In vitro studies (human cell lines)
The synergistic potentiation of interferon activity with Maitake mushroom on bladder cancer cells has recently been reported (Louie et al., 2010). The combination of interferon-alpha2b (10 000 IU/mL) and Maitake mushroom D fraction (200 g/mL) reduced growth by ~75% in T24 bladder cancer cells. This effect may be due to triggering double-stranded DNA-dependent protein kinase activation that may act on the cell cycle to cease cancer cell growth.
Cordycepin (3'-deoxyadenosine), a compound of Cordyceps militaris, has been shown to have anti-tumour effects in two different bladder cancer cell lines, 5637 and T-24 cells. Cordycepin treatment, at a dose of 200 microM (IC50) during cell-cycle progression resulted in significant and dose-dependent growth inhibition, which was largely due to G2/M-phase arrest, and resulted in an up-regulation of p21WAF1 expression, independent of the p53 pathway. In addition, treatment with cordycepin induced phosphorylation of JNK (c-Jun N-terminal kinases). Blockade of JNK function using SP6001259 (JNK-specific inhibitor) and small interfering RNA (si-JNK1) rescued cordycepin-dependent p21WAF1 expression, inhibited cell growth, and decreased cell cycle proteins. These results suggest that cordycepin may be an effective treatment for bladder cancer (Lee et al., 2009d), although further confirmatory data with human trials are required.
Hispolon extracted from Phellinus linteus has also been shown to have antiproliferative effects in breast and bladder cancer cells (Lu et al., 2009).