Abstract: An objective of the present invention is to provide chimeric receptors containing a mouse Fc? receptor extracellular domain and a human Fc? receptor transmembrane domain, or chimeric receptors containing a mouse Fc? receptor extracellular domain and a human ? chain transmembrane domain. Another objective of the present invention is to provide methods for measuring the ADCC activity of mouse antibodies and methods of screening for mouse antibodies having ADCC activity, using the chimeric receptors. To accomplish the above-mentioned objectives, the present inventors produced chimeric molecules by fusing the extracellular domain of mouse Fc?R3 or mouse Fc?R4 with the transmembrane domain/intracellular domain of human ? chain or human Fc?R3, and expressed the chimeric molecules in human NK92 cells.

Abstract: Methods that entail detection of an epiregulin (EREG) protein for cancer diagnosis are disclosed. In colon cancer, lung adenocarcinoma, pancreatic cancer, stomach cancer, and kidney cancer, the gene and protein expressions of EREG were frequently found to be elevated. Antibodies that recognize an EREG protein are used for diagnosing or treating cancer in the present invention. Pharmaceutical compositions, cell proliferation inhibitors, and anticancer agents containing an EREG-binding antibody as an active ingredient are also disclosed. Methods of inducing cell damage in EREG-expressing cells and methods of suppressing the proliferation of EREG-expressing cells by contacting the EREG-expressing cells with EREG-binding antibodies are also disclosed.