Ectopic expression of N-acetylglucosaminyltransferase V accelerates hepatic triglyceride synthesis.

AIM: Glycosylation changes induce various types of biological phenomena in human diseases. N-Acetylglucosaminyltransferase V (GnT-V) is one of the most important glycosyltransferases involved in cancer biology. Recently, many researchers have challenged studies of lipid metabolism in cancer. To elucidate the relationships between cancer and lipid metabolism more precisely, we investigated the effects of GnT-V on lipid metabolism. In this study, we investigated the effects of aberrant glycosylation by GnT-V on hepatic triglyceride production. METHODS: We compared lipid metabolism in GnT-V transgenic (Tg) mice with that of wild-type (WT) mice fed with normal chow or a choline-deficient amino acid-defined (CDAA) diet in vivo. HepG2 cells and GnT-V transfectants of Hep3B cells were used in an in vitro study. RESULTS: Serum triglyceride levels and hepatic very low-density lipoprotein (VLDL) secretion in Tg mice were significantly elevated compared with that of WT mice. Hepatic lipogenic genes (Lxrα, Srebp1, Fas and Acc) and VLDL secretion-related gene (Mttp1) were significantly higher in Tg mice. Expression of these genes was also significantly higher in GnT-V transfectants than in mock cells. Knockdown of GnT-V decreased, while both epidermal growth factor and transforming growth factor-ß1 stimulation increased LXRα gene expression in HepG2 cells. Finally, we found that the blockade of VLDL secretion by CDAA diet induced massive hepatic steatosis in Tg mice. CONCLUSION: Our study demonstrates that enhancement of hepatic GnT-V activity accelerates triglyceride synthesis and VLDL secretion. Glycosylation modification by GnT-V regulation could be a novel target for a therapeutic approach to lipid metabolism.

Identification of sialylated glycoproteins in Doxorubicin-treated hepatoma cells with glycoproteomic analyses.

Sialylation is one of the most important types of glycosylation involved in carcinogenesis and establishment of cancer stemness. We previously showed that increased sialylation is a characteristic glycan change in cancer stem cells (CSCs) from hepatocellular carcinoma. However, the identities of glycoproteins targeted for sialylation remain unknown. In the present study, we identified glycoproteins targeted for sialylation in doxorubicin (DXR)-treated hepatocarcinoma cell line, Huh7, using glycoproteomic analyses. Since CSCs constitute a small subset of cells within carcinoma cell lines, it is difficult to identify sialylated proteins using general glycoproteomic strategies. It is known that treatment with anticancer drug can condense CSCs, we used DXR to concentrate CSCs. In DXR-treated Huh7 cells, isobaric tag for relative and absolute quantitation (iTRAQ) analysis identified 17 sialylated glycoproteins. Most of the identified glycoproteins were cancer-associated proteins. Furthermore, two proteins of approximately 70 kDa were detected using Sambucus sieboldoana agglutinin (SSA) blot analysis and identified as beta-galactosidase and alpha-2-HS-glycoprotein (fetuin-A) by SSA precipitation followed by liquid chromatography-tandem mass spectrometry analyses. Sialylation levels of fetuin-A were increased in DXR-treated Huh7 cell lysates. These changes in sialylation of glycoproteins might be involved in the establishment of cancer stemness.

A qualitative study of blood glucose and side effect self-management among patients with type 2 diabetes undergoing chemotherapy for cancer.

Objective: This study aimed to identify the process by which patients with type 2 diabetes who are undergoing chemotherapy for cancer personally manage their blood glucose levels and side effects. Methods: Semi-structured interviews were conducted with 16 patients with cancer who had completed chemotherapy while taking hypoglycemic drugs. The interview data were analyzed using the modified grounded theory approach proposed by Kinoshita. Results: Self-management comprised balancing the management of blood glucose levels and side effects according to physical condition. After commencing chemotherapy, participants experienced confusion regarding the side effects and hyperglycemia they have not previously experienced, started struggling with side effects while paying attention to blood glucose fluctuations, experienced simplification of convalescence based on the diabetes experience, and used trial and error to cope with side effects. When participants learned to understand the changes in blood glucose fluctuations and the pattern of physical recovery, they completed chemotherapy by adjusting their physical condition to the treatment by varying self-control. Conclusions: Healthcare providers need to assist patients receiving chemotherapy to promote self-management of both blood glucose levels and side effects of the chemotherapy, depending on their physical condition. It is essential that patients with type 2 diabetes who are undergoing chemotherapy achieve the ability to self-monitor their blood glucose levels and side effects.

Establishment of a novel 70K Mac-2 binding protein antibody through screening of fucosylation-related antibodies.

Mac-2 binding protein (Mac-2bp) is a serum glycoprotein that contains seven N-glycans, and Mac-2bp serum levels are increased in patients with several types of cancer and liver disease. Mac-2bp glycosylation isomer has been applied as a clinical biomarker of several diseases, including liver fibrosis. In the present study, we identified fucosylated Mac-2bp in the conditioned medium of cancer cells resistant to anticancer therapies using glycoproteomic analyses. Fucosylation is one of the most important types of glycosylation involved in carcinogenesis and cancer stemness. To establish a next-generation glycan antibody for fucosylated Mac-2bp, we used fucosylation-deficient HEK293T cells to prepare reference Mac-2bp antigens and performed antibody screening. Unexpectedly, the 19-8H mAb obtained with our screen recognized 70K Mac-2bp, which is C-terminus-truncated product, rather than specifically recognizing fucosylated Mac-2bp. We performed immunocytochemistry using our novel 19-8H mAb, which resulted in strong cell surface staining of anticancer drug-resistant cancer cells. Therefore, our novel 19-8H mAb represents a valuable tool for cancer biology research that can help elucidate the biological function of 70K Mac-2bp.

Analysis of polarized secretion of fucosylated alpha-fetoprotein in HepG2 cells.

Fucosylated alpha-fetoprotein (AFP) is a more specific biomarker for hepatocellular carcinoma (HCC) than AFP. However, the mechanisms underlying the increase in fucosylated AFP in sera of HCC patients remain largely unknown. Recently, we reported that fucosylation is a possible signal for the secretion of hepatic glycoproteins into bile and that the fucosylation-based sorting machinery might be disrupted in the liver bearing HCC. In this study, we investigated the selective secretion of fucosylated AFP into bile canaliculus (BC) structures of the human hepatoma cell line HepG2. The proportion of fucosylated AFP in BC structures was higher than that in the medium, as judged by lectin affinity electrophoresis. Suppression of fucosylation by the double knock-down of GDP-mannose-4,6-dehydratase and the human homologue of GDP-4-keto-6-deoxymannose-3,5-epimerase-4-reductase, which contribute to the synthesis of GDP-fucose, a donor substrate for fucosyltransferases, did not decrease the proportion of fucosylated AFP in BC structures but decreased this proportion in conditioned medium. Furthermore, increased AFP fucosylation was observed in medium, but not in BC structures, upon adding free fucose. These results suggest that saturation of fucosylated AFP in BC structures is accompanied by its increase in conditioned medium, probably leading to increased fucosylated AFP in sera of HCC patients.

Glycemic Excursion, Adverse Drug Reactions, and Self-Management in Diabetes Patients Undergoing Chemotherapy: A Literature Review.

The purpose of this study was to identify the state of self-management in patients with diabetes who underwent chemotherapy, by referring to fluctuations in glycemic excursion and adverse drug reaction. We conducted a literature search in May 2021 using PubMed, CINAHL, and Ichushi-Web databases with "Cancer AND Diabetes AND Chemotherapy" as keywords. Based on our criteria, 25 articles were selected, and a review matrix sheet was created for the analysis of fluctuations in glycemic excursion and any adverse drug reaction to diabetes in patients undergoing chemotherapy. Substantial increases and unpredictable fluctuations in glycemic excursion were observed in these patients. In addition, an increase or change in the treatment dose was prevalent. Primarily, peripheral neuropathy and infection were reported as common adverse drug reactions. The risk of adverse drug reactions was especially high for patients with diabetes undergoing chemotherapy; furthermore, among this cohort, the detrimental effects were more likely to exacerbate into a severe condition that required special attention. Almost inevitably, the implementation rate of diabetes self-management programs decreased on the 8th week after the commencement of chemotherapy. Considering the findings of large individual differences in fluctuation in this cohort, tailored assistance that is appropriate for each patient's chemotherapy regimen or blood glucose level is of paramount importance. Support of patient self-management to achieve stable blood glucose levels and thus prevent adverse drug reactions was a key component in the successful completion of chemotherapy and improved patient outcomes for this group of special needs patients.

Fucosylation is a common glycosylation type in pancreatic cancer stem cell-like phenotypes.

AIM: To evaluate/isolate cancer stem cells (CSCs) from tissue or cell lines according to various definitions and cell surface markers. METHODS: Lectin microarray analysis was conducted on CSC-like fractions of the human pancreatic cancer cell line Panc1 by establishing anti-cancer drug-resistant cells. Changes in glycan structure of CSC-like cells were also investigated in sphere-forming cells as well as in CSC fractions obtained from overexpression of CD24 and CD44. RESULTS: Several types of fucosylation were increased under these conditions, and the expression of fucosylation regulatory genes such as fucosyltransferases, GDP-fucose synthetic enzymes, and GDP-fucose transporters were dramatically enhanced in CSC-like cells. These changes were significant in gemcitabine-resistant cells and sphere cells of a human pancreatic cancer cell line, Panc1. However, downregulation of cellular fucosylation by knockdown of the GDP-fucose transporter did not alter gemcitabine resistance, indicating that increased cellular fucosylation is a result of CSC-like transformation. CONCLUSION: Fucosylation might be a biomarker of CSC-like cells in pancreatic cancer.

Establishment of a novel lectin-antibody ELISA system to determine core-fucosylated haptoglobin.

BACKGROUND: Fucosylated haptoglobin (Fuc-Hpt) is a novel cancer biomarker that increases in various pathological conditions. We previously established a Fuc-Hpt lectin-antibody assay using Aleuria aurantia lectin (AAL), and applied this to diagnose several diseases, including various cancers. AAL recognizes both α1-3/1-4 and α1-6 fucosylation on N/O-linked glycans. These fucosylation types differ in biological function, and in regulation by different fucosyltransferases. Recently, we identified a novel lectin, Pholiota squarrosa lectin (PhoSL), which specifically recognizes α1-6 fucosylation (core-fucosylation). METHODS: We developed a lectin-antibody ELISA kit using PhoSL to determine core-Fuc-Hpt levels in sera from colorectal or pancreatic cancer patients. RESULTS: Serum levels of AAL-reactive Hpt are higher in pancreatic cancer patients, whereas those of PhoSL-reactive Hpt are higher in colorectal cancer patients. Mass spectrometry analyses of Hpt fucosylation levels were consistent with lectin-antibody ELISA results. Hpt-transfected colorectal cancer cell lines produced significant amounts of core-Fuc-Hpt, suggesting that colorectal cancer tissues produce core-Fuc-Hpt. CONCLUSIONS: These differences in Fuc-Hpt patterns might depend on cancer cells and the surrounding cells, which produce Hpt.

Reevaluation of a lectin antibody ELISA kit for measuring fucosylated haptoglobin in various conditions.

BACKGROUND: Fucosylated haptoglobin (Fuc-Hpt) is a novel cancer biomarker in a variety of pathological conditions. We previously found that the level of Fuc-Hpt is increased in the sera of patients with pancreatic cancer, and established a lectin antibody ELISA using Aleuria aurantia lectin, which specifically binds to fucosylated residues on oligosaccharides. METHODS: To apply this assay system to the clinical detection of several diseases, several assay conditions such as serum dilutions and inhibitory factors were investigated. The Fuc-Hpt kit was available for 25-625 fold serum dilution. RESULTS: While the values of Fuc-Hpt assay using sera and plasma were different, they showed positive correlation. The addition of bilirubin and formagine did not influence on Fuc-Hpt assay, but hemoglobin inhibited this assay in a dose-dependent manner. CONCLUSIONS: We reevaluated this lectin antibody ELISA kit for measuring fucosylated haptoglobin in various conditions in this study.

Fucosylation is a promising target for cancer diagnosis and therapy.

Oligosaccharides, sequences of carbohydrates conjugated to proteins and lipids, are arguably the most abundant and structurally diverse class of molecules. Fucosylation is one of the most important oligosaccharide modifications involved in cancer and inflammation. Recent advances in glycomics have identified several types of glyco-biomarkers containing fucosylation that are linked to certain types of cancer. Fucosylated alpha-fetoprotein (AFP) is widely used in the diagnosis of hepatocellular carcinoma because it is more specific than alpha-fetoprotein. High levels of fucosylated haptoglobin have also been found in sera of patients with various carcinomas. We have recently established a simple lectin-antibody ELISA to measure fucosylated haptoglobin and to investigate its clinical use. Cellular fucosylation is dependent upon fucosyltransferase activity and the level of its donor substrate, guanosine diphosphate (GDP)-fucose. GDP-mannose-4,6-dehydratase (GMDS) is a key enzyme involved in the synthesis of GDP-fucose. Mutations of GMDS found in colon cancer cells induced a malignant phenotype, leading to rapid growth in athymic mice resistant to natural killer cells. This review describes the role of fucosylated haptoglobin as a cancer biomarker, and discusses the possible biological role of fucosylation in cancer development.

Evaluation of the Use of PenNeedle(®) 32G Taper in Children being Treated with Growth Hormone.

Pain resulting from needle injection is a serious problem for patients that self-administer medication at home. We studied impressions of needle use by comparing PenNeedle® 32G Taper (NovoFine® 32G Tip), developed to reduce the sense of fear and pain of injection, with a conventional needle, in children self-injecting GH. A total of 34 patients self-injected themselves with needles coupled with Norditropin® NordiFlex® pre-filled recombinant human GH, and impressions of use were evaluated by a series of questionnaires. Compared to the conventional needle, PenNeedle 32G Taper was slightly less painful at time of insertion according to patient responses, though the difference was not statistically significant (P=0.06). PenNeedle 32G Taper has the same inner diameter as the conventional needle, thus there was no difference in the pain felt at time of injection between these two needles. Large differences in pain perception between the two needles were not seen probably due to their similar shape and appearance and as the subjects of this study were young. Nevertheless, based on the results of post-study questionnaires, significantly more patients (68%, P=0.02) expressed a desire to use PenNeedle 32G Taper for daily injections of GH. PenNeedle 32G Taper thus appears to be a superior needle which reduces insertion-associated pain in children receiving recombinant GH and improves patient QOL.