Radiation-Induced Survivin Nuclear Accumulation is Linked to DNA Damage Repair

Journal Article · Sat May 01 00:00:00 EDT 2010 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2009.12.001· OSTI ID:21372264

Capalbo, Gianni ^[1]; Dittmann, Klaus ^[2]; Weiss, Christian; Reichert, Sebastian ^[1]; Hausmann, Eva ^[2]; Roedel, Claus ^[1]; Roedel, Franz ^[1]

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1. Departments of Radiation Therapy and Oncology, University of Frankfurt/Main, 60590 Frankfurt (Germany)
2. Division of Radiobiology and Molecular Environmental Research, Department of Radiation Oncology, University of Tuebingen, 72076 Tuebingen (Germany)

Purpose: Increased expression of survivin has been identified as a negative prognostic marker in a variety of human cancers. We have previously shown that survivin is a radiation-resistance factor and that the therapeutic effect of survivin knock-down might result from an impaired DNA repair capacity. In this study, we aimed to elucidate an interrelationship between survivin's cellular localization and DNA double-strand break repair. Methods and Materials: Survivin's cellular distribution and nuclear complex formation were assayed by Western blotting of subcellular fractions, by immunofluorescence staining, and co-immunoprecipitation in SW480 colorectal cancer cells. DNA repair capacity was analyzed by kinetics of gamma-H2AX foci formation, and by DNA-dependent protein kinase (DNA-PKcs) assays in the presence of survivin-specific or nonspecific control siRNA. Results: Following irradiation, we observed a rapid nuclear accumulation of survivin and subsequent phosphorylation of the protein in the nucleus. Co-immunoprecipitation analyses from nuclear extracts revealed an interaction among survivin, Ku70, gamma-H2AX, MDC1, and DNA-PKcs that was confirmed by immunofluorescence co-localization in nuclear foci. Survivin knock down by siRNA resulted in an impaired DNA double strand break repair, as demonstrated by an increased detection of gamma-H2AX foci/nucleus at 60 min and a higher amount of residual gamma-H2AX foci at 24 hr postirradiation. Furthermore, we detected in survivin-depleted cells a hampered S2056 autophosphorylation of DNA-PKcs and a significantly decreased DNA-PKcs kinase activity. Conclusion: These data indicate that nuclear survivin is linked to DNA double-strand break repair by interaction with members of the DNA double-strand breaks repair machinery, thus regulating DNA-PKcs activity.

• OSTI ID: 21372264
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 77, Issue 1; Other Information: DOI: 10.1016/j.ijrobp.2009.12.001; PII: S0360-3016(09)03605-0; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS
62 RADIOLOGY AND NUCLEAR MEDICINE
DNA REPAIR
NEOPLASMS
PHOSPHORYLATION
PROTEINS
STRAND BREAKS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CHEMICAL REACTIONS
DISEASES
DNA DAMAGES
ORGANIC COMPOUNDS
REPAIR