Apical membrane expression of distinct sulfated glycans represents a novel marker of cholangiolocellular carcinoma

Paradoxical Expression of R-10G-reactive Antigen in Human Testicular Embryonal Carcinoma

Thus far, several monoclonal antibodies directed against cell-surface carbohydrate antigens have been generated. Among them, R-10G reportedly reacts selectively with human embryonic stem and induced pluripotent stem cells, but not with embryonal carcinoma (EC) cells. However, EC cells derived from patients' EC tumors may exhibit varying levels of R-10G-reactive antigen expression. Thus, we asked whether human EC tissues or germ cell tumor (GCT) tissues other than EC express R-10G-reactive antigen. To do so, we quantitatively analyzed R-10G-reactive antigen expression in 83 testicular GCT surgical specimens containing a total of 125 various GCT components. Accordingly, in all EC components examined, the EC cell plasma membrane was immunolabeled with R-10G, while most seminoma components were R-10G-negative. In non-seminomatous GCT (NSGCT) other than EC (non-EC NSGCT), R-10G-reactive antigen expression was variable, but signal distribution was focal, and the average intensity was weaker than that seen in EC. The percentages of R-10G-positive cells in these three groups varied with high statistical significance (p<0.001 for all combinations). These findings indicate that the R-10G-reactive antigen is preferentially expressed in human testicular EC tissues and, thus, could be used as a diagnostic marker for this malignancy.

CHST2-mediated sulfation of MECA79 antigens is critical for breast cancer cell migration and metastasis

Snail is a denoted transcriptional repressor that plays key roles in epithelial-mesenchymal transition (EMT) and metastasis. Lately, a plethora of genes can be induced by stable expression of Snail in multiple cell lines. However, the biological roles of these upregulated genes are largely elusive. Here, we report identification of a gene encoding the key GlcNAc sulfation enzyme CHST2 is induced by Snail in multiple breast cancer cells. Biologically, CHST2 depletion results in inhibition of breast cancer cell migration and metastasis, while overexpression of CHST2 promotes cell migration and lung metastasis in nude mice. In addition, the expression level of MECA79 antigen is elevated and blocking the cell surface MECA79 antigen with specific antibodies can override cell migration mediated by CHST2 upregulation. Moreover, the sulfation inhibitor sodium chlorate effectively inhibits the cell migration induced by CHST2. Collectively, these data provide novel insights into the biology of Snail/CHST2/MECA79 axis in breast cancer progression and metastasis as well as potential therapeutic strategy for the diagnosis and treatment of breast cancer metastasis.

Expression and Clinical Significance of Spi-B in B-cell Acute Lymphoblastic Leukemia

Spi-B, a member of the E26 transformation-specific (ETS) family of transcription factors, plays an important role in B cell differentiation. Spi-B also functions in development of diffuse large B-cell lymphoma; thus, we hypothesized that it may participate in leukemogenesis of B-cell acute lymphoblastic leukemia (B-ALL). To test this hypothesis, we first generated an anti-Spi-B monoclonal antibody that recognized Spi-B on formalin-fixed, paraffin-embedded tissue sections. This antibody, designated S28-5, selectively stained B cell nuclei at the pre-plasma cell stage (including centrocytes and centroblasts in germinal centers) and nuclei of plasmacytoid dendritic cells, but not fully differentiated plasma cells, T cells, macrophages, or follicular dendritic cells. Employing S28-5, we then performed immunohistochemical staining of bone marrow aspiration biopsy specimens obtained from B-ALL patients (n=62). Cases that showed stronger nuclear S28-5 signals than T-cell ALL were scored positive. In 26 (42%) of 62 specimens, leukemic cells showed nuclear Spi-B expression, and positivity was associated with patient age at diagnosis, and serum uric acid and creatinine levels. Moreover, Spi-B-positive patients demonstrated significantly shorter overall survival than did Spi-B-negative patients. These results suggest that Spi-B expression may serve as a prognostic indicator of B-ALL.

Tertiary Lymphatic Structures in Primary Hepatic Carcinoma: Controversy Cannot Overshadow Hope

Tertiary lymphoid structures (TLSs) are organized aggregates of immune cells found in the tumor microenvironment. TLS can influence primary hepatic carcinoma (PHC) occurrence and have an active role in cancer. TLS can promote or inhibit the growth of PHC depending on their location, and although available findings are controversial, they suggest that TLS have a protective role in PHC tissues and a non-protective role in paracancerous tissues. In addition, the cellular composition of TLS can also influence the outcome of PHC. As an immunity marker, TLS can act as a marker of immunotherapy to predict its effect and help to identify patients who will respond well to immunotherapy. Modulation of TLS formation through the use of chemokines/cytokines, immunotherapy, or induction of high endothelial vein to interfere with tumor growth has been studied extensively in PHC and other cancers. In addition, new tools such as genetic interventions, cellular crosstalk, preoperative radiotherapy, and advances in materials science have been shown to influence the prognosis of malignant tumors by modulating TLS production. These can also be used to develop PHC treatment.

In vivo non-invasive confocal fluorescence imaging beyond 1,700 nm using superconducting nanowire single-photon detectors

Light scattering by biological tissues sets a limit to the penetration depth of high-resolution optical microscopy imaging of live mammals in vivo. An effective approach to reduce light scattering and increase imaging depth is to extend the excitation and emission wavelengths to the second near-infrared window (NIR-II) at >1,000 nm, also called the short-wavelength infrared window. Here we show biocompatible core-shell lead sulfide/cadmium sulfide quantum dots emitting at ~1,880 nm and superconducting nanowire single-photon detectors for single-photon detection up to 2,000 nm, enabling a one-photon excitation fluorescence imaging window in the 1,700-2,000 nm (NIR-IIc) range with 1,650 nm excitation-the longest one-photon excitation and emission for in vivo mouse imaging so far. Confocal fluorescence imaging in NIR-IIc reached an imaging depth of ~1,100 μm through an intact mouse head, and enabled non-invasive cellular-resolution imaging in the inguinal lymph nodes of mice without any surgery. We achieve in vivo molecular imaging of high endothelial venules with diameters as small as ~6.6 μm, as well as CD169 + macrophages and CD3 + T cells in the lymph nodes, opening the possibility of non-invasive intravital imaging of immune trafficking in lymph nodes at the single-cell/vessel-level longitudinally.

Vascular E-selectin Expression Detected in Formalin-fixed, Paraffin-embedded Sections With an E-selectin Monoclonal Antibody Correlates With Ulcerative Colitis Activity

It is widely accepted that E-selectin, an inducible endothelial cell adhesion molecule, plays a critical role in the initial step of neutrophil recruitment to sites of acute inflammation. However, immunohistological analysis of E-selectin has been hampered by lack of E-selectin-specific monoclonal antibodies that can stain formalin-fixed, paraffin-embedded (FFPE) tissue sections. Here, we employed E-selectin•IgM (a soluble form of E-selectin) as immunogen, and then, after negative selection with L-selectin•IgM and P-selectin•IgM and screening of FFPE sections of both COS-1 cells overexpressing E-selectin and acute appendicitis tissues, we successfully generated an E-selectin-specific monoclonal antibody capable of staining FFPE tissue sections. We used this antibody, designated U12-12, to perform quantitative immunohistological analysis of 390 colonic mucosal biopsy specimens representing ulcerative colitis. We found that the higher the histological disease activity, the greater the number of vessels expressing E-selectin, an observation consistent with previous analyses of frozen tissue sections. Furthermore, in active ulcerative colitis, E-selectin-expressing vessels contained neutrophils attached to endothelial cells, presumably in the process of extravasation, which eventually could cause epithelial damage. These results overall indicate that U12-12 is effective for E-selectin immunohistochemistry in archived FFPE samples representing various human diseases.

Association between the expression of core 3 synthase and survival outcomes of patients with cholangiocarcinoma

Cholangiocarcinoma (CCA) is a highly aggressive and metastatic type of malignant carcinoma that is associated with high mortality rates and is difficult to detect at early stages. Core 3 structure is a mucin-type O-glycans synthesized by β1,3-N-acetylglucosaminyltransferase 6 (core 3 synthase), which plays an important role in the digestive system, in particular gastrointestinal goblet cells. It has been reported that core 3 synthase-expressing cells show lower migratory and invasive rates, and lower metastatic activity. A immunohistochemical study also showed that this enzyme was expressed in normal epithelial cells of the colon, but completely disappeared in colorectal cancer cells. The present study aimed to identify biomarkers that could be used to predict the prognosis of patients with CCA. Pathological specimens of 185 CCA tissues were immunohistochemically stained with two antibodies, G8-144 and MECA-79, which recognize core 3 synthase and 6-sulfated N-acetyllactosamine on the extended core-1 O-glycans, respectively. The association between G8-144 or MECA-79 positivity and patient prognosis was statistically analyzed. Positive expression of G8-144 was associated with improved prognosis in patients with distal CCA (dCCA). Patients with dCCA positive for G8-144 showed lower mortality rates than those with negative expression. However, the positive expression of MECA-79 was associated with CCA progression and metastasis, indicating that it is a poor prognostic marker for CCA. In conclusion, as both antibodies resulted in mirror-image staining, the involvement of G8-144 and MECA-79 in O-glycan synthesis could be considered as potential favorable and unfavorable biomarkers, respectively, for CCA prognosis.

Apical Membrane Expression of Distinct Sulfated Glycans Is a Characteristic Feature of Ductules and Their Reactive and Neoplastic Counterparts

Intrahepatic bile ducts transport bile between bile canaliculi and the extrahepatic bile duct. The luminal surface of this tract is lined by a layer of biliary epithelial cells, or cholangiocytes, which secrete mucins consisting of scaffold proteins and O-glycosidically linked carbohydrate side chains. Although mucin core proteins have been extensively investigated, the structure and function of carbohydrate side chains have not. Here, we demonstrate that distinct sulfated glycans positive for MECA-79, R-10G, and 297-11A, but not 5D4, monoclonal antibodies are expressed in the cytoplasm of cells of large-sized ducts and in the apical membrane of cells in ductules, and that R-10G immunolabeling is partially eliminated by endo-β-galactosidase digestion, supporting the presence of N-acetylglucosamine-6-O-sulfated N-acetyllactosamine structures. We observed comparable apical membrane-predominant staining in ductular reactions seen during regeneration that occurs in various liver diseases and in cholangiolocarcinoma, a subtype of small duct-type intrahepatic cholangiocarcinoma (iCCA). Apical membrane expression of distinct sulfated glycans in large duct-type iCCA was negligible. Intriguingly, under pathological conditions, endo-β-galactosidase digestion almost completely eliminated R-10G immunoreactivity. These findings suggest that apical membrane expression of distinct sulfated glycans is a characteristic feature of ductules and their reactive and neoplastic counterparts.

Epithelial apical glycosylation changes associated with thin endometrium in women with infertility - a pilot observational study

BACKGROUND

Low endometrial receptivity is one of the major factors affecting successful implantation in assisted reproductive technologies (ART). Infertile patients with thin endometrium have a significantly lower cumulative clinical pregnancy rate than patients with normal endometrium. Molecular pathophysiology of low receptivity of thin endometrium remains understudied. We have investigated composition of glycocalyx of the apical surface of luminal and glandular epithelial cells in thin endometrium of infertile women.

METHODS

Thirty-two patients with tubal-peritoneal infertility undergoing in vitro fertilization (IVF) were included in the study. Endometrial samples were obtained in a natural menstrual cycle. Patients were divided into two groups: patients with normal endometrium (≥8 mm) and with thin endometrium (< 8 mm). Histochemical and immunohistochemical analysis of paraffin-embedded endometrial samples was performed using six biotinylated lectins (UEA-I, MAL-II, SNA, VVL, ECL, Con A) and anti-LeY and MECA-79 monoclonal antibodies (MAbs).

RESULTS

Complex glycans analysis taking into account the adjusted specificity of glycan-binding MAbs revealed 1.3 times less expression of MECA-79 glycans on the apical surface of the luminal epithelial cells of thin endometrium compared to normal endometrium; this deficiency may adversely affect implantation, since MECA-79 glycans are a ligand of L-selectin and mediate intercellular interactions. The glycans containing a type-2 unit Galβ1-4GlcNAcβ (LacNAc) but lacking sulfo-residues at 6-OH of GlcNAcβ, and binding to MECA-79 MAbs were found; they can be considered as potential markers of endometrium receptivity. Expression of the lectins-stained glycans on the apical surfaces of the luminal and glandular epithelial cells did not differ significantly. Correlation between the expression of difucosylated oligosaccharide LeY on the apical surfaces of the luminal and glandular epithelial cells was found in patients with thin endometrium and recurrent implantation failure. A similar relationship was shown for mannose-rich glycans.

CONCLUSIONS

Specific features of key glycans expression in epithelial compartments of thin endometrium may be essential for morphogenesis of the endometrial functional layer and explain its low receptivity.

miRNA-mRNA Regulatory Network and Factors Associated with Prediction of Prognosis in Hepatocellular Carcinoma

The aim of this study was to identify novel gene and miRNA biomarkers of risk and prognostic factors for hepatocarcinogenesis using methods in systems biology. Differentially expressed genes (DEGs), microRNAs (miRNAs), and long non-coding RNA (lncRNAs) were compared between hepatocellular carcinoma (HCC) tumour tissue and normal liver tissues in the Cancer Genome Atlas (TCGA) database. Subsequently, the prognosis-associated gene co-expression network, mRNA-miRNA, and mRNA-miRNA-lncRNA regulatory networks were constructed to identify biomarkers of risk for HCC through Cox survival analysis. Seven prognosis-associated gene co-expression modules were obtained by analyzing these DEGs. An expression module including 120 genes significantly correlated with HCC patient survival. Combined with patient survival data, several mRNAs and miRNAs, including CHST4, SLC22A8, STC2, hsa-miR-326, and hsa-miR-21 were identified from the network to predict HCC patient prognosis. Clinical significance was investigated using tissue microarray analysis of samples from 258 patients with HCC. Functional annotation of hsa-miR-326 and hsa-miR-21-5p indicated specific associations with several cancer-related pathways. The present study provides a bioinformatics method for biomarker screening, which led to the identification of an integrated mRNA-miRNA-lncRNA regulatory network and their co-expression in relation to predicting HCC patient survival.

Carbohydrate Sulfotransferase 4 Inhibits the Progression of Hepatitis B Virus-Related Hepatocellular Carcinoma and Is a Potential Prognostic Marker in Several Tumors

Carbohydrate sulfotransferase 4 (CHST4) plays an important role in lymphocyte homing and is abnormally expressed in several cancer types; however, its precise function in tumor development and progression is unknown. Here we confirm that CHST4 is aberrantly expressed in various tumor subtypes. In particular, we found that CHST4 expression was downregulated in hepatitis B virus-related hepatocellular carcinoma (HBV-HCC) tumors compared to paired normal tissue. We also showed that CHST4 overexpression inhibited the proliferation and metastasis of HCC cells in vitro. Clinically, CHST4 was identified as an independent prognostic factor for HBV-HCC patients. We further illuminated the anti-tumor role and mechanism of CHST4 in HBV-HCC by constructing a FENDRR–miR-10b-5p–CHST4 competing endogenous RNA network. We found that downregulation of CHST4 expression may promote HBV expression and regulate ribonucleoprotein complex biogenesis to promote malignant behaviors in HBV-HCC. CHST4 may also recruit CD4+ T cells, macrophages, dendritic cells, and neutrophils into the tumor microenvironment to inhibit the progression of HBV-HCC. Overall, our findings suggest that CHST4 acts as a tumor suppressor in HCC-HBV and represents a potential diagnostic and therapeutic target.

Preferential expression of sialyl 6'-sulfo N-acetyllactosamine-capped O-glycans on high endothelial venules in human peripheral lymph nodes

Lymphocyte "homing", the physiologic trafficking of lymphocytes from the circulation to secondary lymphoid organs, is regulated by sequential adhesive interactions between lymphocytes and endothelial cells that constitute high endothelial venules (HEVs). Initial lymphocyte "rolling" is mediated by relatively weak, transient adhesive interactions between L-selectin expressed on lymphocytes and sulfated mucin-type O-glycans expressed on HEVs. Keratan sulfate galactose (Gal)-6-O-sulfotransferase (KSGal6ST) catalyzes 6-O-sulfation of Gal in keratan sulfate glycosaminoglycan chains but also transfers sulfate to Gal in much shorter glycan chains, such as sialylated N-acetyllactosamine (LacNAc)-capped O-glycans. In mice, KSGal6ST is reportedly expressed in HEVs and functions in synthesizing 6-sulfo Gal-containing O-glycans on HEVs. However, in humans, the presence of 6-sulfo Gal-containing O-glycans on HEVs is not reported. Employing the newly developed monoclonal antibody 297-11A, which recognizes non-sialylated terminal 6'-sulfo LacNAc, we demonstrate that sialyl 6'-sulfo (and/or 6,6'-disulfo) LacNAc-capped O-glycans are preferentially displayed on HEVs in human peripheral lymph nodes (PLNs) and to a lesser extent in mesenteric LNs (MLNs) but not in Peyer's patches (PPs). We also found that the scaffold protein mucosal addressin cell adhesion molecule 1 (MAdCAM-1), which is expressed on HEVs in PPs and MLNs but not PLNs, was modified by 297-11A-positive sulfated glycans less efficiently than was CD34. Moreover, 297-11A-positive sulfated glycans were also displayed on HEV-like vessels induced in tumor-infiltrating lymphocyte (TIL) aggregates formed in various cancers. These findings collectively indicate that 297-11A-positive sulfated glycans potentially play a role in physiologic lymphocyte homing as well as in lymphocyte recruitment under pathologic conditions.

Mucins: the Old, the New and the Promising Factors in Hepatobiliary Carcinogenesis

Mucins are large O-glycoproteins with high carbohydrate content and marked diversity in both the apoprotein and the oligosaccharide moieties. All three mucin types, trans-membrane (e.g., MUC1, MUC4, MUC16), secreted (gel-forming) (e.g., MUC2, MUC5AC, MUC6) and soluble (non-gel-forming) (e.g., MUC7, MUC8, MUC9, MUC20), are critical in maintaining cellular functions, particularly those of epithelial surfaces. Their aberrant expression and/or altered subcellular localization is a factor of tumour growth and apoptosis induced by oxidative stress and several anti-cancer agents. Abnormal expression of mucins was observed in human carcinomas that arise in various gastrointestinal organs. It was widely believed that hepatocellular carcinoma (HCC) does not produce mucins, whereas cholangiocarcinoma (CC) or combined HCC-CC may produce these glycoproteins. However, a growing number of reports shows that mucins can be produced by HCC cells that do not exhibit or are yet to undergo, morphological differentiation to biliary phenotypes. Evaluation of mucin expression levels in precursors and early lesions of CC, as well as other types of primary liver cancer (PLC), conducted in in vitro and in vivo models, allowed to discover the mechanisms of their action, as well as their participation in the most important signalling pathways of liver cystogenesis and carcinogenesis. Analysis of mucin expression in PLC has both basic research and clinical value. Mucins may act as oncogenes and tumour-promoting (e.g., MUC1, MUC13), and/or tumour-suppressing factors (e.g., MUC15). Given their role in promoting PLC progression, both classic (MUC1, MUC2, MUC4, MUC5AC, MUC6) and currently tested mucins (e.g., MUC13, MUC15, MUC16) have been proposed to be important diagnostic and prognostic markers. The purpose of this review was to summarize and update the role of classic and currently tested mucins in pathogenesis of PLC, with explaining the mechanisms of their action in HCC carcinogenesis. It also focuses on determination of the diagnostic and prognostic role of these glycoproteins in PLC, especially focusing on HCC, CC and other hepatic tumours with- and without biliary differentiation.

A case of intrahepatic cholangiocarcinoma that was difficult to diagnose prior to surgery: A case report

The present study reports a case of mass-forming intrahepatic cholangiocarcinoma (ICC), which mimicked cholangiocellular carcinoma (CoCC) during imaging and a needle biopsy examination. A 51-year-old female with no relevant medical history was referred to the National Defense Medical College hospital with an intrahepatic tumor. Computed tomography demonstrated non-homogeneous enhancement in the early arterial phase and persistent enhancement in the portal and equilibrium phases, together with notable swelling of the para-aortic lymph nodes. Gadolinium-ethoxybenzyl diethylenetriamine-pentaacetic acid-enhanced magnetic resonance imaging revealed low signal intensity in the hepatobiliary phase. The liver tumor and lymph nodes exhibited increased radiotracer uptake (maximum standardized uptake value=14.0) with positron emission tomography. A histological examination of a percutaneous needle biopsy specimen of the liver tumor indicated a diagnosis of CoCC. The patient underwent left hepatectomy and lymphadenectomy. The surgical specimen contained a poorly differentiated adenocarcinoma with anaplastic changes, which was immunohistochemically positive for epithelial membrane antigen (at the luminal membrane), cytokeratins 7 and 19, and negative for α-fetoprotein, hepatocyte-specific antigen, cluster of differentiation 56 and KIT. Based on these histopathological and immunohistochemical findings, the patient was diagnosed with ICC.

Clinicopathological implications to micropapillary bladder urothelial carcinoma of the presence of sialyl Lewis X-decorated mucin 1 in stroma-facing membranes

OBJECTIVES

Bladder urothelial carcinoma (UC) comprises more than 90% of all bladder cancers. Among several UC variants, micropapillary UC (MPUC) is a rare one with high potential for lymphovascular invasion and subsequent lymph node metastasis. Histologically, MPUC is characterized by the presence of small papillary carcinoma cell clusters surrounded by lacunar spaces. Immunohistochemically, the outer circumference of these clusters, that is, the stroma-facing membrane of carcinoma cells, is reportedly almost invariably positive for mucin 1 (MUC1) protein and to a lesser extent for sialyl Lewis X (sLeX) carbohydrates; however, the clinicopathological implications of these expression patterns have not been fully investigated.

MATERIALS AND METHODS

We performed immunohistochemical analysis of MPUC (n = 11) and conventional UC (n = 57) for MUC1 and sLeX to determine whether these factors immunolocalized. Dual immunofluorescence staining was also carried out to assess MUC1 and sLeX colocalization. We also performed Western blot analysis of Chinese hamster ovary cells misexpressing both recombinant epitope-tagged MUC1 and glycosyltransferases enabling sLeX biosynthesis.

RESULTS

MPUC samples preferentially exhibited both MUC1 protein and sLeX carbohydrate expression on the stroma-facing membrane of carcinoma cells. Based on univariate analysis, MUC1 expression in that pattern was positively correlated with tumor extension, lymphovascular invasion, lymph node metastasis, disease stage, and relatively poor patient prognosis. A comparable sLeX expression pattern also correlated positively with tumor extension and nodal metastasis. Based on multivariate analysis, localization of MUC1 and sLeX on the stroma-facing side of the membrane was positively correlated with lymph node metastasis.

CONCLUSIONS

Overall, our immunofluorescence findings as well as immunoprecipitation analyses of Chinese hamster ovary cell transfectants strongly suggest that MUC1 is a potential scaffold protein for sLeX carbohydrates in MPUC. Both MUC1 and sLeX may cooperatively contribute to MPUC histogenesis and clinicopathological characteristics.