ABSTRACT
Introduction Multiple previous studies have shown the monoclonal antibody Das-1 (formerly called 7E12H12) specifically recognizes metaplastic and carcinomatous lesions in multiple organs of the gastrointestinal system (e.g. Barrett’s esophagus, intestinal-type metaplasia of the stomach, gastric adenocarcinoma, high-grade pancreatic intraepithelial neoplasm, and pancreatic ductal adenocarcinoma) as well as in other organs (bladder and lung carcinomas). Beyond being a useful biomarker in tissue, mAb Das-1 has recently proven to be more accurate than current paradigms for identifying cysts harboring advanced neoplasia. Though this antibody has been used extensively for clinical, basic science, and translational applications for decades, its epitope has remained elusive.
Methods In this study, we chemically deglycosylated a standard source of antigen, which resulted in near complete loss of the signal as measured by western blot analysis. The epitope recognized by mAb Das-1 was determined by affinity to a comprehensive glycan array and validated by inhibition of a direct ELISA.
Results The epitope recognized by mAb Das-1 is 3’-Sulfo-Lewis A (3’-Sulfo-LeA). 3’-Sulfo-LeA is broadly reexpressed across numerous GI epithelia and elsewhere only after metaplastic and carcinomatous transformation.
Discussion 3’-Sulfo-LeA is a clinically important antigen that can be detected both intracellularly in tissue using immunohistochemistry and extracellularly in cyst fluid and serum by ELISA. The results open new avenues for tumorigenic risk stratification of various gastrointestinal lesions.
Competing Interest Statement
KMD and KKD have been granted a patent for the use of Das-1 in the detection of cancerous pancreatic lesions. KKD is providing Das-1 antibody to Interpace Biosciences for commercial use in risk stratifying pancreatic cystic lesions. JWB, VK, and JCM have no conflicts of interest.
Footnotes
Disclosures / Conflicts of Interest: KMD and KKD have been granted a patent for the use of Das-1 in the detection of cancerous pancreatic lesions. KKD is providing Das-1 antibody to Interpace Biosciences for commercial use in risk stratifying pancreatic cystic lesions. JWB, VK, and JCM have no conflicts of interest.
Glycan Profiling: www.functionalglycomics.org
Grant Support
JWB: Department of Defense W81XWH-20-1-0630, NIH T32 DK007130-42, the Digestive Disease Research Core Centers Pilot and Feasibility Grant as part of P30 DK052574, and the American Gastroenterological Association AGA2021-5101.
JCM: R21DK111369, R01DK094989, R01DK105129, R01DK110406, P30 CA09182, R01 CA239645, R01 CA246208, the Alvin J. Siteman Cancer Center-Barnes Jewish Foundation Cancer Frontier Fund, and the BETRNet (U54CA163060).
V.K.: T32 GM07200
KMD: R01 DK47673, R01 DK63618
Other: The National Center for Functional Glycomics Glycan Array resource and much appreciated assistance with the analysis was supported by R24 GM098791, R24 GM137763, and P41 GM103694.
Abbreviations used in this paper
- BSA
- Bovine Serum Albumin
- ELISA
- Enzyme Linked Immunosorbent Assay
- Gal
- Galactose
- GlcNAc
- N-Acetylglucosamine
- PBS
- Phosphate Buffered Saline
- Gal
- Galactose
- LeA
- Lewis A
- LeX
- Lewis X
- TFMS
- Trifluoromethanesulfonic Acid