In Vitro Drug Sensitivity of Acute Myeloid Leukemic Cells Using the Methyl-Thazol-Tetrazolium Assay
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.
KeywordsLeukemia Etoposide Diphenyl Tetrazolium Spectrophotometry
Unable to display preview. Download preview PDF.
- 1.Weisenthal LM, Lippman ME (1985) Clonogenic and non-clonogenic in vitro chemosensitivity assay. Cane Treat Rep 69: 616–32Google Scholar
- 2.Karney DN, Winkler CF (1985) In vitro assays of chemotherapeutic sensitivity. In: Important advances in oncology. De Vita et al (eds). p.78 JB Lippincott: PhiladelphiaGoogle Scholar
- 4.Weisenthal LM, Marsden JA, Dill PL, Macaluso CK (1983) A novel dye exclusion method for testing in vitro chemosensitivity of human tumors. Cane Res 43: 749–57Google Scholar
- 6.Berridge MV, An S. Tan. (1993) Characterization of the cellular reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT): Subcellular localization, substrate dependence, and involvement of mitochondrial electron transport in MTT reduction. Arch. Biochem. Biophys. 303: 474–82PubMedCrossRefGoogle Scholar
- 9.Zittoun R, Liso V, Mandelli F, Rotoli B, de Witte T et al. (1992) Intensive consolidation chemotheraphy versus standard consolidation maintenance in acute myelogenous leukemia (AML) in first remission: an EORTC/GIMEMA phase III trial (AML 8B). Leukemia 6: Suppl 2: 120–3Google Scholar
- 13.Colton T (1974) Statistics in medicine. Little, Brown, BostonGoogle Scholar
- 18.Weisenthal LM, Dill PL, Finkelstein JZ, Duarte TE, Baker JA, Moran EN (1976) Laboratory detection of primary and acquired drug resistance in human lymphatic neoplasm. Cancer Treat Rep 70: 1283–88Google Scholar
- 19.Boekhorst PAW, Lowenberg B, Sonneveld P (1993) Enhance chemosensitivity acute myeloid leukemia by hematopoietic growth factors: a comparison of the MTT assay with a clonogenic assay. Leukemia 7:1637–44Google Scholar
- 21.Larsonn R, Nygren P (1989) A semi-automated fluorometric method for determination of cytotoxicity and cellular proliferation of human tumor cell lines in microculture. Anticancer Res 9: 1111–20Google Scholar