| Popis: |
Drugs that disorganize or overstabilize cytoplasmic microtubules (colchicine, vinblastine, griseofulvin, or taxol) can at certain concentrations totally block proliferation of SV40 and polyoma virus transformants with only a minimal effect on the proliferation of the parental rat 3T3 cells. This difference in sensitivity is not due to a more active drug uptake by transformed cells. Examination of cytoplasmic microtubules in actively proliferating normal or transformed cells reveals two categories in each case: cells with microtubules and cells without distinct microtubules. The proportion of cells without distinct microtubules did not differ much between normal and transformed cells. However, transformed cells with a clear microtubule network appear to have fewer microtubules than normal cells. This may contribute to the higher sensitivity of transformed cells. These results render even more rational the use of antimicrotubule drugs in cancer chemotherapy. |
