demecolcine and staurosporine-aglycone

Polyploid cells are made by DNA reduplication without cell division, however, it is not easy to establish polyploid mammalian cell lines. It is worth studying the difference in cell character between hyperploid and parent cell lines. Meth-A cells were polyploidized by demecolcine, K-252a, staurosporine and paclitaxel. The cell-cycle responses of highly polyploid Meth-A cells after the removal of the drugs were examined by flow cytometry (FCM). Meth-A cells were highly polyploidized by these drugs. The polyploid Meth-A cells gradually decreased in ploidy after the drug release. A tetraploid Meth-A cell line was established only from the demecolcine-induced polyploid Meth-A cells. The duration of G1, S and G2/M phases of the tetraploid cell line were mostly the same as those of the parent diploid cells, except that the G2/M phase was 1.5 h longer. The chromosome number of tetraploid Meth-A cell line was about twice of the diploidy. A tetraploid Meth-A cell line was established.

Topics: Animals; Antineoplastic Agents, Phytogenic; Carbazoles; Cell Count; Cell Cycle; Cell Division; Demecolcine; DNA; Enzyme Inhibitors; Flow Cytometry; Indole Alkaloids; Karyotyping; Mice; Paclitaxel; Ploidies; Sarcoma; Staurosporine; Tumor Cells, Cultured

To examine whether or not cells polyploidized by different mechanisms behave in a different manner after drug removal, V79 Chinese hamster cells were assessed by flow cytometry (FCM) after their polyploidization by demecolcine and K-252a, inhibitors of spindle-fiber formation and protein kinase, respectively. Cell cycle analysis of DNA histograms of V79 cells before and after the drug release was performed. With both drugs, the ploidy of V79 cells increased just after the drug removal and was maintained for a week. A difference was evident 10 days after the release. Tetraploid cells were the main population from 10 to 18 days after the release of K-252a, but not demecolcine. Cell cycle parameters were almost the same in pseudo diploid and tetraploid V79 cells, except for the tetraploid S phase which was 2h longer.

Topics: Animals; Carbazoles; Cell Count; Cell Cycle; CHO Cells; Cricetinae; Demecolcine; DNA; Enzyme Inhibitors; Indole Alkaloids; Polyploidy; Protein Kinase C

The cellular responses of the V79 cell cycle to K-252a, a protein kinase inhibitor, were examined by flow cytometry (FCM) and by time-lapse videomicrography. At a concentration of 0.5 microM of K-252a for 72 h, V79 cells became hyperploid, having above 32c DNA content. The cycle times in the hyperploidizing process were 11.2 (4c-8c), 16.3 (8c-16c) and 19.3 (16c-32c) hours, values which were less than twice that of the control (10.5 h). After the washout of K-252a, the DNA content was widely distributed in the V79 cell population and hyperploid V79 cells reduced DNA content through a variety of cell division modes. These cellular responses to hyperploidization of V79 cells by K-252a were in reasonable agreement with those by demecolcine.

Topics: Animals; Carbazoles; Cell Cycle; Cell Division; Cricetinae; Cricetulus; Demecolcine; DNA Replication; Indole Alkaloids; Models, Biological; Ploidies; Protein Kinase C; Signal Transduction; Tumor Cells, Cultured