120 research outputs found

    Can human xylosyltransferase-1 serve as a biomarker and therapeutic target for corneal fibrosis?

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    Tested was the hypothesis that XYLT1 plays an important role in corneal wound healing and scarring and may allow development of newer strategies for curing corneal fibrosis. The specific aims were: 1) to characterize XYLT1 expression in normal and wounded human and rabbit corneas, 2) investigate its role in corneal wound healing, and 2) determine whether XYLT1 can serve as a biomarker for corneal fibrosis

    Efficacy and Safety Comparison Between Suberoylanilide Hydroxamic Acid and Mitomycin C in Reducing the Risk of Corneal Haze After PRK Treatment In Vivo

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    PURPOSE: This study compared the efficacy and safety of suberoylanilide hydroxamic acid (SAHA) and mitomycin C (MMC) up to 4 months in the prevention of corneal haze induced by photorefractive keratectomy (PRK) in rabbits in vivo. METHODS: Corneal haze in rabbits was produced with −9.00 diopter PRK. A single application of SAHA (25 μM) or MMC (0.02%) was applied topically immediately after PRK. Effects of the two drugs were analyzed by slit-lamp microscope, specular microscope, TUNEL assay, and immunofluorescence. RESULTS: Single topical adjunct use of SAHA (25 μM) or MMC (0.02%) after PRK attenuated more than 95% corneal haze and myofibroblast formation (P \u3c .001). SAHA did not reduce keratocyte density, cause keratocyte apoptosis, or increase immune cell infiltration compared to MMC (P \u3c .01 or .001). Furthermore, SAHA dosing did not compromise corneal endothelial phenotype, density, or function in rabbit eyes, whereas MMC application did (P \u3c .01 or .001). CONCLUSIONS: SAHA and MMC significantly decreased corneal haze after PRK in rabbits in vivo. SAHA exhibited significantly reduced short- and long-term damage to the corneal endothelium compared to MMC in rabbits. SAHA is an effective and potentially safer alternative to MMC for the prevention of corneal haze after PRK. Clinical trials are warranted

    Epigenetic Modification Prevents Excessive Wound Healing and Scar Formation After Glaucoma Filtration Surgery

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    PURPOSE. The purpose of this study was to determine the efficacy of suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor (HDACi), in prevention of excessive wound healing and scar formation in a rabbit model of glaucoma filtration surgery (GFS). METHODS. A rabbit model of GFS was used. Rabbits that underwent GFS received balanced salt solution, or SAHA (50 lM), or mitomycin C (0.02%). Clinical scores of IOP, bleb vascularity, and slit-lamp examination were performed. On postoperative day 14, rabbits were killed and the bleb tissues were collected for evaluation of tissue fibrosis with hematoxylin and eosin, Masson trichrome, a-smooth muscle actin (aSMA), and F-actin staining. Furthermore, SAHA-mediated acetylation of histones in corneal fibroblasts and conjunctiva were determined by Western blot analysis. RESULTS. Suberoylanilide hydroxamic acid treatment after GFS showed no signs of edema, corneal opacity, endophthalmitis, or cataract formation. Morphometric analysis of SAHA-treated eyes showed higher bleb length (P \u3c 0.001), bleb area (P \u3c 0.05), lower IOP (P \u3c 0.01), and decreased vascularity compared to control. Furthermore, SAHA treatment showed significantly reduced levels of aSMA (P \u3c 0.001), F-actin (P \u3c 0.01), and collagen deposition (P \u3c 0.05) at the sclerotomy site. In addition, SAHA treatment increased the acetylation status of H3 and H4 histones in corneal fibroblasts and conjunctiva. CONCLUSIONS. This study demonstrates that HDAC inhibition is an attractive pharmacologic target to modulate GFS wound healing, and SAHA, an HDACi, can be a useful adjunct to improve the GFS outcome

    Flow-based pipeline for systematic modulation and analysis of 3D tumor microenvironments

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    The cancer microenvironment, which incorporates interactions with stromal cells, extracellular matrix (ECM), and other tumor cells in a 3-dimensional (3D) context, has been implicated in every stage of cancer development, including growth of the primary tumor, metastatic spread, and response to treatment. Our understanding of the tumor microenvironment and our ability to develop new therapies would greatly benefit from tools that allow us to systematically probe microenvironmental cues within a 3D context. Here, we leveraged recent advances in microfluidic technology to develop a platform for high-throughput fabrication of tunable cellular microniches (“microtissues”) that allow us to probe tumor cell response to a range of microenvironmental cues, including ECM, soluble factors, and stromal cells, all in 3D. We further combine this tunable microniche platform with rapid, flow-based population level analysis (n > 500), which permits analysis and sorting of microtissue populations both pre- and post-culture by a range of parameters, including proliferation and homotypic or heterotypic cell density. We used this platform to demonstrate differential responses of lung adenocarcinoma cells to a selection of ECM molecules and soluble factors. The cells exhibited enhanced or reduced proliferation when encapsulated in fibronectin- or collagen-1-containing microtissues, respectively, and they showed reduced proliferation in the presence of TGF-β, an effect that we did not observe in monolayer culture. We also measured tumor cell response to a panel of drug targets and found, in contrast to monolayer culture, specific sensitivity of tumor cells to TGFβR2 inhibitors, implying that TGF-β has an anti-proliferative affect that is unique to the 3D context and that this effect is mediated by TGFβR2. These findings highlight the importance of the microenvironmental context in therapeutic development and that the platform we present here allows the high-throughput study of tumor response to drugs as well as basic tumor biology in well-defined microenvironmental niches.American Association for Cancer Research (Stand Up to Cancer Charitable Initiative)National Institute for Biomedical Imaging and Bioengineering (U.S.) (National Research Service Award Fellowship)National Science Foundation (U.S.) (Graduate Research Fellowship Program Grant 1122374)Howard Hughes Medical Institut

    An expression meta-analysis of predicted microRNA targets identifies a diagnostic signature for lung cancer

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    <p>Abstract</p> <p>Background</p> <p>Patients diagnosed with lung adenocarcinoma (AD) and squamous cell carcinoma (SCC), two major histologic subtypes of lung cancer, currently receive similar standard treatments, but resistance to adjuvant chemotherapy is prevalent. Identification of differentially expressed genes marking AD and SCC may prove to be of diagnostic value and help unravel molecular basis of their histogenesis and biologies, and deliver more effective and specific systemic therapy.</p> <p>Methods</p> <p>MiRNA target genes were predicted by union of miRanda, TargetScan, and PicTar, followed by screening for matched gene symbols in NCBI human sequences and Gene Ontology (GO) terms using the PANTHER database that was also used for analyzing the significance of biological processes and pathways within each ontology term. Microarray data were extracted from Gene Expression Omnibus repository, and tumor subtype prediction by gene expression used Prediction Analysis of Microarrays.</p> <p>Results</p> <p>Computationally predicted target genes of three microRNAs, miR-34b/34c/449, that were detected in human lung, testis, and fallopian tubes but not in other normal tissues, were filtered by representation of GO terms and their ability to classify lung cancer subtypes, followed by a meta-analysis of microarray data to classify AD and SCC. Expression of a minimal set of 17 predicted miR-34b/34c/449 target genes derived from the developmental process GO category was identified from a training set to classify 41 AD and 17 SCC, and correctly predicted in average 87% of 354 AD and 82% of 282 SCC specimens from total 9 independent published datasets. The accuracy of prediction still remains comparable when classifying 103 AD and 79 SCC samples from another 4 published datasets that have only 14 to 16 of the 17 genes available for prediction (84% and 85% for AD and SCC, respectively). Expression of this signature in two published datasets of epithelial cells obtained at bronchoscopy from cigarette smokers, if combined with cytopathology of the cells, yielded 89–90% sensitivity of lung cancer detection and 87–90% negative predictive value to non-cancer patients.</p> <p>Conclusion</p> <p>This study focuses on predicted targets of three lung-enriched miRNAs, compares their expression patterns in lung cancer by their GO terms, and identifies a minimal set of genes differentially expressed in AD and SCC, followed by validating this gene signature in multiple published datasets. Expression of this gene signature in bronchial epithelial cells of cigarette smokers also has a great sensitivity to predict the patients having lung cancer if combined with cytopathology of the cells.</p

    Comparison of Gene Expression Profiles in Chromate Transformed BEAS-2B Cells

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    Hexavalent chromium [Cr(VI)] is a potent human carcinogen. Occupational exposure has been associated with increased risk of respiratory cancer. Multiple mechanisms have been shown to contribute to Cr(VI) induced carcinogenesis, including DNA damage, genomic instability, and epigenetic modulation, however, the molecular mechanism and downstream genes mediating chromium's carcinogenicity remain to be elucidated.We established chromate transformed cell lines by chronic exposure of normal human bronchial epithelial BEAS-2B cells to low doses of Cr(VI) followed by anchorage-independent growth. These transformed cell lines not only exhibited consistent morphological changes but also acquired altered and distinct gene expression patterns compared with normal BEAS-2B cells and control cell lines (untreated) that arose spontaneously in soft agar. Interestingly, the gene expression profiles of six Cr(VI) transformed cell lines were remarkably similar to each other yet differed significantly from that of either control cell lines or normal BEAS-2B cells. A total of 409 differentially expressed genes were identified in Cr(VI) transformed cells compared to control cells. Genes related to cell-to-cell junction were upregulated in all Cr(VI) transformed cells, while genes associated with the interaction between cells and their extracellular matrices were down-regulated. Additionally, expression of genes involved in cell proliferation and apoptosis were also changed.This study is the first to report gene expression profiling of Cr(VI) transformed cells. The gene expression changes across individual chromate exposed clones were remarkably similar to each other but differed significantly from the gene expression found in anchorage-independent clones that arose spontaneously. Our analysis identified many novel gene expression changes that may contribute to chromate induced cell transformation, and collectively this type of information will provide a better understanding of the mechanism underlying chromate carcinogenicity

    CD160-Associated CD8 T-Cell Functional Impairment Is Independent of PD-1 Expression.

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    Expression of co-inhibitory molecules is generally associated with T-cell dysfunction in chronic viral infections such as HIV or HCV. However, their relative contribution in the T-cell impairment remains unclear. In the present study, we have evaluated the impact of the expression of co-inhibitory molecules such as 2B4, PD-1 and CD160 on the functions of CD8 T-cells specific to influenza, EBV and CMV. We show that CD8 T-cell populations expressing CD160, but not PD-1, had reduced proliferation capacity and perforin expression, thus indicating that the functional impairment in CD160+ CD8 T cells may be independent of PD-1 expression. The blockade of CD160/CD160-ligand interaction restored CD8 T-cell proliferation capacity, and the extent of restoration directly correlated with the ex vivo proportion of CD160+ CD8 T cells suggesting that CD160 negatively regulates TCR-mediated signaling. Furthermore, CD160 expression was not up-regulated upon T-cell activation or proliferation as compared to PD-1. Taken together, these results provide evidence that CD160-associated CD8 T-cell functional impairment is independent of PD-1 expression

    Restoration of TGF-β signalling reduces tumorigenicity in human lung cancer cells

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    Members of the transforming growth factor-β (TGF-β) family regulate a wide range of biological processes including cell proliferation, migration, differentiation, apoptosis, and extracellular matrix deposition. Resistance to TGF-β-mediated tumour suppressor function in human lung cancer may occur through the loss of type II receptor (TβRII) expression. In this study, we investigated the expression pattern of TβRII in human lung cancer tissues by RT–PCR and Western blot analyses. We observed downregulation of TβRII in 30 out of 46 NSCLC samples (65%) by semiquantitative RT–PCR. Western blot analyses with tumour lysates showed reduced expression of TβRII in 77% cases. We also determined the effect of TβRII expression in lung adenocarcinoma cell line (VMRC-LCD) that is not responsive to TGF-β due to lack of TβRII expression. Stable expression of TβRII in these cells restored TGF-β-mediated effects including Smad2/3 and Smad4 complex formation, TGF-β-responsive reporter gene activation, inhibition of cell proliferation and increased apoptosis. Clones expressing TβRII showed reduced colony formation in soft-agarose assay and significantly reduced tumorigenicity in athymic nude mice. Therefore, these results suggest that reestablishment of TGF-β signalling in TβRII null cells by stable expression of TβRII can reverse malignant behaviour of cells and loss of TβRII expression may be involved in lung tumour progression

    Cytokine Plasma Levels: Reliable Predictors for Radiation Pneumonitis?

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    BACKGROUND: Radiotherapy (RT) is the primary treatment modality for inoperable, locally advanced non-small-cell lung cancer (NSCLC), but even with highly conformal treatment planning, radiation pneumonitis (RP) remains the most serious, dose-limiting complication. Previous clinical reports proposed that cytokine plasma levels measured during RT allow to estimate the individual risk of patients to develop RP. The identification of such cytokine risk profiles would facilitate tailoring radiotherapy to maximize treatment efficacy and to minimize radiation toxicity. However, cytokines are produced not only in normal lung tissue after irradiation, but are also over-expressed in tumour cells of NSCLC specimens. This tumour-derived cytokine production may influence circulating plasma levels in NSCLC patients. The aim of the present study was to investigate the prognostic value of TNF-alpha, IL-1beta, IL-6 and TGF-beta1 plasma levels to predict radiation pneumonitis and to evaluate the impact of tumour-derived cytokine production on circulating plasma levels in patients irradiated for NSCLC. METHODOLOGY/PRINCIPAL FINDINGS: In 52 NSCLC patients (stage I-III) cytokine plasma levels were investigated by ELISA before and weekly during RT, during follow-up (1/3/6/9 months after RT), and at the onset of RP. Tumour biopsies were immunohistochemically stained for IL-6 and TGF-beta1, and immunoreactivity was quantified (grade 1-4). RP was evaluated according to LENT-SOMA scale. Tumour response was assessed according to RECIST criteria by chest-CT during follow-up. In our clinical study 21 out of 52 patients developed RP (grade I/II/III/IV: 11/3/6/1 patients). Unexpectedly, cytokine plasma levels measured before and during RT did not correlate with RP incidence. In most patients IL-6 and TGF-beta1 plasma levels were already elevated before RT and correlated significantly with the IL-6 and TGF-beta1 production in corresponding tumour biopsies. Moreover, IL-6 and TGF-beta1 plasma levels measured during follow-up were significantly associated with the individual tumour responses of these patients. CONCLUSIONS/SIGNIFICANCE: The results of this study did not confirm that cytokine plasma levels, neither their absolute nor any relative values, may identify patients at risk for RP. In contrast, the clear correlations of IL-6 and TGF-beta1 plasma levels with the cytokine production in corresponding tumour biopsies and with the individual tumour responses suggest that the tumour is the major source of circulating cytokines in patients receiving RT for advanced NSCLC
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