Endocrine Abstracts

Adrenocortical carcinoma (ACC) carries a 5-year prognosis of <10%. Therapeutic options are limited including surgery and mitotane – a poorly tolerated and efficacious insecticide. Recent data have demonstrated that the immune environment of ACC is deficient in lymphocytes while demonstrating a relative rich monocyte/macrophage population in the tumour microenvironment. We have investigated the migration of circulating monocytes to ACC. ACC cells were seeded in the bottom chamber of the transwell system. Monocytes were isolated from human fresh blood using magnetic beads with high purity (>95%) and quality. Migration of monocytes at 24/48h was evaluated by identifying those remaining in the top chamber, the floating fraction in the bottom chamber and those adherent to ACC cells in the bottom chamber. Analysis of monocyte/macrophages was undertaken by flow cytometry. At 24h, when compared to control conditions, more monocytes had migrated to the ACC cells seeded lower chamber and attached to the bottom. Similar results were observed in migration at 48h. Predominantly Classical monocytes (CD14++CD16-HLA-DR+) migrated to metastatic cancer cells (MUC1), and Non-Classical monocytes (CD14+CD16+HLA-DR+) migrated to primary cancer cells (H295R/ HAC15) at 48h. We then investigated the polarization cytokine profile of migrated monocytes with or without ACC cells at 72 h by multiplex bead-based assay. Migrated monocytes indicated a significant shift toward the M2 phenotype in the presence of H295R or HAC15. The production of the pro-inflammatory factors of IL-6, TNF-alpha, etc. decreased and immunosuppressive factors of IL-10, TARC, etc. increased. MUC1 didn’t increase M2 or M1 cytokine secretion. Moreover, surface markers of migrated monocytes were evaluated at 72h by flow cytometry. All ACC cell lines switched macrophages into M2 phenotype, as evidenced by the decrease in the expression of the M1 marker CD86 and the increase in the expression of the M2 markers CD163 and CD206.