Becker Daniela, Elsässer Thilo, Tonn Torsten, Seifried Erhard, Durante Marco, Ritter Sylvia, Fournier Claudia
GSI, Biophysics, Darmstadt, Germany.
Int J Radiat Biol. 2009 Nov;85(11):1051-9. doi: 10.3109/09553000903232850.
To characterise the radiation response of human hematopoietic stem and progenitor cells (HSPC) with respect to X and carbon ion irradiation.
HSPC from peripheral blood of healthy donors treated with granulocyte-colony stimulating factor (G-CSF) were enriched for the transmembrane glycoprotein CD34 (cluster of differentiation) and irradiated with X rays or carbon ions (29 keV/microm monoenergetic beam and 60-85 keV/microm spread-out Bragg peak), mimicking radiotherapy conditions. Apoptotic cell death, cell cycle progression and the frequency of chromosomal aberrations were determined.
After radiation exposure no inhibition in the progression of the cell cycle was detected. However, an enhanced frequency of apoptotic cells and an increase in aberrant cells were observed, both effects being more pronounced for carbon ions than X rays, resulting in a relative biological effectiveness (RBE) of 1.4-1.7. The fraction of complex-type aberrations was higher following carbon ion exposure.
RBE values of carbon ions are low, as expected for radiosensitive cells. The observed frequencies of apoptotic cells and chromosome aberrations in HSPC are similar to those reported for human peripheral blood lymphocytes suggesting that at least with respect to apoptosis and chromosomal aberrations mature lymphocytes reflect the respective radiation responses of their proliferating progenitors.
表征人类造血干细胞和祖细胞（HSPC）对X射线和碳离子辐射的反应。
从接受粒细胞集落刺激因子（G-CSF）治疗的健康供体的外周血中富集跨膜糖蛋白CD34（分化簇），并用X射线或碳离子（29 keV/μm单能束和60-85 keV/μm扩展布拉格峰）进行照射，模拟放射治疗条件。测定凋亡细胞死亡、细胞周期进程和染色体畸变频率。
辐射暴露后未检测到细胞周期进程受到抑制。然而，观察到凋亡细胞频率增加和异常细胞增多，这两种效应在碳离子照射下比X射线照射更为明显，导致相对生物效应（RBE）为1.4-1.7。碳离子照射后复杂型畸变的比例更高。
正如对放射敏感细胞所预期的那样，碳离子的RBE值较低。在HSPC中观察到的凋亡细胞和染色体畸变频率与人类外周血淋巴细胞报道的频率相似，这表明至少在凋亡和染色体畸变方面，成熟淋巴细胞反映了其增殖祖细胞各自的辐射反应。
