Cell growth and gene modulatory activities of Yunzhi ( Windsor Wunxi ) from mushroom Trametes versicolor in androgen-dependent and androgen-insensitive human prostate cancer cells .
The incidence of prostate cancer varies greatly throughout the world ; it is highest in African-Americans and lowest in the Asian populations of China , India , and Japan .
Geographical differences in both prevalence of latent prostate cancer and mortality have been postulated to be influenced by diverse tumor-promoting and protective factors , both environmental and dietary .
Prostate cancer is a tumor with an extremely long latency ; the pattern of prostate tumorigenesis , in terms of the display and sequence of appearance of particular molecular or biochemical features , or morphological changes , characterizing different stages of the carcinogenic process , is expected to be heterogeneous .
Some insights into tumor heterogeneity and progression can be obtained from studies using cell lines , particularly those derived from different anatomical sites .
The present study aims to investigate whether hormone-responsive LNCaP and androgen-refractory JCA-1 , PC-3 , and DU-145 prostate cancer cells are responsive to Yunzhi ( YZ ) , a proprietary dietary supplement prepared from extracts of Trametes versicolor , also known as Coriolus versicolor ( a mushroom consumed by Chinese for its purported health benefits ) , and to elucidate its mechanism of action .
Ethanolic extracts ( 70 % ) of YZ significantly reduced LNCaP cell growth , down-regulated the levels of secreted PSA , but had less effects on the expression of intracellular PSA and did not affect levels of the androgen receptor .
In androgen-unresponsive prostate cancer cells , YZ had a much less pronounced suppressive effect on proliferation of PC-3 and DU-145 cells , compared to LNCaP , and was inactive against JCA-1 cells .
Western blot analyses show that the expression of Rb , a key regulatory protein in G1/S transition , and PCNA , integrally involved in mammalian cell DNA replication , were significantly reduced by treatment with YZ in PC-3 and DU-145 cells , respectively .
In contradiction , none of these biochemical parameters were affected in JCA-1 cells under identical treatment conditions .
Further analysis shows that YZ increased the levels of signal transducer and activator family of transcription factors STAT 1 and STAT 3 in JCA-1 and not LNCaP cells .
The greater sensitivity of LNCaP cells to this polysaccharopeptide raises the possibility that YZ may be considered as an adjuvant therapy in the treatment of hormone responsive prostate cancer ; additionally , it may have chemopreventive potential to restrict prostate tumorigenic progression from the hormone-dependent to the hormone-refractory state .