Synthesis and secretion of an hEGF-like immunoreactive factor by human gastric cancer cells (MKN-45).
A large amount of an immunoreactive factor was detected in the medium conditioned by human gastric cancer cells, strain MKN-45, by our enzyme immunoassay system for human epidermal growth factor (hEGF) based on hEGF isolated from urine. However, the dose-response curve of the immunoreactive factor (designated as MKN-45 EGF) was not parallel with the standard curve of hEGF. The molecular weight of MKN-45 EGF was slightly larger than that of hEGF and was estimated to be 7,000-8,000 by gel filtration on Sephadex G-50. On isoelectric focusing analysis, MKN-45 EGF gave a major peak at pH 5.0 and a minor one at pH 4.3. These results demonstrate that MKN-45 cells synthesize and secrete into the culture medium a polypeptide immunologically related to hEGF.
D002850:Chromatography, Gel; D003470:Culture Media; D004815:Epidermal Growth Factor / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007525:Isoelectric Focusing; D008970:Molecular Weight; D010455:Peptides / Q000302:isolation & purification; D013274:Stomach Neoplasms / Q000032:analysis / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D003470:Culture Media; D010455:Peptides; D004815:Epidermal Growth Factor