Insulin-like growth factor binding protein-3 (IGFBP-3) acts as an invasion-metastasis suppressor in ovarian endometrioid carcinoma

Metastasis and invasion occur in the majority of epithelial ovarian carcinoma at diagnosis. To delineate the molecular signature in ovarian cancer invasion, we established and characterized a human ovarian endometrioid carcinoma (EC) cell line OVTW59-P0 and its invasion-related sublines (P1-P4, in the order of increasing invasive activity). P4 showed faster migration and larger xenograft formation with metastasis than P0. By microarray analysis of different gene expression among P0-P4 sublines, one group of gene was found negatively correlated with cancer invasion. Among these genes, IGFBP-3 was identified as one of the most remarkably suppressed gene that showed lower gene expression in P4 than P0. Re-expression of IGFBP-3 in P4 effectively inhibited cell migration, invasion and metastasis, but did not affect cell proliferation. In 35 patients with EC tumors, low IGFBP-3 expression correlated clinically with higher tumor grade, advanced stage and poor survival. Our results provide evidence and indicate that IGFBP-3 plays an important role as an invasion-metastasis suppressor in ovarian EC.