Radiosensitivity of hypoxic and proliferating clonogen in a human lung cancer grown in nude mice

  • Authors:
    • Tadaaki Miyamoto
    • Sachiko Ishii
    • Kiyomi Eguchi-Kasai
    • Kumiko Koyama-Saegusa
  • View Affiliations

  • Published online on: December 1, 2005     https://doi.org/10.3892/or.14.6.1421
  • Pages: 1421-1428
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Abstract

Using cultured and nude mouse tumor cells (IA) derived from a human lung cancer, we studied their radiosensitivity by focusing attention on the dynamics of tumor clonogens. The movement of clonogens in the regrowing IA tumor after irradiation can be divided into three phases: first, the early and rapid survival recovery (PLD repair) phase; second, the delay phase involving a certain lag in survival change; and third, the repopulation phase consisting of two stages: the anoxic repopulation before angiogenesis and the hypoxic repopulation in the presence of a poorly developed vascular network. Clonogens in a regrowing tumor after irradiation were found to actively proliferate even in an anoxic environment before angiogenesis and under the hypoxic conditions prevailing after the formation of a tumor with a poorly developed vascular system. This re-grown tumor was found to be more radioresistant than a sham-treated control tumor. It is believed that these clonogens are genetically selected under hypoxic conditions throughout the process of tumor growth and regrowth, and may be primarily involved in tumor recurrence or accelerated repopulation in fractionated irradiation.

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December 2005
Volume 14 Issue 6

Print ISSN: 1021-335X
Online ISSN:1791-2431

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Spandidos Publications style
Miyamoto T, Ishii S, Eguchi-Kasai K and Koyama-Saegusa K: Radiosensitivity of hypoxic and proliferating clonogen in a human lung cancer grown in nude mice. Oncol Rep 14: 1421-1428, 2005
APA
Miyamoto, T., Ishii, S., Eguchi-Kasai, K., & Koyama-Saegusa, K. (2005). Radiosensitivity of hypoxic and proliferating clonogen in a human lung cancer grown in nude mice. Oncology Reports, 14, 1421-1428. https://doi.org/10.3892/or.14.6.1421
MLA
Miyamoto, T., Ishii, S., Eguchi-Kasai, K., Koyama-Saegusa, K."Radiosensitivity of hypoxic and proliferating clonogen in a human lung cancer grown in nude mice". Oncology Reports 14.6 (2005): 1421-1428.
Chicago
Miyamoto, T., Ishii, S., Eguchi-Kasai, K., Koyama-Saegusa, K."Radiosensitivity of hypoxic and proliferating clonogen in a human lung cancer grown in nude mice". Oncology Reports 14, no. 6 (2005): 1421-1428. https://doi.org/10.3892/or.14.6.1421