title: Global quantification of heterochromatin-associated histone methylations in cell lines with differential sensitivity to ionizing radiation.
abstract: Histone modifications are involved in the DNA damage response (DDR). Here, by utilizing an ELISA immunoassay we assessed the methylation at H3K9 (H3K9me2 and H3K9me3) in two cell lines with differential sensitivity to radiation-induced apoptosis, HeLa (sensitive) and MCF-7 (resistant). We found that DNA damage induction by γ-irradiation leads to considerable accumulation (up to 5-fold) of H3K9me2 and H3K9me3, but not of H4K20me3 (control modification) in MCF-7 cells (p<0.05). Interestingly, a lower dose (2 Gy) was more effective than 5 Gy. In HeLa cells a smaller effect (approx. 1.5-1.8-fold) was evident only at 5 Gy. In conclusion, our findings reveal that DNA damage leads to specific accumulation of H3K9me2 and H3K9me3 in a cell-type specific manner.
authors.affiliation: Department of Basic Oncology, Oncology Institute, Istanbul University, Istanbul, Turkey.
authors.forename: Merve
authors.initials: M
authors.lastname: Cetinkaya
authors.affiliation: Department of Basic Oncology, Oncology Institute, Istanbul University, Istanbul, Turkey.
authors.forename: Emre
authors.initials: E
authors.lastname: Özgür
authors.affiliation: Department of Basic Oncology, Oncology Institute, Istanbul University, Istanbul, Turkey.
authors.forename: Nejat
authors.initials: N
authors.lastname: Dalay
authors.affiliation: Department of Basic Oncology, Oncology Institute, Istanbul University, Istanbul, Turkey.
authors.forename: Ugur
authors.initials: U
authors.lastname: Gezer
mesh_terms: D004249:DNA Damage / Q000502:physiology / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D006367:HeLa Cells / Q000378:metabolism / Q000528:radiation effects; D006570:Heterochromatin / Q000378:metabolism* / Q000528:radiation effects; D006657:Histones / Q000378:metabolism*; D006801:Humans; D008239:Lysine / Q000378:metabolism; D061986:MCF-7 Cells / Q000378:metabolism / Q000528:radiation effects; D008745:Methylation; D011836:Radiation Tolerance; D011839:Radiation, Ionizing; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D006570:Heterochromatin; D006657:Histones; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D008239:Lysine