ABSTRACT
Chemotherapy is currently one of the
most common therapeutic options for cancer patients despite the poor efficacy
with considerable side effects. We then examined if D-fraction (DF), a
bioactive mushroom extract, could potentiate (poor) anticancer effects of those
drugs in vitro. Three urologic cancers, prostate, bladder, and
kidney cancers, were tested with various chemotherapeutic drugs and their combinations
with DF. Compared to individual drugs alone, combinations of drugs and DF have
improved anticancer activity, resulting in the significant (P < 0.05) cell
viability reduction in all three cancer cells. As vitamin C (VC) has been
postulated to potentiate the bioactivity of DF, this possibility was also
examined. The specific combination of DF (300 μg/ml) and VC (200 μM) indeed led
to the drastic (≥90%) viability reductions in all three cancer cells. To have a
better understanding of such a profound viability reduction, the effect of
DF/VC combination on cell cycle was examined next. Cell cycle analysis
indicated that this combination induced a G1cell cycle arrest, which
was also confirmed by the down-regulation of specific cell cycle regulators
(CDK2, CDK4, and cyclin D1) detected on western blots. Moreover, it
was crucial to address if the DF/VC-induced viability reduction could be also
linked to apoptosis. Western blot analysis revealed that anti-apoptotic bcl-2
was down-regulated while pro-apoptotic Bax was up-regulated with DF/VC
combination in all cancer cells, indicating induction of apoptosis. Therefore,
the DF/VC combination could ultimately induce apoptosis, accounting for the
severe cell viability reduction. In conclusion, DF appears to be a promising
agent with chemosensitizing effect, enhancing the efficacy of chemotherapeutic
drugs, and its combination with VC exhibits a potent anticancer effect, which
is far superior to any combinations of drugs and DF tested in three prevalent
urologic cancer cells.
Share and Cite:
Freilich, D. , Moskowitz, E. , Feuer, N. , Choudhury, M. , Phillips, J. and Konno, S. (2014) Possible Chemosensitizing and Potent Anticancer Effects of D-Fraction in Combination with Vitamin C on Three Prevalent Urologic Cancer Cells.
Journal of Cancer Therapy,
5, 1402-1411. doi:
10.4236/jct.2014.514142.