Figure 2.
The effects of cell cycle blocking agents on telomerase activity. HT1080 cells were treated with various compounds designed to inhibit cell cycle progression. Cells were either harvested directly for use in the TRAP assay (unsorted) (A) or processed for flow cytometry (sorted) into G1 (thymidine/aphidicolin, hydroxyurea, Ara-C, methotrexate), or G2/M (colcemid, nocodazole) fractions (B). FACS sorting of the arrested cells was performed in an attempt to increase the synchrony of the experiment. Cells treated with doxorubicin were not sorted as they appeared dead by flow cytometry analysis. Below each lane is the relative telomerase activity ratios as compared with the untreated fraction in A.