Effects of alpha-particles on survival and chromosomal aberrations in human mammary epithelial cells

• Published in: Radiation and environmental biophysics Vol. 34; no. 3; p. 195
• Main Authors: Durante, M., Grossi, G. F., Gialanella, G., Pugliese, M., Nappo, M., Yang, T. C.
• Format: Journal Article
• Language: English
• Published: Johnson Space Center 01.08.1995
• Subjects: Alpha Particles; Animals; Breast; Cell Division - radiation effects; Cell Line; Cell Survival - radiation effects; Chromosome Aberrations; Chromosome Deletion; Dose-Response Relationship, Radiation; Epithelial Cells; Epithelium - radiation effects; Female; Fibroblasts - radiation effects; Humans; Kinetics; Life Sciences (General); Lymphocytes - radiation effects; Metaphase - radiation effects; Mice; Mice, Nude; Mitosis; Time Factors; Transplantation, Heterologous; Tumor Cells, Cultured; X-Rays; Nasa Discipline Radiation Health; Nasa Center Jsc; NASA Discipline Radiation Health; NASA Center JSC
• ISSN: 0301-634X

We have studied the radiation responses of a human mammary epithelial cell line, H184B5 F5-1 M/10. This cell line was derived from primary mammary cells after treatment with chemicals and heavy ions. The F5-1 M/10 cells are immortal, density-inhibited in growth, and non-tumorigenic in athymic nude mice and represent an in vitro model of the human epithelium for radiation studies. Because epithelial cells are the target of alpha-particles emitted from radon daughters, we concentrated our studies on the efficiency of alpha-particles. Confluent cultures of M/10 cells were exposed to accelerated alpha-particles [beam energy incident at the cell monolayer = 3.85 MeV, incident linear energy transfer (LET) in cell = 109 keV/microns] and, for comparison, to 80 kVp x-rays. The following endpoints were studied: (1) survival, (2) chromosome aberrations at the first postirradiation mitosis, and (3) chromosome alterations at later passages following irradiation. The survival curve was exponential for alpha-particles (D0 = 0.73 +/- 0.04 Gy), while a shoulder was observed for x-rays (alpha/beta = 2.9 Gy; D0 = 2.5 Gy, extrapolation number 1.6). The relative biological effectiveness (RBE) of high-LET alpha-particles for human epithelial cell killing was 3.3 at 37% survival. Dose-response curves for the induction of chromosome aberrations were linear for alpha-particles and linearquadratic for x-rays. The RBE for the induction of chromosome aberrations varied with the type of aberration scored and was high (about 5) for chromosome breaks and low (about 2) for chromosome exchanges..