Radiosensitization of human leukemic HL-60 cells by ATR kinase inhibitor (VE-821): phosphoproteomic analysis

• Published in: International journal of molecular sciences Vol. 15; no. 7; pp. 12007 - 12026
• Main Authors: Šalovská, Barbora, Fabrik, Ivo, Ďurišová, Kamila, Link, Marek, Vávrová, Jiřina, Řezáčová, Martina, Tichý, Aleš
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 07.07.2014; MDPI
• Subjects: Ataxia Telangiectasia Mutated Proteins - antagonists & inhibitors; ATR kinase; Cell Line, Tumor; Cellular biology; DNA damage; DNA damage response; Gamma Rays; HL-60 cells; Humans; Inhibitor drugs; Kinases; Leukemia; Phosphorylation - drug effects; Phosphorylation - radiation effects; Protein Kinase Inhibitors - pharmacology; Proteome - metabolism; Pyrazines - pharmacology; quantitative phosphoproteomics; Radiation-Sensitizing Agents - pharmacology; radio-sensitization; SILAC; small-molecule kinase inhibitors; Sulfones - pharmacology; titanium dioxide chromatography; VE-821
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms150712007

DNA damaging agents such as ionizing radiation or chemotherapy are frequently used in oncology. DNA damage response (DDR)-triggered by radiation-induced double strand breaks-is orchestrated mainly by three Phosphatidylinositol 3-kinase-related kinases (PIKKs): Ataxia teleangiectasia mutated (ATM), DNA-dependent protein kinase (DNA-PK) and ATM and Rad3-related kinase (ATR). Their activation promotes cell-cycle arrest and facilitates DNA damage repair, resulting in radioresistance. Recently developed specific ATR inhibitor, VE-821 (3-amino-6-(4-(methylsulfonyl)phenyl)-N-phenylpyrazine-2-carboxamide), has been reported to have a significant radio- and chemo-sensitizing effect delimited to cancer cells (largely p53-deficient) without affecting normal cells. In this study, we employed SILAC-based quantitative phosphoproteomics to describe the mechanism of the radiosensitizing effect of VE-821 in human promyelocytic leukemic cells HL-60 (p53-negative). Hydrophilic interaction liquid chromatography (HILIC)-prefractionation with TiO2-enrichment and nano-liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed 9834 phosphorylation sites. Proteins with differentially up-/down-regulated phosphorylation were mostly localized in the nucleus and were involved in cellular processes such as DDR, all phases of the cell cycle, and cell division. Moreover, sequence motif analysis revealed significant changes in the activities of kinases involved in these processes. Taken together, our data indicates that ATR kinase has multiple roles in response to DNA damage throughout the cell cycle and that its inhibitor VE-821 is a potent radiosensitizing agent for p53-negative HL-60 cells.