Liver-specific zona pellucida domain-containing protein (OIT3)

Liver-specific zona pellucida domain-containing protein (OIT3) is a glycoprotein predominantly expressed in the liver, encoded by the OIT3 gene on chromosome 10q21.3[2][4]. It features a signal peptide, three EGF-like domains, and a C-terminal ZP domain, with primary localization on the nuclear envelope of hepatocytes and secretion into the blood[2]. OIT3 regulates biological processes such as differentiation, immune modulation, and lipid metabolism, and maintains calcium ion homeostasis[1][5]. It is significantly downregulated in hepatocellular carcinoma (HCC), where reduced expression correlates with poor prognosis and may result from promoter methylation or copy number loss[1][2][5]. Overexpression of OIT3 in liver cancer cells inhibits proliferation, migration, and invasion by inducing ferroptosis—primarily through upregulating ALOX15 and CYP4F3 and activating the arachidonic acid metabolic pathway—leading to oxidative stress and lipid peroxidation[1][5]. OIT3 also modulates immune characteristics of tumor-associated macrophages, promotes PD-L1 expression, and facilitates tumor immune escape through NF-κB signaling, reinforcing its role in HCC progression[3]. The protein is considered a promising biomarker and a potential therapeutic target for liver cancer, although no specific drugs currently target OIT3[1][5].

Other names

Oncoprotein-induced transcript 3 proteinOIT3LZPUNQ826/PRO1753FLJ39116Liver-specific ZP domain-containing protein

None currently reported (no known drugs target OIT3 directly; potential mechanism would include modulation of ferroptosis and immune microenvironment if developed)