PHILADELPHIA Researchers at Wayne State University have tested a breast cancer vaccine they say completely eliminated HER2-positive tumors in mice - even cancers resistant to current anti-HER2 therapy - without any toxicity.
The study, reported in the September 15 issue of Cancer Research, a journal of the American Association for Cancer Research, suggests the vaccine could treat women with HER2-positive, treatment-resistant cancer or help prevent cancer recurrence. The researchers also say it might potentially be used in cancer-free women to prevent initial development of these tumors.
HER2 receptors promote normal cell growth, and are found in low amounts on normal breast cells. But HER2-positive breast cells can contain many more receptors than is typical, promoting a particularly aggressive type of tumor that affects 20 to 30 percent of all breast cancer patients. Therapies such as trastuzumab and lapatinib, designed to latch on to these receptors and destroy them, are a mainstay of treatment for this cancer, but a significant proportion of patients develop a resistance to them or cancer metastasis that is hard to treat.
This treatment relied on activated, own-immunity to wipe out the cancer, says the study's lead investigator, Wei-Zen Wei, Ph.D., a professor of immunology and microbiology at the Karmanos Cancer Institute.
"The immune response against HER2-positive receptors we saw in this study is powerful, and works even in tumors that are resistant to current therapies," she said. "The vaccine could potentially eliminate the need to even use these therapies."
The vaccine consists of "naked" DNA genes that produce the HER2 receptor as well as an immune stimulant. Both are housed within an inert bacterial plasmid. In this study, the researchers used pulses of electricity to deliver the injected vaccine into leg muscles in mice, where the gene produced a huge quantity of HER2 receptors that activated bo
|Contact: Jeremy Moore|
American Association for Cancer Research