Immunologic quantitation of the carcinoma specific human carcinoma antigen in clinical samples

Biochemical and Biophysical Research Communications

Childs

et al. 2011

The term human epithelial carcinoma antigen (HCA) has been applied collectively to mucin-type high molecular weight (>1000 kDa) glycoproteins that are over-expressed in epithelial cancers. Since the 1990s, over 40 monoclonal antibodies have been raised that recognize HCA. There has been evidence that the antigenic determinants are mostly carbohydrates, but details have been elusive. Here we have carried out carbohydrate microarray in analyses of one of the monoclonal antibodies, AE3, that has been regarded the ‘most carcinoma specific’ in respect to its ability to detect HCA in sera of patients with epithelial cancers. The microarrays encompassed a series of 492 sequence-defined glycan probes in the form of glycolipids and neoglycolipids. We have thus established that the antigen recognized by antibody AE3 is a carbohydrate sequence distinct from the A, B, H, Lewisa/b, Lewisx/y and T antigens, but that it is strongly expressed on the monosulfated tetra-glycosyl ceramide, SM1a, Galβ1-3GalNAcβ1-4(3-O-sulfate)Galβ1-4GlcCer. This is the first report of an anti-HCA to be characterized with respect to its recognition sequence and of the occurrence of the antigen on a glycolipid as well as on glycoproteins. Knowledge of a discrete glycan sequence as target antigen now opens the way to its exploration as a serologic cancer biomarker, namely to determine if the antigen elicits an autoantibody response in early non-metastatic cancer, or if it is shed and immunochemically detectable in more advanced disease.

Section: Introductionmentioning

confidence: 99%

The human epithelial carcinoma antigen recognized by monoclonal antibody AE3 is expressed on a sulfoglycolipid in addition to neoplastic mucins

Palma

Biochemical and Biophysical Research Communications

Childs

et al. 2011

“…In the first set of experiments, we screened a panel of four tumor cell lines by cell surface staining in flow cytometry. These include (a) a breast cancer line, T-47D, which was selected owing to the fact that breast cancer patients were found to produce substances in circulation that are highly effective in inhibiting HAE3 binding of epiglycanin [ 12 , 23 ], (b) a lung cancer line, A549, which is known to produce an HAE3-positive substance in cell culture, (c) a prostate cancer line, PC3, which is found to express a blood group B-related F77 glycoepitope [ 24 , 25 ], and (d) a melanoma cell line SKMEL-28, which is derived from skin but not epithelial tissue. As shown in Figure 3(a) , melanoma SKMEL-28 and prostate cancer PC3 were negative for HAE3.…”

Section: Resultsmentioning

confidence: 99%

“…However, the antibody differed from PNA in that the concentration of the blood group T disaccharide required for inhibition of binding to epiglycanin was 10 4 times greater than for PNA. Moreover, a T-specific mAb HH8 was found to be negative with epiglycanin in ELISA microtiter plates [ 12 ]. HH8 is specific for the T-terminal disaccharide moiety expressed by asialoglycophorin A [ 13 ].…”

Section: Introductionmentioning

confidence: 99%

Carbohydrate Microarrays Identify Blood Group Precursor Cryptic Epitopes as Potential Immunological Targets of Breast Cancer

Wang

Tang

Journal of Immunology Research

et al. 2015

Using carbohydrate microarrays, we explored potential natural ligands of antitumor monoclonal antibody HAE3. This antibody was raised against a murine mammary tumor antigen but was found to cross-react with a number of human epithelial tumors in tissues. Our carbohydrate microarray analysis reveals that HAE3 is specific for an O-glycan cryptic epitope that is normally hidden in the cores of blood group substances. Using HAE3 to screen tumor cell surface markers by flow cytometry, we found that the HAE3 glycoepitope, gpHAE3, was highly expressed by a number of human breast cancer cell lines, including some triple-negative cancers that lack the estrogen, progesterone, and Her2/neu receptors. Taken together, we demonstrate that HAE3 recognizes a conserved cryptic glycoepitope of blood group precursors, which is nevertheless selectively expressed and surface-exposed in certain breast tumor cells. The potential of this class of O-glycan cryptic antigens in breast cancer subtyping and targeted immunotherapy warrants further investigation.

“…These include (a) a BCa line, T-47D, which was selected owing to the fact that breast cancer patients were found to produce substances in circulation that are highly effective in inhibiting AE3-binding of epiglycanin (Codington et al 2002; Codington et al 1997); (b) a lung cancer (LCa) line, A549, which is known to produce an HAE3-positive substance in cell culture; (c) a prostate cancer (PCa) line, PC3, which is found to express a blood group B-related F77 glyco-epitope (Gao et al 2014; Nonaka et al 2014); and (d) a melanoma cell line SKMEL-28, which is derived from skin but not epithelial tissue. As shown in Fig.…”

Section: Flow Cytometry Analysis To Examine Tumor Cell Surface Expresmentioning

confidence: 99%

Glycan Markers as Potential Immunological Targets in Circulating Tumor Cells

Wang

Advances in Experimental Medicine and Biology

2017

We present here an experimental approach for exploring a new class of tumor biomarkers that are overexpressed by circulating tumor cells (CTCs) and are likely targetable in immunotherapy against tumor metastasis. Using carbohydrate microarrays, anti-tumor monoclonal antibodies (mAbs) were scanned against a large panel of carbohydrate antigens to identify potential tumor glycan markers. Subsequently, flow cytometry and fiber-optic array scanning technology (FAST) were applied to determine whether the identified targets are tumor-specific cell-surface markers and are, therefore, likely suitable for targeted immunotherapy. Finally, the tumor glycan-specific antibodies identified were validated using cancer patients’ blood samples for their performance in CTC-detection and immunotyping analysis. In this article, identifying breast CTC-specific glycan markers and targeting mAbs serve as examples to illustrate this tumor biomarker discovery strategy.