Study of MTT Assay for Bone and Soft Tissue Tumor

本研究旨在探讨四甲基偶氮唑盐比色法作为骨肉瘤和软组织肉瘤药敏试验的可行性。在11个人骨肉瘤细胞系中，发现增溶福尔马赞的吸光度与细胞数量成正比。在细胞株中，最大血药浓度的有效药物为放线菌素-D、阿霉素、顺铂、甲氨蝶呤、环磷酰胺、长春新碱。然而，在1/10峰值血药浓度时，这些药物无效。据报道，这些药物对骨肉瘤有效。因此，建议在血药浓度峰值时进行评估。依托泊苷对骨肉瘤细胞株的有效率也较高，有望成为骨肉瘤化疗的候选药物。在细胞系实验的基础上，采用四甲基偶氮唑盐比色法对临床标本进行药敏试验。采用67例经手术或活检获得的骨肉瘤和软组织肉瘤标本。在67份标本中，64份(96%)的检测结果在技术上是成功的。所有病例接种1×10~(-4)细胞/孔均获得成功。在成功的样本中检测到的药物数量平均为8.4个。对30例患者进行前瞻性或回顾性的临床评价。与临床反应的关系为：真阳性15例，假阳性2例，真阴性10例，假阴性3例。真阳性率为88%，真阴性率为77%，总预测准确率为83%。该方法可对多种样品和抗癌药物进行简便、快速的分析。本研究还显示了该检测方法的高成功率和高预测准确性。因此，四甲基偶氮唑盐比色法是治疗骨肉瘤和软组织肉瘤的一种实用的药敏试验。

The present study was performed to examine practicality of the MTT assay as chemosensitivity test for bone and soft tissue sarcomas. In eleven human osteosarcoma cell lines, the absorbance of the solubilized formazan was found to be directly proportional to the number of cells. On cell lines, effective drugs at the peak plasma concentration were actinomycin-D, adriamycin, cis-platinum, methotrexate, cyclophosphamide, vincristine. However, at 1/10 peak plasma concentration, these drugs were not effective. These drugs had been reported their efficacy against osteosarcoma. Therefore, it was suggested that the evaluation at peak plasma concentration was appropriate. Etoposide also showed high efficacy rate for cell lines, it would be a candidate for chemotherapy of osteosarcoma. On the basis of experimental results on cell lines, chemosensitivity test using the MTT assay for clinical specimens were performed. Sixty seven specimens of bone and soft tissue sarcomas obtained by surgery or biopsy were used. Of the 67 specimens, sixty four (96%) gave technically successful assay results. All cases seeded over 1X10^4 cell/well were successful. The number of drugs tested in successful specimens were 8.4 (mean). Thirty cases were clinically evaluated prospectively or retrospectively. The relationship between this assay and clinical response was 15 true positives, 2 false positives, 10 true negatives and 3 false negatives. True positive rate was 88%, true negative rate was 77%, and overall predictive accuracy was 83%. In this assay, many samples and anticancer drugs can be analyzed simply and rapidly. A high success rate and a high predictive accuracy of this assay were also showed in this study. Therefore, the MTT assay would be a practical chemosensitivity test for the treatment of bone and soft tissue sarcomas.