Radiation and Environmental Biophysics

, Volume 40, Issue 4, pp 295–300

Micronuclei and apoptosis in glioma and neuroblastoma cell lines and role of other lesions in the reconstruction of cellular radiosensitivity

  • J. M. Akudugu
  • L. Böhm
Original Paper

Abstract 

It is now well established that micronuclei frequency does not always rank cell lines according to radiosensitivity. There is, however, a growing interest in reconstructing cellular radiosensitivity (measured by colony assay) from concurrent micronucleus and apoptosis data. Using a variety of radiosensitive and radioresistant cell lines, we have derived a missing parameter –Poe, the probability of cell death by other events such as small deletions, chromosome aberrations, late apoptosis and necrosis which are undetectable by micronucleus and apoptosis assays performed at a single time point. In the radioresistant glioma cell lines G120, G60, G28, G44 and G62 (SF2 ≥0.59), a characteristic threshold dose exists above which cell loss due to undetectable lesions occurs. In the radiosensitive SK-N-SH and KELLY cell lines (SF2 ≤0.43), the Poe parameter is positive at very low doses, reaches a maximum and declines at higher doses. In the radiation resistant G28 cells, Poe was found to be below zero for doses up to 6 Gy. In the G62, G44 and G120 cell lines, the threshold doses to induce Poe events were 0.87, 3.04 and 3.85 Gy, respectively. Cell death by undetectable lesions is a cell-specific and time-dependent variable. Micronucleus and apoptosis assays performed concurrently and at a specific time point miss cell death due to other events and this may be the reason why reconstruction of cellular radiosensitivity from micronucleus and apoptosis data fails.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • J. M. Akudugu
    • 1
  • L. Böhm
    • 1
  1. 1.Department of Radiation Oncology, Faculty of Medical Sciences and Tygerberg Hospital, University of Stellenbosch, P.O. Box 19063, Tygerberg 7505, South Africa e-mail: elb@gerga.sun.ac.za Tel.: +27-21-9389539, Fax: +27-21-9338886ZA

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