Synergistic potentiation of interferon activity with maitake mushroom d-fraction on bladder cancer cells
Version of Record online: 4 SEP 2009
© 2009 THE AUTHORS. JOURNAL COMPILATION © 2009 BJU INTERNATIONAL
Volume 105, Issue 7, pages 1011–1015, April 2010
How to Cite
Louie, B., Rajamahanty, S., Won, J., Choudhury, M. and Konno, S. (2010), Synergistic potentiation of interferon activity with maitake mushroom d-fraction on bladder cancer cells. BJU International, 105: 1011–1015. doi: 10.1111/j.1464-410X.2009.08870.x
- Issue online: 4 MAR 2010
- Version of Record online: 4 SEP 2009
- Accepted for publication 9 June 2009
- combined therapy;
- bladder cancer
To examine whether the combination of interferon (IFN)-α and maitake mushroom D-fraction (PDF), a bioactive mushroom extract, might potentiate the anticancer activity of IFN-α in bladder cancer T24 cells in vitro.
MATERIALS AND METHODS
Effects of recombinant IFN-α2b (0–50 000 IU/mL), PDF (0–700 µg/mL), or their combinations were assessed on T24 cell growth at 72 h. Cell cycle analysis and assays for double-stranded DNA-dependent protein kinase (DNA-PK) were performed to explore possible antiproliferative mechanism of these agents.
IFN-α2b was able to induce a significant (≈50%) growth reduction at 20 000 IU/mL, which further declined to ≈66% at 50 000 IU/mL. PDF had no effects up to 200 µg/mL, but there was an ≈20% and ≈53% growth reduction at 400 and 700 µg/mL, respectively. When the varying concentrations of IFN-α2b and PDF were combined, 10 000 IU/mL of IFN-α2b combined with 200 µg/mL of PDF resulted in an ≈75% growth reduction. This was accompanied by a G1 cell cycle arrest, shown by cell cycle analysis. Concurrently, DNA-PK activity in IFN-α2b/PDF-treated cells was almost three-fold higher than controls.
The combination of IFN-α2b (10 000 IU/mL) and PDF (200 µg/mL) reduced growth by ≈75% in T24 cells. This appears to be due to a synergistic potentiation of these two agents, inducing a G1 arrest with DNA-PK activation. Therefore, the IFN-α2b/PDF combination could trigger DNA-PK activation that may act on the cell cycle to cease cancer cell growth.