[THE PROLIFERATIVE EFFECT OF DENDRITIC CELLS IN OVARIAN CANCER AND THE RELATIONSHIP WITH THE IGF SIGNALING PATHWAY].

INTRODUCTION: Epithelial ovarian cancer (EOC) is the principal cause of death from gynecologic cancer in developed countries. While surgery and chemotherapy can improve survival, the mortality and morbidity rates remain significantly high. The insulin-like growth factor (IGF) axis has been shown to play an important part in carcinogenesis of several human malignancies. Preclinical studies reported a significant anti-proliferative activity of IGF1 receptor (IGF1R) inhibitors in ovarian malignancies, however, clinical studies have shown variable response rates. Recent data indicate that immunotherapy could hold promise in improving EOC treatment. Dendritic cells (DCs) which are antigen presenting cells evoke a positive immune response. Moreover, a recent study shows that IGF treatment can inhibit DC maturation.

AIMS: To investigate the involvement of IGF1R signaling in DCs and the effect of combined DCs and IGF1R inhibitor treatment on EOC cells growth.

METHODS: HL-60 leukemic cells were differentiated to DCs and ligand induced phosphorylated IGF1R levels were measured by Western blotting. Next, inhibition of IGF1R in DCs was applied and the effect of this inhibition on EOC cell lines ES2 and SKOV3 was examined using the migration assay method.

RESULTS: The differentiation of HL-60 into DCs was associated with decreased levels of both IGF1R phosphorylation and total IGF1R protein. In addition, in-vitro growth assays (scratch assay) demonstrated an increased growth of both ES2 and SKOV3 cells into the scratch zone when co-cultured with DCs which were not pre-treated with IGF1R inhibitor as compared to treated DCs.

CONCLUSIONS: Preliminary data suggest that DC differentiation is associated with IGF1R signaling downregulation. Moreover, inhibition of IGF1R signaling in DCs might decrease EOC growth.