Zijno Andrea, Saini Francesca, Crebelli Riccardo
Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Rome, Italy.
Mutagenesis. 2007 Sep;22(5):311-5. doi: 10.1093/mutage/gem018. Epub 2007 Jun 4.
In order to assess the applicability of the cytokinesis-block micronucleus assay to frozen cells in human biomonitoring and in vitro radiosensitivity studies, basal and radiation-induced micronuclei and nucleoplasmic bridges (NPBs) were analysed in 28 lymphocyte samples stored frozen from 18 to 123 weeks. All samples successfully proliferated and produced a sufficient number of binucleated cells to be analysed. The length of the cryopreservation period did not influence cell proliferation, nor the incidence of micronuclei and NPBs, both in untreated and irradiated cells. Spontaneous levels of micronuclei were modulated by age (P=0.007) and by gender (P=0.024), as previously shown for cultures set up using fresh cell samples. Irradiation with 2 Gy gamma-rays significantly increased both micronuclei and NPBs, which were significantly correlated to each other (P=0.004). Radiation-induced micronuclei significantly increased with the age of donors (P=0.035), confirming previous findings obtained with fresh cell samples. The spontaneous incidences of micronuclei observed in cultures set up with frozen lymphocytes were compared with data recorded from the same subjects 5 years before using fresh blood samples. A high correlation was observed between the two data sets (P=0.004 after removing age and gender effects), highlighting the stability during the time of micronuclei as a biomarker of genomic stability, and supporting the suitability of frozen cells for cytogenetic analyses in biomonitoring and susceptibility studies.
为了评估胞质分裂阻滞微核试验在人类生物监测和体外放射敏感性研究中对冷冻细胞的适用性，对28份冷冻保存18至123周的淋巴细胞样本中的基础微核和辐射诱导微核以及核质桥（NPBs）进行了分析。所有样本均成功增殖，并产生了足够数量的双核细胞用于分析。冷冻保存期的长短对未处理和受辐照细胞的细胞增殖、微核和NPBs的发生率均无影响。微核的自发水平受年龄（P=0.007）和性别（P=0.024）的调节，这与之前使用新鲜细胞样本建立的培养物的情况一致。2 Gy γ射线辐照显著增加了微核和NPBs，且二者显著相关（P=0.004）。辐射诱导的微核随供体年龄显著增加（P=0.035），证实了之前使用新鲜细胞样本获得的结果。将冷冻淋巴细胞建立的培养物中观察到的微核自发发生率与5年前同一受试者使用新鲜血液样本记录的数据进行比较。在去除年龄和性别影响后，两个数据集之间观察到高度相关性（P=0.004），突出了微核作为基因组稳定性生物标志物在时间上的稳定性，并支持冷冻细胞在生物监测和易感性研究中进行细胞遗传学分析的适用性。
