HEALTH NEWS

Study Title:

Gamma Tocotrienol Targets Prostate Cancer Stem Cells

Study Abstract

Emerging evidence supports that prostate cancer originates from a rare sub-population of cells, namely prostate cancer stem cells (CSCs). Conventional therapies for prostate cancer are believed to mainly target the majority of differentiated tumor cells but spare CSCs, which may account for the subsequent disease relapse after treatment. Therefore, successful elimination of CSCs may be an effective strategy to achieve complete remission from this disease. Gamma-tocotrienols (gamma-T3) is one of the vitamin-E constituents which have been shown to have anticancer effects against a wide-range of human cancers. Recently, we have reported that gamma-T3 treatment not only inhibits prostate cancer cell invasion but also sensitizes the cells to docetaxel-induced apoptosis, suggesting that gamma-T3 may be an effective therapeutic agent against advanced stage prostate cancer. Here, we demonstrate for the first time that gamma-T3 can down-regulate the expression of prostate CSC markers (CD133/CD44) in androgen independent (AI) prostate cancer cell lines (PC-3 & DU145), as evident from western blotting analysis. Meanwhile, the spheroid formation ability of the prostate cancer cells was significantly hampered by gamma-T3 treatment. In addition, pre-treatment of PC-3 cells with gamma-T3 was found to suppress tumor initiation ability of the cells. More importantly, while CD133-enriched PC-3 cells were highly resistant to docetaxel treatment, these cells were as sensitive to gamma-T3 treatment as the CD133-depleted population. Our data suggest that gamma-T3 may be an effective agent in targeting prostate CSCs, which may account for its anticancer and chemosensitizing effects reported in previous studies.

Study Information

Luk SU, Yap WN, Chiu YT, Lee DT, Ma S, Lee TK, Vasireddy RS, Wong YC, Ching YP, Nelson C, Yap YL, Ling MT.
Gamma-tocotrienol as an effective agent in targeting prostate cancer stem cell-like population.
Int J Cancer.
2010 July
Department of Anatomy, the University of Hong Kong, Hong Kong, SAR, China.