Expression of epidermal growth factor and transforming growth factor-beta in human salivary gland adenocarcinoma cell...

Neoplastic intercalated duct cells that originated from a human submandibular salivary gland release transforming growth factor and human epidermal growth factor into serum-free medium. The transforming growth factor with the soft agar colony-forming activity when assayed in the presence of mouse epidermal growth factor on normal rat kidney clone 49F indicator cells, but without mitogenic action to quiescent 3T3 cells, does not compete with epidermal growth factor for receptor binding, is heat and acid resistant but trypsin and dithiothreitol sensitive, and therefore is of the transforming growth factor-beta class. The immunoreactive human epidermal growth factor is detected by radioimmunoassay on certain fractions obtained by the Bio-Gel P-60 chromatography of neoplastic epithelial duct cells originated from a human submandibular salivary gland-conditioned medium and is biologically very similar to mouse epidermal growth factor. Moreover, the presence of human epidermal growth factor in cultured neoplastic epithelial duct cells originated from a human submandibular salivary gland is demonstrated by the peroxidase:antiperoxidase method.