Department of Anatomy, The University of Hong Kong, Hong Kong, Hong Kong SAR.
PLoS One. 2011;6(5):e19804. doi: 10.1371/journal.pone.0019804. Epub 2011 May 16.
Recent evidence suggested that prostate cancer stem/progenitor cells (CSC) are responsible for cancer initiation as well as disease progression. Unfortunately, conventional therapies are only effective in targeting the more differentiated cancer cells and spare the CSCs. Here, we report that PSP, an active component extracted from the mushroom Turkey tail (also known as Coriolus versicolor), is effective in targeting prostate CSCs. We found that treatment of the prostate cancer cell line PC-3 with PSP led to the down-regulation of CSC markers (CD133 and CD44) in a time and dose-dependent manner. Meanwhile, PSP treatment not only suppressed the ability of PC-3 cells to form prostaspheres under non-adherent culture conditions, but also inhibited their tumorigenicity in vivo, further proving that PSP can suppress prostate CSC properties. To investigate if the anti-CSC effect of PSP may lead to prostate cancer chemoprevention, transgenic mice (TgMAP) that spontaneously develop prostate tumors were orally fed with PSP for 20 weeks. Whereas 100% of the mice that fed with water only developed prostate tumors at the end of experiment, no tumors could be found in any of the mice fed with PSP, suggesting that PSP treatment can completely inhibit prostate tumor formation. Our results not only demonstrated the intriguing anti-CSC effect of PSP, but also revealed, for the first time, the surprising chemopreventive property of oral PSP consumption against prostate cancer.
最近的证据表明，前列腺癌干细胞/祖细胞（CSC）是癌症发生以及疾病进展的罪魁祸首。不幸的是，传统疗法仅能有效针对分化程度较高的癌细胞，而对 CSC 则束手无策。在这里，我们报告称，PSP 是从蘑菇土耳其尾巴（也称为云芝）中提取的一种活性成分，可有效靶向前列腺 CSC。我们发现，PSP 处理前列腺癌细胞系 PC-3 可导致 CSC 标志物（CD133 和 CD44）在时间和剂量依赖性方式下调。同时，PSP 治疗不仅抑制了 PC-3 细胞在非贴壁培养条件下形成前列腺球体的能力，而且还抑制了其体内的致瘤性，进一步证明 PSP 可抑制前列腺 CSC 特性。为了研究 PSP 的抗 CSC 作用是否可能导致前列腺癌的化学预防，我们用 PSP 对自发形成前列腺肿瘤的转基因小鼠（TgMAP）进行了为期 20 周的口服喂养。在用水喂养的所有小鼠中，实验结束时 100%的小鼠都发生了前列腺肿瘤，但在用 PSP 喂养的任何小鼠中均未发现肿瘤，这表明 PSP 治疗可完全抑制前列腺肿瘤的形成。我们的研究结果不仅证明了 PSP 的抗 CSC 作用令人着迷，而且还首次揭示了口服 PSP 消耗对前列腺癌具有惊人的化学预防特性。
