1
|
Klümper T, Bruckmueller H, Diewock T, Kaehler M, Haenisch S, Pott C, Bruhn O, Cascorbi I. Expression differences of miR-142-5p between treatment-naïve chronic myeloid leukemia patients responding and non-responding to imatinib therapy suggest a link to oncogenic ABL2, SRI, cKIT and MCL1 signaling pathways critical for development of therapy resistance. Exp Hematol Oncol 2020; 9:26. [PMID: 32999756 PMCID: PMC7519530 DOI: 10.1186/s40164-020-00183-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 09/21/2020] [Indexed: 12/22/2022] Open
Abstract
Background Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by constitutive activity of the tyrosine kinase BCR-ABL1. Although the introduction of tyrosine kinase inhibitors (TKIs) has substantially improved patients’ prognosis, drug resistance remains one of the major challenges in CML therapy. MicroRNAs (miRNAs), a class of short non-coding RNAs acting as post-transcriptional regulators, are implicated in CML progression and drug resistance. The aim of the present study was to analyze the miRNA expression profiles of 45 treatment-naïve CML patients in chronic phase (28 peripheral blood and 17 bone marrow samples) with respect to future response to imatinib therapy. Methods TaqMan low density arrays were used to analyze the miRNA expression pattern of the patient samples. For selected microRNAs, reporter gene assays were performed to study their ability to regulate CML associated target genes. Results Significant lower expression levels of miR-142-5p were identified in both, peripheral blood and bone marrow samples of future non-responders suggesting a potential tumor suppressor role of this miRNA. This was supported by reporter gene assays that identified the survival, proliferation and invasion promoting CML related genes ABL2, cKIT, MCL1 and SRI as targets of miR-142-5p and miR-365a-3p, the latter identified as potential biomarker in peripheral blood samples. Conclusion MiR-142-5p and to a certain extend also miR-365a-3p were able to discriminate treatment-naïve CML patients not responding to imatinib in the course of their treatment from patients, who responded to therapy. However, further large-scale studies should clarify if the identified miRNAs have the potential as predictive biomarkers for TKI resistance.
Collapse
Affiliation(s)
- Theresa Klümper
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Henrike Bruckmueller
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Tobias Diewock
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Meike Kaehler
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Sierk Haenisch
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Christiane Pott
- Department of Medicine II, Haematology and Oncology, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Oliver Bruhn
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| | - Ingolf Cascorbi
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany
| |
Collapse
|
2
|
Bruhn O, Lindsay M, Wiebel F, Kaehler M, Nagel I, Böhm R, Röder C, Cascorbi I. Alternative Polyadenylation of ABC Transporters of the C-Family (ABCC1, ABCC2, ABCC3) and Implications on Posttranscriptional Micro-RNA Regulation. Mol Pharmacol 2019; 97:112-122. [PMID: 31757862 DOI: 10.1124/mol.119.116590] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 11/12/2019] [Indexed: 12/31/2022] Open
Abstract
ATP-binding cassette (ABC) transporters represent a large group of efflux pumps that are strongly involved in the pharmacokinetics of various drugs and nutrient distribution. It was recently shown that micro-RNAs (miRNAs) may significantly alter their expression as proven, e.g., for miR-379 and ABCC2 However, alternative mRNA polyadenylation may result in expression of 3'-untranslated regions (3'-UTRs) with varying lengths. Thus, length variants may result in presence or absence of miRNA binding sites for regulatory miRNAs with consequences on posttranscriptional control. In the present study, we report on 3'-UTR variants of ABCC1, ABCC2, and ABCC3 mRNA. Applying in vitro luciferase reporter gene assays, we show that expression of short ABCC2 3'-UTR variants leads to a significant loss of miR-379/ABCC2 interaction and subsequent upregulation of ABCC2 expression. Furthermore, we show that expression of ABCC2 3'-UTR lengths varies significantly between human healthy tissues but is not directly correlated to the respective protein level in vivo. In conclusion, the presence of altered 3'-UTR lengths in ABC transporters could lead to functional consequences regarding posttranscriptional gene expression, potentially regulated by alternative polyadenylation. Hence, 3'-UTR length variability may be considered as a further mechanism contributing to variability of ABCC transporter expression and subsequent drug variation in drug response. SIGNIFICANCE STATEMENT: micro-RNA (miRNA) binding to 3'-untranslated region (3'-UTR) plays an important role in the control of ATP-binding cassette (ABC)-transporter mRNA degradation and translation into proteins. We disclosed various 3'-UTR length variants of ABCC1, C2, and C3 mRNA, with loss of mRNA seed regions partly leading to varying and tissue-dependent interaction with miRNAs, as proven by reporter gene assays. Alternative 3'-UTR lengths may contribute to variable ABCC transporter expression and potentially explains inconsistent findings in miRNA studies.
Collapse
Affiliation(s)
- Oliver Bruhn
- Institute of Experimental and Clinical Pharmacology (O.B., M.L., F.W., M.K., I.N., R.B., I.C.) and Institute for Experimental Cancer Research (C.R.), University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Marie Lindsay
- Institute of Experimental and Clinical Pharmacology (O.B., M.L., F.W., M.K., I.N., R.B., I.C.) and Institute for Experimental Cancer Research (C.R.), University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Friederike Wiebel
- Institute of Experimental and Clinical Pharmacology (O.B., M.L., F.W., M.K., I.N., R.B., I.C.) and Institute for Experimental Cancer Research (C.R.), University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Meike Kaehler
- Institute of Experimental and Clinical Pharmacology (O.B., M.L., F.W., M.K., I.N., R.B., I.C.) and Institute for Experimental Cancer Research (C.R.), University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Inga Nagel
- Institute of Experimental and Clinical Pharmacology (O.B., M.L., F.W., M.K., I.N., R.B., I.C.) and Institute for Experimental Cancer Research (C.R.), University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Ruwen Böhm
- Institute of Experimental and Clinical Pharmacology (O.B., M.L., F.W., M.K., I.N., R.B., I.C.) and Institute for Experimental Cancer Research (C.R.), University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Christian Röder
- Institute of Experimental and Clinical Pharmacology (O.B., M.L., F.W., M.K., I.N., R.B., I.C.) and Institute for Experimental Cancer Research (C.R.), University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Ingolf Cascorbi
- Institute of Experimental and Clinical Pharmacology (O.B., M.L., F.W., M.K., I.N., R.B., I.C.) and Institute for Experimental Cancer Research (C.R.), University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| |
Collapse
|
3
|
Kaehler M, Ruemenapp J, Gonnermann D, Nagel I, Bruhn O, Haenisch S, Ammerpohl O, Wesch D, Cascorbi I, Bruckmueller H. MicroRNA-212/ABCG2-axis contributes to development of imatinib-resistance in leukemic cells. Oncotarget 2017; 8:92018-92031. [PMID: 29190894 PMCID: PMC5696160 DOI: 10.18632/oncotarget.21272] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 09/08/2017] [Indexed: 12/27/2022] Open
Abstract
BCR-ABL-independent resistance against tyrosine kinase inhibitor is an emerging problem in therapy of chronic myeloid leukemia. Such drug resistance can be linked to dysregulation of ATP-binding cassette (ABC)-transporters leading to increased tyrosine kinase inhibitor efflux, potentially caused by changes in microRNA expression or DNA-methylation. In an in vitro-imatinib-resistance model using K-562 cells, microRNA-212 was found to be dysregulated and inversely correlated to ABC-transporter ABCG2 expression, targeting its 3'-UTR. However, the functional impact on drug sensitivity remained unknown. Therefore, we performed transfection experiments using microRNA-mimics and -inhibitors and investigated their effect on imatinib-susceptibility in sensitive and resistant leukemic cell lines. Under imatinib-treatment, miR-212 inhibition led to enhanced cell viability (p = 0.01), reduced apoptosis (p = 0.01) and cytotoxicity (p = 0.03). These effects were limited to treatment-naïve cells and were not observed in cells, which were resistant to various imatinib-concentrations (0.1 μM to 2 μM). Further analysis in treatment-naïve cells revealed that miR-212 inhibition resulted in ABCG2 upregulation and increased ABCG2-dependent efflux. Furthermore, we observed miR-212 promoter hypermethylation in 0.5 and 2 μM IM-resistant sublines, whereas ABCG2 methylation status was not altered. Taken together, the miR-212/ABCG2-axis influences imatinib-susceptibility contributing to development of imatinib-resistance. Our data reveal new insights into mechanisms initiating imatinib-resistance in leukemic cells.
Collapse
Affiliation(s)
- Meike Kaehler
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Johanna Ruemenapp
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Daniel Gonnermann
- Institute of Immunology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Inga Nagel
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Oliver Bruhn
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Sierk Haenisch
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Ole Ammerpohl
- Institute of Human Genetics, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Daniela Wesch
- Institute of Immunology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Ingolf Cascorbi
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Henrike Bruckmueller
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| |
Collapse
|
4
|
Böhm R, von Hehn L, Herdegen T, Klein HJ, Bruhn O, Petri H, Höcker J. OpenVigil FDA - Inspection of U.S. American Adverse Drug Events Pharmacovigilance Data and Novel Clinical Applications. PLoS One 2016; 11:e0157753. [PMID: 27326858 PMCID: PMC4915658 DOI: 10.1371/journal.pone.0157753] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/03/2016] [Indexed: 12/03/2022] Open
Abstract
Pharmacovigilance contributes to health care. However, direct access to the underlying data for academic institutions and individual physicians or pharmacists is intricate, and easily employable analysis modes for everyday clinical situations are missing. This underlines the need for a tool to bring pharmacovigilance to the clinics. To address these issues, we have developed OpenVigil FDA, a novel web-based pharmacovigilance analysis tool which uses the openFDA online interface of the Food and Drug Administration (FDA) to access U.S. American and international pharmacovigilance data from the Adverse Event Reporting System (AERS). OpenVigil FDA provides disproportionality analyses to (i) identify the drug most likely evoking a new adverse event, (ii) compare two drugs concerning their safety profile, (iii) check arbitrary combinations of two drugs for unknown drug-drug interactions and (iv) enhance the relevance of results by identifying confounding factors and eliminating them using background correction. We present examples for these applications and discuss the promises and limits of pharmacovigilance, openFDA and OpenVigil FDA. OpenVigil FDA is the first public available tool to apply pharmacovigilance findings directly to real-life clinical problems. OpenVigil FDA does not require special licenses or statistical programs.
Collapse
Affiliation(s)
- Ruwen Böhm
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
- * E-mail:
| | - Leocadie von Hehn
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Thomas Herdegen
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Hans-Joachim Klein
- Department of Computer Science, Christian-Albrechts University, Kiel, Germany
| | - Oliver Bruhn
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Holger Petri
- Hospital pharmacy, Wicker Kliniken, Bad Wildungen-Reinhardshausen, Germany
| | - Jan Höcker
- Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| |
Collapse
|
5
|
Bruhn O, Drerup K, Kaehler M, Haenisch S, Röder C, Cascorbi I. Length variants of the ABCB1 3′-UTR and loss of miRNA binding sites: possible consequences in regulation and pharmacotherapy resistance. Pharmacogenomics 2016; 17:327-40. [DOI: 10.2217/pgs.15.175] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Aim: To identify the exact length and possible length variations of the ABCB1 3′-UTR as important regulatory site for miRNA interaction of this drug transporter and its possible contribution to drug resistance. Materials & methods: 3′-RACE and various standard PCR experiments were performed using cDNA of different human cell lines and liver tissue. The abundance of 3′-UTR fragments was analyzed using quantitative RT-PCR. Results: Five different ABCB1 3′-UTR length variants were identified. miRNA binding sites were located only on the three longer fragments. Imatinib-resistant leukemia cells expressed predominantly shorter 3′-UTRs, where miRNA binding sites are absent. Conclusion: Shortening of the ABCB1 3′-UTR causes loss of miRNA-dependent translational control leading to elevated ABCB1 protein levels.
Collapse
Affiliation(s)
- Oliver Bruhn
- Institute of Experimental & Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Germany
| | - Katharina Drerup
- Institute of Experimental & Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Germany
| | - Meike Kaehler
- Institute of Experimental & Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Germany
| | - Sierk Haenisch
- Institute of Experimental & Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Germany
| | - Christian Röder
- Division of Molecular Oncology, Institute for Experimental Cancer Research, University Hospital Schleswig-Holstein, Campus Kiel, Germany
| | - Ingolf Cascorbi
- Institute of Experimental & Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel, Germany
| |
Collapse
|
6
|
Bruhn O, Cascorbi I. Polymorphisms of the drug transporters ABCB1, ABCG2, ABCC2 and ABCC3 and their impact on drug bioavailability and clinical relevance. Expert Opin Drug Metab Toxicol 2014; 10:1337-54. [PMID: 25162314 DOI: 10.1517/17425255.2014.952630] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Human ATP-binding cassette (ABC) transporters act as translocators of numerous substrates across extracellular and intracellular membranes, thereby contributing to bioavailability and consequently therapy response. Genetic polymorphisms are considered as critical determinants of expression level or activity and subsequently response to selected drugs. AREAS COVERED Here the influence of polymorphisms of the prominent ABC transporters P-glycoprotein (MDR1, ABCB1), breast cancer resistance protein (BCRP, ABCG2) and the multidrug resistance-associated protein (MRP) 2 (ABCC2) as well as MRP3 (ABCC3) on the pharmacokinetic of drugs and associated consequences on therapy response and clinical outcome is discussed. EXPERT OPINION ABC transporter genetic variants were assumed to affect interindividual differences in pharmacokinetics and subsequently clinical response. However, decades of medical research have not yielded in distinct and unconfined reproducible outcomes. Despite some unique results, the majority were inconsistent and dependent on the analyzed cohort or study design. Therefore, variability of bioavailability and drug response may be attributed only by a small amount to polymorphisms in transporter genes, whereas transcriptional regulation or post-transcriptional modification seems to be more critical. In our opinion, currently identified genetic variants of ABC efflux transporters can give some hints on the role of transporters at interfaces but are less suitable as biomarkers to predict therapeutic outcome.
Collapse
Affiliation(s)
- Oliver Bruhn
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein , Campus Kiel, Arnold-Heller-Str. 3, 24105 Kiel , Germany +49 431 597 3500 ; +49 431 597 3522 ;
| | | |
Collapse
|
7
|
Nies AT, Schaeffeler E, van der Kuip H, Cascorbi I, Bruhn O, Kneba M, Pott C, Hofmann U, Volk C, Hu S, Baker SD, Sparreboom A, Ruth P, Koepsell H, Schwab M. Cellular uptake of imatinib into leukemic cells is independent of human organic cation transporter 1 (OCT1). Clin Cancer Res 2013; 20:985-94. [PMID: 24352644 DOI: 10.1158/1078-0432.ccr-13-1999] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE In addition to mutated BCR-ABL1 kinase, the organic cation transporter 1 (OCT1, encoded by SLC22A1) has been considered to contribute to imatinib resistance in patients with chronic myeloid leukemia (CML). As data are conflicting as to whether OCT1 transports imatinib and may serve as a clinical biomarker, we used a combination of different approaches including animal experiments to elucidate comprehensively the impact of OCT1 on cellular imatinib uptake. EXPERIMENTAL DESIGN Transport of imatinib was studied using OCT1-expressing Xenopus oocytes, mammalian cell lines (HEK293, MDCK, V79) stably expressing OCT1, human leukemic cells, and Oct1-knockout mice. OCT1 mRNA and protein expression were analyzed in leukemic cells from patients with imatinib-naïve CML as well as in cell lines. RESULTS Transport and inhibition studies showed that overexpression of functional OCT1 protein in Xenopus oocytes or mammalian cell lines did not lead to an increased cellular accumulation of imatinib. The CML cell lines (K562, Meg-01, LAMA84) and leukemic cells from patients expressed neither OCT1 mRNA nor protein as demonstrated by immunoblotting and immunofluorescence microscopy, yet they showed a considerable imatinib uptake. Oct1 deficiency in mice had no influence on plasma and hepatic imatinib concentrations. CONCLUSIONS These data clearly demonstrate that cellular uptake of imatinib is independent of OCT1, and therefore OCT1 is apparently not a valid biomarker for imatinib resistance.
Collapse
Affiliation(s)
- Anne T Nies
- Authors' Affiliations: Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, and University of Tübingen; Institute of Pharmacy, Department of Pharmacology, University of Tübingen; Department of Clinical Pharmacology, University Hospital Tübingen, Tübingen; Institute of Experimental and Clinical Pharmacology, Second Medical Department, University Hospital Schleswig-Holstein, Campus Kiel; Institute of Anatomy and Cell Biology, University of Würzburg, Würzburg, Germany; and Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, Tennessee
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Cascorbi I, Bruhn O, Werk AN. Challenges in pharmacogenetics. Eur J Clin Pharmacol 2013; 69 Suppl 1:17-23. [DOI: 10.1007/s00228-013-1492-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 02/19/2013] [Indexed: 12/20/2022]
|
9
|
Bruhn O, Diewock T, Pott C, Kneba M, Cascorbi I, Haenisch S. Abstract 1097: MicroRNA expression in white blood cells of CML patients: Differential expression in responders and non-responders to imatinib. Cancer Res 2012. [DOI: 10.1158/1538-7445.am2012-1097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction: Treatment of chronic myeloid leukemia (CML) with the BCR/ABL-inhibitor imatinib led to a tremendous progress of over-all survival. However therapy resistance in a significant proportion of patients remains a severe clinical problem. Aside mutations of the BCR/ABL gene, regulation of cellular transporters or downstream factors may contribute to non-response. We aimed to investigate micro-RNA expression profiles in peripheral leukocytes of 21 newly diagnosed CML patients without BCR/ABL-mutations in order to identify biomarkers to treatment-response of imatinib. Methods: Ten responders (molecular remission) and 11 non-responders were included. Expression of 667 microRNAs was analyzed using a TaqMan Low-Density Array system. Relative fold change of microRNAs between groups was calculated according to the 2^-ΔΔCt method. MicroRNAs with a fold change>2 and a P-value<0.01 were considered significant. MicroRNAs with minor expression (Ct-value>20) were not included. Putative targets of dysregulated microRNAs were considered, if predicted by at least three databases, and further analyzed using the DAVID-bioinformatic database. Results: Four microRNAs were significantly deregulated (miR-7, miR-744*, miR-616, miR-212) between responders and non-responders, when being treatment-naïve, predicted to have 97 potential targets. In depth target analysis showed that transcription regulators (21% of the predicted targets) are highly enriched compared to normal gene expression background of humans. Pathway analysis revealed six genes involved in cancer pathways, whereas four of them are directly involved in the chronic myeloid leukemia pathway (SMAD4, NRAS, RB1, RAF1). In responders seven microRNAs were deregulated before and after therapy, whereas five other microRNAs were deregulated within the group of non-responders. Three deregulated microRNAs were identified in both groups. Most predicted target genes are involved in MAPK signaling and exocytosis, 13% of the targets were predicted to be transcription regulators, and 18% cellular (especially uptake) transporters. Conclusion: We identified distinct microRNA pattern comparing blood samples of responders and non-responders prior to imatinib therapy. Predicted target genes were primarily transcription factors and oncogenes. In contrast, transporters and exocytotic pathways are in addition frequent targets of microRNAs deregulated after imatinib therapy. The suitability as biomarkers for prediction of imatinib-response requires further confirmation.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1097. doi:1538-7445.AM2012-1097
Collapse
Affiliation(s)
- Oliver Bruhn
- 1Institute of Experimental and Clinical Pharmacology, Kiel, Germany
| | - Tobias Diewock
- 1Institute of Experimental and Clinical Pharmacology, Kiel, Germany
| | | | | | - Ingolf Cascorbi
- 1Institute of Experimental and Clinical Pharmacology, Kiel, Germany
| | - Sierk Haenisch
- 1Institute of Experimental and Clinical Pharmacology, Kiel, Germany
| |
Collapse
|
10
|
Schlusselhuber M, Jung S, Bruhn O, Goux D, Leippe M, Leclercq R, Laugier C, Grötzinger J, Cauchard J. In vitro potential of equine DEFA1 and eCATH1 as alternative antimicrobial drugs in rhodococcosis treatment. Antimicrob Agents Chemother 2012; 56:1749-55. [PMID: 22232283 PMCID: PMC3318344 DOI: 10.1128/aac.05797-11] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 12/30/2011] [Indexed: 11/20/2022] Open
Abstract
Rhodococcus equi, the causal agent of rhodococcosis, is a severe pathogen of foals but also of immunodeficient humans, causing bronchopneumonia. The pathogen is often found together with Klebsiella pneumoniae or Streptococcus zooepidemicus in foals. Of great concern is the fact that some R. equi strains are already resistant to commonly used antibiotics. In the present study, we evaluated the in vitro potential of two equine antimicrobial peptides (AMPs), eCATH1 and DEFA1, as new drugs against R. equi and its associated pathogens. The peptides led to growth inhibition and death of R. equi and S. zooepidemicus at low micromolar concentrations. Moreover, eCATH1 was able to inhibit growth of K. pneumoniae. Both peptides caused rapid disruption of the R. equi membrane, leading to cell lysis. Interestingly, eCATH1 had a synergic effect together with rifampin. Furthermore, eCATH1 was not cytotoxic against mammalian cells at bacteriolytic concentrations and maintained its high killing activity even at physiological salt concentrations. Our data suggest that equine AMPs, especially eCATH1, may be promising candidates for alternative drugs to control R. equi in mono- and coinfections.
Collapse
Affiliation(s)
- Margot Schlusselhuber
- Bacteriology and Parasitology Unit, Dozulé Laboratory for Equine Diseases, ANSES, Goustranville, Dozulé, France.
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Bruhn O, Grötzinger J, Cascorbi I, Jung S. Antimicrobial peptides and proteins of the horse--insights into a well-armed organism. Vet Res 2011; 42:98. [PMID: 21888650 PMCID: PMC3179947 DOI: 10.1186/1297-9716-42-98] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 09/02/2011] [Indexed: 12/14/2022] Open
Abstract
Antimicrobial peptides play a pivotal role as key effectors of the innate immune system in plants and animals and act as endogenous antibiotics. The molecules exhibit an antimicrobial activity against bacteria, viruses, and eukaryotic pathogens with different specificities and potencies depending on the structure and amino-acid composition of the peptides. Several antimicrobial peptides were comprehensively investigated in the last three decades and some molecules with remarkable antimicrobial properties have reached the third phase of clinical studies. Next to the peptides themselves, numerous organisms were examined and analyzed regarding their repertoire of antimicrobial peptides revealing a huge number of candidates with potencies and properties for future medical applications. One of these organisms is the horse, which possesses numerous peptides that are interesting candidates for therapeutical applications in veterinary medicine. Here we summarize investigations and knowledge on equine antimicrobial peptides, point to interesting candidates, and discuss prospects for therapeutical applications.
Collapse
Affiliation(s)
- Oliver Bruhn
- Institute for Experimental and Clinical Pharmacology, Hospitalstraße 4, University Hospital Schleswig-Holstein, Campus Kiel, 24105 Kiel, Germany.
| | | | | | | |
Collapse
|
12
|
Haenisch S, Laechelt S, Bruckmueller H, Werk A, Noack A, Bruhn O, Remmler C, Cascorbi I. Down-regulation of ATP-binding cassette C2 protein expression in HepG2 cells after rifampicin treatment is mediated by microRNA-379. Mol Pharmacol 2011; 80:314-20. [PMID: 21540293 DOI: 10.1124/mol.110.070714] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
microRNAs (miRNAs), which contribute to the post-transcriptional processing through 3'-untranslated region-interference, have been shown to be involved in the regulation of ATP-binding cassette (ABC) membrane transporters. The aim of this study was to investigate whether ABCC2, an important efflux transporter for various endogenous and exogenous compounds at several compartment barriers, is subject to miRNA-mediated post-transcriptional gene regulation. We screened the expression of 377 human miRNAs in HepG2 cells after 48 h of treatment with 5 μM rifampicin [a pregnane X receptor (PXR) ligand] or vehicle using reverse transcription-polymerase chain reaction-based low-density arrays. Specific miRNA, ABCC2 mRNA, and protein expression were monitored in HepG2 cells undergoing rifampicin treatment for 72 h. Loss- and gain-of-function experiments and reporter gene assays were performed for further confirmation. Highly deregulated miRNAs compared with in silico data revealed miRNA (miR) 379 as candidate miRNA targeting ABCC2 mRNA. Under rifampicin treatment, ABCC2 mRNA increased significantly, with a maximal fold change of 1.56 ± 0.43 after 24 h. In addition, miR-379 increased (maximally 4.10 ± 1.33-fold after 48 h), whereas ABCC2 protein decreased with a maximal fold change of 0.47 ± 0.08 after 72 h. In contrast, transfection of miR-379 inhibitor led to an elevation of ABCC2 protein expression after rifampicin incubation for 48 h. We identify a miRNA negatively regulating ABCC2 on the post-transcriptional level and provide evidence that this miRNA impedes overexpression of ABCC2 protein after a PXR-mediated external transcriptional stimulus in HepG2 cells.
Collapse
Affiliation(s)
- Sierk Haenisch
- Institute for Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Bldg. 30, Arnold-Heller-Str. 3, D-24105 Kiel, Germany
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Bruhn O, Paul S, Gelhaus C, Michalek M, Thaller G, Podschun R, Leippe M, Grötzinger J. Equine α-defensins. Pneumologie 2010. [DOI: 10.1055/s-0029-1247904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
14
|
Abstract
Background Defensins represent an important class of antimicrobial peptides. These effector molecules of the innate immune system act as endogenous antibiotics to protect the organism against infections with pathogenic microorganisms. Mammalian defensins are classified into three distinct sub-families (α-, β- and θ-defensins) according to their specific intramolecular disulfide-bond pattern. The peptides exhibit an antimicrobial activity against a broad spectrum of microorganisms including bacteria and fungi. Alpha-Defensins are primarily synthesised in neutrophils and intestinal Paneth cells. They play a role in the pathogenesis of intestinal diseases and may regulate the flora of the intestinal tract. An equine intestinal α-defensin (DEFA1), the first characterised in the Laurasiatheria, shows a broad antimicrobial spectrum against human and equine pathogens. Here we report a first investigation of the repertoire of equine intestinal α-defensins. The equine genome was screened for putative α-defensin genes by using known α-defensin sequences as matrices. Based on the obtained sequence information, a set of oligonucleotides specific to the α-defensin gene-family was designed. The products generated by reverse-transcriptase PCR with cDNA from the small intestine as template were sub-cloned and numerous clones were sequenced. Results Thirty-eight equine intestinal α-defensin transcripts were determined. After translation it became evident that at least 20 of them may code for functional peptides. Ten transcripts lacked matching genomic sequences and for 14 α-defensin genes apparently present in the genome no appropriate transcript could be verified. In other cases the same genomic exons were found in different transcripts. Conclusions The large repertoire of equine α-defensins found in this study points to a particular importance of these peptides regarding animal health and protection from infectious diseases. Moreover, these findings make the horse an excellent species to study biological properties of α-defensins. Interestingly, the peptides were not found in other species of the Laurasiatheria to date. Comparison of the obtained transcripts with the genomic sequences in the current assembly of the horse (EquCab2.0) indicates that it is yet not complete and/or to some extent falsely assembled.
Collapse
Affiliation(s)
- Oliver Bruhn
- Institute of Animal Breeding and Husbandry, Christian-Albrechts-University of Kiel, Hermann-Rodewald-Strasse 6, D-24118 Kiel, Germany.
| | | | | | | |
Collapse
|
15
|
Bruhn O, Cauchard J, Schlusselhuber M, Gelhaus C, Podschun R, Thaller G, Laugier C, Leippe M, Grötzinger J. Antimicrobial properties of the equine α-defensin DEFA1 against bacterial horse pathogens. Vet Immunol Immunopathol 2009; 130:102-6. [DOI: 10.1016/j.vetimm.2009.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Revised: 01/09/2009] [Accepted: 01/15/2009] [Indexed: 11/15/2022]
|
16
|
Bruhn O, Regenhard P, Michalek M, Paul S, Gelhaus C, Jung S, Thaller G, Podschun R, Leippe M, Grötzinger J, Kalm E. A novel horse alpha-defensin: gene transcription, recombinant expression and characterization of the structure and function. Biochem J 2008; 407:267-76. [PMID: 17620056 PMCID: PMC2049026 DOI: 10.1042/bj20070747] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Defensins are a predominant class of antimicrobial peptides, which act as endogenous antibiotics. Defensins are classified into three distinct sub-families: theta-, beta-, and alpha-defensins. Synthesis of alpha-defensin has been confirmed only in primates and glires to date and is presumably unique for a few tissues, including neutrophils and Paneth cells of the small intestine. Antimicrobial activities of these peptides were shown against a wide variety of microbes including bacteria, fungi, viruses and protozoan parasites. In the present study, we report the characterization of the equine alpha-defensin DEFA (defensin alpha) 1. Transcription analysis revealed that the transcript of the gene is present in the small intestine only. An alignment with known alpha-defensins from primates and glires displayed a homology with Paneth-cell-specific alpha-defensins. DEFA1 was recombinantly expressed in Escherichia coli and subsequently analysed structurally by CD and molecular modelling. To examine the antimicrobial properties, a radial diffusion assay was performed with 12 different micro-organisms and the LD90 (lethal dose killing > or =90% of target organism) and MBC (minimal bactericidal concentration) values were examined. DEFA1 showed an antimicrobial activity against different Gram-positive and Gram-negative bacteria and against the yeast Candida albicans. Using viable bacteria in combination with a membrane-impermeable fluorescent dye, as well as depolarization of liposomes as a minimalistic system, it became evident that membrane permeabilization is at least an essential part of the peptide's mode of action.
Collapse
Affiliation(s)
- Oliver Bruhn
- *Institute of Animal Breeding and Husbandry, University of Kiel, Hermann-Rodewald-Strasse 6, 24118 Kiel, Germany
| | - Petra Regenhard
- *Institute of Animal Breeding and Husbandry, University of Kiel, Hermann-Rodewald-Strasse 6, 24118 Kiel, Germany
| | - Matthias Michalek
- †Institute of Biochemistry, University of Kiel, Rudolf-Höber-Straße 1, 24118 Kiel, Germany
- ‡Department of Zoophysiology, Zoological Institute, University of Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Sven Paul
- *Institute of Animal Breeding and Husbandry, University of Kiel, Hermann-Rodewald-Strasse 6, 24118 Kiel, Germany
| | - Christoph Gelhaus
- ‡Department of Zoophysiology, Zoological Institute, University of Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Sascha Jung
- †Institute of Biochemistry, University of Kiel, Rudolf-Höber-Straße 1, 24118 Kiel, Germany
| | - Georg Thaller
- *Institute of Animal Breeding and Husbandry, University of Kiel, Hermann-Rodewald-Strasse 6, 24118 Kiel, Germany
| | - Rainer Podschun
- §Institute for Infection Medicine, University of Kiel, Brunswiker Strasse 4, 24105 Kiel, Germany
| | - Matthias Leippe
- ‡Department of Zoophysiology, Zoological Institute, University of Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Joachim Grötzinger
- †Institute of Biochemistry, University of Kiel, Rudolf-Höber-Straße 1, 24118 Kiel, Germany
| | - Ernst Kalm
- *Institute of Animal Breeding and Husbandry, University of Kiel, Hermann-Rodewald-Strasse 6, 24118 Kiel, Germany
- To whom correspondence should be addressed (email )
| |
Collapse
|
17
|
Leeb T, Bruhn O, Philipp U, Kuiper H, Regenhard P, Paul S, Distl O, Chowdhary BP, Kalm E, Looft C. Assignment of the equine S100A7 gene (psoriasin 1) to chromosome 5p12→p13 by fluorescence in situ hybridization and radiation hybrid mapping. Cytogenet Genome Res 2005; 109:533. [PMID: 15906470 DOI: 10.1159/000084216] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- T Leeb
- Institute of Animal Breeding and Genetics, School of Veterinary Medicine Hannover, Hannover; Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Bruhn O. [Prehospital treatment. They must do it like we do it. Interview by Peter Skeel Hjorth]. Sygeplejersken 1992; 92:4-9, 13. [PMID: 1297225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|