Gamma-Tocotrienol may help fight pancreatic cancer
Experiments conducted at The University of Texas MD Anderson Cancer Center in Houston, demonstrated that gamma-Tocotrienol helped suppress pancreatic tumor growth as well as render tumors more sensitive to gemcitabine, one of two drugs approved to treat the disease. In their introduction to the article, Dr Bharat Aggarwal and colleagues note that the transcription factor NF-kappaB (nuclear factor-kappaB sets genes into motion) has been associated with cell proliferation (multiplication of cancer cells), invasion, angiogenesis (creation of a tumors personal blood supply), metastasis, antiapoptosis (preventing the death of the cancer) and resistance to the effects of chemotherapeutic drugs in multiple tumors. Gamma-Tocotrienol, one of the eight members of the vitamin E family, has been shown to inhibit the activation of NF-kappaB in several cancer cell lines, in addition to suppressing the proliferation of a variety of tumor cells.
In tests using four cultured pancreatic cancer cell lines, gamma-Tocotrienol suppressed the proliferation of all lines, with higher doses and longer exposures producing a greater benefit. Administration of a 50 micromole dose of gamma-Tocotrienol resulted in almost complete suppression of tumor cell proliferation. The vitamin was found to inhibit NF-kappaB activation and proteins involved with inflammation, in addition to sensitizing the cells to gemcitabine.
The researchers then tested the effects of gamma-Tocotrienol and gemcitabine alone and in combination in a mouse model of human pancreatic cancer. Oral gamma-Tocotrienol administered alone was shown to inhibit tumor growth, a finding that is a first, according to the authors. As was demonstrated in the cultured cell experiments, gamma-Tocotrienol enhanced the tumor-fighting ability of gemcitabine. Gamma-Tocotrienol alone was found to suppress NF-kappaB activation, and further suppressed NF-kappaB in gemcitabine-treated tissues.
“Our study is the first report to suggest that gamma-Tocotrienol can enhance the apoptotic effect of gemcitabine in various pancreatic cancer cell lines in vitro,” the authors announce. “Our findings suggest that gamma-Tocotrienol can inhibit the growth of human pancreatic tumors and sensitize them to gemcitabine by suppressing of NF-kappaB-mediated inflammatory pathways linked to tumorigenesis.” The study is reported online on September 23, 2010 in the journal Cancer Research.