ABSTRACT
<p><b>BACKGROUND</b>To investigate the effects of cisplatin on proliferation, telomerase activity, cell cycle, p53, bcl-2 and proliferating cell nuclear antigen (PCNA) expressions of human lung adenocarcinoma SLC-89 cells induced by cisplatin and to find out the possible mechanisms.</p><p><b>METHODS</b>SLC-89 cells were treated with cisplatin of different concentrations for 72 h. Then, the proliferation of the cells was measured by MTT method, telomerase activity was measured by telomeric repeat amplification protocol with ELISA (TRAP-ELISA), and cell cycle, p53, bcl-2 and PCNA expressions of the cells were detected by flow cytometry (FCM) respectively.</p><p><b>RESULTS</b>Cisplatin could obviously inhibit the proliferation of the cells, and IC₅₀ value for cisplatin treatment was 18.47 mg/L. Cisplatin could obviously down-regulate telomerase activity, decrease S phase cells, increase G₀/G₁ phase cells, decline the expressions of bcl-2 and PCNA proteins and induce the expression of p53 protein of SLC-89 cells in a concentration-dependent fashion.</p><p><b>CONCLUSIONS</b>Cisplatin can obviously inhibit the proliferation of SLC-89, change the distribution of cell cycle, decline telomerase activity and expressions of bcl-2 and PCNA proteins, and induce expression of p53 protein, which may be the important mechanisms of cisplatin's anticancer action.</p>
ABSTRACT
Objective To investigate effect on telomerase activity of Hep-2 cells treated by anticancer drugs(hydroxycamptothecine, cisplatin and cytoxan).Methods By MTT method,we measured the 50% inhibitory concentration(IC 50 ) at 72h,and compared to untreated control cells. Telomerase activity of Hep-2 cells treated by the drugs in different concentration based on IC 50 for different time was observed by Telomeric Repeat Amplification Protocol with ELISA(TRAP-ELISA).Results Hydroxycamptothecine and cytoxan could inhibit proliferation of Hep-2 and down-regulate telomerase activity of Hep-2 cell. However, cisplatin promoted proliferation of Hep-2 and up-regulated telomerase activity of Hep-2 cell.Conclusions Hydroxycamptothecine and cytoxan could down-regulate telomerase activity of Hep-2 cell by direct or indirect pattern, which may correlate with drug concentration and time-dependent pattern.Cisplatin could up-regulate telomerase activity of Hep-2 cell, which mechanism is not clear.