Clinical implications of expression of ETS-1 related to angiogenesis in metastatic lesions of ovarian cancers

Objective: ETS-1 has been identified as a proto-oncogene and a transcription factor for tumor angiogenesis, which is essential for the growth, invasion and metastasis of solid tumors. The aim is to investigate the clinical implications of ETS-1 expression in peritoneal metastatic lesions of ovarian cancers. Methods: In primary tumors and peritoneal metastatic lesions from 30 patients with stage III ovarian cancers, ETS-1 histoscores and ets-1 mRNA levels were determined by immunohistochemistry and competitive RT-PCR-Southern blot analysis using recombinant RNA, respectively. Results: Immunohistochemical staining revealed that ETS-1 was expressed in the cancer cells and vascular endothelial cells. ETS-1 histoscores in the endothelial cells and ets-1 mRNA levels were significantly ( p <0.05) increased in 20 of 30 peritoneal metastatic lesions of ovarian cancers. There was a significant correlation between microvessel counts (MVCs) and ETS-1 histoscores in the endothelial cells ( p < 0.001) and between MVCs and ets-1 mRNA levels in the primary tumor and the peritoneal metastatic lesion of ovarian cancers ( p <0.001). Furthermore, the 24-month survival rate of patients with significantly increased ets-1 mRNA level (2/20, 10%) was significantly ( p < 0.01) lower than that of patients with no change in the level (6/10, 60%) from the primary tumor to the peritoneal metastatic lesion. Conclusions: ETS-1 might be associated with peritoneal metastasis dominantly as an angiogenic mediator and additionally as an oncogene product to activate tumor invasion in ovarian cancers. Copyright (C) 2004 S. Karger AG, Basel.