Monoclonal antibodies against nucleophosmin mutants: Potentials for the detection of acute myeloid leukemia

Abstract

Nucleophosmin (NPM1) gene mutations resulting in cytoplasmic delocalization of Nucleo-phosmin (NPMc+) are the most common genetic alteration in acute myeloid leukemia (AML). Here, we attempted to prepare monoclonal antibodies (mAbs) against NPM1 mutation A (NPM-mA) and investigated the mAbs' clinical utility in immunohistochemical detection of NPMc+AML. The pET-32a-NPM-mA vector with the whole open reading frame of the NPM-mA gene was constructed. E.coli BL21 transformed with the vector were induced to express the NPM-mA recombinant protein. BALB/c mice were immunized with the recom-binant NPM-mA. Positive clones were selected by indirect ELISA and the mAbs were ob-tained. Immunohistochemistry was performed to detect the NPMc+ in bone marrow smears from 10 AML patients with NPM-mA. The results showed that the pET-32a-NPM-mA vector was successfully constructed and the NPM-mA recombinant protein was used to immunize the mice. Two positive clones (2G3 and 3F9) were selected. The mAbs against NPM-mA were raised, but did cross-react with wild type NPM1. The mAbs can be used to detect the cyto-plasmic dislocation of NPM1 in all AMLs carrying NPM-mA. Our results show that an-ti-NPM-mA mAbs were produced. Though they would cross-react with wild type NPM1, the mAbs may still have potential in the detection of NPMc+AMLs. © Ivyspring International Publisher.