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Huang JJ, Tseng CC. Emphysematous pyelonephritis: clinicoradiological classification, management, prognosis, and pathogenesis. ARCHIVES OF INTERNAL MEDICINE 2000; 160:797-805. [PMID: 10737279 DOI: 10.1001/archinte.160.6.797] [Citation(s) in RCA: 435] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Emphysematous pyelonephritis (EPN) is a rare, severe gas-forming infection of renal parenchyma and its surrounding areas. The radiological classification and adequate therapeutic regimen are controversial and the prognostic factors and pathogenesis remain uncertain. OBJECTIVES To elucidate the clinical features, radiological classification, and prognostic factors of EPN; to compare the modalities of management (ie, antibiotic treatment alone, percutaneous catheter drainage combined with antibiotic treatment, or nephrectomy) and outcome among the various radiological classes of EPN; and to clarify the gas-forming mechanism and pathogenesis of EPN by gas analysis and pathological findings. PATIENTS AND METHODS Forty-eight EPN cases from our institution were enrolled between August 1,1989, and November 30, 1997. According to the radiological findings on computed tomographic scan, they were classified into the following classes: (1) class 1: gas in the collecting system only; (2) class 2: gas in the renal parenchyma without extension to extrarenal space; (3) class 3A: extension of gas or abscess to perinephric space; class 3B: extension of gas or abscess to pararenal space; and (4) class 4: bilateral EPN or solitary kidney with EPN. The clinical manifestations, management, and outcome were compared. The gas contents of specimens from 6 patients were analyzed. The pathological findings from 8 patients who received nephrectomy were reviewed. The statistical methods consisted of the Fisher exact test (2 tailed) for categorical variables and Wilcoxon rank sum test for continuous variables to test the predictors of poor prognosis. RESULTS Forty-six patients (96%) had diabetes mellitus, and 10 (22%) of the 46 also had urinary tract obstruction in the corresponding renoureteral unit. The other 2 nondiabetic patients (4%) had severe hydronephrosis. Twenty-one (72%) of the 29 patients with diabetes mellitus also had a glycosylated hemoglobin A(1c) level higher than 0.08. Escherichia coli (69%) and Klebsiella pneumoniae (29%) were the most common pathogens. The mortality rate in patients who received antibiotic treatment alone was 40% (2 of 5 patients). The success rate of management by percutaneous catheter drainage (PCD) combined with antibiotic treatment was 66% (27 of 41 patients). In classes 1 and 2 EPN, all the patients who were treated using a PCD or ureteral catheter combined with antibiotic treatment survived. In extensive EPN (classes 3 and 4), 17 (85%) of the 20 patients with fewer than 2 risk factors (ie, thrombocytopenia, acute renal function impairment, disturbance of consciousness, or shock) were successfully treated using PCD combined with antibiotic treatment; and the patients with 2 or more risk factors had a significantly higher failure rate than those with no or only 1 risk factors (92% vs 15%, P<.001). Eight of the 14 patients who had an unsuccessful treatment using a PCD underwent subsequent nephrectomy, 7 of whom survived. Only 2 patients were managed by direct nephrectomy and survived. The overall success rate of nephrectomy was 90% (9 of 10 patients). The total mortality was 18.8% (9 of 48 patients). Five of the 6 gas samples contained hydrogen (average, 12.8%), and all had carbon dioxide (average, 14.4%). The pathological findings from 8 of 10 who underwent nephrectomy revealed poor perfusion in most cases (ie, infarction, 5 patients; vascular thrombosis, 3 patients; and arteriosclerosis and/or glomerulosclerosis, 4 patients). CONCLUSION Acute renal infection with E coli or K pneumoniae in patients with diabetes mellitus and/or urinary tract obstruction is the cornerstone for the development of EPN. Mixed acid fermentation of glucose by Enterobacteriaceae is the major pathway of gas formation. For localized EPN (classes 1 and 2), PCD combined with antibiotic treatment can provide a good outcome. (ABSTRACT TRUNCATED)
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Gershenwald JE, Colome MI, Lee JE, Mansfield PF, Tseng C, Lee JJ, Balch CM, Ross MI. Patterns of recurrence following a negative sentinel lymph node biopsy in 243 patients with stage I or II melanoma. J Clin Oncol 1998; 16:2253-60. [PMID: 9626228 DOI: 10.1200/jco.1998.16.6.2253] [Citation(s) in RCA: 397] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To determine the patterns of recurrence and causes of regional nodal basin failure in stage I or II melanoma patients who had a histologically negative sentinel lymph node (SLN) and whose regional nodal basins were not dissected following lymphatic mapping and SLN biopsy. PATIENTS AND METHODS The records of 344 patients with primary cutaneous melanoma who underwent lymphatic mapping and SLN biopsy between 1991 and 1995 at The University of Texas M.D. Anderson Cancer Center were reviewed. Of 322 patients who underwent successful lymphatic mapping procedures, 270 had histologically negative SLNs; mapped nodal basins were observed without further surgical intervention in 243 of these 270 patients. Recurrence patterns were analyzed from this cohort and a histologic reevaluation of all previously identified SLNs on which a biopsy had been taken was performed in patients who developed recurrent disease. RESULTS Of 243 patients with a histologically negative SLN, 27 (11%) developed local, in-transit, regional nodal, and/or distant metastases after a median follow-up time of 35 months. Ten patients (4.1%) developed a nodal recurrence in the previously mapped basin, either solely or as a component of the first site of recurrence. Detailed analysis of the SLNs in these 10 patients demonstrated evidence of occult metastases in 80% by serial sectioning or immunohistochemical staining. CONCLUSION Regional nodal failures in melanoma patients following a negative SLN biopsy are infrequent and to date have most commonly occurred because conventional histologic evaluation was unable to identify occult metastatic disease. These data provide further evidence that lymphatic mapping and SLN biopsy accurately reflect the status of the regional nodal basin. Specialized pathologic techniques are necessary to reduce further the already low false-negative rates and to improve disease staging.
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Cox D, Tseng CC, Bjekic G, Greenberg S. A requirement for phosphatidylinositol 3-kinase in pseudopod extension. J Biol Chem 1999; 274:1240-7. [PMID: 9880492 DOI: 10.1074/jbc.274.3.1240] [Citation(s) in RCA: 318] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phagocytosis requires actin assembly and pseudopod extension, two cellular events that coincide spatially and temporally. The signal transduction events underlying both processes may be distinct. We tested whether phagocytic signaling resembles that of growth factor receptors, which induce actin polymerization via activation of phosphatidylinositol 3-kinase (PI 3-kinase). Fcgamma receptor-mediated phagocytosis was accompanied by a rapid increase in the accumulation of phosphatidylinositol 3,4,5-trisphosphate in vivo, and addition of wortmannin (WM) or LY294002, two inhibitors of PI 3-kinase(s), inhibited phagocytosis but not Fcgamma receptor-directed actin polymerization. However, both compounds prevented maximal pseudopod extension, suggesting that PI 3-kinase inhibition produced a limitation in membrane required for pseudopod extension. Availability of plasma membrane was not limiting for phagocytosis, because blockade of ingestion in the presence of WM was not overcome by reducing the number of particles adhering to macrophages. However, decreasing bead size, and hence the magnitude of pseudopod extension required for particle engulfment, relieved the inhibition of phagocytosis in the presence of WM or LY294002 by up to 80%. The block in phagocytosis of large particles occurred before phagosomal closure, because both compounds inhibited spreading of macrophages on substrate-bound IgG. Macrophage spreading on IgG was accompanied by exocytic insertion of membrane from an intracellular source, as measured by the dye FM1-43. These results indicate that one or more isoforms of PI 3 kinase are required for maximal pseudopod extension but not phagocytosis per se. We suggest that PI 3-kinase is required for coordinating exocytic membrane insertion and pseudopod extension.
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Tangpricha V, Flanagan JN, Whitlatch LW, Tseng CC, Chen TC, Holt PR, Lipkin MS, Holick MF. 25-hydroxyvitamin D-1alpha-hydroxylase in normal and malignant colon tissue. Lancet 2001; 357:1673-4. [PMID: 11425375 DOI: 10.1016/s0140-6736(00)04831-5] [Citation(s) in RCA: 208] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Vitamin D affects calcium metabolism and prevents proliferation of colon cells in vitro. In human beings the main circulating form of vitamin D is 25-hydroxyvitamin D; to regulate calcium homoeostasis, this form must be converted to 1alpha, 25-dihydroxyvitamin D by 1alpha-hydroxylation in the kidney with 25-hydroxyvitamin D-1alpha-hydroxylase. Cultured transformed colon cancer cells can convert 25-hydroxyvitamin D(3) to 1alpha,25-dihydroxyvitamin D(3). We identified messenger RNA (mRNA) for 25-hydroxyvitamin D-1alpha-hydroxylase in normal colon tissue and in malignant and adjacent normal colon tissue. These findings support the notion that vitamin D might have a role in cell growth regulation and cancer protection, and might be the explanation for why the risk of dying from colorectal cancer is highest in areas with the least amount of sunlight.
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Shie JL, Chen ZY, Fu M, Pestell RG, Tseng CC. Gut-enriched Krüppel-like factor represses cyclin D1 promoter activity through Sp1 motif. Nucleic Acids Res 2000; 28:2969-76. [PMID: 10908361 PMCID: PMC102679 DOI: 10.1093/nar/28.15.2969] [Citation(s) in RCA: 179] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2000] [Revised: 06/01/2000] [Accepted: 06/12/2000] [Indexed: 11/14/2022] Open
Abstract
Cancer cells differ from normal cells in many characteristics including loss of differentiation and uninhibited cell proliferation. Recent studies have focused on the identification of factors contributing to cell growth and differentiation. Gut-enriched Krüppel-like factor (GKLF or KLF4) is a newly identified eukaryotic transcription factor and has been shown to play a role in regulating growth arrest. We have previously shown that GKLF mRNA levels were significantly decreased in colon cancer tissues, and that over-expression of GKLF in colonic adenocarcinoma cells (HT-29) resulted in reduction of cyclin D1 (CD1) mRNA and protein levels. The current study was undertaken to determine the mechanisms by which GKLF inhibited CD1 expression. In a transient transfection system, GKLF suppressed CD1 promoter activity by 55%. Sequential deletion and site-directed mutation analysis of the CD1 promoter have identified the sequence between -141 and -66, a region containing an Sp1 response element, to be essential for GKLF function. By electrophoretic mobility gel shift assay, recombinant GKLF and nuclear extracts from HT-29 cells were found to bind to the Sp1 motif on the CD1 promoter. The inhibitory effect of GKLF on the CD1 promoter activity was completely abolished by excessive amount of Sp1 DNA and GKLF significantly reduced the stimulatory function of Sp1 suggesting that GKLF and Sp1 may compete for the same binding site on the CD1 promoter. These results indicate that GKLF is a transcriptional repressor of the CD1 gene and that the inhibitory effect of GKLF is, in part, mediated by interaction with the Sp1 binding domain on its promoter.
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Chiou SK, Tseng CC, Rao L, White E. Functional complementation of the adenovirus E1B 19-kilodalton protein with Bcl-2 in the inhibition of apoptosis in infected cells. J Virol 1994; 68:6553-66. [PMID: 8083992 PMCID: PMC237076 DOI: 10.1128/jvi.68.10.6553-6566.1994] [Citation(s) in RCA: 178] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Expression of the adenovirus E1A oncogene induces apoptosis which impedes both the transformation of primary rodent cells and productive adenovirus infection of human cells. Coexpression of E1A with the E1B 19,000-molecular-weight protein (19K protein) or the Bcl-2 protein, both of which have antiapoptotic activity, is necessary for efficient transformation. Induction of apoptosis by E1A in rodent cells is mediated by the p53 tumor suppressor gene, and both the E1B 19K protein and the Bcl-2 protein can overcome this p53-dependent apoptosis. The functional similarity between Bcl-2 and the E1B 19K protein suggested that they may act by similar mechanisms and that Bcl-2 may complement the requirement for E1B 19K expression during productive infection. Infection of human HeLa cells with E1B 19K loss-of-function mutant adenovirus produces apoptosis characterized by enhanced cytopathic effects (cyt phenotype) and degradation of host cell chromosomal DNA and viral DNA (deg phenotype). Failure to inhibit apoptosis results in premature host cell death, which impairs virus yield. HeLa cells express extremely low levels of p53 because of expression of human papillomavirus E6 protein. Levels of p53 were substantially increased by E1A expression during adenovirus infection. Therefore, E1A may induce apoptosis by overriding the E6-induced degradation of p53 and promoting p53 accumulation. Stable Bcl-2 overexpression in HeLa cells infected with the E1B 19K- mutant adenovirus blocked the induction of the cyt and deg phenotypes. Expression of Bcl-2 in HeLa cells also conferred resistance to apoptosis mediated by tumor necrosis factor alpha and Fas antigen, which is also an established function of the E1B 19K protein. A comparison of the amino acid sequences of Bcl-2 family members and that of the E1B 19K protein indicated that there was limited amino acid sequence homology between the central conserved domains of E1B 19K and Bcl-2. This domain of the E1B 19K protein is important in transformation and regulation of apoptosis, as determined by mutational analysis. The limited sequence homology and functional equivalency provided further evidence that the Bcl-2 and E1B 19K proteins may possess related mechanisms of action and that the E1B 19K protein may be the adenovirus equivalent of the cellular Bcl-2 protein.
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Zhang Q, Cox D, Tseng CC, Donaldson JG, Greenberg S. A requirement for ARF6 in Fcgamma receptor-mediated phagocytosis in macrophages. J Biol Chem 1998; 273:19977-81. [PMID: 9685333 DOI: 10.1074/jbc.273.32.19977] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phagocytosis requires extension of F-actin-rich pseudopods and is accompanied by membrane fusion events. Members of the ARF family of GTPases are essential for many aspects of membrane trafficking. To test a role for this family of proteins in Fcgamma receptor-mediated phagocytosis, we utilized the fungal metabolite brefeldin A (BFA). The addition of 100 microM BFA to a subclone of RAW 264.7 macrophages disrupted the appearance and function of the Golgi apparatus as indicated by altered immunofluorescent distribution of beta-COP and reduced efflux of BODIPY C5-ceramide, a phospholipid that normally accumulates in the Golgi apparatus. In contrast, BFA had no effect on phagocytosis of IgG-coated erythrocytes. These results suggested that activation of BFA-sensitive ARFs is not required for phagocytosis. ARF6 is unique among members of the ARF family in that its membrane association is unaffected by BFA. Expression of ARF6 mutants defective in either GTP hydrolysis (Q67L) or binding (T27N) inhibited phagocytosis of IgG-coated erythrocytes and attenuated the focal accumulation of F-actin beneath the test particles. These results indicate a requirement for ARF6 in Fcgamma receptor-mediated phagocytosis and suggest that ARF6 is an important mediator of cytoskeletal alterations after Fcgamma receptor activation.
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Lin MH, Chen TC, Kuo TT, Tseng CC, Tseng CP. Real-time PCR for quantitative detection of Toxoplasma gondii. J Clin Microbiol 2000; 38:4121-5. [PMID: 11060078 PMCID: PMC87551 DOI: 10.1128/jcm.38.11.4121-4125.2000] [Citation(s) in RCA: 161] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The protozoan Toxoplasma gondii is one of the most common infectious pathogenic parasites and can cause severe medical complications in infants and immunocompromised individuals. We report here the development of a real-time PCR-based assay for the detection of T. gondii. Oligonucleotide primers and a fluorescence-labeled TaqMan probe were designed to amplify the T. gondii B1 gene. After 40 PCR cycles, the cycle threshold values (C(T)) indicative of the quantity of the target gene were determined. Typically, a C(T) of 25.09 was obtained with DNA from 500 tachyzoites of the T. gondii RH strain. The intra-assay coefficients of variation (CV) were 0.4, 0.16, 0.24, and 0.79% for the four sets of quadruplicate assays, with a mean interassay CV of 0.4%. These values indicate the reproducibility of this assay. Upon optimization of assay conditions, we were able to obtain a standard curve with a linear range (correlation coefficient = 0.9988) across at least 6 logs of DNA concentration. Hence, we were able to quantitatively detect as little as 0.05 T. gondii tachyzoite in an assay. When tested with 30 paraffin-embedded fetal tissue sections, 10 sections (33%) showed a C(T) of <40 and were scored as positive for this test. These results were consistent with those obtained through our nested-PCR control experiments. We have developed a rapid, sensitive, and quantitative real-time PCR for detection of T. gondii. The advantages of this technique for the diagnosis of toxoplasmosis in a clinical laboratory are discussed.
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Tsai YL, Zhang Y, Tseng CC, Stanciauskas R, Pinaud F, Lee AS. Characterization and mechanism of stress-induced translocation of 78-kilodalton glucose-regulated protein (GRP78) to the cell surface. J Biol Chem 2015; 290:8049-64. [PMID: 25673690 DOI: 10.1074/jbc.m114.618736] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Glucose-regulated protein (GRP78)/BiP, a major chaperone in the endoplasmic reticulum, is recently discovered to be preferably expressed on the surface of stressed cancer cells, where it regulates critical oncogenic signaling pathways and is emerging as a target for anti-cancer therapy while sparing normal organs. However, because GRP78 does not contain classical transmembrane domains, its mechanism of transport and its anchoring at the cell surface are poorly understood. Using a combination of biochemical, mutational, FACS, and single molecule super-resolution imaging approaches, we discovered that GRP78 majorly exists as a peripheral protein on plasma membrane via interaction with other cell surface proteins including glycosylphosphatidylinositol-anchored proteins. Moreover, cell surface GRP78 expression requires its substrate binding activity but is independent of ATP binding or a membrane insertion motif conserved with HSP70. Unexpectedly, different cancer cell lines rely on different mechanisms for GRP78 cell surface translocation, implying that the process is cell context-dependent.
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Research Support, Non-U.S. Gov't |
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Wack A, Soldaini E, Tseng C, Nuti S, Klimpel G, Abrignani S. Binding of the hepatitis C virus envelope protein E2 to CD81 provides a co-stimulatory signal for human T cells. Eur J Immunol 2001; 31:166-75. [PMID: 11169450 DOI: 10.1002/1521-4141(200101)31:1<166::aid-immu166>3.0.co;2-l] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Chronic hepatitis C virus (HCV) infection frequently develops into liver disease and is accompanied by extra-hepatic autoimmune manifestations. The tetraspanin CD81 is a putative HCV receptor as it binds the E2 envelope glycoprotein of HCV and bona fide HCV particles. Here we show that HCV E2 binding to CD81 on human cells in vitro lowers the threshold for IL-2 receptor alpha expression and IL-2 production, resulting in strongly increased T cell proliferation. HCV E2-induced co-stimulation also enhances the production of IFN-gamma and IL-4 and causes increased TCR down-regulation. This suggests that binding of HCV particles to CD81 on T cells in vivo may lead to activation by otherwise suboptimal stimuli. Therefore, co-stimulation of autoreactive T cells by HCV may contribute to liver damage and autoimmune phenomena observed in HCV infection.
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Carlos AJ, Ha DP, Yeh DW, Van Krieken R, Tseng CC, Zhang P, Gill P, Machida K, Lee AS. The chaperone GRP78 is a host auxiliary factor for SARS-CoV-2 and GRP78 depleting antibody blocks viral entry and infection. J Biol Chem 2021; 296:100759. [PMID: 33965375 PMCID: PMC8102082 DOI: 10.1016/j.jbc.2021.100759] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/27/2021] [Accepted: 05/05/2021] [Indexed: 12/15/2022] Open
Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the COVID-19 global pandemic, utilizes the host receptor angiotensin-converting enzyme 2 (ACE2) for viral entry. However, other host factors might also play important roles in SARS-CoV-2 infection, providing new directions for antiviral treatments. GRP78 is a stress-inducible chaperone important for entry and infectivity for many viruses. Recent molecular docking analyses revealed putative interaction between GRP78 and the receptor-binding domain (RBD) of the SARS-CoV-2 Spike protein (SARS-2-S). Here we report that GRP78 can form a complex with SARS-2-S and ACE2 on the surface and at the perinuclear region typical of the endoplasmic reticulum in VeroE6-ACE2 cells and that the substrate-binding domain of GRP78 is critical for this interaction. In vitro binding studies further confirmed that GRP78 can directly bind to the RBD of SARS-2-S and ACE2. To investigate the role of GRP78 in this complex, we knocked down GRP78 in VeroE6-ACE2 cells. Loss of GRP78 markedly reduced cell surface ACE2 expression and led to activation of markers of the unfolded protein response. Treatment of lung epithelial cells with a humanized monoclonal antibody (hMAb159) selected for its safe clinical profile in preclinical models depleted cell surface GRP78 and reduced cell surface ACE2 expression, as well as SARS-2-S-driven viral entry and SARS-CoV-2 infection in vitro. Our data suggest that GRP78 is an important host auxiliary factor for SARS-CoV-2 entry and infection and a potential target to combat this novel pathogen and other viruses that utilize GRP78 in combination therapy.
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Research Support, N.I.H., Extramural |
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111 |
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Zhang Y, Tseng CC, Tsai YL, Fu X, Schiff R, Lee AS. Cancer cells resistant to therapy promote cell surface relocalization of GRP78 which complexes with PI3K and enhances PI(3,4,5)P3 production. PLoS One 2013; 8:e80071. [PMID: 24244613 PMCID: PMC3823711 DOI: 10.1371/journal.pone.0080071] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 10/08/2013] [Indexed: 12/26/2022] Open
Abstract
Traditionally, GRP78 has been regarded as an endoplasmic reticulum (ER) lumenal protein due to its carboxyl KDEL retention motif. Recently, a subfraction of GRP78 is found to localize to the surface of specific cell types, serving as co-receptors and regulating signaling. However, the physiological relevance of cell surface GRP78 (sGRP78) expression in cancer and its functional interactions at the cell surface are just emerging. In this report, we combined biochemical, imaging and mutational approaches to address these issues. For detection of sGRP78, we utilized a mouse monoclonal antibody highly potent and specific for GRP78 or epitope-tagged GRP78, coupled with imaging and biochemical techniques that allowed detection of sGRP78 but not intracellular GRP78. Our studies revealed that breast and prostate cancer cells resistant to hormonal therapy actively promote GRP78 to the cell surface, which can be further elevated by a variety of ER stress-inducing conditions. We showed that sGRP78 forms complex with PI3K, and overexpression of sGRP78 promotes PIP3 formation, indicative of PI3K activation. We further discovered that an insertion mutant of GRP78 at its N-terminus domain, while retaining stable expression and the ability to translocate to the cell surface as the wild-type protein, exhibited reduced complex formation with p85 and production of PIP3. Thus, our studies provide a mechanistic explanation for the regulation of the PI3K/AKT signaling by sGRP78. Our findings suggest that targeting sGRP78 may suppress therapeutic resistance in cancer cells and offer a novel strategy to suppress PI3K activity.
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Research Support, N.I.H., Extramural |
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Tseng CC, Kieffer TJ, Jarboe LA, Usdin TB, Wolfe MM. Postprandial stimulation of insulin release by glucose-dependent insulinotropic polypeptide (GIP). Effect of a specific glucose-dependent insulinotropic polypeptide receptor antagonist in the rat. J Clin Invest 1996; 98:2440-5. [PMID: 8958204 PMCID: PMC507699 DOI: 10.1172/jci119060] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) is a 42-amino acid peptide produced by K cells of the mammalian proximal small intestine and is a potent stimulant of insulin release in the presence of hyperglycemia. However, its relative physiological importance as a postprandial insulinotropic agent is unknown. Using LGIPR2 cells stably transfected with rat GIP receptor cDNA, GIP (1-42) stimulation of cyclic adenosine monophosphate (cAMP) production was inhibited in a concentration-dependent manner by GIP (7-30)-NH2. Competition binding assays using stably transfected L293 cells demonstrated an IC50 for GIP receptor binding of 7 nmol/liter for GIP (1-42) and 200 nmol/liter for GIP (7-30)-NH2, whereas glucagonlike peptide-1 (GLP-1) binding to its receptor on ++betaTC3 cells was minimally displaced by GIP (7-30)-NH2. In fasted anesthetized rats, GIP (1-42) stimulated insulin release in a concentration-dependent manner, an effect abolished by the concomitant intraperitoneal administration of GIP (7-30)-NH2 (100 nmol/ kg). In contrast, glucose-, GLP-1-, and arginine-stimulated insulin release were not affected by GIP (7-30)-NH2. In separate experiments, GIP (7-30)-NH2 (100 nmol/kg) reduced postprandial insulin release in conscious rats by 72%. It is concluded that GIP (7-30)-NH2 is a GIP-specific receptor antagonist and that GIP plays a dominant role in mediating postprandial insulin release.
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Shie JL, Chen ZY, O'Brien MJ, Pestell RG, Lee ME, Tseng CC. Role of gut-enriched Krüppel-like factor in colonic cell growth and differentiation. Am J Physiol Gastrointest Liver Physiol 2000; 279:G806-14. [PMID: 11005769 DOI: 10.1152/ajpgi.2000.279.4.g806] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cancer cells differ from normal cells in many aspects, including hyperproliferation and loss of differentiation. Recent research has focused on the role of transcription factors in regulating abnormal cell growth. Gut-enriched Krüppel-like factor (GKLF) is a newly identified eukaryotic zinc finger protein expressed extensively in the gastrointestinal tract. In the current study, we demonstrated that GKLF mRNA levels were significantly decreased in the dysplastic epithelium of the colon, including adenomatous polyp and cancer. GKLF immunostains in the normal colon were higher at the surface epithelium and gradually decreased toward the crypt, but this gradient was not present in the adenomatous and cancerous mucosa. Constitutive overexpression of GKLF DNA in a human colonic adenocarcinoma cell line (HT-29) decreased [(3)H]thymidine incorporation, whereas suppression of GKLF gene increased DNA synthesis, indicating that downregulation of the GKLF gene might contribute to cellular hyperproliferation. Cyclin D1 (CD1) protein level and CD1-associated kinase activity were decreased in HT-29 cell overexpressed GKLF cDNA, and CD1 promoter activity was profoundly suppressed by GKLF. When HT-29 cells were cultured in the presence of sodium butyrate, GKLF mRNA levels increased as cells acquired more differentiated phenotypes. These results suggest that GKLF plays an important role in regulating cell growth and differentiation in the colonic epithelium and that downregulation of GKLF expression may cause colonic cells to become hyperproliferative. Furthermore, GKLF appears to be a transcriptional repressor of the CD1 gene.
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Abstract
Our objective was to infer the genetic model for the quantitative traits using a variety of methods developed in our group. Only a single data set was analyzed in any one analysis, although some comparison between data sets was made. In addition, the simulated model was not known during the course of the analysis. Basic modeling and segregation analyses for the five quantitative traits was followed by several simple genome scans to indicate areas of interest. A Markov chain Monte Carlo (MCMC) multipoint quantitative trait locus (QTL) mapping approach was then used to estimate the posterior probabilities of linkage of QTL to each chromosome simultaneously with trait model parameters, and to further localize the genes. Comparisons between the nuclear family and pedigree data sets indicated a greater power for QTL detection and mapping with the pedigree data sets. Even with the pedigree data, however, precise localization of the QTL did not appear to be possible using single replicate data sets. Two of the three genes with effects on trait Q1 were detected by the MCMC method.
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Millstein J, Budden T, Goode EL, Anglesio MS, Talhouk A, Intermaggio MP, Leong HS, Chen S, Elatre W, Gilks B, Nazeran T, Volchek M, Bentley RC, Wang C, Chiu DS, Kommoss S, Leung SCY, Senz J, Lum A, Chow V, Sudderuddin H, Mackenzie R, George J, Fereday S, Hendley J, Traficante N, Steed H, Koziak JM, Köbel M, McNeish IA, Goranova T, Ennis D, Macintyre G, Silva De Silva D, Ramón Y Cajal T, García-Donas J, Hernando Polo S, Rodriguez GC, Cushing-Haugen KL, Harris HR, Greene CS, Zelaya RA, Behrens S, Fortner RT, Sinn P, Herpel E, Lester J, Lubiński J, Oszurek O, Tołoczko A, Cybulski C, Menkiszak J, Pearce CL, Pike MC, Tseng C, Alsop J, Rhenius V, Song H, Jimenez-Linan M, Piskorz AM, Gentry-Maharaj A, Karpinskyj C, Widschwendter M, Singh N, Kennedy CJ, Sharma R, Harnett PR, Gao B, Johnatty SE, Sayer R, Boros J, Winham SJ, Keeney GL, Kaufmann SH, Larson MC, Luk H, Hernandez BY, Thompson PJ, Wilkens LR, Carney ME, Trabert B, Lissowska J, Brinton L, Sherman ME, Bodelon C, Hinsley S, Lewsley LA, Glasspool R, Banerjee SN, Stronach EA, Haluska P, Ray-Coquard I, Mahner S, Winterhoff B, Slamon D, Levine DA, Kelemen LE, Benitez J, Chang-Claude J, Gronwald J, et alMillstein J, Budden T, Goode EL, Anglesio MS, Talhouk A, Intermaggio MP, Leong HS, Chen S, Elatre W, Gilks B, Nazeran T, Volchek M, Bentley RC, Wang C, Chiu DS, Kommoss S, Leung SCY, Senz J, Lum A, Chow V, Sudderuddin H, Mackenzie R, George J, Fereday S, Hendley J, Traficante N, Steed H, Koziak JM, Köbel M, McNeish IA, Goranova T, Ennis D, Macintyre G, Silva De Silva D, Ramón Y Cajal T, García-Donas J, Hernando Polo S, Rodriguez GC, Cushing-Haugen KL, Harris HR, Greene CS, Zelaya RA, Behrens S, Fortner RT, Sinn P, Herpel E, Lester J, Lubiński J, Oszurek O, Tołoczko A, Cybulski C, Menkiszak J, Pearce CL, Pike MC, Tseng C, Alsop J, Rhenius V, Song H, Jimenez-Linan M, Piskorz AM, Gentry-Maharaj A, Karpinskyj C, Widschwendter M, Singh N, Kennedy CJ, Sharma R, Harnett PR, Gao B, Johnatty SE, Sayer R, Boros J, Winham SJ, Keeney GL, Kaufmann SH, Larson MC, Luk H, Hernandez BY, Thompson PJ, Wilkens LR, Carney ME, Trabert B, Lissowska J, Brinton L, Sherman ME, Bodelon C, Hinsley S, Lewsley LA, Glasspool R, Banerjee SN, Stronach EA, Haluska P, Ray-Coquard I, Mahner S, Winterhoff B, Slamon D, Levine DA, Kelemen LE, Benitez J, Chang-Claude J, Gronwald J, Wu AH, Menon U, Goodman MT, Schildkraut JM, Wentzensen N, Brown R, Berchuck A, Chenevix-Trench G, deFazio A, Gayther SA, García MJ, Henderson MJ, Rossing MA, Beeghly-Fadiel A, Fasching PA, Orsulic S, Karlan BY, Konecny GE, Huntsman DG, Bowtell DD, Brenton JD, Doherty JA, Pharoah PDP, Ramus SJ. Prognostic gene expression signature for high-grade serous ovarian cancer. Ann Oncol 2020; 31:1240-1250. [PMID: 32473302 PMCID: PMC7484370 DOI: 10.1016/j.annonc.2020.05.019] [Show More Authors] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 05/06/2020] [Accepted: 05/06/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Median overall survival (OS) for women with high-grade serous ovarian cancer (HGSOC) is ∼4 years, yet survival varies widely between patients. There are no well-established, gene expression signatures associated with prognosis. The aim of this study was to develop a robust prognostic signature for OS in patients with HGSOC. PATIENTS AND METHODS Expression of 513 genes, selected from a meta-analysis of 1455 tumours and other candidates, was measured using NanoString technology from formalin-fixed paraffin-embedded tumour tissue collected from 3769 women with HGSOC from multiple studies. Elastic net regularization for survival analysis was applied to develop a prognostic model for 5-year OS, trained on 2702 tumours from 15 studies and evaluated on an independent set of 1067 tumours from six studies. RESULTS Expression levels of 276 genes were associated with OS (false discovery rate < 0.05) in covariate-adjusted single-gene analyses. The top five genes were TAP1, ZFHX4, CXCL9, FBN1 and PTGER3 (P < 0.001). The best performing prognostic signature included 101 genes enriched in pathways with treatment implications. Each gain of one standard deviation in the gene expression score conferred a greater than twofold increase in risk of death [hazard ratio (HR) 2.35, 95% confidence interval (CI) 2.02-2.71; P < 0.001]. Median survival [HR (95% CI)] by gene expression score quintile was 9.5 (8.3 to -), 5.4 (4.6-7.0), 3.8 (3.3-4.6), 3.2 (2.9-3.7) and 2.3 (2.1-2.6) years. CONCLUSION The OTTA-SPOT (Ovarian Tumor Tissue Analysis consortium - Stratified Prognosis of Ovarian Tumours) gene expression signature may improve risk stratification in clinical trials by identifying patients who are least likely to achieve 5-year survival. The identified novel genes associated with the outcome may also yield opportunities for the development of targeted therapeutic approaches.
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Meta-Analysis |
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Chen H, Tseng CC, Hubbard BK, Walsh CT. Glycopeptide antibiotic biosynthesis: enzymatic assembly of the dedicated amino acid monomer (S)-3,5-dihydroxyphenylglycine. Proc Natl Acad Sci U S A 2001; 98:14901-6. [PMID: 11752437 PMCID: PMC64956 DOI: 10.1073/pnas.221582098] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Four proteins, DpgA-D, required for the biosynthesis by actinomycetes of the nonproteinogenic amino acid monomer (S)-3,5-dihydroxyphenylglycine (Dpg), that is a crosslinking site in the maturation of vancomycin and teicoplanin antibiotic scaffolds, were expressed in Escherichia coli, purified in soluble form, and assayed for enzymatic activity. DpgA is a type III polyketide synthase, converting four molecules of malonyl-CoA to 3,5-dihydroxyphenylacetyl-CoA (DPA-CoA) and three free coenzyme A (CoASH) products. Almost no turnover was observed for DpgA until DpgB was added, producing a net k(cat) of 1-2 min(-1) at a 3:1 ratio of DpgB:DpgA. Addition of DpgD gave a further 2-fold rate increase. DpgC had the unusual catalytic capacity to convert DPA-CoA to 3,5-dihydroxyphenylglyoxylate, which is a transamination away from Dpg. DpgC performed a net CH(2) to C=O four-electron oxidation on the Calpha of DPA-CoA and hydrolyzed the thioester linkage with a k(cat) of 10 min(-1). Phenylacetyl-CoA was also processed, to phenylglyoxylate, but with about 500-fold lower k(cat)/K(M). DpgC showed no activity in anaerobic incubations, suggesting an oxygenase function, but had no detectable bound organic cofactors or metals. A weak enoyl-CoA hydratase activity was detected for both DpgB and DpgD.
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Yuan K, Chang CJ, Hsu PC, Sun HS, Tseng CC, Wang JR. Detection of putative periodontal pathogens in non-insulin-dependent diabetes mellitus and non-diabetes mellitus by polymerase chain reaction. J Periodontal Res 2001; 36:18-24. [PMID: 11246700 DOI: 10.1034/j.1600-0765.2001.90613.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
It has been assumed that there is a relationship between periodontal diseases and diabetes mellitus, however the putative periodontal microorganisms in non-diabetes mellitus (non-DM) individuals and non-insulin-dependent diabetes mellitus (NIDDM) patients have not been well studied. In this study, the detection rates of 5 putative periodontal pathogens: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Eikenella corrodens, Treponema denticola, and Candida albicans by polymerase chain reaction (PCR) between NIDDM and non-DM adults were compared. A total of 246 adults were randomly recruited and periodontal parameters including: plaque index (P1I), gingival index (GI), probing depth (PD) and attachment level (AL) were recorded. Subgingival plaque samples were collected by sterile curettes from the most diseased and healthy sites based on PD and AL. The differences in periodontal parameters and microbiological data in healthy and diseased sites between non-DM and NIDDM patients were compared by chi-square analysis. The results showed no significant differences in age, gender, GI, P1I, PD, and prevalence of the 5 microorganisms between the NIDDM and the non-diabetic groups. However, except for A. actinomycetemcomitans, the prevalence of the periodontal microorganisms tested was significantly higher (p <0.001) in diseased sites than in the healthy sites in both groups. The P1I, GI, PD and AL were significantly higher in T. denticola positive sites than in negative sites. The results suggested that P. gingivalis, T. denticola, E. corrodens and C. albicans may play important roles in the periodontitis of both NIDDM and non-DM individuals, however the etiology of periodontitis in both groups may not be different from each other.
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Clark WB, Beem JE, Nesbitt WE, Cisar JO, Tseng CC, Levine MJ. Pellicle receptors for Actinomyces viscosus type 1 fimbriae in vitro. Infect Immun 1989; 57:3003-8. [PMID: 2570751 PMCID: PMC260762 DOI: 10.1128/iai.57.10.3003-3008.1989] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Actinomyces viscosus T14V-J1 and its fimbria-deficient mutant strain possessing type 1 fimbriae strongly aggregated with latex beads treated with acidic proline-rich protein 1, basic proline-rich proteins, and proline-rich glycoprotein and its deglycosylated derivative. These type 1+ strains did not aggregate with latex beads treated with other proteins, such as salivary amylase, salivary histidine-rich polypeptides, laminin, type 1 collagen, fibronectin, or C1q. The type 1+ strains also adsorbed well to experimental pellicles formed with acidic proline-rich protein 1, basic proline-rich proteins, and proline-rich glycoprotein and its deglycosylated derivative on hydroxyapatite (HA) surfaces. These interactions were inhibited with immunoglobulins and Fabs specific for type 1 fimbriae. Type 1- actinomyces exhibited feeble adsorption to latex beads or HA treated with any of the aforementioned proteins. Collectively, these data indicate that actinomyces type 1 fimbriae may specifically interact with several proline-rich salivary molecules, forming experimental pellicles on HA or polystyrene surfaces.
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Wu MS, Chang MC, Huang SP, Tseng CC, Sheu JC, Lin YW, Shun CT, Lin MT, Lin JT. Correlation of histologic subtypes and replication error phenotype with comparative genomic hybridization in gastric cancer. Genes Chromosomes Cancer 2001; 30:80-6. [PMID: 11107179 DOI: 10.1002/1098-2264(2000)9999:9999<::aid-gcc1062>3.0.co;2-r] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
To characterize phenotypic and genotypic changes in gastric cancer (GC), DNA copy number aberrations (CNAs) were assessed in 53 tumors using comparative genomic hybridization (CGH) and correlated with clinicopathologic characteristics and status of TP53 and replication error (RER). The number of CNAs per tumor was 6.8 (gain 5.3, loss 1.5), and the number of changes was significantly higher in tumors with advanced stage, TP53 mutation, and without RER than in those with early stage (7.7 vs. 3.0), no TP53 mutations (12.4 vs. 4.8) or RER phenotype (8.2 vs. 2.6). Frequent abnormalities included gains on chromosomal arms 8q (43%), 6q (26%), 11q (26%), 13q (24%), 7p (23%), 17q (23%), and 20q (23%), and losses on chromosomal arms 16q (26%), 19p (23%), 5q (19%), 3p (15%), 4q(15%), and 1p (15%). Advanced GC demonstrated a higher prevalence of gains of 8q (51% vs. 10%, P < 0.05) and loss of 16q (33% vs. 0%, P < 0.05) than early GC. Gains on 8q (64% vs. 20%, P < 0.05), 17q (39% vs. 4%, P < 0.05) and losses on 3p (25% vs. 4%, P = 0.05) and 5q (32% vs. 4%, P < 0.05) were higher in intestinal GC than in diffuse GC. On the other hand, gains on 13q were more common in the diffuse type (40% vs. 11%, P < 0.05). As compared with noncardia cancer, cardia cancer showed more gains on 7p (58% vs. 12%, P < 0.05) and 20q (58% vs. 12%, P < 0.05) and more losses on 4q (50% vs. 5%, P < 0.05). The finding of histology-related aberrations and the combination of CGH and molecular data thus provide additional evidence suggesting genetic heterogeneity of GC.
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Comparative Study |
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Daquinag AC, Tseng C, Salameh A, Zhang Y, Amaya-Manzanares F, Dadbin A, Florez F, Xu Y, Tong Q, Kolonin MG. Depletion of white adipocyte progenitors induces beige adipocyte differentiation and suppresses obesity development. Cell Death Differ 2014; 22:351-63. [PMID: 25342467 PMCID: PMC4291494 DOI: 10.1038/cdd.2014.148] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 07/29/2014] [Accepted: 08/06/2014] [Indexed: 12/21/2022] Open
Abstract
Overgrowth of white adipose tissue (WAT) in obesity occurs as a result of adipocyte hypertrophy and hyperplasia. Expansion and renewal of adipocytes relies on proliferation and differentiation of white adipocyte progenitors (WAP); however, the requirement of WAP for obesity development has not been proven. Here, we investigate whether depletion of WAP can be used to prevent WAT expansion. We test this approach by using a hunter-killer peptide designed to induce apoptosis selectively in WAP. We show that targeted WAP cytoablation results in a long-term WAT growth suppression despite increased caloric intake in a mouse diet-induced obesity model. Our data indicate that WAP depletion results in a compensatory population of adipose tissue with beige adipocytes. Consistent with reported thermogenic capacity of beige adipose tissue, WAP-depleted mice display increased energy expenditure. We conclude that targeting of white adipocyte progenitors could be developed as a strategy to sustained modulation of WAT metabolic activity.
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Chen ZY, Shie J, Tseng C. Up-regulation of gut-enriched krüppel-like factor by interferon-gamma in human colon carcinoma cells. FEBS Lett 2000; 477:67-72. [PMID: 10899312 DOI: 10.1016/s0014-5793(00)01764-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Interferon-gamma (IFN-gamma) induces growth arrest and apoptosis of tumor cells but the mechanisms for these functions are unknown. Recently, gut-enriched krüppel-like factor (GKLF) was found to possess similar biological properties. Treatment of HT-29 cells with IFN-gamma inhibited cell proliferation and induced apoptosis, the effect was found to associate with GKLF expression. IFN-gamma stimulates GKLF mRNA and protein levels in a dose- and time-dependent manner and this process is independent of p53, occurs rapidly and does not require de novo protein synthesis indicating that GKLF is an immediate-early IFN-gamma-responsive gene. Moreover, overexpression of GKLF results in similar effect as IFN-gamma suggesting that GKLF may function as a downstream target of IFN-gamma.
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Chen WT, Tseng CC, Pfaffenbach K, Kanel G, Luo B, Stiles BL, Lee AS. Liver-specific knockout of GRP94 in mice disrupts cell adhesion, activates liver progenitor cells, and accelerates liver tumorigenesis. Hepatology 2014; 59:947-57. [PMID: 24027047 PMCID: PMC4214272 DOI: 10.1002/hep.26711] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 08/23/2013] [Indexed: 12/29/2022]
Abstract
UNLABELLED Liver cancer is one of the most common solid tumors, with poor prognosis and high mortality. Mutation or deletion of the tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is strongly correlated with human liver cancer. Glucose-regulated protein 94 (GRP94) is a major endoplasmic reticulum (ER) chaperone protein, but its in vivo function is still emerging. To study the role of GRP94 in maintaining liver homeostasis and tumor development, we created two liver-specific knockout mouse models with the deletion of Grp94 alone, or in combination with Pten, using the albumin-cre system. We demonstrated that while deletion of GRP94 in the liver led to hyperproliferation of liver progenitor cells, deletion of both GRP94 and PTEN accelerated development of liver tumors, including both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC), suggestive of progenitor cell origin. Furthermore, at the premalignant stage we observed disturbance of cell adhesion proteins and minor liver injury. When GRP94 was deleted in PTEN-null livers, ERK was selectively activated. CONCLUSION GRP94 is a novel regulator of cell adhesion, liver homeostasis, and tumorigenesis.
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Tseng CC, Jarboe LA, Landau SB, Williams EK, Wolfe MM. Glucose-dependent insulinotropic peptide: structure of the precursor and tissue-specific expression in rat. Proc Natl Acad Sci U S A 1993; 90:1992-6. [PMID: 8446620 PMCID: PMC46006 DOI: 10.1073/pnas.90.5.1992] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Glucose-dependent insulinotropic peptide (GIP) is a 42-amino acid gastrointestinal regulatory peptide that stimulates insulin secretion from pancreatic beta cells in the presence of glucose. Approximately 7.8 x 10(5) recombinant clones of a neonatal rat intestinal cDNA library were screened by using plaque hybridization, and three clones were identified and sequenced with the dideoxynucleotide chain-termination method. The translated amino acid sequence deduced from the nucleotide sequence of the cDNA indicated that rat GIP was derived by proteolytic processing of a 144-amino acid precursor polypeptide. The mature peptide is flanked by a 43-amino acid NH2-terminal peptide that contains a 21-amino acid signal peptide and by a 59-amino acid COOH-terminal peptide. Analysis of the nucleotide and amino acid sequence of rat GIP revealed only two substitutions from the known human GIP peptide. The use of high-stringency RNA blot-hybridization analysis of total RNA extracted from various organs demonstrated expression of the GIP gene in the duodenum and jejunum and, to a lesser extent, in the ileum. In addition, expression of the GIP gene was observed in the submandibular salivary gland both by RNA analysis and RIA. In response to duodenal perfusion of a 20% Lipomul meal for 60 min, duodenal mucosal GIP mRNA concentrations increased by 42.8% and 48.2% at 30 and 60 min, respectively.
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Fanchiang YT, Chen KHM, Tseng CC, Chen CC, Cheng CK, Yang SR, Wu CN, Lee SF, Hong M, Kwo J. Strongly exchange-coupled and surface-state-modulated magnetization dynamics in Bi 2Se 3/yttrium iron garnet heterostructures. Nat Commun 2018; 9:223. [PMID: 29335558 PMCID: PMC5768741 DOI: 10.1038/s41467-017-02743-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 12/20/2017] [Indexed: 12/03/2022] Open
Abstract
Harnessing the spin–momentum locking of topological surface states in conjunction with magnetic materials is the first step to realize novel topological insulator-based devices. Here, we report strong interfacial coupling in Bi2Se3/yttrium iron garnet (YIG) bilayers manifested as large interfacial in-plane magnetic anisotropy (IMA) and enhancement of damping probed by ferromagnetic resonance. The interfacial IMA and damping enhancement reaches a maximum when the Bi2Se3 film approaches its two-dimensional limit, indicating that topological surface states play an important role in the magnetization dynamics of YIG. Temperature-dependent ferromagnetic resonance of Bi2Se3/YIG reveals signatures of the magnetic proximity effect of TC as high as 180 K, an emerging low-temperature perpendicular magnetic anisotropy competing the high-temperature IMA, and an increasing exchange effective field of YIG steadily increasing toward low temperature. Our study sheds light on the effects of topological insulators on magnetization dynamics, essential for the development of topological insulator-based spintronic devices. Understanding the effects of topological insulators on magnetization dynamics of adjacent magnetic materials is essential for novel spintronic devices. Here, Fanchiang et al. report thickness dependence of interfacial in-plane magnetic anisotropy and damping enhancement in Bi2Se3/yttrium iron garnet (YIG) bilayers, indicating an important role of topological surface states in the magnetization dynamics of YIG.
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Research Support, Non-U.S. Gov't |
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