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@INPROCEEDINGS{Schmitz:842638,
      author       = {Schmitz, Sabine and Pinkawa, Michael and Eble, Michael and
                      Kriehuber, Ralf},
      title        = {{P}ersisting ring chromosomes detected by m{FISH} in
                      {L}ymphocytes of a cancer patient - a case study},
      reportid     = {FZJ-2018-00845},
      year         = {2013},
      abstract     = {Background: We report the case of an 84 years old prostate
                      cancer patient with severe side effects after radiotherapy
                      in 2006. He was cytogenetically analysed in 2009 and in 2012
                      in a comparative study for individual radiosensitivity of
                      prostate cancer patients. No other patient had clonal
                      aberrations, but this patient showed ring chromosomes in the
                      range of 21-25 $\%$ of lymphocytes. He received 5 cycles of
                      5-fluorouracil/folic acid for chemotherapy of sigmoid colon
                      carcinoma in 2003, three years before radiotherapy of
                      prostate cancer.Material und Methods: Blood samples were
                      irradiated ex vivo with Cs-137 γ-rays (0.7 Gy/min) in the
                      G0-phase of the cell cycle. 100 FISH painted metaphases were
                      analysed for the control and the irradiated samples each.
                      Multicolour in situ hybridisation techniques like mFISH and
                      mBand as well as MYC locus, telomere and centromere painting
                      probes were used to characterize ring metaphases. Metaphase
                      search and autocapture was performed with a Zeiss Axioplan 2
                      imaging microscope followed by scoring and image analysis
                      using Metafer 4/ISIS software (MetaSystems).Results: In 2009
                      chromosome 8 rings were found in about 25 $\%$ of
                      lymphocytes. Rings were stable over time and increased to
                      about 30 $\%$ until 2012. The ring chro-mosome 8 always
                      lacked telomere signals and a small amount of rings
                      displayed up to four centromere signals. In aberrant
                      metaphases 8pter and 8qter were either translocated or
                      deleted. Further analyses revealed that the breakpoint at
                      the p arm is localized at 8p21.2-22. The breakpoint at the q
                      arm turned out to be distal from the MYC locus at
                      8q23-24.Conclusion: We hypothesize that the ring chromosome
                      8 has been developed dur-ing the 5 FU/folic acid treatments
                      in 2003. The long term persistence might be due to clonal
                      expansion of a damaged but viable hematopoietic stem cell
                      giving rise to cy-cling progenitor cells that permit cell
                      survival and proliferation.Funded by Dr.
                      Erich-Schmitt-Stiftung},
      month         = {Sep},
      date          = {2013-09-25},
      organization  = {16th Annual Meeting of the German
                       Society for Biological Radiation
                       Research, Darmstadt (Germay), 25 Sep
                       2013 - 27 Sep 2013},
      subtyp        = {Invited},
      cin          = {S-US},
      cid          = {I:(DE-Juel1)S-US-20090406},
      pnm          = {899 - ohne Topic (POF3-899)},
      pid          = {G:(DE-HGF)POF3-899},
      typ          = {PUB:(DE-HGF)6},
      url          = {https://juser.fz-juelich.de/record/842638},
}