Abstract 5072: Immunohistochemical expression of CC-chemokine receptor-like 2/CCRL2 in a prostate cancer tissue microarray

Abstract

Abstract Background: CCRL2 is a presumed member of the atypical chemokine receptor family, whose members are increasingly recognized as key components of the regulatory network of inflammation and immunity in cancer and may have a major effect on anti-inflammatory and immunotherapeutic strategies. Recent studies have reported the expression of CCRL2 in different human cancer cell lines and tissues. However, its function and expression in prostate cancer has not been previously addressed. The aim of this work was to determine the protein expression profile of the atypical chemokine receptor CCRL2 in human prostate cancer tissue using a tumor microarray approach. Methods: A tissue microarray was constructed using 231 cores of matched prostate cancer and benign prostatic tissue from 47 patients with a previous diagnosis of localized prostate cancer, which underwent surgical resection as their primary treatment. CCRL2 expression was evaluated by immunohistochemistry using a monoclonal, anti-human-CCRL2 antibody. An H score was calculated in each spot as the sum of expression intensity (0-3+) by extent (0%-100%). Differences in CCRL2 protein expression were assessed by comparing H-Scores between benign and cancerous tissues using Mann-Whitney test for non-Gaussian distribution. Results: Immunohistochemical evaluation of CCRL2 at the protein level in a prostate tissue microarray constructed with clinical specimens confirmed its overexpression in malignant prostatic tissue. CCRL2 staining was present predominantly in the cytoplasm of prostate cancer tumor cells. Compared to benign epithelial cells, CCRL2 expression was significantly higher in epithelial tumor cells in cores with prostate cancer compared to cores with benign tissue (p=0.0001). Conclusions: Immunohistochemistry of prostate cancer tissue specimens arrayed in a tissue microarray revealed that CCRL2 expression was significantly stronger in epithelial cells in cancerous acini compared to epithelial cells in matched adjacent benign acini from the same patient. To this point, the physiological effects of CCRL2 expression in epithelial cancer cells are unclear. Citation Format: Niradiz Reyes, Ines Benedetti, Jan Geliebter. Immunohistochemical expression of CC-chemokine receptor-like 2/CCRL2 in a prostate cancer tissue microarray [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5072.