Response of cultured human airway epithelial cells to X-rays and energetic alpha-particles.
Radon and its progeny, which emit alpha-particles during decay, may play an important role in inducing human lung cancer. To gain a better understanding of the biological effects of alpha-particles in human lung we studied the response of cultured human airway epithelial cells to X-rays and monoenergetic helium ions. Our experimental results indicated that the radiation response of primary cultures was similar to that for airway epithelial cells that were transformed with a plasmid containing an origin-defective SV40 virus. The RBE for cell inactivation determined by the ratio of D0 for X-rays to that for 8 MeV helium ions was 1.8-2.2. The cross-section for helium ions, calculated from the D0 value, was about 24 microm 2 for cells of the primary culture. This cross-section is significantly smaller than the average geometric nuclear area (approximately 180 microms 2), suggesting that an average of 7.5 alpha-particles (8 MeV helium ions) per cell nucleus are needed to induce a lethal lesion.
Yang
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Cell and Molecular Biology Division, Lawrence Berkeley Laboratory, University of California, Berkeley 94720.
Gruenert
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Holley
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Curtis
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D000512:Alpha Particles; D001980:Bronchi / Q000166:cytology*; D002461:Cell Line, Transformed; D002470:Cell Survival / Q000528:radiation effects*; D004847:Epithelial Cells; D006801:Humans; D066298:In Vitro Techniques; D012062:Relative Biological Effectiveness; D014132:Trachea / Q000166:cytology*