Cytokine Receptor CXCR4 Worsens Breast Cancer Outcomes
Posted Jan 28 2011 10:25am
Cytokines are small protein molecules produced by many cells throughout our bodies and are important for cell to cell communication which takes place by binding to specific cytokine receptors. However, under certain conditions these cytokines and their receptors can also be involved in breast cancer (and other cancers) development and growth. Two new breast cancer research studies outline the negative impact of the cytokine receptor CXCR4 on breast cancer outcomes.
In a study published in the January 15th issue of Cancer Research, breast cancer researchers examined the effect of CXCR4 overexpression in breast cancer cells . Using breast cancer cells that were not prone to becoming metastatic, the researchers showed that activation of the CXCR4 receptors resulted in increased tumor growth and metastasis. Furthermore, overexpression of this cytokine receptor made the breast cancer cells less dependent on estrogen for continued growth. Overall, the effect of excess numbers of CXCR4 receptors on breast cancer cells drove them to become metastatic and resistant to endocrine therapy. However, the breast cancer researchers also reported that blocking the ability of the CXCR4 receptor to work properly prevented the breast cancer growth and metastasis, suggesting that this cytokine receptor might make an appropriate target for individualized breast cancer treatments.
A second study published in the current issue of Surgery, breast cancer researchers tested the link between CXCR4 levels and the risk for breast cancer recurrence . For this study, the investigators recruited 101 breast cancer patients with hormone receptor-positive, node-negative breast cancers and measured CXCR4 levels. The study authors reported that all benign breast tissues had no detectable CXCR4 levels, whereas all 101 breast cancer patients showed at least some level of this cytokine receptor. Of these breast cancer patients, 79 had low levels of CXCR4 and 22 had high levels of CXCR4. These high CXCR4 levels were linked with increased breast cancer recurrence and worse chances of survival.
These two new breast cancer studies clearly indicate that overexpression of CXCR4 cytokine receptors is linked to worse breast cancer outcomes. The excess production of this cytokine receptor in breast cancer tumors and the activation of this cell communication pathway led to increased chances of metastasis, recurrence, and mortality. Fortunately, early study results suggest that blocking the activation of this cellular communication can suppress these adverse outcomes. Therefore, blocking this pathway might become a valuable breast cancer treatment for patients overexpressing this cytokine receptor.