| Popis: |
Different assays (clonogenic, dye exclusion, etc.) have been developed to assess the chemosensitivity of malignant cells. The MTT assay, in particular, based on the reduction by living cells of MTT [3-4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) to a formazan product, provides a simple, automated, and efficient method for chemosensitivity testing in leukemias. In this study, in vitro drug sensitivity was assessed in the cells from 46 adult acute myeloid leukemias (AML). Dose-response curves were obtained for cytosine arabinoside (ara-C), daunorubicin (DNR), idarubicin (IDA), mitoxantrone (MIT), etoposide (VP-16). There were marked interindividual differences in leukemic cell survival (LCS) values (expressed as the percentage of cell survival with respect to the untreated controls). LCS was less than 50% in 30/46 samples (65%) tested with ara-C, in 38/41 (98%) with IDA, in 41/42 (98%) with DNR, in 40/46 (87%) with MIT, and in 30/45 (67%) with VP-16. The in vitro results were compared with the clinical response in 31 patients treated by combination chemotherapy according to GIMEMA protocols (AML 10 and P 491). The MTT test correlated with in vivo response in 18 (58%) out of 31 patients. Sensitive chemotherapeutic response in vitro but resistance in vivo was observed in 12 patients. Only one AML patient was found to be resistant in vitro and sensitive in vivo. Our preliminary results suggest that the MTT assay may be useful in evaluating chemosensitivity in some AML patients, although further studies are needed to assess the clinical utility of in vitro chemosensitivity tests. |
