Generation of a Rat Monoclonal Antibody for Human Nucleophosmin

Nucleophosmin (NPM1) is abundant in the nucleolus, and it shuttles between the nucleolus, nucleus, and cytoplasm to facilitate its roles in ribosome biogenesis, chromatin remodeling, DNA repair, and cell cycle regulation. It is overexpressed in various types of cancer and is related to malignancy. Furthermore, its localization is important for its cellular function and the malignant transformation of cancer cells. In this study, we describe our novel rat monoclonal antibody (mAb) 4H7, which recognizes NPM1. Our results indicated that this mAb recognizes endogenous human NPM1 in several cancer cell lines and is suitable for immunoprecipitation, immunofluorescence staining, and immunoblotting. Therefore, mAb 4H7 is expected to be useful for the functional analysis of human NPM1 in cancer and for the diagnosis of malignant transformation via expression and localization assays.