Study of MTT Assay for Bone and Soft Tissue Tumor

本研究是为了检验MTT试验作为骨和软组织肉瘤的化学敏感性试验的实用性。在11个人骨肉瘤细胞系中，发现溶解甲醛的吸光度与细胞数量成正比。在细胞系上，血药浓度峰值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血药浓度峰值时，这些药物无效。这些药物治疗骨肉瘤的疗效已被报道。因此，建议在血药浓度峰值时进行评价是合适的。依托泊苷对细胞系也有较高的疗效，有望成为骨肉瘤化疗的候选药物。在细胞系实验结果的基础上，采用MTT法对临床标本进行化学敏感性试验。通过手术或活检获得的骨和软组织肉瘤标本67例。在67个标本中，64个（96%）给出了技术上成功的分析结果。所有播种超过1X10^4细胞/孔的病例均成功。成功标本检测药物的数量为8.4种（平均）。对30例进行前瞻性或回顾性临床评价。该检测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%，总体预测准确率为83%。在这种分析中，许多样品和抗癌药物可以简单而快速地分析。本研究还显示了该方法的高成功率和高预测准确性。因此，MTT试验将是治疗骨和软组织肉瘤的一种实用的化学敏感性试验。

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.