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c-Myc activation promotes cofilin-mediated F-actin cytoskeleton remodeling and telomere homeostasis as a response to oxidant-based DNA damage in medulloblastoma cells.
Journal article

c-Myc activation promotes cofilin-mediated F-actin cytoskeleton remodeling and telomere homeostasis as a response to oxidant-based DNA damage in medulloblastoma cells.

  • Lewinska A Department of Cell Biochemistry, Faculty of Biotechnology, University of Rzeszow, Poland. Electronic address: lewinska@ur.edu.pl.
  • Klukowska-Rötzler J Division of Pediatric Hematology/Oncology, University Hospital, Bern, Switzerland; Department of Emergency Medicine, University Hospital, Bern, Switzerland.
  • Deregowska A Department of Genetics, Faculty of Biotechnology, University of Rzeszow, Pigonia 1, 35-310 Rzeszow, Poland.
  • Adamczyk-Grochala J Department of Cell Biochemistry, Faculty of Biotechnology, University of Rzeszow, Poland.
  • Wnuk M Department of Genetics, Faculty of Biotechnology, University of Rzeszow, Pigonia 1, 35-310 Rzeszow, Poland. Electronic address: mwnuk@ur.edu.pl.
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  • 2019-03-23
Published in:
  • Redox biology. - 2019
Actin
Cofilin
DNA damage
Medulloblastoma
Telomere maintenance
c-Myc
Actin Cytoskeleton
Actin Depolymerizing Factors
Cell Cycle
Cell Line, Tumor
DNA Damage
Humans
Medulloblastoma
Models, Biological
Oxidants
Oxidative Stress
Proto-Oncogene Proteins c-myc
Telomere Homeostasis
Transcriptional Activation
English Medulloblastoma (MB) is a common and highly aggressive pediatric brain tumor of a heterogeneous nature. According to transcriptome-based profiling, four molecular subgroups of MB have been revealed, namely WNT, SHH, Group 3 and Group 4. High MYC mRNA expression and MYC gene amplification in MB have been considered as indicators of poor prognosis. However, the role of c-Myc in MB biology is still not well established. In the present study, the effects of c-Myc activation in UW228-MycER MB cell line were investigated using 4-hydroxytamoxifen (4-OHT) induction system. Upon 4-OHT stimulation, an increase in metabolic activity, large-cell/anaplastic (LC/A) phenotype and oxidative stress-mediated DNA damage were observed. However, 53BP1 foci were not implicated in DNA damage response. Instead, cofilin nuclear translocation, changes in F-actin cytoskeleton and the levels of cytoskeletal proteins were shown. Moreover, the telomere length was found to be unaffected that may be associated with the upregulation of TRF proteins. Transcription of nascent RNA (synthesis of new rRNA) and the expression of RNA polymerase I-specific transcription initiation factor RRN3/TIF-IA were also elevated. Moreover, increased levels of DNMT2, a modulator of stress responses, were observed. A small fraction of cells responded differently as oncogene-induced senescence was also noticed. We postulate that c-Myc-mediated modulation of genetic stability of MB cells may trigger cellular heterogeneity and affect adaptive responses to changing environment.
Language
  • English
Open access status
gold
Identifiers
Persistent URL
https://sonar.ch/global/documents/270192
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