P073 Enhancing the MFSD2A protein for the treatment of colitis-associated cancer: novel insights for pathogenesis and treatment

Abstract

Abstract Background The intrinsic connection between inflammation and tumor promotion is well characterized and is a key pathogenic event in patients with colorectal cancer (CRC). A small fraction of patients with CRC suffers from genetic predisposition. However chronic inflammation, such as ulcerative colitis (UC), increases the risk of intestinal carcinogenesis, thus strengthening the connection between these conditions. A few years ago, our laboratory described that the intestinal endothelium isolated from actively inflamed UC patients displayed defective production of inflammation-resolving DHA-derived metabolites, by comparison with healthy controls and tissues in remission. We also reported that the Major Facilitator Superfamily Domain containing 2A (MFSD2A) participated in the production of the inflammation-resolving DHA-derived metabolites by the intestinal endothelium of patients with UC in remission, ameliorating colonic inflammation. Therefore, we hypothesized that the endothelial MFSD2A also has a role in preventing and/or counteracting cancer-associated inflammation. Methods Human Intestinal Microvascular Endothelial Cells (HIMEC) isolated from CRC and healthy samples were transduced with either MFSD2A protein-encoding lentiviral vectors (MFSD2A) or GFP as control, or MFSD2A targeting shRNA or its scramble, and were analyzed by lipidomics. Furthermore, Caco-2 cells co-cultured with HIMEC-MFSD2A were analyzed by FACS, evaluating their proliferation. Moreover, an orthotopic model of CRC was made intrarectally injecting CD1 nude mice with a cell mixture of Caco-2 and HUVEC overexpressing MFSD2A or GFP as control. Mice were gavaged with DHA-ethyl-ester or PBS. FACS analysis was performed on tumor and colonic samples. Results Lipidomic analysis revealed that the loss of MFSD2A in CRC is detrimental because there is a reduced production of pro-resolving lipids confirming that, as for UC, MFSD2A is important for the maintenance of an adequate balance between pro-resolving and pro-inflammatory phenotype. Moreover, enhancing MFSD2A expression at endothelial level limits Caco-2 cell proliferation, supporting its beneficial role. In addition, DHA administration in mice ameliorated clinical symptoms of inflammation upon intestinal endothelial MFSD2A overexpression, supporting the beneficial role of MFSD2A in vivo. Conclusion Tumor-associated inflammation remains a crucial hallmark of CRC. Our study seeks to identify the role of MFSD2A in the resolution phase of inflammation, pointing out alternative therapies for CRC treatment. These data suggested that MFSD2A might contrast the tumor-associated inflammation and ensure the correct balance between pro-inflammatory and pro-resolving milieu.