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Sircar M, Koutcher L, Wolden S, Chou J, Zhang Z, Sherman E, Wong R, Kraus D, Pfister D, Lee N. Predicting Outcomes after Salvage Reirradiation of Recurrent Head and Neck Cancer. Int J Radiat Oncol Biol Phys 2010. [DOI: 10.1016/j.ijrobp.2010.07.1037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Chou J, Voong LN, Chen X, Yee C, Warren EH. Abstract 4778: Epigenetic modulation of colorectal cancer cells for cancer-testis antigen-targeted immunotherapy. Cancer Res 2010. [DOI: 10.1158/1538-7445.am10-4778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Cancer-testis (C-T) antigens represent attractive potential targets for cancer immunotherapy due to their limited expression in normal somatic tissues and their widespread expression in malignant cells of diverse histologies. The utility of C-T antigens for immunotherapy of colorectal cancer (CRC), however, is limited because expression of C-T genes is repressed in most CRC cells by hypermethylation. We investigated whether treatment of CRC lines with the hypomethylating agent 5-aza-2′-deoxycytidine (DAC) could induce C-T gene expression in CRC cells and thereby sensitize them to recognition by CD8+ cytotoxic T lymphocytes (CTL) specific for the highly immunogenic C-T antigen NY-ESO-1.
A panel of CRC and primary dermal fibroblast lines was cultured with DAC or medium alone for 48 hours followed by culture with exposure to interferon γ (IFNγ) or medium alone for an additional 48 hours. After the treatment period, cells were harvested for collection of RNA, DNA, and protein; studied with flow cytometry for analysis of MHC class I and II expression; and tested for recognition by HLA-A*0201-restricted CTL specific for NY-ESO-1157–165 in a 51Cr release-cytotoxicity assay.
Quantitative RT-PCR analysis of the expression of 20 C-T genes in untreated and DAC-treated cells using a custom PCR array showed that the majority of C-T genes were expressed at low levels in untreated CRC cells but were induced in most CRC cell lines by DAC exposure. Fibroblasts did not show any significant C-T gene expression with or without DAC treatment. Western blot analysis for NY-ESO-1 expression confirmed that DAC induction of NY-ESO-1 transcription was also associated with increased protein expression. DAC-treated HLA-A*0201+ CRC lines were also recognized by CD8+ HLA-A*0201-restricted NY-ESO-1-specific CTL. CTL recognition was enhanced when the cells were treated with IFNγ in combination with DAC, with the most significant effect seen in CRC cells with low baseline expression of MHC class I molecules.
These data suggest that epigenetic modulation with DAC or related agents could be used to selectively induce expression of C-T antigens in CRC cells and thereby make them susceptible to C-T antigen-directed immunotherapy.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4778.
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Goldberg J, Chou J, Jakubowski A, Arcila M, Teruya-Feldstein J, Horwitz S, Barker J, Boulad F, Castro-Malaspina H, Hsu K, Jenq R, Kernan N, Koehne G, O'Reilly R, Prockop S, Scaradavou A, Small T, van den Brink M, Young J, Zhang Z, Papadopoulos E, Perales MA. The Memorial Sloan-Kettering Experience With Allogeneic Stem Cell Transplantation For T Cell Non-Hodgkins Lymphomas. Biol Blood Marrow Transplant 2010. [DOI: 10.1016/j.bbmt.2009.12.245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Dhillon RS, Choudhary A, Chou J. HS07�COMPARISON OF BETADINE PAINT AND PLASTIC BAG IMMERSION TECHNIQUES FOR SURGICAL SITE SKIN PREPARATION IN HAND SURGERY. ANZ J Surg 2009. [DOI: 10.1111/j.1445-2197.2009.04918_7.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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80
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Chou J, Shimmon R, Ben-Nissan B. Bisphosphonate determination using1H-NMR spectroscopy for biomedical applications. J Tissue Eng Regen Med 2009; 3:92-6. [DOI: 10.1002/term.142] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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81
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Tykodi SS, Fujii N, Vigneron N, Lu SM, Mito JK, Miranda MX, Chou J, Voong LN, Thompson JA, Sandmaier BM, Cresswell P, Van den Eynde B, Riddell SR, Warren EH. C19orf48 encodes a minor histocompatibility antigen recognized by CD8+ cytotoxic T cells from renal cell carcinoma patients. Clin Cancer Res 2008; 14:5260-9. [PMID: 18698046 DOI: 10.1158/1078-0432.ccr-08-0028] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Tumor regression has been observed in some patients with metastatic renal cell carcinoma (RCC) after nonmyeloablative allogeneic hematopoietic cell transplantation (HCT). Cellular and molecular characterization of antigens recognized by tumor-reactive T cells isolated from responding patients could potentially provide insight into the mechanisms of tumor regression. EXPERIMENTAL DESIGN CD8+ CTL clones that recognized a novel RCC-associated minor histocompatibility (H) antigen presented by HLA-A*0201 were isolated from two patients with metastatic RCC who experienced tumor regression or stable disease following nonmyeloablative allogeneic HCT. These clones were used to screen a cDNA library and isolate the unique cDNA encoding the antigen. RESULTS An alternative open reading frame in the C19orf48 gene located on chromosome 19q13 encodes the HLA-A*0201-restricted minor H antigen recognized by the RCC-reactive T cells. The differential T-cell recognition of donor- and recipient-derived target cells is attributable to a nonsynonymous single-nucleotide polymorphism within the nucleotide interval that encodes the antigenic peptide. Assays for gene expression and CTL recognition showed that the C19orf48-encoded peptide is widely expressed in renal tumors and solid tumors of other histologies. The antigenic peptide can be processed for CTL recognition via both TAP-dependent and TAP-independent pathways. CONCLUSIONS Donor T-cell responses against the HLA-A*0201-restricted minor H antigen encoded by C19orf48 may contribute to RCC regression after MHC-matched allogeneic HCT.
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MESH Headings
- Antigens, Neoplasm/genetics
- Antigens, Neoplasm/immunology
- Base Sequence
- CD8-Positive T-Lymphocytes/immunology
- Carcinoma, Renal Cell/genetics
- Carcinoma, Renal Cell/immunology
- Carcinoma, Renal Cell/therapy
- Cell Line, Tumor
- Chromosomes, Human, Pair 19/genetics
- Epitopes, T-Lymphocyte/genetics
- Epitopes, T-Lymphocyte/immunology
- Gene Library
- HLA-A Antigens/immunology
- HLA-A2 Antigen
- Hematopoietic Stem Cell Transplantation
- Humans
- Kidney Neoplasms/genetics
- Kidney Neoplasms/immunology
- Kidney Neoplasms/therapy
- Minor Histocompatibility Antigens/genetics
- Minor Histocompatibility Antigens/immunology
- Molecular Sequence Data
- Polymorphism, Single Nucleotide
- Reverse Transcriptase Polymerase Chain Reaction
- Transfection
- Transplantation, Homologous
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Minoshima M, Chou J, Lefebvre S, Bando T, Shinohara KI, Gottesfeld JM, Sugiyama H. Targeting specific gene by alkylating pyrrole-imidazole polyamides. ACTA ACUST UNITED AC 2008:363-4. [DOI: 10.1093/nass/nrn183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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83
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Jamshidi A, Pauzauskie PJ, Schuck PJ, Ohta AT, Chiou PY, Chou J, Yang P, Wu MC. Dynamic manipulation and separation of individual semiconducting and metallic nanowires. NATURE PHOTONICS 2008; 2:86-89. [PMID: 19789729 PMCID: PMC2752982 DOI: 10.1038/nphoton.2007.277] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The synthesis of nanowires has advanced in the last decade to a point where a vast range of insulating, semiconducting, and metallic materials1 are available for use in integrated, heterogeneous optoelectronic devices at nanometer scales 2. However, a persistent challenge has been the development of a general strategy for the manipulation of individual nanowires with arbitrary composition. Here we report that individual semiconducting and metallic nanowires with diameters below 20 nm, are addressable with forces generated by optoelectronic tweezers (OET) 3. Using 100,000x less optical power density than optical tweezers, OET is capable of transporting individual nanowires with speeds 4x larger than maximum speeds achieved by optical tweezers. A real-time array of silver nanowires is formed using photopatterned virtual-electrodes, demonstrating the potential for massively parallel assemblies. Furthermore, OET enables the separation of semiconducting and metallic nanowires, suggesting a broad range of applications for the separation and heterogenous integration of one-dimensional nanoscale materials.
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84
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Chiang YH, Chen GJ, Shen H, Chou J, Wang Y. Histogranin reduced brain injury after transient focal ischemia in rats. Neurosci Lett 2006; 406:211-5. [PMID: 16904827 DOI: 10.1016/j.neulet.2006.07.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2006] [Revised: 07/13/2006] [Accepted: 07/19/2006] [Indexed: 11/26/2022]
Abstract
Excitatory amino acids (EAAs) play an important role during ischemic brain injury. In this study we examined the protective effect of histogranin (HN), an endogenous peptide that antagonizes excitatory amino acids-mediated activity noncompetitively, in an animal model of cerebral ischemia. Adult rats were anesthetized with chloral hydrate. Histogranin was given intracerebroventricularly before a 60-min middle cerebral artery occlusion (MCAo). Animals were examined for their locomotor activity 2 days after MCAo. Histogranin significantly increased locomotor activity in the stroke rats. Histogranin pretreatment reduced the volume of cerebral infarction and the caspase-3 immunoreactivity in the stroke animals. Taken together, our data suggest that histogranin is protective against ischemic brain injury. The protective effect may involve anti-apoptotic mechanisms.
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85
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Thung E, Chou J, You L, Xu Z, Jablons D. Hypermethylation Silences Wnt Inhibitory Factor 1 in Nasopharyngeal Carcinoma. J Investig Med 2006. [DOI: 10.1177/108155890605401s28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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86
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Thung EG, Chou J, You L, Xu Z, Jablons DM. 144 HYPERMETHYLATION SILENCES WNT INHIBITORY FACTOR 1 IN NASOPHARYNGEAL CARCINOMA. J Investig Med 2006. [DOI: 10.2310/6650.2005.x0004.143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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87
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Harvey BK, Mark A, Chou J, Chen GJ, Hoffer BJ, Wang Y. Neurotrophic effects of bone morphogenetic protein-7 in a rat model of Parkinson's disease. Brain Res 2004; 1022:88-95. [PMID: 15353217 DOI: 10.1016/j.brainres.2004.06.072] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2004] [Indexed: 02/06/2023]
Abstract
Previous studies have demonstrated that pretreatment with bone morphogenetic protein-7 (BMP7) reduces ischemic neuronal injury in vivo. Moreover, exogenous application of BMP7 increases both the number of tyrosine hydroxylase (+) cells and dopamine (DA) uptake in rat mesencephalic cell cultures. The purpose of this study was to investigate the in vivo effects of BMP7 on 6-hydroxydopamine (6-OHDA) induced lesioning of midbrain DA neurons. Adult Fischer 344 rats were anesthetized and injected with BMP7 or vehicle into the left substantia nigra, followed by local administration of 9 microg of 6-OHDA into the left medial forebrain bundle. The lesioned animals that received BMP7 pretreatment, as compared to vehicle/6-OHDA controls, had a significant reduction in methamphetamine-induced rotation 1 month after the surgery. BMP7-pretreatment partially preserved KCl-induced dopamine release in the lesioned striatum and significantly increased TH immunoreactivity in the lesioned nigra and striatum. In summary, our data suggest that BMP7 has neuroprotective and/or neuroreparative effects against 6-OHDA lesioning of the nigrostriatal DA pathway in an animal model of Parkinson's disease (PD).
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88
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Feldman K, Chou J, Macnab A. 500 DECISION-MAKING IN THE EMERGENCY DEPARTMENT—WHO DO FAMILIES WANT TO HAVE INVOLVED? J Investig Med 2004. [DOI: 10.1136/jim-52-suppl1-500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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89
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Chou J, Anders MT, Baker RS. 260 SENSITIVITY AND SPECIFICITY OF AMERICAN ACADEMY OF OPHTHALMOLOGY'S GLAUCOMA RISK FACTOR ANALYSIS. J Investig Med 2004. [DOI: 10.1136/jim-52-suppl1-260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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90
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Chou J, Burke NA, Iwabu A, Watkins SC, Wells A. Directional motility induced by epidermal growth factor requires Cdc42. Exp Cell Res 2003; 287:47-56. [PMID: 12799181 DOI: 10.1016/s0014-4827(03)00119-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cell motility is actuated by a host of intracellular signaling cascades that result in movement of the cell in one direction, even without an external gradient. Phospholipase C-gamma (PLCgamma) has been shown to be important for growth factor-induced lamellipodial protrusion at the front of the cell while Cdc42 has been implicated in both filopodium formation at the leading edge and control of polarity of migrating cells. We asked whether these asymmetries in effector molecules may be linked. When we overexpressed either constitutively active, dominant negative, or GFP-tagged Cdc42, wild-type NR6 fibroblasts lost directionality, as expected. On epidermal growth factor (EGF) exposure these cells produced multiple, transient protrusions in every direction; these extensions failed to result in productive motility. GFP-tagged Cdc42 appeared transiently at edges of newly formed protrusions in EGF-stimulated cells while they moved haphazardly. While PLCgamma is distributed throughout the cell, the ratio of active, tyrosyl-phosphorylated PLCgamma was increased at the leading edge, where phosphatidylinositol (4,5)-bisphosphate (PIP(2)) hydrolysis is concentrated. This co-localization of activities may be due to Cdc42 directing PLCgamma to the cell front, as PLCgamma associated with Cdc42 in an EGF-dependent manner. We conclude that Cdc42 controls cell polarity, likely in part, through its binding to active PLCgamma.
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91
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Chang CF, Morales M, Chou J, Chen HL, Hoffer B, Wang Y. Bone morphogenetic proteins are involved in fetal kidney tissue transplantation-induced neuroprotection in stroke rats. Neuropharmacology 2002; 43:418-26. [PMID: 12243771 DOI: 10.1016/s0028-3908(02)00092-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Both bone morphogenetic proteins (BMPs) and glial cell line-derived neurotrophic factor (GDNF) reduce ischemia-induced cerebral injury in rats. Intracerebral transplantation of fetal kidney tissue, which normally expresses BMPs and GDNF during development, reduces ischemic injury in cerebral cortex. In this study, we tested the hypothesis that BMP is involved in this neuroprotective response. Fetal kidney tissue was cut into small pieces and transplanted into cortical areas adjacent to the right middle cerebral artery (MCA) in adult rats. In situ hybridization of brain indicated that these fetal kidney transplants contained high levels of BMP-7 mRNA three days after grafting. Immunohistochemical analysis of grafted brain showed co-localization of BMP-7 and PAX-2 immunoreactivity in the graft, suggesting that these transplants contained BMP protein. Some animals were grafted with fetal kidney tissue after intraventricular administration (ICV) of the BMP antagonist noggin (1 micro g) or after vehicle, followed by MCA ligation for 60 min. Animals receiving fetal kidney tissue transplantation developed significantly less body asymmetry, as compared to stroke animals that either did not receive transplantation or received fetal kidney grafts and noggin pretreatment. Analysis of these brains after triphenyltetrazolium chloride staining showed that fetal kidney tissue transplantation reduced the volume of infarction in the cerebral cortex. Noggin pretreatment reduced the protection induced by fetal kidney grafting, although noggin itself did not cause increase in cerebral infarction. Eight hours after ischemia, brain homogenates were obtained from grafted and control animals to assay caspase-3 enzymatic activity. This analysis demonstrated that fetal kidney grafts significantly reduced ischemia-induced caspase-3 activity. Reduction of caspase-3 activity could also be antagonized by noggin pretreatment. In conclusion, our data suggest that fetal kidney transplantation reduces ischemia/reperfusion-induced cortical infarction and behavioral deficits in adult rats, which are, at least partially, mediated through the effect of BMPs from the transplants.
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92
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Chou J, Stolz DB, Burke NA, Watkins SC, Wells A. Distribution of gelsolin and phosphoinositol 4,5-bisphosphate in lamellipodia during EGF-induced motility. Int J Biochem Cell Biol 2002; 34:776-90. [PMID: 11950594 DOI: 10.1016/s1357-2725(01)00177-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
During induced cell motility the actin cytoskeleton at the leading edge must undergo constant reorganization. Recently, phosphoinositides have been shown to be central to cytoskeleton-membrane linkages and actin organization and turnover. Epidermal growth factor (EGF) receptor (EGFR)-mediated cell motility requires phospholipase C-gamma (PLCgamma), hydrolysis of phosphoinsotide 4,5-bisphosphate (PIP(2)) and subsequent release of gelsolin. We hypothesized this led to the mobilization of PIP(2)-binding proteins which modify the actin cytoskeleton and thus sought to determine whether the leading edge was a site of active PIP(2) hydrolysis and gelsolin redistribution to cytoskeleton. Herein, we report that during EGF-induced motility, the leading edge's submembranous region constitutes a distinct subcellular locale. The relevant phosphoinositide composition of this space was determined by probing with an antibody to PIP(2) and a green fluorescence protein (GFP)-tagged pleckstrin homology (PH) domain of PLCdelta (GFP-PH) that recognizes both PIP(2) and inositol 1,4,5-trisphosphate (IP(3)). PIP(2) was absent from leading lamellipodia despite an increase in IP(3) generation, suggesting an increase in PIP(2) hydrolysis at the leading edge. Visualized with immunofluorescence, gelsolin preferentially concentrated near the leading edge in a punctate fashion. Examining the Triton X-insoluble actin cytoskeleton fractions, we observe a PLCgamma-dependent increase of gelsolin incorporation upon EGF stimulation. At a molecular level, field emission scanning electron microscopy (FE-SEM) shows that gelsolin incorporates preferentially into the submembranous actin arcs at the leading edge of the lamellipodia. Together these data suggest a model of PIP(2) hydrolysis at the leading edge causing a localized release of PIP(2)-binding proteins-particularly gelsolin-that drives cytoskeletal rearrangement and protrusion.
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93
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Shiraha H, Glading A, Chou J, Jia Z, Wells A. Activation of m-calpain (calpain II) by epidermal growth factor is limited by protein kinase A phosphorylation of m-calpain. Mol Cell Biol 2002; 22:2716-27. [PMID: 11909964 PMCID: PMC133710 DOI: 10.1128/mcb.22.8.2716-2727.2002] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2001] [Revised: 08/20/2001] [Accepted: 01/04/2002] [Indexed: 01/30/2023] Open
Abstract
We have shown previously that the ELR-negative CXC chemokines interferon-inducible protein 10, monokine induced by gamma interferon, and platelet factor 4 inhibit epidermal growth factor (EGF)-induced m-calpain activation and thereby EGF-induced fibroblast cell motility (H. Shiraha, A. Glading, K. Gupta, and A. Wells, J. Cell Biol. 146:243-253, 1999). However, how this cross attenuation could be accomplished remained unknown since the molecular basis of physiological m-calpain regulation is unknown. As the initial operative attenuation signal from the CXCR3 receptor was cyclic AMP (cAMP), we verified that this second messenger blocked EGF-induced motility of fibroblasts (55% +/- 4.5% inhibition) by preventing rear release during active locomotion. EGF-induced calpain activation was inhibited by cAMP activation of protein kinase A (PKA), as the PKA inhibitors H-89 and Rp-8Br-cAMPS abrogated cAMP inhibition of both motility and calpain activation. We hypothesized that PKA might negatively modulate m-calpain in an unexpected manner by directly phosphorylating m-calpain. A mutant human large subunit of m-calpain was genetically engineered to negate a putative PKA consensus sequence in the regulatory domain III (ST369/370AA) and was expressed in NR6WT mouse fibroblasts to represent about 30% of total m-calpain in these cells. This construct was not phosphorylated by PKA in vitro while a wild-type construct was, providing proof of the principle that m-calpain can be directly phosphorylated by PKA at this site. cAMP suppressed EGF-induced calpain activity of cells overexpressing a control wild-type human m-calpain (83% +/- 3.7% inhibition) but only marginally suppressed that of cells expressing the PKA-resistant mutant human m-calpain (25% +/- 5.5% inhibition). The EGF-induced motility of the cells expressing the PKA-resistant mutant also was not inhibited by cAMP. Structural modeling revealed that new constraints resulting from phosphorylation at serine 369 would restrict domain movement and help "freeze" m-calpain in an inactive state. These data point to a novel mechanism of negative control of calpain activation, direct phosphorylation by PKA.
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94
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Flanagan LA, Chou J, Falet H, Neujahr R, Hartwig JH, Stossel TP. Filamin A, the Arp2/3 complex, and the morphology and function of cortical actin filaments in human melanoma cells. J Cell Biol 2001; 155:511-7. [PMID: 11706047 PMCID: PMC2198874 DOI: 10.1083/jcb.200105148] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The Arp2/3 complex and filamin A (FLNa) branch actin filaments. To define the role of these actin-binding proteins in cellular actin architecture, we compared the morphology of FLNa-deficient human melanoma (M2) cells and three stable derivatives of these cells expressing normal FLNa concentrations. All the cell lines contain similar amounts of the Arp2/3 complex. Serum addition causes serum-starved M2 cells to extend flat protrusions transiently; thereafter, the protrusions turn into spherical blebs and the cells do not crawl. The short-lived lamellae of M2 cells contain a dense mat of long actin filaments in contrast to a more three-dimensional orthogonal network of shorter actin filaments in lamellae of identically treated FLNa-expressing cells capable of translational locomotion. FLNa-specific antibodies localize throughout the leading lamellae of these cells at junctions between orthogonally intersecting actin filaments. Arp2/3 complex-specific antibodies stain diffusely and label a few, although not the same, actin filament overlap sites as FLNa antibody. We conclude that FLNa is essential in cells that express it for stabilizing orthogonal actin networks suitable for locomotion. Contrary to some proposals, Arp2/3 complex-mediated branching of actin alone is insufficient for establishing an orthogonal actin organization or maintaining mechanical stability at the leading edge.
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Ryan JA, Zhang P, Hesterberg D, Chou J, Sayers DE. Formation of chloropyromorphite in a lead-contaminated soil amended with hydroxyapatite. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2001; 35:3798-3803. [PMID: 11783662 DOI: 10.1021/es010634l] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Conversion of soil Pb to pyromorphite [Pb5(PO4)3Cl] was evaluated by reacting a Pb contaminated soil collected adjacent to a historical smelter with hydroxyapatite [Ca5(PO4)3OH]. In a dialysis experiment where the soil and hydroxyapatite solids were placed in separate dialysis bags suspended in 0.01 M NaNO3 solution a crystalline precipitate, identified as chloropyromorphite, formed on the dialysis membrane containing the soil. The aqueous composition of the solution indicated that dissolution of solid-phase soil Pb was the rate-limiting step for pyromorphite formation. Addition of hydroxyapatite to the soil caused a decrease in each of the first four fractions of sequential extractable Pb and a 35% increase in the recalcitrant extraction residue. After a 240-d incubation at field-moisture content there was a further increase in the recalcitrant extraction residue fraction of the hydroxyapatite-amended soil to 45% of the total soil Pb. The increase in the extraction residue fraction in the hydroxyapatite amended 0-d incubated soil as compared to the control soil illustrates that the chemical extraction procedure itself caused changes in extractability. Thus, the chemical extraction procedure cannot easily be utilized to confirm changes occurring in amended soils. The further increase after the 240-d incubation implies that the reaction also occurs in the soil during incubation. Extended X-ray absorption fine structure (EXAFS) spectroscopy indicated that after the 240-d incubation the hydroxyapatite treatment caused a change in the average, local molecular bonding environment of soil Pb. Low-temperature EXAFS spectra (chi data and radial structure functions--RSFs) showed a high degree of similarity between the chemical extraction residue and synthetic pyromorphite, providing additional evidence that the change of soil Pb to pyromorphite is possible by simple amendments of hydroxyapatite to soil.
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Deng X, Wang Y, Chou J, Cadet JL. Methamphetamine causes widespread apoptosis in the mouse brain: evidence from using an improved TUNEL histochemical method. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2001; 93:64-9. [PMID: 11532339 DOI: 10.1016/s0169-328x(01)00184-x] [Citation(s) in RCA: 174] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Terminal deoxynucleotidyl transferase (TdT)-mediated dNTP nick end labeling (TUNEL) histochemistry is a sensitive method to expose DNA strand breaks in apoptotic cells, but it is difficult to conduct on slide-mounted sections. By using a 80 degrees C/0.5% Triton X-100 pretreatment, we have developed a TUNEL histochemical approach with high specificity and sensitivity using sections from ischemic rat brains. Thereafter, methamphetamine (METH)-induced neuronal death was investigated in mice brains. The results showed that a single injection of 40 mg/kg METH caused neuronal death in several brain areas including the striatum, cortex (frontal, parietal, and piriform), indusium griseum, medial habenular nucleus, and hippocampus. These results further confirmed the presence of METH-induced deleterious effects in nondopaminergic neurons. The significance of these findings is also discussed.
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97
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Wang Y, Chang CF, Morales M, Chou J, Chen HL, Chiang YH, Lin SZ, Cadet JL, Deng X, Wang JY, Chen SY, Kaplan PL, Hoffer BJ. Bone morphogenetic protein-6 reduces ischemia-induced brain damage in rats. Stroke 2001; 32:2170-8. [PMID: 11546913 DOI: 10.1161/hs0901.095650] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Bone morphogenetic protein-6 (BMP6) and its receptors are expressed in adult and fetal brain. Receptors for BMP6 are upregulated in adult brain after injury, leading to the suggestion that BMP6 is involved in the physiological response to neuronal injury. The purpose of this study was to determine whether there was a neuroprotective effect of BMP6 in vivo and in vitro. METHODS Lactate dehydrogenase and microtubule-associated protein-2 (MAP-2) activities were used to determine the protective effect of BMP6 against H(2)O(2) in primary cortical cultures. The neuroprotective effects of BMP6 were also studied in chloral hydrate-anesthetized rats. BMP6 or vehicle was injected into right cerebral cortex before transient right middle cerebral artery (MCA) ligation. Animals were killed for triphenyl-tetrazolium chloride staining, caspase-3 immunoreactivity and enzymatic assays, and TUNEL assay. A subgroup of animals were used for locomotor behavioral assays. RESULTS Application of H(2)O(2) increased lactate dehydrogenase activity and decreased the density of MAP-2(+) neurons in culture. Both responses were attenuated by BMP6 pretreatment. Complementary in vivo studies showed that pretreatment with BMP6 increased motor performance and generated less cerebral infarction induced by MCA ligation/reperfusion in rats. Pretreatment with BMP6 did not alter cerebral blood flow or physiological parameters. There was decreased ischemia-induced caspase-3 immunoreactivity, caspase-3 enzymatic activity, and density of TUNEL-positive cells in ischemic cortex in BMP6-treated animals. CONCLUSIONS BMP6 reduces ischemia/reperfusion injury, perhaps by attenuating molecular events underlying apoptosis.
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Okuda Y, Peña J, Chou J, Field JB. Acute effects of growth hormone on metabolism of pancreatic hormones, glucose and ketone bodies. Diabetes Res Clin Pract 2001; 53:1-8. [PMID: 11378207 DOI: 10.1016/s0168-8227(01)00232-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Controversy exists as to whether acute administration of growth hormone has insulin-like effects. In conscious dogs, acute effects on plasma flows, plasma glucose, hepatic glucose output, free fatty acids, ketone bodies, insulin, and glucagon were determined following intravenous injection of 1 mg of growth hormone extracted from the canine pituitary gland. The following results were obtained: (1) Plasma flows in the portal vein, hepatic artery and hepatic vein were significantly increased 20 min after growth hormone administration. (2) By 40 min after growth hormone, the glucose concentration in these three vessels was significantly increased. (3) Hepatic glucose output was significantly increased 60 min after growth hormone administration. (4) Free fatty acids levels were significantly but transiently increased at 20 min, while ketone body concentrations were elevated at 120-180 min. (5) The insulin levels in the three vessels demonstrated a biphasic response. In the portal vein, they were significantly higher 20 min after growth hormone and again at 150-180 min. Glucagon concentrations were increased in all three vessels by 20 min and remained elevated for the remainder of the experiment. These results do not support an acute insulin-like action of growth hormone in normal dogs.
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Leone-Bay A, Sato M, Paton D, Hunt AH, Sarubbi D, Carozza M, Chou J, McDonough J, Baughman RA. Oral delivery of biologically active parathyroid hormone. Pharm Res 2001; 18:964-70. [PMID: 11496956 DOI: 10.1023/a:1010936227570] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE Parathyroid hormone (PTH), the only drug known to stimulate bone formation. is a peptide therapeutic indicated in the treatment of osteoporosis. Unfortunately, PTH is only effective when dosed by injection because it has no oral bioavailability. Herein we report the oral absorption of PTH in rats and monkeys facilitated by the novel delivery agent, N-[8-(2-hydroxy-4-methoxy)bensoyl]amino caprylic acid (4-MOAC). METHODS 4-MOAC was selected from a group of 100 delivery agents based on in vitro chromotography studies and in vivo screening studies in rats. The PTH/4-MOAC combination was then tested in monkeys. The interaction of 4-MOAC and PTH was evaluated by nuclear magnetic resonance (NMR) spectroscopy. RESULTS Monkeys were administered an aqueous solution containing 4-MOAC and PTH and mean peak serum PTH concentrations of about 3000 pg/mL were obtained. The relative bioavailability of oral PTH was 2.1% relative to subcutaneous administration. The biological activity of the orally-delivered PTH was further evaluated in a rat model of osteoporosis. These studies showed that the bone formed following oral PTH/4-MOAC administration was comparable to that formed following PTH injections. The 4-MOAC mediated absorption of PTH is hypothesized to be the result of a noncovalent interaction between 4-MOAC and PTH. The preliminary evaluation of this interaction by NMR is described. CONCLUSIONS 4-MOAC facilitates the absorption of PTH following oral administration to both rats and monkeys. The orally-absorbed PTH is biologically active as demonstrated in a rat model of osteoporosis.
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Garlapati S, Chou J, Wang CC. Specific secondary structures in the capsid-coding region of giardiavirus transcript are required for its translation in Giardia lamblia. J Mol Biol 2001; 308:623-38. [PMID: 11350165 DOI: 10.1006/jmbi.2001.4568] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Enhanced translation of giardiavirus (GLV)-luciferase chimeric mRNA in Giardia lamblia requires the presence of the initial 264 nucleotides of the viral capsid-coding region. A 13 nt downstream box (DB) sequence within this region, complementary to a 15 nt sequence near the 3' end of G. lamblia 16 S-like ribosomal RNA (rRNA), was found to be essential for the enhanced translation. However, DB is located 64-78 nt downstream of the initiation codon, whereas an exponential increase of translation efficiency depends on a further increment of the coding region from nucleotides 111 to 264. Thus, there could be additional structural requirements for translation enhancement in the region downstream from DB. Four major stem-loop structures, designated I to IV, were identified in the MFOLD-predicted secondary structure of the 264 nt capsid-coding region with an estimated minimum free energy (DeltaG degrees ) of -77.16 kcal x mol(-1). Our chemical probing analysis of the free 264 nt RNA molecule in solution supports the predicted presence of stem-loops I, II and III, but casts doubts on stem-loop IV. It suggests, instead, the presence of a stem-loop IVA at a nearby location in the molecule. Site-directed mutagenesis designed to disrupt stem-loop structures I, II, III or IVA resulted in drastic reduction of translation efficiency, which was restored by compensatory sequence changes to regenerate individual stem-loop structures. Mutations disrupting the originally designated stem-loop IV did not exert any detectable effect on translation. However, alterations of the sequence UCUCC between nucleotides 216 and 220 in the flexible loop region of the revised secondary structure led to a precipitous drop in translation. Another stem-loop predicted by MFOLD that consists of a major portion of the DB sequence was examined by chemical probing but found little experimental support. Changes of the DB sequence without affecting the postulated stem structure led to drastic losses of translation efficiency. Thus, a simple structural basis for the enhanced translation could be that stem-loops I, II, III and IVA and the UCUCC sequence may facilitate the interaction between DB and the anti-DB in 16 S-like rRNA in initiating translation of GLV mRNA in G. lamblia.
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