Here, we report the development of an antibody-drug conjugate, ASG-5ME, which targets the solute carrier receptor SLC44A4. SLC44A4 is a member of a family of putative choline transporters that we show to be markedly upregulated in a variety of epithelial tumors, most notably prostate and pancreatic cancer. SLC44A4 is normally expressed on the apical surface of secretory epithelial cells, but in cancer we show expression is not restricted to the luminal surface in advanced and undifferentiated tumors.
View Article and Find Full Text PDFThe identification of optimal target antigens on tumor cells is central to the advancement of new antibody-based cancer therapies. We performed suppression subtractive hybridization and identified nectin-4 (PVRL4), a type I transmembrane protein and member of a family of related immunoglobulin-like adhesion molecules, as a potential target in epithelial cancers. We conducted immunohistochemical analysis of 2,394 patient specimens from bladder, breast, lung, pancreatic, ovarian, head/neck, and esophageal tumors and found that 69% of all specimens stained positive for nectin-4.
View Article and Find Full Text PDFPurpose: New cancer-specific antigens are required for the design of novel antibody-drug conjugates (ADC) that deliver tumor-specific and highly potent cytotoxic therapy.
Experimental Design: Suppression subtractive hybridization identified ectonucleotide pyrophosphatase/phosphodiesterase 3 (ENPP3 or CD203c) as a potential human cancer-specific antigen. Antibodies targeting the extracellular domain of human ENPP3 were produced and selected for specific binding to ENPP3.
rBPI23, a recombinant N-terminal fragment of human bactericidal/permeability-increasing protein (BPI), kills Gram-negative bacteria and neutralizes endotoxin. rBPI21, a variant in which cysteine 132 is changed to alanine, retains the activities of rBPI23. Analysis of certain purified rBPI21 preparations revealed that some of the molecules had lost nine amino acids from the amino terminus.
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