N-glycan signature of serum immunoglobulins as a diagnostic biomarker of urothelial carcinomas.

Discriminating between urothelial carcinoma (UC), including bladder cancer (BCa) and upper urinary tract UC (UTUC), is often challenging. Thus, the current study evaluated the diagnostic performance of N-glycosylation signatures of immunoglobulins (Igs) for detecting UC, including BCa and UTUC. N-glycosylation signatures of Igs from serum samples of the training cohort, including 104 BCa, 68 UTUC, 10 urinary tract infection, and 5 cystitis cases, as well as 62 healthy volunteers, were measured retrospectively using automated capillary-electrophoresis-based N-glycomics. UTUC or BCa scores were then established through discriminant analysis using N-glycan signatures of Igs. Diagnostic performance was evaluated using the area under receiver operating characteristics curve (AUC) and decision curve analyses (DCA). Our result showed that BCa and UTUC scores for discriminating BCa (AUC: 0.977) and UTUC (AUC: 0.867), respectively, provided significantly better clinical performance compared to urine cytology, gross hematuria, or clinical T1 cases. DCA revealed that adding BCa and UTUC scores to gross hematuria status was the best combination for detecting UC and avoiding the need for more intervention without overlooking UC (risk threshold: 13%-93%). The UC nomogram based on the combination of gross hematuria, UTUC score, and BCa score could detect UC with an AUC of 0.891, indicating significantly better performance compared to gross hematuria status in the validation cohort (251 patients). The limitations of this study include its small sample size and retrospective nature. The UC nomogram based on gross hematuria and N-glycosylation signatures of Igs can be a promising approach for the diagnosis of UC.

Essential hyaluronan structure for binding with hyaluronan-binding protein (HABP) determined by glycotechnological approach.

Hyaluronan specifically binds to aggrecan globular domain 1, which is often referred to as just hyaluronan binding protein (HABP), however, the hyaluronan carbohydrate structure recognized by HABP had not been studied in detail. The aim of the present study was to investigate the important structure of hyaluronan for binding to HABP. We prepared hybrid oligosaccharides from hyaluronan and chondroitin, with or without modification of the reducing or non-reducing terminus, as tools to determine the preferred structure of hyaluronan for binding to the HABP by a competitive ELISA-like method. The non-reducing terminal structure was critical, especially, the glucuronic acid (GlcUA) and N-acetylglucosamine (GlcNAc) of the hyaluronan-unit are essential for complete HABP binding activity, and for any HABP binding activity, respectively. It is possible to replace GlcUAß-1-3GlcNAc of the internal disaccharide units with GlcUAß-1-3N-acetylgalactosamine (GalNAc), if the chain length is decasaccharide or larger.

Increase of Tumor Infiltrating γδ T-cells in Pancreatic Ductal Adenocarcinoma Through Remodeling of the Extracellular Matrix by a Hyaluronan Synthesis Suppressor, 4-Methylumbelliferone.

OBJECTIVES: Desmoplastic changes of extracellular matrix (ECM) containing large amounts of hyaluronan (HA) are of interest in chemo- and immunoresistance of pancreatic ductal adenocarcinoma (PDAC). The goal of this study was to evaluate the effects of 4-methylumbelliferone (MU), a selective inhibitor of HA, on ECM and to examine how MU affects adoptive immunotherapy. METHODS: The effect of MU on cell proliferation, HA synthesis and formation of ECM were investigated in four PDAC cell lines. In addition, the cytotoxicity of γδ T-cell-rich peripheral blood mononuclear cells (PBMCs) collected from healthy donors and stimulated with zoledronate and interleukin-2 was examined in the presence of MU. The amount of HA and tumor-infiltrating lymphocytes were also investigated in mice xenograft models. RESULTS: In vitro, 1.0 mM MU inhibited cell proliferation by 45-70% and HA synthesis by 55-80% in all four PDAC cell lines, and enhanced γδ T-cell-rich PBMC-mediated cytotoxicity against PDAC cells. In vivo, MU reduced intratumoral HA and promoted infiltration of inoculated γδ T-cells into tumor tissue, and consequently suppressed tumor growth. CONCLUSIONS: 4-methylumbelliferone may be an effective immunosensitizer against PDAC through induction of structural changes in the ECM.

4-Methylumbelliferone Decreases the Hyaluronan-rich Extracellular Matrix and Increases the Effectiveness of 5-Fluorouracil.

BACKGROUND/AIM: Pancreatic cancer responds poorly to most chemotherapeutic agents. Several studies have reported that hyaluronan (HA)-rich extracellular matrix (ECM) is a biological barrier against chemotherapeutic agents. 4-methylumbelliforone (MU) led to inhibition of HA synthesis and its preservation in ECM, which may enhance 5-fluorouracil (5-FU) cytotoxicity. Thus, new therapy with MU and 5-FU may be developed for pancreatic cancer. MATERIALS AND METHODS: A 5-fluorouracil (5-FU) concentration and 4-methylumbelliferone (MU) dosage was analyzed by high-performance liquid chromatography (HPLC). Change in antitumor efficacy of 5-FU in combination with MU was also examined in vivo and in vitro. RESULTS: Combined 5-FU and MU treatment inhibited cell proliferation better than 5-FU alone; 0.01 mM 5-FU alone decreased cell proliferation by 37.7 %, while 0.01 mM 5-FU with 0.5 mM MU decreased cell proliferation by 57.4%. MU enhanced the intracellular concentration of 5-FU by 47.3% compared to control. Mice tumors treated with 5-FU and MU decreased in size and animal survival was prolonged. Moreover, MU decreased cohesiveness of the intercellular space. CONCLUSION: Combination therapy of 5-FU with MU was effective. A novel therapy can be designed for pancreatic cancer by using ECM modulation.

Novel roles of glycosaminoglycans in the degradation of type I collagen by cathepsin K.

Glycosaminoglycans (GAGs) and collagen are the major organic components of bone matrix. However, their roles and functional relationships remain elusive. To investigate the role of GAGs in bone matrix degradation, the effects of GAGs on collagen were examined under acidic conditions that recapitulate the microenvironment of osteoclast resorption pits. We found that sulfated GAGs protect collagen fibrils against acid denaturation. Scanning electron microscopy demonstrated that collagen fibrils retain the fibril structure at pH 4.0 in the presence of chondroitin 6-sulfate. By surface plasmon resonance analysis, we found that sulfated GAGs, but not non-sulfated GAGs, bind to triple-helix type I collagen below pH 4.5. The binding of collagen in an acidic solution was dependent upon the GAG sugar chain length. Functionally, the acid-resistant collagen fibrils generated in the presence of sulfated GAGs were resistant to cathepsin K degradation in vitro below pH 4.0. As the pH increased from 4.0 to 5.0, the acid-resistant collagen fibrils were degraded by cathepsin K. Our results highlight the possibility that the interaction between GAGs and collagen under acidic conditions has a regulatory impact on cathepsin K-mediated bone degradation.

4-Methylumbelliferone Suppresses Hyaluronan Synthesis and Tumor Progression in SCID Mice Intra-abdominally Inoculated With Pancreatic Cancer Cells.

OBJECTIVES: Pancreatic ductal adenocarcinoma contains large amounts of the glycosaminoglycan hyaluronan (HA), which is involved in various physiological processes. Here, we aimed to clarify the anticancer mechanisms of 4-methylumbelliferone (MU), a well-known HA synthesis inhibitor. METHODS: MIA PaCa-2 human pancreatic cancer cells were used. We evaluated cellular proliferation, migration, and invasion in the presence of MU, exogenous HA, and an anti-CD44 antibody. We also analyzed apoptosis, CD44 expression, and HA-binding ability using flow cytometry. The HA content in tumor tissue was quantified and histopathologically investigated in mice who had been inoculated with cancer cells. RESULTS: In vitro, MU inhibited pericellular HA matrix formation; however, HAS3 mRNA was up-regulated. Treatment with 0.5 mM MU suppressed cellular proliferation by 26.4%, migration by 14.7%, and invasion by 22.7%. Moreover, MU also significantly increased apoptosis. CD44 expression and HA-binding ability were not altered by MU. In vivo, MU suppressed HA accumulation in pancreatic tumors and improved survival times in tumor-bearing mice. CONCLUSIONS: 4-Methylumbelliferone indirectly caused apoptosis in pancreatic cancer cells by inhibiting HA production. 4-Methylumbelliferone may be a promising agent in the treatment of pancreatic cancer.

Antitumor effects of the hyaluronan inhibitor 4-methylumbelliferone on pancreatic cancer.

Hyaluronan (HA) is a major component of the extracellular matrix (ECM), and influences tumor invasion and metastasis. In a previous study, the present authors reported for the first time that 4-methylumbelliferone (MU) inhibited HA synthesis and suppressed tumor growth. However, the localization of HA and the changes in ECM morphology caused by MU in pancreatic cancer remain to be examined in detail. In the present study, the cytotoxicity of MU and its effect on cellular proliferation was evaluated in the human pancreatic cancer cell line MIA PaCa-2. The amount of HA synthesized and the retention of HA around the cells were quantitatively and immunohistochemically analyzed in vitro and in vivo. Structural changes in the ECM in the tumor tissue were investigated using an electron microscope. MU treatment led to a decrease in extracellular HA retention, as evidenced by a particle exclusion assay and immunohistochemical staining. Cell proliferation was suppressed by MU in a dose-dependent manner. The release of lactate dehydrogenase into the culture medium due to damage to the cellular membrane did not increase following MU administration. In tumor-inoculated mice, MU suppressed any increase in tumor volume and decreased the quantity of HA. Electron microscopy revealed that MU attenuated the intercellular space and caused it to be less cohesive. These data indicate that MU inhibits HA synthesis and reduces the amount of HA in the ECM while exhibiting no obvious cytotoxic effect. These findings suggest that MU has potential as a novel therapeutic agent for pancreatic cancer.

Preparation of proteoglycan from salmon nasal cartilage under nondenaturing conditions.

Salmon nasal cartilage was micronized in ethanol using a rotor-stator homogenizer for the high yield of proteoglycan extraction. This procedure also brought about depressing the degradation of proteoglycan and the contamination of collagens. Proteoglycan was extracted by 4 M magnesium chloride and isolated by anion-exchange chromatography. The gel filtration HPLC and the antibody reactivity showed that the core protein was intact.

Chondroitin sulfate cluster of epiphycan from salmon nasal cartilage defines binding specificity to collagens.

Epiphycan (EPY) from salmon nasal cartilage has a glycosaminoglycan (GAG) domain that is heavily modified by chondroitin 4-sulfate and chondroitin 6-sulfate. The functional role of the GAG domain has not been investigated. The interaction of EPY with collagen was examined in vitro using surface plasmon resonance analysis. EPY was found to bind to type I collagen via clustered chondroitin sulfate (CS), while a single chain of CS was unable to bind. Types I, III, VII, VIII and X collagen showed high binding affinity with EPY, whereas types II, IV, V, VI and IX showed low binding affinities. Chemical modification of lysine residues in collagen decreased the affinity with the clustered CS. These results suggest that lysine residues of collagen are involved in the interaction with the clustered CS, and the difference in lysine modification defines the binding affinity to EPY. The clustered CS was also involved in an inter-saccharide interaction, and formed self-associated EPY. CS of EPY promoted fibril formation of type I collagen.

One set system for the synthesis and purification of glycosaminoglycan oligosaccharides reconstructed using a hyaluronidase-immobilized column.

Using the transglycosylation reaction as a reverse reaction for the hydrolysis of hyaluronidase, new artificial oligosaccharides may be synthesized by reconstructing natural glycosaminoglycans (GAGs) according to preliminary planned arrangements. However, as some problems have been associated with the method, including the low yields of reaction products and complicated processes of separation and purification, improvements in this method were investigated. Transglycosylation reactions were carried out using bovine testicular hyaluronidase-immobilized resin packed in a column. For the transglycosylation reaction, pyridylaminated (PA) GAG hexasaccharides, which were the minimum size for hydrolysis sensitivity and the transglycosylation reaction, were used as acceptors, whereas large size GAGs were used as donors. The reaction mixture was pooled after incubation in the hyaluronidase-immobilized resin column and was then introduced into continuously joined HPLC columns constructed from three steps: the first step of ion-exchange HPLC for concentrating newly synthesized GAG oligosaccharides as reaction products, the second step of reverse phase HPLC for separating PA oligosaccharides from non-PA oligosaccharides, and the third step of size fractionation HPLC for fractionating newly synthesized oligosaccharides. Newly synthesized oligosaccharides were obtained by one complete cycle of the transglycosylation reaction and separation.

Epiphycan from salmon nasal cartilage is a novel type of large leucine-rich proteoglycan.

Chum salmon (Oncorhynchus keta) nasal cartilage was examined by next-generation DNA sequencing and mass spectrometric analyses, and 14 types of proteoglycans including epiphycan (EPY) were found. A cDNA encoding EPY was cloned and sequenced. The cDNA encoded 589 amino acids comprised a glycosaminoglycan (GAG) domain containing 55 potential GAG-modified sites (Ser-Gly and/or Gly-Ser), a cysteine cluster and 6 leucine-rich repeats. EPY was purified from salmon nasal cartilage and the structure of the GAG was characterized. As a result of unsaturated disaccharide analysis, GAG was found to be composed of chondroitin 6-sulfate (58.0%), chondroitin 4-sulfate (26.5%) and non-sulfated chondroitin (15.3%). The average molecular weight of GAG was estimated to be 3.0 × 10(4). Ser-100 and Ser-103 were identified as serine residues substituted by GAG chains by chemical modification and mass spectrometric analysis. More than 50 serine residues were assumed to be substituted by GAG chains. EPY is heavily substituted by chondroitin sulfate, giving an overall molecular weight of just under 2 × 10(6). EPY from salmon nasal cartilage is a novel type of large leucine-rich proteoglycan.

Hyaluronan-chondroitin hybrid oligosaccharides as new life science research tools.

Hyaluronan and chondroitin are glycosaminoglycans well-known as components of pharmaceutical agents and health foods. From these attractive molecules, using transglycosylation reaction of testicular hyaluronidase, we synthesized hybrid neo-oligosaccharides not found in nature. We also found a new site between the chondroitin disaccharide unit and hyaluronan disaccharide unit recognized by a hyaluronan lyase specific to hyaluronan using these hybrid oligosaccharides as substrates. We hope that these hybrid oligosaccharides will help to elucidate the involvement of hyaluronan, chondroitin, and chondroitin sulfates in the mechanisms of cell functions and diseases, based on the structures of these glycosaminoglycans.

Effects of divalent cations on bovine testicular hyaluronidase catalyzed transglycosylation of chondroitin sulfates.

Glycosaminoglycans were prepared as salts of different divalent cations and tested as donors in bovine testicular hyaluronidase catalyzed transglycosylation reactions. All of the metal cations examined had similar binding efficiency of divalent cations to hyaluronan. However, cations bound with different efficiencies to chondroitin sulfate species and the differences were marked in the case of chondroitin 6-sulfate; the numbers of cations bound per disaccharide unit were estimated to be 0.075 for Mn, 1.231 for Ba, 0.144 for Zn, and 0.395 for Cu. While barium salt of chondroitin sulfates enhanced transglycosylation, the zinc salt of chondroitin sulfates inhibited transglycosylation. Therefore, by selecting the proper divalent cation salt of chondroitin sulfates as a donor in the transglycosylation reaction it is possible to improve the yields of the products.