Taxol (paclitaxel) induces a microtubule hyperassembled state, and effectively blocks cells in mitosis. Here we report that Taxol also induces a stable late-G1 block in nontransformed REF-52 and WI-38 mammalian fibroblast cells, but not in T antigen-transformed cells of the same parental lineage. G1 arrest is characterized by partially dephosphorylated pRb, and inactive cdk2 kinase. Nontransformed cells recover normally from Taxol arrest. In contrast, T antigen transformed cells continue inappropriately past both G1 and G2-M in the presence of Taxol, and undergo a rapid death upon release. These results demonstrate a microtubule sensitive step in G1 regulation of nontransformed fibroblast cells. Also, Taxol selectively induces death of transformed cells, possibly because they slip the Taxol-dependent G1 arrest, as well as G2/M arrest, which are both specific to nontransformed cells.
Differential Taxol-dependent arrest of transformed and nontransformed cells in the G1 phase of the cell cycle, and specific-related mortality of transformed cells.
M O Trielli, P R Andreassen, F B Lacroix, R L Margolis; Differential Taxol-dependent arrest of transformed and nontransformed cells in the G1 phase of the cell cycle, and specific-related mortality of transformed cells.. J Cell Biol 1 November 1996; 135 (3): 689–700. doi: https://doi.org/10.1083/jcb.135.3.689
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