Shibamoto Y, Ike O, Mizuno H, Fukuse T, Hitomi S, Takahashi M
Department of Oncology, Chest Disease Research Institute, Kyoto University, Japan.
Clin Cancer Res. 1998 Mar;4(3):677-82.
We previously proposed a new assay using the cytokinesis-block micronucleus (MN) technique to estimate the fraction of cells undergoing mitosis in vitro [dividing fraction (DF)], potential doubling time (Tpot), and radiosensitivity (in terms of MN frequency) of human tumors. In the present study, we applied this technique to primary lung cancers to evaluate their biological characteristics, and the assay results for the proliferative activity were compared with the treatment outcome. Tumor tissues were disaggregated to single cells, which were cultured in the presence of cytochalasin B after (or without) radiation. At intervals, the proportion of multinucleate cells (its maximum value is the DF), the average number of nuclei/cell, and MNs in binucleate cells were scored. The Tpot was the extrapolated time for the nuclei:cell ratio to reach 2.0. Of the 71 tumor samples obtained, the DF and Tpot were evaluable in 61 (86%), and the MN frequency was evaluable in 52 (73%). The median DF and Tpot values were 23% and 7.7 days, respectively, for adenocarcinoma (n = 41), 26% and 8.9 days for squamous cell carcinoma (n = 13), 27% and 6.5 days for large cell carcinoma (n = 3), and 30% and 7.0 days for small cell carcinoma (n = 4). There was no significant difference in the mean DF or Tpot values according to the histological type or disease stage. The mean MN frequency after 2 Gy of radiation (minus the 0 Gy frequency) was 0.15 for adenocarcinoma, 0.17 for squamous cell carcinoma, 0.16 for large cell carcinoma, and 0.20 for small cell carcinoma. The MN frequency after radiation was positively correlated with both the DF and the baseline (at 0 Gy) MN frequency. In non-small cell lung cancer, a DF above the median was associated with an increased recurrence rate after operation, and the Tpot was correlated with the time until relapse in patients who developed recurrence. Although the clinical significance of the MN frequency needs to be clarified in future studies, the DF and Tpot determined by this assay appear to be good parameters of tumor proliferative activity.
我们之前提出了一种新的检测方法，即使用胞质分裂阻滞微核（MN）技术来估计体外进行有丝分裂的细胞比例[分裂比例（DF）]、潜在倍增时间（Tpot）以及人类肿瘤的放射敏感性（根据MN频率）。在本研究中，我们将该技术应用于原发性肺癌以评估其生物学特性，并将增殖活性的检测结果与治疗结果进行比较。将肿瘤组织解离为单细胞，在辐射后（或无辐射）于细胞松弛素B存在的情况下进行培养。每隔一段时间，对多核细胞的比例（其最大值即为DF）、每个细胞的平均核数以及双核细胞中的MN进行计数。Tpot是细胞核与细胞比例达到2.0时的外推时间。在获取的71个肿瘤样本中，61个（86%）的DF和Tpot可评估，52个（73%）的MN频率可评估。腺癌（n = 41）的DF和Tpot中位数分别为23%和7.7天，鳞状细胞癌（n = 13）为26%和8.9天，大细胞癌（n = 3）为27%和6.5天，小细胞癌（n = 4）为30%和7.0天。根据组织学类型或疾病分期，平均DF或Tpot值无显著差异。2 Gy辐射后（减去0 Gy时的频率）的平均MN频率，腺癌为0.15，鳞状细胞癌为0.17，大细胞癌为0.16，小细胞癌为0.20。辐射后的MN频率与DF以及基线（0 Gy时）MN频率均呈正相关。在非小细胞肺癌中，DF高于中位数与术后复发率增加相关，Tpot与复发患者的复发时间相关。尽管MN频率的临床意义在未来研究中有待阐明，但通过该检测方法确定的DF和Tpot似乎是肿瘤增殖活性的良好参数。
