Chemerin modulation of tumor growth: potential clinical applications in cancer.

Chemerin is a relatively newly described, yet increasingly studied multifunctional protein that mediates a variety of important biological functions. With significant roles in immune trafficking and adipo/angiogenesis, chemerin has gained traction in recent years for its potential functions in cancer, tumorigenesis, and immune surveillance. Chemerin's main chemotactic cellular receptor, CMKLR1, is expressed on both immune cells and malignant tumor cells, while a second non-signaling receptor, CCRL2, may act to help concentrate chemerin along activated endothelial cells and at sites of inflammation. With recent findings that chemerin expression is altered in a multitude of cancer types, there is evidence that chemerin may play significant roles in suppressing -- or potentially promoting -- tumor growth, depending on the context. Several studies suggest a key role for chemerin in recruiting innate immune defenses to sites of inflammation via its concentration gradient, with additional studies identifying chemerin as a tumor suppressive cytokine. Thus, therapeutically targeting the chemerin/CMKLR1 axis may have the potential to favorably modulate tumor growth. Here, we conduct a brief review of chemerin's various roles in cancer, compiling the most recent data regarding its expression and function, with an emphasis on its potential for future prognostic and clinical applications.