Indole-3-carbinol inhibits telomerase activity and gene expression in prostate cancer cell lines.

Background: Indole-3-carbinol (I3C) is a phytochemical with anticarcinogenic properties. Telomerase activity is key in carcinogenesis. We investigated the effect of I3C on telomerase in human prostate cancer cell lines LNCaP and PC3.

Materials And Methods: Cells were treated with I3C at 100 and 250 μM with and without 10-50 μM diethylstilbestrol (DES). Telomerase activity was performed using TRAPaze Telomerase Detection Kit, and hTERT gene expression by real time quantitative RT-PCR.

Results: I3C (250 μM) inhibited telomerase activity and mRNA expression of hTERT in LNCaP and PC3 cells. I3C at 250 μM combined with any concentration of DES was cytotoxic to LNCaP. Telomerase activity in PC3 cells with 250 μM of I3C and 25 or 50 μM of DES was significantly reduced or inhibited, respectively. I3C combined with DES reduced PC3 viability and eliminated LNCaP cells.

Conclusion: I3C significantly inhibited telomerase activity and hTERT mRNA expression in LNCaP and PC3 cells. Combination of I3C and DES enhanced the inhibitory effect on telomerase activity, gene expression, and cell viability. These results implied that I3C and DES combined might help in prostate cancer treatment.