| Research Abstract |
Telomere length and telomere terminal transferase, telomerase, activity were measured in peripheral blood leukocytes from normal donors and human immortal leukemia cell lines, HL60, U937, K562, Ball, Reh, Namalwa, and CMK.Telomeres in normal leukocytes have shorten with age of donors but no telomerease activity was detected. An apparent shortening of telomeres occurred in most of immortal cells and they showed telomerase activities with a high processivity. Only CMX cells in seven leukemia cell lines tesited showed a poor shortening of telomeres and a nonprocessive telomerase activity. The enzyme activity was sensitive to pretreatment with RNase A and proteinase K, suggesting the nature of this enzyme as a ribonucleoprotein. The telomerase may constitute a certain complex with some other components. In a high molecular fraction with an approximate molecular weight of 300K, telomerase, DNA polymerase and helicase activities were co-exist. And the extents of these activities were correlated in these cells, indicating the higher telomerase activity may be induced in the more actively proliferating cells.
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