WASHINGTON, Jan. 4 (Xinhua) -- U.S. researchers have claimed to have spotted a link between breast cancer and inflammation receptor and the link might be incorporated into future ways of treatment, a Health Promotion Committee handout said on Monday.

    Researchers at the University of Michigan Comprehensive Cancer Center identified a receptor, CXCR1, which triggers growth of breast cancer stem cells in response to inflammation and tissue damage, the handout said.

    Receptor CXCR1, or IL-8 for short, is a protein produced during chronic inflammation and tissue injury.

    The researchers also uncovered that the drug of repertaxin, originally developed to prevent organ transplant rejection, blocks this receptor, so as to kill breast cancer stem cells and to prevent these cells' metastasis or metabolism in mice.

    Their study, therefore, suggests a new way to target breast cancer stem cells, the small number of cells that fuel a tumor's growth, which are believed to be resistant to current chemo-therapies and radiation treatment.

    The researchers say that the resistance may be the reason that cancer so often returns after treatment.

    "Developing treatments to effectively target the cancer stem cell population is essential for improving outcomes. This work (research) suggests a new strategy to target cancer stem cells that can be readily translated into the clinic," said Max S. Wicha, senior study author and director of the University of Michigan Comprehensive Cancer Center.

    Wicha was part of the research team that first identified stem cells in breast cancer.

    Results of the current study will appear in the February issue of the Journal of Clinical Investigation.

    "These studies suggest that important links between inflammation, tissue damage and breast cancer may be mediated by cancer stem cells. Furthermore, anti-inflammatory drugs such as repertaxin may provide a means of blocking these interactions, thereby targeting breast cancer stem cells," Wicha added.

    When tumors are exposed to chemo-therapy, the dying cells produce IL-8 which stimulates cancer stem cells to replicate.

    The addition of the drug repertaxin to chemo-therapy specifically targets and kills breast cancer stem cells by blocking CXCR1.

    Laboratory tests showed that mice treated with repertaxin or the combination of repertaxin and chemo-therapy had dramatically fewer cancer stem cells than those treated with chemo-therapy alone.

    In addition, repertaxin-treated mice developed significantly fewer metastases than mice treated with chemo-therapy alone.

    Early-phase clinical trials have shown that repertaxin has minimal side effects, but there have been no reports of using repertaxin to treat cancer.