Breast cancer drugs used to treat patients with high levels of HER2 may also be effective for head and neck cancers, according to research presented at the 2011 National Cancer Research Institute (NCRI) Cancer Conference this week.
Scientists at Massachusetts General Hospital Cancer Centre, Harvard Medical School, and the biotechnology firm Genentech scanned nearly 700 human cell lines from a range of cancer types and identified all cells that responded to lapatinib, a type of HER2 kinase inhibitor.
Unexpectedly, the researchers found that some cells with low levels of HER2 (head and neck cancers cells in particular) also responded well to lapatinib.
These cells had high levels of neuregulin-1 (NRG1), a signaling protein. In the study, researchers found that NRG1 switched on a protein “cousin” of HER2 called HER3. A “switched on” HER3 can unite with and activate HER2.
The results showed that when enabled by NRG1, very small amounts of HER2 became activated to a greater degree than would be anticipated.
Although drugs like lapatinib would not be considered as an effective treatment for patients with low levels of HER2, this study suggests that treatment with HER2 inhibitors could be beneficial.
The paper’s author, professor Jeff Settleman, from Massachusetts General Hospital Cancer Centre and Harvard Medical School, said, “These findings reveal that the protein NRG1 can act as a ‘biological flag’ and identify another patient group who may benefit from HER2-targeted kinase inhibitors. It’s particularly exciting because it may mean that some head and neck cancers can be effectively treated with currently available drugs, such as the breast cancer drug, lapatinib.”
Source: NCRI.