A precursor of vitamin E has been shown to be effective against breast cancer cell lines which over-express human epidermal growth factor receptor (HER2).

About 30% of breast cancers exhibit high levels of HER2 – a feature that appears to make the disease resistant to many common treatments including chemotherapeutic agents. Now researchers in Griffith University’s School of Medical Science have shown that pro-vitamin E or alpha-tocopheryl succinate can reduce tumor volume in experimental animals with high levels of HER2.

Chief investigator Associate Professor Jiri Neuzil said alpha-tocopheryl succinate (alpha-TOS) had the potential to be an inexpensive, safe and selective therapy for hard-to-treat breast cancers. "Alpha-TOS has already shown promise as a potent anticancer agent in diseases such as colon cancer and mesothelioma. It induces controlled cell death or apoptosis in tumor cells."

Transgenic mice with high HER2 breast cancers were treated over a three week period and tumor size was monitored every three days by ultrasound imaging. The high resolution ultrasound allows for more accurate measurement of tumor volume than any other non-invasive technique.

The research team found that while alpha-TOS is effective alone, it can be delivered into the tumor cells more efficiently when given in a conjugate form with a targeting peptide.

"Tumor volume reduced more than 50% when animals were treated with the conjugate rather than free alpha-TOS," Neuzil said. He added that one of the benefits of alpha-TOS as a potential anti-cancer drug was that it was metabolized in the liver to vitamin E and unlikely to cause dangerous side effects.

SOURCE:
Research Australia (http://www.researchaustralia.com.au)