High Levels of MFG-E8 Confer a Good Prognosis in Prostate and Renal Cancer Patients

Abstract

Milk fat globule-epidermal growth factor-8 (MFG-E8) is a glycoprotein secreted by different cell types, including apoptotic cells and activated macrophages. MFG-E8 is highly expressed in a variety of cancers and is classically associated with tumor growth and poor patient prognosis through reprogramming of macrophages into the pro-tumoral/pro-angiogenic M2 phenotype. To date, correlations between levels of MFG-E8 and patient survival in prostate and renal cancers remain unclear. Here, we quantified MFG-E8 and CD68/CD206 expression by immunofluorescence staining in tissue microarrays constructed from renal (n = 190) and prostate (n = 274) cancer patient specimens. Percentages of MFG-E8-positive surface area were assessed in each patient core and Kaplan–Meier analyses were performed accordingly. We found that MFG-E8 was expressed more abundantly in malignant regions of prostate tissue and papillary renal cell carcinoma but was also increased in the normal adjacent regions in clear cell renal carcinoma. In addition, M2 tumor-associated macrophage staining was increased in the normal adjacent tissues compared to the malignant areas in renal cancer patients. Overall, high tissue expression of MFG-E8 was associated with less disease progression and better survival in prostate and renal cancer patients. Our observations provide new insights into tumoral MFG-E8 content and macrophage reprogramming in cancer.

MFG-E8 promotes M2 polarization of macrophages and is associated with poor prognosis in patients with gastric cancer

“…This may be due to genetic changes in the tumor microenvironment that are initiated by cancer cells or immune helper cells during tumor progression, with macrophages exhibiting predominantly M2-type polarization; It exhibits an immunosuppressive tumor phenotype and promotes tumor progression, metastasis, and treatment resistance. MFG-E8 expression has been found to be associated with M2 polarization in a variety of cancers, including the oral cavity, prostate, and melanoma [ 25 ]. In our study, we found that MFG-E8 can promote the transformation of macrophages from GC patients to M2.…”