Davos Demonstrates Cancer-Killing Mechanism in Tocotrienol

Researchers from Davos Life Science in Singapore, in collaboration with scientists at the University of Hong Kong, have shown that gamma-tocotrienol, a member of the vitamin E family, is potent in killing prostate tumor cells in animal model studies.

In this study, immuno-compromised mice with human-grafted prostate tumors were given two weeks’ dosing of gamma-tocotrienol. Researchers saw that gamma-tocotrienol was selectively deposited in solid tumors, and this led to over 50 percent tumor shrinkage. Linked to this tumor shrinkage ability, gamma-tocotrienol showed two effects associated with the killing of cancer cells.

Firstly, there was a decrease in the expression of two cell proteins (PCNA and Ki67) associated with cell proliferation. Secondly, there was the activation of cellular processes called caspase cascades that are associated with programmed cell death. These inhibitive properties have been previously reported in studies investigating the effect of gammatocotrienol on breast cancer and melanoma.

Together, these data suggest a common mechanism by which gamma-tocotrienol is able to reverse the growth of cancer cells.

This study also found that the anti-tumor effect of gamma-tocotrienol was mediated by the suppression of the NF-KB cell signaling pathway. NF-KB is a protein that signals to the cell to produce chemicals that promotes the body’s natural inflammation response and cell survival. Over activation of NF-KB is associated with chronic inflammation. There is emerging evidence that chronic inflammation contributes to carcinogenesis and the development of malignancy in various organs, including the prostate, breast and skin.

The inhibition of tumour growth was achieved when used in a combination treatment of gamma-tocotrienol and Docetaxel (DTX). Currently, DTX is the first-line chemotherapy treatment in patients with prostate cancer that is resistant to hormone therapy.

However, DTX can only extend the patient’s overall survival by an average of 2-3 months. As the gamma-tocotrienol’s anti-tumour effects were observed using physiologically-relevant doses that do not negatively affect animal health, this may provide a treatment strategy that can improve the therapeutic efficacy of DTX against advanced stage prostate tumours, while reducing toxicity often seen in patients treated with DTX.