Globo H ceramide is an independent prognostic marker for gallbladder cancer

In recent studies, there has been growing interest in developing cancer therapeutics targeting Globo H ceramide, which is considered as the most prevalent tumor-associated carbohydrate antigen in epithelial cancers. In this study, we aimed to evaluate the expression of Globo H and investigate its prognostic significance in gallbladder cancer (GBC). The tumor specimens and clinical characteristics of GBC patients were collected from the tumor bank and database of Chang Gung Memorial Hospital. Globo H in tumor specimens was detected by immunohistochemistry (IHC) and mass spectrometry analysis. Through data mining, it was discovered that FUT1 and FUT2, which are key enzymes involved in the biosynthesis of Globo H, were significantly up-regulated in human gallbladder cancer (GBC). Consistent with this finding, Globo H expression was detected in 86% (128 out of 149) of GBC specimens using immunohistochemical (IHC) staining. This was the highest frequency among Globo H expressing cancers. Patients with tumors exhibiting higher Globo H expression (H-score ≥ 80) demonstrated significantly shorter disease-free survival (DFS) and overall survival (OS) (P = 0.0001 and P = 0.0004, respectively). In a multivariable Cox regression analysis, elevated Globo H expression was identified as an independent unfavorable predictor for DFS and OS (hazard ratio: 2.29 and 2.32, respectively, P = 0.008 and 0.001) in primary GBC. Globo H is an independent prognostic marker for GBC.

High expression of embryonic stem cell marker SSEA3 confers poor prognosis and promotes epithelial mesenchymal transition in hepatocellular carcinoma

BACKGROUND

Malignant cells may arise from dedifferentiation of mature cells and acquire features of the progenitor cells. Definitive endoderm from which liver is derived, expresses glycosphingolipids (GSLs) such as stage-specific embryonic antigen 3 (SSEA3), Globo H, and stage-specific embryonic antigen 4 (SSEA4). Herein, we evaluated the potential prognosis value of the three GSLs and biological functions of SSEA3 in hepatocellular carcinoma (HCC).

METHODS

The expression of SSEA3, Globo H, and SSEA4 in tumor tissues obtained from 328 patients with resectable HCC was examined by immunohistochemistry staining. Epithelial mesenchymal transition (EMT) and their related genes were analyzed by transwell assay and qRT-PCR, respectively.

RESULTS

Kaplan Meier survival analysis showed significantly shorter relapse-free survival (RFS) for those with higher expression of SSEA3 (p < 0.001), Globo H (p < 0.001), and SSEA4 (p = 0.005) and worse overall survival (OS) for those with high expression of either SSEA3 (p < 0.001) or SSEA4 (p = 0.01). Furthermore, multivariable Cox regression analysis identified the SSEA3 as an independent predictor for RFS (HR: 2.68, 95% CI: 1.93-3.72, p < 0.001) and OS (HR: 2.99, 95% CI: 1.81-4.96, p < 0.001) in HCC. Additionally, SSEA3-ceramide enhanced the EMT of HCC cells, as reflected by its ability to increase migration, invasion and upregulate the expression of CDH2, vimentin, fibronectin, and MMP2, along with ZEB1. Moreover, ZEB1 silencing abrogated the EMT-enhancing effects of SSEA3-ceramide.

CONCLUSIONS

Higher expression of SSEA3 was an independent predictor for RFS and OS in HCC and promoted EMT of HCC via upregulation of ZEB1.

GLORIA: phase III, open-label study of adagloxad simolenin/OBI-821 in patients with high-risk triple-negative breast cancer

Triple-negative breast cancer (TNBC) has the highest rate of distant metastasis and poorest overall survival among breast cancer subtypes. In a phase II study, adagloxad simolenin (AdaSim), a synthetic Globo H conjugate vaccine administered with adjuvant OBI-821, was shown to induce IgM and IgG anti-Globo H humoral responses in patients with metastatic breast cancer overexpressing the glycosphingolipid Globo H. GLORIA is an ongoing phase III, randomized, open-label clinical trial to evaluate the safety and efficacy of AdaSim and the quality of life (QoL) of patients receiving AdaSim plus standard of care (SOC) versus SOC alone in high-risk, early-stage TNBC. The primary end point is invasive progression-free survival; secondary end points include overall survival, QoL, breast cancer-free interval, distant disease-free survival, safety, and tolerability.

The role of Globo H and SSEA-4 in the development and progression of cancer, and their potential as therapeutic targets

Glycans, chains of sugar molecules found conjugated to cell proteins and lipids, contribute to their growth, movement and differentiation. Aberrant glycosylation is a hallmark of several medical conditions including tumorigenesis. Glycosphingolipids (GSLs), consisting of glycans conjugated to a lipid (ceramide) core, are found in the lipid bilayer of eukaryotic cell membranes. GSLs, play an active role in cell processes. Several GSLs are expressed by human embryonic stem cells and have been found to be overexpressed in several types of cancer. In this review, we discuss the data, hypotheses and perspectives related to the GSLs Globo H and SSEA-4.

Targeting glycosphingolipids for cancer immunotherapy

Aberrant expression of glycosphingolipids (GSLs) is a unique feature of cancer and stromal cells in tumor microenvironments. Although the impact of GSLs on tumor progression remains largely unclear, anticancer immunotherapies directed against GSLs are attracting growing attention. Here, we focus on GD2, a disialoganglioside expressed in tumors of neuroectodermal origin, and Globo H ceramide (GHCer), the most prevalent cancer-associated GSL overexpressed in a variety of epithelial cancers. We first summarize recent advances on our understanding of GD2 and GHCer biology and then discuss the clinical development of the first immunotherapeutic agent targeting a glycolipid, the GD2-specific antibody dinutuximab, its approved indications, and new strategies to improve its efficacy for neuroblastoma. Next, we review ongoing clinical trials on Globo H-targeted immunotherapeutics. We end with highlighting how these studies provide sound scientific rationales for targeting GSLs in cancer and may facilitate a rational design of new GSL-targeted anticancer therapeutics.

Globo H expression is associated with driver mutations and PD-L1 expressions in stage I non-small cell lung cancer

BACKGROUND

Globo H is a tumor-associated carbohydrate antigen exclusively expressed in cancer cells rather than normal tissue. Globo H has been found on many cancers of epithelial origins, and become an attractive target for cancer vaccine.

OBJECTIVES

We aimed to study the expression of Globo H in non-small cell lung cancer (NSCLC) patients, and correlated its expression with common driver mutations, clinical outcomes, and status of immune checkpoint, programmed death-ligand 1 (PD-L1).

METHODS

The study enrolled 228 patients with surgically resected stage I NSCLC, including 139 patients with adenocarcinoma (ADC) and 89 patients with squamous cell carcinoma (SqCC). Using immunohistochemistry, tumors with moderate to strong membranous staining in ⩾ 1% tumor cells per section were scored as positive Globo H expression. Driver mutations including EGFR, KRAS, BRAF were detected by direct sequencing, while ALK, PI3KCA, FGFR1 and PD-L1 expression was detected by immunohistochemical (IHC) staining.

RESULTS

Positive Globo H expression was detected in 88 of the 228 (38.6%) patients. These included 51 of 139 (36.7%) patients with ADC and 37 of 89 (41.6%) patients with SqCC. Positive Globo H expression was significantly associated with EGFR mutation and PD-L1 expression in the ADC group, and PI3KCA overexpression in the SqCC group. The survival analysis showed that Globo H expression was not an independent prognostic factor in stage I NSCLC.

CONCLUSIONS

Globo H expression was correlated with specific driver mutations in ADC and SqCC NSCLC tumors, as well as PD-L1 status. Immunotherapy targeting Globo H may have potential application in lung cancer treatment.

A set of cancer stem cell homing peptides associating with the glycan moieties of glycosphingolipids

Cancer stem cells (CSCs) are currently believed to be involved in tumor metastasis and relapse. And treatments against CSCs are well concerned issues. Peptides targeting to mouse and human CSCs were screened from an M13 phage display library. The first subset of cancer stem cell homing peptides (CSC HPs), CSC HP-1 to -12, were screened with mouse EMT6 breast cancer stem cells. Among them, CSC HP-1, CSC HP-3, CSC HP-8, CSC HP-9, and CSC HP-10 can bind to mouse CT26 colon CSCs; CSC HP-1, CSC HP-2, CSC HP-3, and CSC HP-8 can bind to mouse Hepa1-6 liver CSCs; as well as CSC HP-1, CSC HP-2, CSC HP-3, CSC HP-8, CSC HP-9, CSC HP-10, and CSC HP-11 can bind to human PANC-1 pancreatic CSCs. The second subset of cancer stem cell homing peptides, CSC HP-hP1 to -hP3, were screened with human PANC-1 pancreatic CSCs. Both CSC HP-hP1 and CSC HP-hP2 were demonstrated able to bind mouse EMT6, CT26 and Hepa1-6 CSCs as well as human colorectal HT29 and lung H1650 CSCs. CSC HP-1 and CSC HP-hP1 could strongly associate with the Globo 4 and Lewis Y glycan epitopes coupled on a microarray chip or Globo 4 and Globo H conjugated on bovine serum albumin. CSC HP-10, CSC HP-11 and CSC HP-hP2 could associate with the disialylated saccharide Neu5Ac-α-2,6-Gal-β-1,3-(Neu5Ac-α-2,6)-GalNAc coupled on a microarray chip. These results indicate that the CSC HPs may target to the known stem cell glycan markers GbH and Lewis Y as well as the disialylated saccharide.

Aberrant expression of tumor-associated carbohydrate antigen Globo H in thyroid carcinoma

BACKGROUND AND OBJECTIVES

The induction of tumor-associated carbohydrate antigen results from altered glycosylation in transformed cells. Globo H is a hexasaccharide glycosphingolipid overexpressed on malignancies of epithelial origin and has become an attractive vaccine target. We aimed to investigate the expression patterns and prognostic value of Globo H in thyroid neoplasms.

METHODS

Globo H expression was examined by immunohistochemical analysis using commercial and in-house tissue microarrays. The expression was correlated with clinicopathologic characteristics in papillary thyroid cancer.

RESULTS

Normal or benign thyroid lesions were negative for Globo H expression. Globo H was positive in 33% medullary, 24% papillary, 11% undifferentiated, and 8% follicular thyroid cancer. Globo H expression in papillary thyroid cancer was associated with extrathyroidal invasion (P = 0.017), BRAF mutation (P = 0.010), AMES high risk (P = 0.045), and increased ATA risk of recurrence (P = 0.022).

CONCLUSIONS

Globo H is specifically expressed in a subset of thyroid malignancies. In papillary thyroid cancer, Globo H expression is associated with invasiveness and BRAF mutation. Immunotherapy targeting Globo H may have potential applications in thyroid cancer. J. Surg. Oncol. 2016;114:853-858. © 2016 2016 Wiley Periodicals, Inc.

Novel substrate specificities of two lacto-N-biosidases towards β-linked galacto-N-biose-containing oligosaccharides of globo H, Gb5, and GA1

We describe the novel substrate specificities of two independently evolved lacto-N-biosidases (LnbX and LnbB) towards the sugar chains of globo- and ganglio-series glycosphingolipids. LnbX, a non-classified member of the glycoside hydrolase family, isolated from Bifidobacterium longum subsp. longum, was shown to liberate galacto-N-biose (GNB: Galβ1-3GalNAc) and 2'-fucosyl GNB (a type-4 trisaccharide) from Gb5 pentasaccharide and globo H hexasaccharide, respectively. LnbB, a member of the glycoside hydrolase family 20 isolated from Bifidobacterium bifidum, was shown to release GNB from Gb5 and GA1 oligosaccharides. This is the first report describing enzymatic release of β-linked GNB from natural substrates. These unique activities may play a role in modulating the microbial composition in the gut ecosystem, and may serve as new tools for elucidating the functions of sugar chains of glycosphingolipids.

Sequence-constructive SELEX: A new strategy for screening DNA aptamer binding to Globo H. Biochem Biophys Res Commun. 2014;452:484-489. [PMID: 25159850 DOI: 10.1016/j.bbrc.2014.08.086]

We proposed to use a novel stepwise sequence-constructive SELEX method to develop DNA aptamers that can recognize Globo H which is a tumor-associated carbohydrate antigen. A combinatorial synthetic library that consisted of DNA molecules with randomized regions of 15-bases was used as the starting library for the first SELEX procedure. The input DNA library for the second round of SELEX consisted of the extension of the 5' and 3'-ends with 7-bases that were randomized from four selected aptamers. The third round of SELEX was performed following the same procedures as described for the second round of SELEX. The experimental results indicate that the binding affinity of DNA aptamers to Globo H was enhanced when using the sequence-constructive SELEX approach. The selectivity of the DNA aptamers for related disaccharides, mannose derivatives, and Globo H analogs demonstrated the ability of the DNA aptamers to discriminate the presence of various glycans with different structures.

Affinity of monoclonal antibodies for Globo-series glycans

Globo-series glycans are human cell-surface carbohydrates that include stem-cell marker SSEA-4 and cancer-cell antigen Globo H. These two hexasaccharides differ only in their terminal saccharide: N-acetylneuraminic acid in SSEA-4 and L-fucose in Globo H. Herein, we evaluated the affinity of the monoclonal antibodies α-SSEA-4 and α-GH for the glycans SSEA-4 and Globo H. Using fluorescence polarization, we find that the two monoclonal antibodies have affinity for their cognate glycan in the low nanomolar range, and have negligible affinity for the non-cognate glycan. Using surface plasmon resonance, we find that each cognate affinity is ∼20-fold greater if the glycan is immobilized on a surface rather than free in solution. We conclude that the terminal saccharide plays a dominant role in the ability of monoclonal antibodies to recognize these Globo-series glycans and that the extraordinary specificity of these antibodies supports their use for identifying and sorting stem-cells (α-SSEA-4) and as an agent in cancer immunotherapy (α-GH).

Downregulation of microRNA-15b by hepatitis B virus X enhances hepatocellular carcinoma proliferation via fucosyltransferase 2-induced Globo H expression

Globo H, a cancer-associated carbohydrate antigen, is highly expressed in various types of cancers. However, the role of Globo H in hepatocellular carcinoma (HCC) remains elusive. In our study, we performed glycan microarray analysis of 134 human serum samples to explore anti-Globo H antibody changes and found that Globo H is upregulated in hepatitis B virus (HBV)-positive HCC. Similarly, immunohistochemistry showed that Globo H expression was higher in tumors compared to normal tissues. In addition, fucosyltransferase 2 (FUT2), the main synthetic enzyme of Globo H, was also increased in HCC cells overexpressing HBV X protein (HBX). HBX plays an important role in promoting cell proliferation and may be related to increased levels of FUT2 and Globo H. Furthermore, using microRNA profiling, we observed that microRNA-15b (miR-15b) was downregulated in patients with HCC and confirmed association of FUT2 expression with expression of its product, Globo H. Therefore, our results suggest that HBX suppressed the expression of miR-15b, which directly targeted FUT2 and then increased levels of Globo H to enhance HCC cell proliferation. Additionally, proliferation of HBX-overexpressing HCC cells was significantly inhibited by treatment with Globo H antibody in vitro. In xenograft animal experiments, we found that overexpression of miR-15b effectively suppressed tumor growth. The newly identified HBX/miR-15b/FUT2/Globo H axis suggests one possible molecular mechanism of HCC cell proliferation and represents a new potential therapeutic target for HCC treatment.

Stage-specific embryonic antigen-4 as a potential therapeutic target in glioblastoma multiforme and other cancers

Glioblastoma multiforme (GBM), the grade IV astrocytoma, is the most common and aggressive brain tumor in adults. Despite advances in medical management, the survival rate of GBM patients remains poor, suggesting that identification of GBM-specific targets for therapeutic development is urgently needed. Analysis of several glycan antigens on GBM cell lines revealed that eight of 11 GBM cell lines are positive for stage-specific embryonic antigen-4 (SSEA-4), and immunohistochemical staining confirmed that 38/55 (69%) of human GBM specimens, but not normal brain tissue, were SSEA-4(+) and correlated with high-grade astrocytoma. In addition, an SSEA-4-specific mAb was found to induce complement-dependent cytotoxicity against SSEA-4(hi) GBM cell lines in vitro and suppressed GBM tumor growth in mice. Because SSEA-4 is expressed on GBM and many other types of cancers, but not on normal cells, it could be a target for development of therapeutic antibodies and vaccines.

A Fully Synthetic Globo H Carbohydrate Vaccine Induces a Focused Humoral Response in Prostate Cancer Patients: A Proof of Principle

Human trials on the globo H carbohydrate vaccine (see picture, KLH=the carrier protein keyhole limpet hemocyanin) show that it produces strong IgM, and in some cases IgG, responses in patients with progressive and recurrent prostate cancer. Furthermore, these antibodies not only recognize synthetic antigens, but also globo H-positive tumors in biopsy extracts and tumor tissues.