UBC Center for Reproductive Research Vancouver, Canada
*Corresponding Author: Gregory Lee, UBC Center for Reproductive Research Vancouver, Canada.
Received: January 29, 2020; Published: February 19, 2020
RP215 monoclonal antibody was initially generated against OC-3-VGH ovarian cancer cell extract and was shown to recognize a carbohydrate-associated epitope located mainly in heavy chain immunoglobulins expressed on the surface of most human cancer cells. Efforts were made to elucidate the primary structure of this unique epitope through comprehensive biochemical and glycosyl-linkage analysis. Upon 48-hr treatments of cancer cells with glycan analogs or neuraminidase, significant changes were observed regarding the ability of RP215 to induce anti-proliferation of cancer cells. Results of this analysis may suggest the involvement of amino acid residues as well as sugar moiety of immunoglobulin heavy chain in the epitope recognition by RP215. Treatment with tunicamycin to cancer cells in culture has little effect on RP215 immunoactivity, indicating the involvement of O-linked glycan in the RP215-specific epitope recognitions. It was further observed that RP215 binding to cancerous immunoglobulins or CA215 was not affected by anti-human IgG-Fc, but completely inhibited by anti-human IgG-Fab. This observation may suggest the epitope locations in the Fab or variable regions of cancerous immunoglobulin heavy chains. Based on the results of glycosyl-linked analysis, it can be suggested that RP215-specific epitope is associated with CORE-1 structure of O-linked glycans such as Tn or TnS. RP215-specific epitope was identified mainly in cancerous immunoglobulins, but not from those produced by normal B cells. This unique antibody can therefore serve as a useful probe in targeting cancer cells of many tissue origins, including blood tumors. Interactions of RP215 with cancer cells of leukemic origins were demonstrated by comprehensive FACS analysis. The humanized forms of RP215 have been developed as antibody-based anti-cancer drugs or cancer therapy with CAR-T cell or related constructs. In addition, RP215-based immunoassays can be used routinely for monitoring serum levels of CA215 among patients with many types of cancer at different stages, when used singly or in combination with other known cancer biomarkers.
Keywords: CA215 Monoclonal Antibody; RP215 Monoclonal Antibody; O-Glycan Linked Epitope; Cancerous Immunoglobulins; Anti-Cancer Drugs and Therapy
Citation: Gregory Lee. “RP215 Monoclonal Antibody with O-Glycan Linked Epitope in Cancerous Immunoglobulins and Potential Clinical Applications”.Acta Scientific Cancer Biology 4.3 (2020): 01-08.
Copyright: © 2020 Gregory Lee. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.