Development of predictive assays for radiosensitivity, chemosensitivit apoptosis, and proliferative activity of tumor and normal tissues

我们应用细胞分裂阻断微核（MN）技术对原发性肺癌进行生物学特性评价。利用该技术，我们估计了体外有丝分裂的细胞比例（分裂分数，DF）、潜在加倍时间（T_<pot>）和人类肿瘤的放射敏感性（以MN频率计算）。将增殖活性测定结果与治疗结果进行比较。肿瘤组织分解成单细胞，在细胞松弛素B存在下（或不存在）放射后培养。每隔一段时间，对多核细胞的比例（其最大值为DF）、每个细胞的平均细胞核数和双核细胞中的微核进行评分。T_<pot>是假定核/细胞比达到2.0的时间。在获得的71例肿瘤样本中，DF和T_<pot>在61例（86%）中可评估，MN频率在52例（73%）中可评估。腺癌（N=41）、鳞状细胞癌（N=13）、大细胞癌（N=3）、小细胞癌（N=4）的中位DF和T_<pot>分别为23%和7.7 d、26%和8.9 d、27%和6.5 d、30%和7.0 d。不同病理类型和疾病分期的平均DF值和T_<pot>值差异无统计学意义。2 Gy辐射后的平均MN频率（减去0 Gy频率）为腺癌0.15，鳞状细胞癌0.17，大细胞癌0.16，小细胞癌0.20。辐射后的MN频率与DF和基线（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，T_<pot>与复发患者的复发时间相关。虽然MN频率的临床意义需要在未来的研究中进一步明确，但通过该试验确定的DF和T_<pot>似乎是肿瘤增殖活性的良好参数。少

We applied the cytokinesis-block micronucleus (MN) technique to primary lung cancers to evaluate their biological characteristics. Using this technique, we estimated the fraction of cells undergoing mitosis in vitro (dividing fraction, DF), potential doubling time (T_<pot>) and radiosensitivity (in terms of MN frequency) of human tumors. 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 per cell, and micronuclei in binucleate cells were scored. The T_<pot> Was the presumed time for the nuclei/cell ratio to reach 2.0. Of the 71 tumor samples obtained, the DF and T_<pot> were evaluable in 61 (86%) and the MN frequency in 52 (73%). The median DF and T_<pot> values were, respectively, 23% and 7.7 days for ad … More enocarcinoma (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% aud 7.0 days for small cell carcinoma (N=4). There was no significant difference in the mean DF or T_<pot> values according to the histologic type or disease stage. The mean MN frequency after 2 Gy 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 T_<pot> 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 T_<pot> determined by this assay appear to be good parameters of tumor proliferative activity. Less