Cloning and expression of the tumor-associated antigen L6.

AUTOR(ES)

Marken, J S

RESUMO

The L6 cell surface antigen, which is highly expressed on lung, breast, colon, and ovarian carcinomas, has attracted attention as a therapeutic target for murine monoclonal antibodies and their humanized counterparts. Its molecular nature has, however, remained elusive. Here we describe the expression cloning of a cDNA encoding the L6 antigen. COS cells transfected with this cDNA direct the expression of an approximately 24-kDa surface protein that reacts with the two anti-L6 monoclonal antibodies available. The predicted L6 peptide sequence is 202 amino acids long and contains three predicted NH2-terminal hydrophobic transmembrane regions, which are followed by a hydrophilic region containing two potential N-linked glycosylation sites and a COOH-terminal hydrophobic transmembrane region. The L6 antigen is related to a number of cell surface proteins with similar predicted membrane topology that have been implicated in cell growth. Two other members of this family of proteins, CD63 (ME491) and CO-029, are also highly expressed on tumor cells. The present findings should make it possible to further study the role of the L6-defined antigen in normal and neoplastic cells and to construct animal models for development of improved agents for active and passive cancer immunotherapy.

Documentos Relacionados

• A Tumor-Associated Antigen in Human Nephroblastomas
• Nature of the tumor-associated determinant(s) of carcinoembryonic antigen.
• Molecular cloning of cDNA for the human tumor-associated antigen CO-029 and identification of related transmembrane antigens.
• Sequence investigation of the major gastrointestinal tumor-associated antigen gene family, GA733.
• Development and characterization of monoclonal antibodies to Marek's disease tumor-associated surface antigen.