Feng Guan

Upregulation of microRNA (miR)‑10b has been confirmed in multiple types of cancer, however, the role of miR‑10b in glycosylation remains unclear. Protein core‑fucosylation is an important N‑linked glycosylation modification and serves important roles in cancer progression. In a previous study, a glycogene array was applied to profile the alterations of glycogene expression in miR‑10b‑overexpressed MCF10A cells. Notably, fucosyltranferase 8 (FUT8), which is responsible for the addition of core‑fucose to N‑glycan, was significantly upregulated by miR‑10b. In the present study, increased motility and proliferation were observed in miR‑10b‑overexpressed MCF10A cells. To assess the mechanism involved, the role of FUT8 in MCF10A cells was studied and it was confirmed that miR‑10b promotes motility and proliferation by regulating FUT8 and activating the protein kinase B (AKT) signaling pathway. Consistent with the aforementioned result, decreased motility and proliferation were detected when miR‑10b expression was inhibited in MDA‑MB‑231 cells, transforming growth factor‑β‑induced and Twist‑overexpressed MCF10A cells. To conclude, the findings from the present study indicate that miR‑10b promotes motility and proliferation by increasing FUT8 and activating AKT in breast cancer cells.

Glycosphingolipids (GSLs), which consist of a hydrophobic ceramide backbone and a hydrophilic carbohydrate residue, are an important type of glycolipid expressed in surface membranes of all animal cells. GSLs play essential roles in maintenance of plasma membrane stability, in regulation of numerous cellular processes (including adhesion, proliferation, apoptosis, and recognition), and in modulation of signal transduction pathways. GSLs have traditionally been classified as ganglio-series, lacto-series, or globo-series on the basis of their diverse types of oligosaccharide chains. Structures and functions of specific GSLs are also determined by their oligosaccharide chains. Different cells and tissues show differential expression of GSLs, and changes in structures of GSL glycan moieties occur during development of numerous types of human cancer. Association of GSLs and/or related enzymes with initiation and progression of cancer has been documented in 100s of studies, and many such GSLs are useful markers or targets for cancer diagnosis or therapy. In this review, we summarize (i) recent studies on aberrant expression and distribution of GSLs in common human cancers (breast, lung, colorectal, melanoma, prostate, ovarian, leukemia, renal, bladder, gastric); (ii) biological functions of specific GSLs in these cancers.

Glycosylation of certain proteins at the mammalian cell surface is an essential event in carcinogenesis. Sialylation, one type of glycosylation, can act on multiple cell-behaviors, such as migration, growth, and malignant invasion. Two polysialyltransferases, ST8Sia II (STX) and ST8Sia IV (PST), are responsible for synthesis of polysialic acid on neural cell adhesion molecule. We showed previously that STX and PST are oppositely expressed in normal murine mammary gland cells undergoing transforming growth factor-β-induced epithelial-mesenchymal transition. The molecular basis for regulation of STX and PST remained unclear. In the present study, we observed that transcription factor Pax3 upregulates STX expression, downregulates PST expression, and modulates upregulated expression of PSA, which attaches primarily to neural cell adhesion molecule to form PSA-NCAM. Overexpression of Pax3 in normal murine mammary gland cells transformed the expression of epithelial-mesenchymal transition markers E-cadherin and N-cadherin, and significantly promoted cell migration, but had no effect on cell proliferation.

The economic consequences of product recalls include the short-term market reactions of investors, the reputation recovery mechanism adopted by the management of the recalling company and the long-term value relevance of the recalling company. Forty-one food and drug recalls by Chinese-listed companies between 2007 and 2012 were selected as the research sample. Using companies in the same industry as paired data, 1534 pairings were obtained. The study findings show that investors had negative reactions to food or drug recall incidents during a short event window; that the recalls had a negative externality on other companies in the same industry; that companies that performed voluntary recalls engaged in reputation recovery behaviour; and that companies that performed voluntary recalls possessed better long-term value relevance than their peers in the same industry.

The term "cancer" refers to a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. Epithelial-mesenchymal transition (EMT), a process whereby epithelial cells lose their cell polarity and cell-cell adhesion ability, and acquire migratory and invasive properties to gain mesenchymal phenotype, is an important step leading to tumor metastasis. Glycans such as N-glycans, O-glycans, and glycosphingolipids are involved in numerous biological processes, including inflammation, virus/bacteria-host interactions, cell-cell interactions, morphogenesis, and cancer development and progression. Aberrant expression of glycans has been observed in several EMT models, and the functional roles of such glycans in cancer development and progression has been investigated. We summarize here recent research progress regarding the functions of glycans in cancer cells undergoing EMT. Better understanding of the mechanisms underlying aberrant glycan patterns in EMT and cancer will facilitate the development of such glycans as cancer biomarkers or as targets in design and synthesis of anti-tumor drugs.

Epithelial-to-mesenchymal transition (EMT) is an essential biological process involved in embryonic development, cancer progression, and metastatic diseases. EMT has often been used as a model for elucidating the mechanisms that underlie bladder cancer progression. However, no study to date has addressed the quantitative global variation of proteins in EMT using normal and non-malignant bladder cells. We treated normal bladder epithelial HCV29 cells and low grade nonmuscle invasive bladder cancer KK47 cells with transforming growth factor-beta (TGF-β) to establish an EMT model, and studied non-treated and treated HCV29 and KK47 cells by the stable isotope labeling amino acids in cell culture (SILAC) method. Labeled proteins were analyzed by 2D ultrahigh-resolution liquid chromatography/LTQ Orbitrap mass spectrometry. Among a total of 2994 unique identified and annotated proteins in HCV29 and KK47 cells undergoing EMT, 48 and 56 proteins, respectively, were significantly upregulated, and 106 and 24 proteins were significantly downregulated. Gene ontology (GO) term analysis and pathways analysis indicated that the differentially regulated proteins were involved mainly in enhancement of DNA maintenance and inhibition of cell-cell adhesion. Proteomes were compared for bladder cell EMT vs. bladder cancer cells, revealing 16 proteins that displayed similar changes in the two situations. Studies are in progress to further characterize these 16 proteins and their biological functions in EMT.

Compartmentalization of cellular components and their associated biological processes is crucial for cellular function. Protein glycosylation provides a basis for diversity of protein functions. Diversity of glycan composition in animal cells remains poorly understood. We used differential centrifugation techniques to isolate four subcellular protein fractions from homogenate of metastatic bladder YTS1 cells, low grade nonmuscle invasive bladder cancer KK47 cells and normal bladder epithelia HCV29 cells: microsomal (Mic), mitochondrial (Mito), nuclear (Nuc), and cytosolic (Cyto). An integrated strategy combining lectin microarray and mass spectrometry (MS) analysis was then applied to evaluate protein glycosylation of the four fractions. Lectin microarray analysis revealed significant differences among the four fractions in terms of glycan binding to the lectins LCA, AAL, MPL, WGA and PWM in YTS1 cell, STL, Jacalin, VVA, LCA and WGA in KK47, and ConA, GNA, VVA and ACA in HCV29 cell. Among a total of 40, 32 and 15 N-glycans in four fractions of three cells detected by MS analysis, high-mannose and fucosylated structures were predominant, 10 N-glycans in YTS1, 5 N-glycans in KK47 and 7 N-glycans in HCV29 were present in all four fractions; and 10 N-glycans in YTS1, 16 N-glycans in KK47, and 3 N-glycans in HCV29 were present in only one fraction. Glycans in the latter category are considered potential markers for the corresponding organelles. The integrated strategy described here allows detailed examination of glycomes subcellular fraction with high resolution and sensitivity, and will be useful for elucidation of the functional roles of glycans and corresponding glycosylated proteins in distinct organelles.