Epothilone D affects cell cycle

Epothilones, macrocyclic lactones from the culture of Sorangium cellulosum Myxobacteriums are designated in human medicine as taxol-like microtubule drugs. To date, nothing is known about the effect of epothilones on known microtubules (MT) in plant cells and / or on the cell cycle of the plant. As shown in this report, processing tomatoes cell cultures in suspension with epothilone D to a continuous increase in the mitotic index. Dose-response curves have shown that epothilone D alters the mitotic index in concentrations as low as 1.5 MikroM. Mitochondrial arrest was observed after treatment only 2 hours and 55% of the cells were discontinued after 24 hours. As shown by immunozytologic methods occur during metaphase abnormal spindles, which leads to a random distribution of chromosomes throughout the cell and prevent the formation of a metaphase plate. The chromosomal de-condensation process does not appear to be affected, since the formation of micronuclei in the same place with the distributed chromosomes. This suggests that the stability of epothilone D influenced plant MTs mainly during the metaphase of a mitotic cycle. In metaphase, the effects of epothilone D appear to be irreversible, as cells with an abnormal pin could not be recovered after drug elimination.