Abstract: The present invention establishes a simple and a highly sensitive detection method for hEPR and provides a novel detection method for human tumors which express hEPR. In particular, the present invention provides a monoclonal antibody which specifically recognizes human epiregulin (hEPR), hybridoma which produces the monoclonal antibody, and a highly sensitive detection method for hEPR using the monoclonal antibody.

Abstract: The present invention establishes a simple and a highly sensitive detection method for hEPR and provides a novel detection method for human tumors which express hEPR. In particular, the present invention provides a monoclonal antibody which specifically recognizes human epiregulin (hEPR), hybridoma which produces the monoclonal antibody, and a highly sensitive detection method for hEPR using the monoclonal antibody.

Abstract: A DNA fragment encoding a novel human-derived tumor cell growth inhibitor can be obtained from a cDNA library originating from human colon tumor cell, using as a DNA probe a DNA fragment encoding mouse human-derived tumor cell growth inhibitor. An expression plasmid bearing a promoter originating from Bacillus brevis, a signal peptide originating from Bacillus brevis and a DNA fragment encoding human-derived tumor cell growth inhibitor downstream of the signal peptide is constructed and Bacillus brevis is transformed by the expression plasmid. The resulting transformant is incubated to secret the novel inhibitor out of the cell so that the novel inhibitor can be produced efficiently.

Abstract: DNA fragments encoding a tumor cell growth inhibitors and having a nucleotide sequence shown by formula (1) below, which are produced by preparing cDNA library from mRNA of the established 3T3 cell-derived cell line, amplifying various DNA fragments considered to encode the tumor cell growth inhibitors by the PCR method, analyzing the nucleotide sequences of these DNA fragments and determining the nucleotide sequences of the DNA fragments encoding the inhibitors: ##STR1## wherein X represents TTC TTT CTA or TTC (SEQ ID NO:1 or SEQ ID NO:2).

Abstract: Novel tumor cell growth inhibitor is a protein which can be obtained from the culture supernatant of 3T3 cell-derived cell line and which has the following properties:(a) molecular weight 3,700.+-.370 daltons when measured by SDS polyacrylamide gel electrophoresis under reducing and non-reducing conditions;(b) column propertythe inhibitor is not substantially adsorbed onto an anionic exchange resin column at pH of about 7.4 but is substantially adsorbed onto a cationic exchange resin column at pH of about 5.0The inhibitor has an inhibitory activity on human promyelogenic leukemia cells and human uterocervical tumor-derived cells and is useful for the treatment of leaukemia or uterus tumor.