[Cyclin D1, hTERT expression and telomerase activity in HL-60 and HL-60A cell lines and their significance].

To observe the expression of cyclin D1, hTERT, and telomerase activity in MNC, HL-60, HL-60A and to explore their effects on leukemogenesis and drug-resistance, normal human peripheral blood mononuclear cells, HL-60 cells sensitive to adriamycin and HL-60A cells resistant to adriamycin were investigated. The cell cycle was analyzed by flow cytometry, and the apoptosis was analyzed by Annexin V-FITC(+) PI staining. Expressions of cyclin D1 and hTERT were determined by real-time PCR and Western blot. Telomerase activity was detected by TRAP-ELISA. The results indicated that the percentage of MNC, HL-60 and HL-60A in S phase was (10.21 + 2.11)%, (44.93 + 3.00)%, and (51.38 + 1.10)% respectively; the percentage of apoptosis cells was (16.14 + 2.13)%, (7.53 + 0.92)%, (4.15 + 0.96)% respectively; the expression of mRNA and protein for cyclin D1 and hTERT increased; the telomerase activities of HL-60 and HL-60A were higher (p = 0.000), whereas the difference between HL-60 and HL-60A was no statistically significant (p = 0.232); positive correlation between cyclin D1, hTERT and telomerase activity had been found (p < 0.01). It is concluded that the cells of S phase increased while the apoptotic cells decreased in HL-60 and HL-60A, especially in HL-60A, which may be due to the up-regulation of cyclin D1, hTERT and telomerase activity.