ESTABLISHMENT AND CHARACTERIZATION OF A NOVEL HUMAN MYOEPITHELIAL CELL-LINE AND MATRIX-PRODUCING XENOGRAFT FROM A PAROTID BASAL-CELL ADENOCARCINOMA

Myoepithelial cells exert important paracrine effects on epithelial mo rphogenesis and mitogenesis through direct cell-cell interactions and through synthesis of a basement membrane extracellular matrix. To stud y these effects further, this study established the first immortalized human myoepithelial cell line, HMS-1, and transplantable xenograft, H MS-X, from the rare parotid basal cell adenocarcinoma. The cell line e xhibited a fully differentiated myoepithelial phenotype and the xenogr aft exhibited the rare property of accumulating an abundant extracellu lar matrix composed of both basement membrane and nonbasement membrane components with the latter predominating, With HMS-1 as a feeder laye r, dramatic and specific induction of epithelial morphogenesis (sphero id formation) occurred with selected normal epithelial and primary car cinoma target cells. HMS-1 and HMS-X provide distinct advantages over the conventional murine matrices in existence. They will be invaluable in future studies of human tumor-myoepithelial and matrix interaction s important for tumor cell growth, invasion, and metastasis.