Production and Characterization of Mouse Monoclonal Antibodies to Human Zinc Finger OZF Protein Overexpressed in Pancreatic Carcinomas

Mouse monoclonal antibodies (MAbs) were raised against the human OZF protein, a zinc finger protein of the Krüppel family, consisting of 10 amino acids followed by 10 zinc finger motives. The OZF gene is amplified in 15-25% of pancreatic carcinomas and protein overexpression occurs in more than half of the tumors. Six MAbs effective in detecting the recombinant and the cellular protein by enzyme-linked immunoadsorbent assay (ELISA), Western immunoblotting, and immunofluorescence were purified and characterized. Five MAbs belong to the IgG₁ subclass and one to the IgG₃ subclass. In contrast to polyclonal antibodies, which detect many related proteins, they recognize an epitope unique to the human OZF protein. The sequence of the epitope, located at the junction between the first 10 amino acids and the zinc finger domain, is not present in other Krüppel proteins, including mouse and bovine OZF proteins. The MAbs are highly specific to the endogenous OZF protein in its denatured and native form. Therefore, they should be useful for OZF functional study and clinical diagnosis of tumors with aberrant OZF expression.