Lewis y antigen is expressed in oral squamous cell carcinoma cell lines and tissues, but disappears in the invasive regions leading to the enhanced malignant properties irrespective of sialyl-Lewis x

Surface glycan targeting for cancer nano-immunotherapy

Cancer immunotherapy is an emerging therapeutic strategy for cancer treatment. Most of the immunotherapeutics approved by the FDA regulate the innate immune system and associated immune cell activity, with immune check inhibitors in particular having transformed the field of cancer immunotherapy due to their significant clinical potential. However, previously reported immunotherapeutics have exhibited undesirable side effects, including autoimmune toxicity and inflammation. Controlling these deleterious responses and designing therapeutics that can precisely target specific regions are thus crucial to improving the efficacy of cancer immunotherapies. Recent studies have reported that cancer cells employ glycan-immune checkpoint interactions to modulate immune cell activity. Thus, the recognition of cancer glycan moieties such as sialoglycans may improve the anticancer activity of immune cells. In this review, we discuss recent advances in cancer immunotherapies involving glycans and glycan-targeting technologies based on nanomaterial-assisted local delivery systems.

Identification of α1,2-fucosylated signaling and adhesion molecules in head and neck squamous cell carcinoma

Head and neck cancer is the seventh most common cancer in the world, and most cases manifest as head and neck squamous cell carcinoma. Despite the prominent role of fucosylated carbohydrate antigens in tumor cell adhesion and metastasis, little is known about the functional role of fucose-modified glycoproteins in head and neck cancer pathobiology. Inactivating polymorphisms of the fut2 gene, encoding for the α1,2-fucosyltransferase FUT2, are associated with an increased incidence of head and neck cancer among tobacco users. Moreover, the presence of the α1,2-fucosylated Lewis Y epitope, with both α1,2- and α1,3-linked fucose, has been observed in head and neck cancer tumors while invasive regions lose expression, suggesting a potential role for α1,2-fucosylation in the regulation of aggressive tumor cell characteristics. Here, we report an association between fut2 expression and head and neck cancer survival, document differential surface expression of α1,2-fucosylated epitopes in a panel of normal, dysplastic, and head and neck cancer cell lines, identify a set of potentially α1,2-fucosylated signaling and adhesion molecules including the epidermal growth factor receptor (EGFR), CD44 and integrins via tandem mass spectrometry, and finally, present evidence that EGFR is among the α1,2-fucosylated and LeY-displaying proteins in head and neck cancer. This knowledge will serve as the foundation for future studies to interrogate the role of LeY-modified and α1,2-fucosylated glycoproteins in head and neck cancer pathogenesis. Data are available via ProteomeXchange with identifier PXD029420.

Carcinoembryonic antigen as a specific glycoprotein ligand of rBC2LCN lectin on pancreatic ductal adenocarcinoma cells

The rBC2LCN lectin, known as a stem cell marker probe that binds to an H type 3 fucosylated trisaccharide motif, was recently revealed to also bind to pancreatic ductal adenocarcinoma (PDAC) cells. A lectin‐drug conjugate was generated by fusing rBC2LCN with a cytocidal toxin, and it showed a strong anticancer effect in in vitro and in vivo PDAC models. However, it is unclear which molecules are carrier proteins of rBC2LCN on PDAC cells. In this study, we identified a rBC2LCN‐positive glycoprotein expressed in PDAC. Tumor lysates of PDAC patient‐derived xenografts (PDXs) were coprecipitated with rBC2LCN lectin and analyzed by liquid chromatography–mass spectrometry. A total of 343 proteins were initially identified. We used a web‐based database to select five glycoproteins and independently evaluated their expression in PDAC by immunohistochemistry (IHC). Among them, we focused on carcinoembryonic antigen 5 (CEA) as the most cancer‐specific carrier protein in PDAC, as it showed the most prominent difference in expression rate between PDAC cells (74%) and normal pancreatic duct cells (0%, P > .0001). rBC2LCN lectin and CEA colocalization in PDAC samples was confirmed by double‐staining analysis. Furthermore, rBC2LCN‐precipitated fractions were blotted with an anti‐CEA polyclonal antibody (pAb), and CEA pAb–precipitated fractions were blotted with rBC2LCN lectin. The results demonstrate that CEA is in fact a ligand of rBC2LCN lectin.

β-Catenin/CBP inhibition alters epidermal growth factor receptor fucosylation status in oral squamous cell carcinoma

Epidermal growth factor receptor (EGFR) is a major driver of head and neck cancer, a devastating malignancy with a major sub-site in the oral cavity manifesting as oral squamous cell carcinoma (OSCC). EGFR is a glycoprotein receptor tyrosine kinase (RTK) whose activity is upregulated in >80% OSCC. Current anti-EGFR therapy relies on the use of cetuximab, a monoclonal antibody against EGFR, although it has had only a limited response in patients. Here, we uncover a novel mechanism regulating EGFR activity, identifying a role of the nuclear branch of the Wnt/β-catenin signaling pathway, the β-catenin/CBP axis, in control of post-translational modification of N-glycans on the EGFR. Genomic and structural analyses reveal that β-catenin/CBP signaling represses fucosylation on the antennae of N-linked glycans on EGFR. By employing nUPLC-MS/MS, we determined that malignant human OSCC cells harbor EGFR with a paucity of N-glycan antennary fucosylation, while indolent cells display higher levels of fucosylation at sites N420 and N579. Additionally, treatment with either ICG-001 or E7386, which are both small molecule inhibitors of β-catenin/CBP signaling, leads to increased transcriptional expression of fucosyltransferases FUT2 and FUT3, with a concomitant increase in EGFR N-glycan antennary fucosylation. In order to discover which fucosylated glycan epitopes are involved in the observed effect, we performed in-depth characterization of multiply-fucosylated N-glycans via tandem mass spectrometry analysis of the EGFR tryptic glycopeptides. Data are available via ProteomeXchange with identifier PXD017060. We propose that β-catenin/CBP signaling promotes EGFR oncogenic activity in OSCC by inhibiting its N-glycan antennary fucosylation through transcriptional repression of FUT2 and FUT3.

The Diverse Contributions of Fucose Linkages in Cancer

Fucosylation is a post-translational modification of glycans, proteins, and lipids that is responsible for many biological processes. Fucose conjugation via α(1,2), α(1,3), α(1,4), α(1,6), and O'- linkages to glycans, and variations in fucosylation linkages, has important implications for cancer biology. This review focuses on the roles that fucosylation plays in cancer, specifically through modulation of cell surface proteins and signaling pathways. How L-fucose and serum fucosylation patterns might be used for future clinical diagnostic, prognostic, and therapeutic approaches will be discussed.

Role of difucosylated Lewis Y antigen in outcome of locally advanced cervical squamous cell carcinoma treated with cisplatin regimen

BACKGROUND

Several mechanisms are involved in the development of resistance to therapy in locally advanced cervical squamous cell carcinoma (LACSCC). Studies have shown that CD44 and Lewis Y antigen (LeY) form a complex that is associated with chemoresistance, tumor invasion and metastasis. We assessed the role of CD44 and LeY in the outcome of LACSCC patients treated with different chemotherapy regimens.

METHODS

126 LACSCC patients at FIGO stages IIB-IVA were selected from the GOCS database: 74 patients included in 3 different prospective phase II trials in the neoadjuvant setting (vinorelbine, docetaxel, ifosfamide-vinorelbine-cisplatin) and 52 patients treated with standard radiochemotherapy based on cisplatin (RCBC). Clinical data at baseline, disease-free survival (DFS) and overall survival (OS) were recorded. Univariate and multivariate Cox models were employed.

RESULTS

Median age was 45.6 years (range: 24.9-80.5). Sixty-three and 47 tumors were CD44+ and LeY+, respectively. Tumors with expansive growth showed higher grade (p = 0.0024), mitotic index (p = 0.0505), tumor necrosis (p = 0.0191), LeY+ (p = 0.0034) and CD44+/LeY+ coexpression (p = 0.0334). CD44+ cells were present in 91.3% of patients with local recurrence (p = 0.0317). Advanced stage was associated with LeY+ tumors. Patients treated with RCBC had worse DFS and OS when their tumors expressed LeY (p = 0.0083 and p = 0.0137, respectively). Pre-treatment hemoglobin level, FIGO stage and tumor response remained the most significant prognostic factors in Cox regression.

CONCLUSIONS

In our cohort of LACSCC patients, the coexpression of CD44 and LeY was not associated with worse outcome. However, in the subgroup of patients receiving RCBC, LeY expression was correlated with shorter DFS and OS.

Carcinoma-associated fucosylated antigens are markers of the epithelial state and can contribute to cell adhesion through CLEC17A (Prolectin)

Terminal fucosylated motifs of glycoproteins and glycolipid chains are often altered in cancer cells. We investigated the link between fucosylation changes and critical steps in cancer progression: epithelial-to-mesenchymal transition (EMT) and lymph node metastasis.Using mammary cell lines, we demonstrate that during EMT, expression of some fucosylated antigens (e.g.: Lewis Y) is decreased as a result of repression of the fucosyltransferase genes FUT1 and FUT3. Moreover, we identify the fucose-binding bacterial lectin BC2L-C-Nt as a specific probe for the epithelial state.Prolectin (CLEC17A), a human lectin found on lymph node B cells, shares ligand specificities with BC2L-C-Nt. It binds preferentially to epithelial rather than to mesenchymal cells, and microfluidic experiments showed that prolectin behaves as a cell adhesion molecule for epithelial cells. Comparison of paired primary tumors/lymph node metastases revealed an increase of prolectin staining in metastasis and high FUT1 and FUT3 mRNA expression was associated with poor prognosis. Our data suggest that tumor cells invading the lymph nodes and expressing fucosylated motifs associated with the epithelial state could use prolectin as a colonization factor.

c-Jun transcriptionally regulates alpha 1, 2-fucosyltransferase 1 (FUT1) in ovarian cancer

Alpha 1, 2-fucosyltransferase (FUT 1/2) is a rate-limiting enzyme that catalyzes the synthesis of Lewis y, a cell membrane-associated carbohydrate antigen. In human ovarian cancer, the upregulated expression of FUT1 and Lewis y is associated with advanced pathological stages and involved in cell proliferation, migration and invasion. However, the mechanism underlying the upregulation of FUT1 is largely unknown. Here, we identify an AP-1 binding site in FUT1 promoter in ovarian cancer cells. c-Jun promotes FUT1 expression, thereby enhancing Lewis y biosynthesis in various ovarian cancer cell lines. Moreover, EMSA, luciferase activity and ChIP assays demonstrate c-Jun directly interacts with FUT1 promoter. Furthermore, FUT1 mediates c-Jun-induced cell proliferation in ovarian cancer cells. In human ovarian cancer samples, c-Jun overexpression is linked to malignant degree and positively correlated to FUT1 and Lewis y expression. Taken together, c-Jun could transcriptionally modulate FUT1 expression in ovarian cancer, implicating the potential application of c-Jun inhibitors for human ovarian cancer therapy.