Active Forms of Chemerin Are Elevated in Human and Mouse Ovarian Carcinoma

Background: Chemerin is a small adipokine that is activated and inactivated by proteolysis of its C-terminus with a role in regulating metabolism, immunity, and inflammation. Significant levels of chemerin are found in circulation and ascitic fluid of ovarian carcinoma patients. Methods: We investigated the levels of different chemerin forms in three cohorts: people with BMI < 25, with BMI > 40, and ovarian carcinoma ascites with ELISAs specific for different chemerin forms. Ascites from a mouse model of ovarian carcinoma were also analyzed, and the model was compared between wild-type and chemerin-deficient mice. Results: Conversion of plasma to serum increased the levels of processed chemerin with lower increases in samples from people with BMI < 25 than in people with BMI > 40. High levels of total chemerin and processed forms of chemerin were found in ascitic fluid from both patients who had a mean BMI of 29 and the mouse model. In chemerin-deficient mice the tumors grew slower than in wild-type mice. Conclusions: Serum has more processed and active chemerin than plasma irrespective of source. Ascites of ovarian carcinoma patients contained high levels of active chemerin, which, based on the mouse data, enhance tumor growth.