Dual Role of Tissue Factor Pathway Inhibitor 2—A Novel Serodiagnostic Marker for Ovarian Cancer—In Human Cancers

Abstract

Background: Tissue factor pathway inhibitors (TFPI1 and TFPI2) are ubiquitously distributed in humans and exhibit inhibitory activity against serine proteinases. TFPI1 inhibits the tissue factor (TF)-dependent extrinsic coagulation pathway, while TFPI2 modulates extracellular matrix remodeling. TFPI2 has been reported to be an epigenetically silenced tumor suppressor and independent prognostic factor in various human cancers. However, elevated serum levels of TFPI2 have been observed in ovarian and endometrial cancers compared to healthy controls, with increased levels correlating with poor prognosis in endometrial cancer. This raises the question of why the tumor suppressor TFPI2 is elevated in the blood of patients with gynecological cancers and is associated with adverse outcomes. Methods: A comprehensive literature search was performed in PubMed and Google Scholar without time restriction. Results: TFPI2 gene expression may be influenced by both cancer cell-specific gene expression profiles (e.g., oncogenic signaling pathways) and epigenetic modifications (e.g., DNA methylation, histone modifications, and non-coding RNAs). Although TFPI2 generally exhibits an anti-invasion effect in most human cancers, it has been reported to have a paradoxical pro-invasive effect in certain cancers. TFPI2 facilitates cancer invasion through aberrant alternative splicing or through a pathophysiological process known as angiotropism or vasculogenic mimicry. The overproduction of TFPI2 in the tumor microenvironment may reinforce the extracellular matrix, thereby enhancing tumor cell adhesion and invasion. Conclusion: This review summarizes the current understanding of the seemingly contradictory functions of TFPI2 in human malignancies, primarily focusing on the mechanisms regulating its expression and function, and discusses future prospects for translational research.