / radiation effects* DNA-Activated Protein Kinase Dose-Response Relationship, Radiation G2 Phase Cell Cycle Checkpoints / radiation effects Histones / metabolism Histones / radiation effects Humans Kinetics Microscopy, Fluorescence Mouth Neoplasms / radiotherapy* Nuclear Proteins / metabolism Protein-Tyrosine Kinases / metabolism Proteins / metabolism Proteins / radiation effects Tumor Suppressor p53-Binding Protein 1 Ubiquitination X-Rays / adverse effects*|
|Human and Animal Cells||HSC-3(RCB1975) HSC-4(RCB1902)|