Influence of long-term treatment with cytosine arabinoside on telomere length in human HL60 cells.

Immortal tumor cells employ a telomere length maintenance mechanism to escape the normal limits on proliferation. We investigated whether treatment with cytosine arabinoside (AraC), whose triphosphate derivative AraCTP might partially inhibit the synthesis of C-rich telomere strands, is effective for inducing telomere shortening in human HL60 cells. Long-term treatment with 0.01 microM AraC was found to cause significant telomere lengthening, but had no marked effects on cell population doubling rates or morphology.