title: Response to low-dose X-irradiation is p53-dependent in a papillary thyroid carcinoma model system.
abstract: The link between high doses of radiation and thyroid cancer has been well established in various studies, as opposed to the effects of low doses. In this study, we investi-gated the effects of low-dose X-ray irradiation in a papillary thyroid carcinoma model with wild-type and mutated p53. A low dose of 62.5 mGy was enough to cause an upregulation of p16 and a decrease in the number of TPC-1 cells in the S phase, but not in the number of BCPAP p53-mutant cells. At a dose of 0.5 Gy, visible signs of senescence appeared only in the TPC-1 cells. We conclude that low doses of X-rays are enough to cause a change in cell cycle distribution, possibly p53-dependent p16 activation, but no significant apoptosis. Senescence requires higher doses of X-irradiation via a mechanism involving both p16 and p21.
authors: Laboratory of Molecular and Cellular Biology, Radiobiology Unit, Belgian Nuclear Research Center (SCK-CEN), 2400 Mol, Belgium.
authors: Khalil
authors: K
authors: Abou-El-Ardat
authors: Hanane
authors: H
authors: Derradji
authors: Winnok
authors: W
authors: de Vos
authors: Tim
authors: T
authors: de Meyer
authors: Sofie
authors: S
authors: Bekaert
authors: Wim
authors: W
authors: van Criekinge
authors: Sarah
authors: S
authors: Baatout
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002277:Carcinoma; D002291:Carcinoma, Papillary; D053148:Caspase 3; D002453:Cell Cycle / Q000528:radiation effects; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects; D006801:Humans; D014176:Protein Biosynthesis; D011879:Radiotherapy Dosage; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000532:radiotherapy*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D015415:Biomarkers; D016207:Cytokines; D053773:Transforming Growth Factor beta1; D016159:Tumor Suppressor Protein p53; D001616:beta-Galactosidase; D053148:Caspase 3