Publications by authors named "Syu L"

Article Synopsis
  • Merkel cell carcinoma (MCC) is a serious skin cancer linked to the Merkel cell polyomavirus and exhibits specific gene expressions related to Merkel cell development.
  • Researchers used a method called in vivo cellular reprogramming with the ATOH1 gene to induce MCC-like tumors in mice from skin cells.
  • The study found that the development of these tumors required the loss of the p53 protein, mirroring the dysfunction of p53 observed in human MCC cases.
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We report the experimental observation of and theoretical explanation for the reduction of dopant ions and enhancement of magnetic properties in Ce-doped TiO diluted magnetic semiconductors from UV-light irradiation. Substantial increase in Ce concentration and creation of oxygen vacancy defects in the sample due to UV-light irradiation was observed by X-ray and optical methods. Magnetic measurements demonstrate a combination of paramagnetism and ferromagnetism up to room temperatures in all samples.

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Gastric cancer is the third most lethal cancer worldwide, and evaluation of the genomic status of gastric cancer cells has not translated into effective prognostic or therapeutic strategies. We therefore hypothesize that outcomes may depend on the tumor microenvironment (TME), in particular, cancer-associated fibroblasts (CAF). However, very little is known about the role of CAFs in gastric cancer.

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Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease characterized by an extensive fibroinflammatory stroma, which includes abundant cancer-associated fibroblast (CAF) populations. PDAC CAFs are heterogeneous, but the nature of this heterogeneity is incompletely understood. The Hedgehog pathway functions in PDAC in a paracrine manner, with ligands secreted by cancer cells signaling to stromal cells in the microenvironment.

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Development of gastric cancer is often preceded by chronic inflammation, but the immune cellular mechanisms underlying this process are unclear. Here we demonstrated that an inflammasome molecule, absent in melanoma 2 (Aim2), was upregulated in patients with gastric cancer and in spasmolytic polypeptide-expressing metaplasia of chronically Helicobacter felis-infected stomachs in mice. However, we found that Aim2 was not necessary for inflammasome function during gastritis.

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Ultraviolet (UV) light irradiation on CeO nanocrystals catalysts has been observed to largely increase the material's catalytic activity and reactive surface area. As revealed by x-ray absorption near edge structure (XANES) analysis, the concentration of subvalent Ce ions in the irradiated ceria samples progressively increases with the UV-light exposure time. The increase of Ce concentration as a result of UV irradiation was also confirmed by the UV-vis diffuse reflectance and photoluminescence spectra that indicate substantially increased concentration of oxygen vacancy defects in irradiated samples.

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Tumor cells expressing programmed cell death ligand 1 (PD-L1) interact with PD-1 on CD8+ cytotoxic T lymphocytes (CTLs) to inhibit CTL effector function. In gastric cancer, the mechanism regulating PD-L1 is unclear. The Hedgehog (Hh) signaling pathway is reactivated in various cancers including gastric.

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The rhizoma of , a Chinese medicinal plant, has long been used as a cosmetic for the whitening and hydrating of the skin in ancient China. In order to investigate the antimelanogenic components of the rhizoma of , we performed an antimelanogenesis assay-guided purification using semi-preparative HPLC accompanied with spectroscopic analysis to determine the active components. Based on the bioassay-guided method, 24 compounds were isolated and identified from the ethyl acetate layer of methanolic extracts of , and among these, 5-[3-(4-hydroxy-3-methoxyphenyl)allyl]ferulic acid () and -4-pentylcyclohex-3-ene-1,2-diol () were new compounds.

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This work reports an unconventional defect engineering approach using synchrotron-radiation-based X-rays on ceria nanocrystal catalysts of particle sizes 4.4-10.6 nm.

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The interaction between the receptor, programmed cell death protein 1 (PD-1) and ligand, programmed cell death 1 (PD-L1) is known to inhibit CD8+ cytotoxic T lymphocyte proliferation, survival, and effector function. The result of this interaction leads to evasion of immune surveillance by tumors and subsequently cancer cell proliferation. Immunotherapy via PD-L1 blockade is used for a variety of malignancies, yet the prognostic value of immune checkpoint inhibition for the treatment of gastric cancer remains controversial.

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Background & Aims: Chronic gastrointestinal inflammation increases the risk of cancer by mechanisms that are not well understood. Indoleamine-2,3-dioxygenase 1 (IDO1) is a heme-binding enzyme that regulates the immune response via catabolization and regulation of tryptophan availability for immune cell uptake. IDO1 expression is increased during the transition from chronic inflammation to gastric metaplasia.

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Gastric adenocarcinoma is the third most common cause of cancer-related death worldwide. Here we report a novel, highly-penetrant mouse model of invasive gastric cancer arising from deregulated Hedgehog/Gli2 signaling targeted to Lgr5-expressing stem cells in adult stomach. Tumor development progressed rapidly: three weeks after inducing the Hh pathway oncogene GLI2A, 65% of mice harbored in situ gastric cancer, and an additional 23% of mice had locally invasive tumors.

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Chronic inflammation in the stomach can lead to gastric cancer. We previously reported that gastrin-deficient (Gast⁻/⁻) mice develop bacterial overgrowth, inflammatory infiltrate, increased Il-1β expression, antral hyperplasia and eventually antral tumors. Since Hedgehog (Hh) signaling is active in gastric cancers but its role in precursor lesions is poorly understood, we examined the role of inflammation and Hh signaling in antral hyperplasia.

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Gastric adenocarcinoma is one of the leading causes of cancer mortality worldwide. It arises through a stepwise process that includes prominent inflammation with expression of interferon-γ (IFN-γ) and multiple other pro-inflammatory cytokines. We engineered mice expressing IFN-γ under the control of the stomach-specific H(+)/K(+) ATPase β promoter to test the potential role of this cytokine in gastric tumorigenesis.

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Uncontrolled Hedgehog (Hh) signaling leads to the development of basal cell carcinoma (BCC), the most common human cancer, but the cell of origin for BCC is unclear. While Hh pathway dysregulation is common to essentially all BCCs, there exist multiple histological subtypes, including superficial and nodular variants, raising the possibility that morphologically distinct BCCs may arise from different cellular compartments in skin. Here we have shown that induction of a major mediator of Hh signaling, GLI2 activator (GLI2ΔN), selectively in stem cells of resting hair follicles in mice, induced nodular BCC development from a small subset of cells in the lower bulge and secondary hair germ compartments.

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Consistent with the common role of Nkx6 family members in specifying motor neuron identity, we show that over-expression of Drosophila Nkx6 results in an increase in the number of Fasiclin II expressing motor neurons in the intersegmental nerve B branch. Our dissection of the regulatory domains of Nkx6 using chimeric cell culture assays revealed the presence of two repression domains and a single activation domain within this transcription factor. As well as its conserved homeodomain, Nkx6 also has a candidate Engrailed homology 1 (Eh1) domain that is conserved amongst all NKx6 family members, through which vertebrate NKx6-type proteins bind the co-repressor, Groucho (Muhr, J.

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Constitutive Hedgehog (Hh) signaling underlies several human tumors, including basal cell carcinoma (BCC) and basaloid follicular hamartoma in skin. Intriguingly, superficial BCCs arise as de novo epithelial buds resembling embryonic hair germs, collections of epidermal cells whose development is regulated by canonical Wnt/beta-catenin signaling. Similar to embryonic hair germs, human BCC buds showed increased levels of cytoplasmic and nuclear beta-catenin and expressed early hair follicle lineage markers.

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Vnd is a dual transcriptional regulator that is essential for Drosophila dorsal-ventral patterning. Yet, our understanding of the biochemical basis for its regulatory activity is limited. Consistent with Vnd's ability to repress target expression in embryos, endogenously expressed Vnd physically associates with the co-repressor, Groucho, in Drosophila Kc167 cells.

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Ind-Gsh-type homeodomain proteins are critical to patterning of intermediate domains in the developing CNS; yet, the molecular basis for the activities of these homeodomain proteins is not well understood. Here we identify domains within the Ind protein that are responsible for transcriptional repression, as well as those required for its interaction with the co-repressor, Groucho. To do this, we utilized a combination of chimeric transient transfection assays, co-immunoprecipitation and in vivo expression assays.

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The transcription factor, Vnd, is a dual regulator that specifies ventral neuroblast identity in Drosophila by both repressing and activating target genes. Vnd and its homologues have a conserved amino acid sequence, the Nk-2 box or Nk specific domain, as well a conserved DNA-binding homeodomain and an EhI-type Groucho interaction domain. However, the function of the conserved Nk-2 box has not been fully defined.

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At the molecular level, members of the NKx2.2 family of transcription factors establish neural compartment boundaries by repressing the expression of homeobox genes specific for adjacent domains [Muhr et al. (2001) Cell, 104, 861-873; Weiss et al.

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Lipotransin is a novel hormone-sensitive lipase (HSL)-interacting protein that appears to translocate HSL to the lipid droplet. The interaction of the two proteins depends upon the phosphorylation of HSL by protein kinase A. Once formed, the complex is dissociated by ATP hydrolysis, due to the ATPase activity of lipotransin.

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Insulin-stimulated glucose transport and GLUT4 translocation require regulated interactions between the v-SNARE, VAMP2, and the t-SNARE, syntaxin 4. We have isolated a novel syntaxin 4-binding protein, Synip, which specifically interacts with syntaxin 4. Insulin induces a dissociation of the Synip:syntaxin 4 complex due to an apparent decrease in the binding affinity of Synip for syntaxin 4.

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The insulin-stimulated uptake of 2-(methylamino)isobutyric acid (MeAIB), a nonmetabolizable substrate for system A, in 3T3-L1 adipocytes was investigated. As cells took on a more adipogenic phenotype, the insulin-stimulated versus the saturable basal MeAIB uptake increased by 5-fold. The induced transport activity showed properties characteristic of system A, with a Km value of 190 microM.

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Activation of protein kinase C (PKC) regulates the processing of Alzheimer amyloid precursor protein (APP) into its soluble form (sAPP) and amyloid beta-peptide (A beta). However, little is known about the intermediate steps between PKC activation and modulation of APP metabolism. Using a specific inhibitor of mitogen-activated protein (MAP) kinase kinase activation (PD 98059), as well as a dominant negative mutant of MAP kinase kinase, we show in various cell lines that stimulation of PKC by phorbol ester rapidly induces sAPP secretion through a mechanism involving activation of the MAP kinase cascade.

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