demecolcine and Lymphoma

Micronucleus induction was compared in human lymphoblastoid TK6 and mouse lymphoma L5178Y cell lines treated with model clastogens and spindle poisons, i.e., X-rays, methyl methanesulfonate, ethyl methanesulfonate, mitomycin C, colcemid, and vincristine. The spontaneous micronucleated cell (MNC) frequency was stable and reproducible in both cell lines. All clastogens and spindle poisons studied here induced micronuclei in both cell lines. They increased MNC frequency at lower concentrations or caused a greater increase at the same concentration in TK6 cells. These clastogens and spindle poisons, however, were also more toxic to TK6 than to L5178Y cells and when comparison was based on cytotoxicity, they showed more efficient MNC induction in L5178Y cells. In conclusion, neither cell line was superior to the other, and both of them can be used as target cells in the in vitro micronucleus assay.

Topics: Animals; B-Lymphocytes; Cell Line; Cell Survival; Demecolcine; Ethyl Methanesulfonate; Humans; Leukemia L5178; Lymphoma; Methyl Methanesulfonate; Mice; Micronucleus Tests; Mitomycin; Mutagens; Tumor Cells, Cultured; Vincristine; X-Rays

Microcell production by means of Colcemid-induced micronucleation and subsequent enucleation with the density gradient technique was adjusted for use with the murine T-lymphoma line ESb-M. Modification of the standard protocol for a cell type on which no experiments had previously been performed required careful monitoring of the multiple steps in the procedure in order to optimize the final microcell yield. Traditional microscopic verification may sometimes be ambiguous, due to the lack of a clear cutoff point between small whole cells and cell fragments; in these conditions, the level of variability increases, thus impairing quantitative estimations. Flow cytometric (FCM) analysis of DNA content and size of donor cells and microcells was therefore applied in parallel to provide additional quantitative information. The FCM results supplemented the microscopic data in assessing which fraction recovered from the gradient has the lowest percentage of contaminant whole cells; however, FCM analysis may provide more statistically significant data due to the large size of the sample examined. Moreover, FCM is of prospective use in providing the basis for subsequent sorting of either pure microcells or specific subpopulations of defined DNA content and size.

Topics: Animals; Cell Line; Cell Nucleus; Cytochalasin B; Demecolcine; DNA; Ficoll; Flow Cytometry; Lymphoma; Mice; T-Lymphocytes; Tumor Cells, Cultured

Topics: Adenocarcinoma; Aneuploidy; Biopsy; Carcinoma, Squamous Cell; Cell Division; Cell Movement; Cell Transformation, Neoplastic; Demecolcine; Diploidy; Ear Neoplasms; Humans; Karyotyping; Lymphoma; Mitosis; Nose Neoplasms; Pharyngeal Neoplasms