The iron chelator deferasirox is widely used in patients with iron overload. Patients with low-grade myelodysplastic syndromes (MDS) get transfusion dependency and need to be treated with deferasirox to avoid iron overload. Moreover, in some patients an increase in both erythroid and platelets have been observed after deferasirox therapy. However, the mechanisms involved in these clinical findings are poorly understood. The aim of this work was to analyze, in patients treated with deferasirox, the changes in the gene expression profile after receiving the treatment. A total of fifteen patients with the diagnosis of low-grade MDS were studied. Microarrays were carried out in RNA from peripheral blood before and after 14 weeks of deferasirox therapy. Changes in 1,457 genes and 54 miRNAs were observed: deferasirox induced the downregulation of genes related to the Nf kB pathway leading of an overall inactivation of this pathway. In addition, the iron chelator also downregulated gamma interferon. Altogether these changes could be related to the improvement of erythroid response observed in these patients after therapy. Moreover, the inhibition of NFE2L2/ NRF2, which was predicted in silico, could be playing a critical role in the reduction of reactive oxygen species (ROS). Of note, miR-125b, overexpressed after deferasirox treatment, could be involved in the reduced inflammation and increased hematopoiesis observed in the patients after treatment. In summary this study shows, for the first time, the mechanisms that could be governing deferasirox impact in vivo.
Genome-wide transcriptomics leads to the identification of deregulated genes after deferasirox therapy in low-risk MDS patients.
Specimen part, Disease, Treatment, Subject
View SamplesRecent studies suggest the potential involvement of common antigenic stimuli on the ontogeny of monoclonal TCRalphabeta+/CD4+/NKa+/CD8-/+dim T-large granular lymphocyte (LGL) lymphocytosis. Since healthy individuals show (oligo)clonal expansions of hCMV-specific TCRVbeta+/CD4+/cytotoxic/memory T-cells, we investigate the potential involvement of hCMV in the origin and/or expansion of monoclonal CD4+ T-LGL. A detailed characterization of those genes that underwent changes in T-LGL cells responding to hCMV was performed by microarray gene expression profile (GEP) analysis.
Expanded cells in monoclonal TCR-alphabeta+/CD4+/NKa+/CD8-/+dim T-LGL lymphocytosis recognize hCMV antigens.
Sex, Subject
View SamplesBackground: Fasciola hepatica infection still remains one of the helminthic neglected tropical diseases (NTDs). It has a huge worldwide distribution, affecting mainly cattle and, sometimes, human beings. In addition to data reported about the immunological response induced by helminthic infections and that induced by Fasciola hepatica, little is known about the gene expression profile in its organ target, the liver, which is where adult worms are established and live for long periods of time, causing its characteristic pathology. In the present work, we study both the early and late gene expression profiles in the livers of mice infected with Fasciola hepatica metacercariae using a microarray-based methodology.
No associated publication
Specimen part
View SamplesTrichodermin is a member of a group of closely related compounds-the 12,13-epoxytrichothecenes that form a medically and economically important class of mycotoxins. This sesquiterpene was purified by HPLC from cultures of the fungi Trichoderma brevicompactum. We report the antitumoral activity of trichodermin and here we show that trichodermin had inhibitory effects against tumoral cell lines (A-549, MCF-7, Hep-G2, Hep-G3). In addition, trichodermin was found to increase the expression level of apoptotic genes such as jun, fos, egr, egr2, casp9, ankd1, socs3 anddkk1 that induce cell death mechanisms, being the nuclear receptor subfamily 4, group A, member 1(NR4A1) one of the central molecule in the network.
No associated publication
Cell line
View SamplesFasciolosis remains an important food-borne tremaode disease causing high morbidity around the world and affecting grazing animals and humans. A deeper understanding concerning the molecular mechanisms by which Fasciola hepatica infection occurs as well as the molecular basis involved in acquiring protection is extremely important in designing and selecting new vaccine candidates. The present study gives a first report of microarray-based technology for describing changes in splenic gene expression profile for mice immunised with a highly effective, protection-inducing,multi-epitope, subunit-based, chemically-synthesised vaccine candidate. Female CD1 mice were immunised with synthetic peptides containing B- and T-cell epitopes as novel vaccine candidates and challenged with Fasciola hepatica metacercariae. Spleen RNA from mice immunised with the highest protection-inducing synthetic peptides was isolated, amplified and labelled using Affymetrix standardised protocols. The Ingenuity Pathway Analysis tool was used to annotate bio-functions and constructing and visualising molecular interaction networks. Immunising mice with a combination of three peptides containing T-cell epitopes induced high protection against experimental challenge according to survival rates and hepatic damage scores. It also induced differential expression of 820 genes; 168 being up-regulated and 652 down-regulated. Functional study revealed changes in pathways related to nitric oxide and reactive oxygen species production, IL-12 signalling and production in macrophages and IL-8 signalling with up-regulation of S100A8, MMP9 and CXCR2 genes. The data obtained in the present study provided us with a more comprehensive overview concerning the possible molecular pathways implied in inducing protection against Fasciola hepatica in a murine model
No associated publication
Specimen part, Treatment
View SamplesAmong the collection of chromatin modifications that influence its function and structure, the substitution of canonical histones by the so-called histone variants is one of the most prominent actions. Since crucial meiotic transactions are modulated by chromatin, here we investigate the functional contribution of the H2A.Z histone variant during both unperturbed meiosis and upon challenging conditions where the meiotic recombination checkpoint is triggered in budding yeast by the absence of the synaptonemal complex component Zip1. We have found that H2A.Z localizes to meiotic chromosomes in an SWR1-dependent manner. Although meiotic recombination is not substantially altered, the htz1 mutant (lacking H2A.Z) shows slower meiotic progression, impaired sporulation and reduced spore viability. These phenotypes are likely accounted for by the misregulation of meiotic gene expression landscape observed in htz1. In the zip1 mutant, the absence of H2A.Z results in a tighter meiotic arrest imposed by the meiotic recombination checkpoint. We have found that Mec1-dependent Hop1-T318 phosphorylation and the ensuing Mek1 activation are not significantly altered in zip1 htz1; however, downstream checkpoint targets, such as the meiosis I-promoting factors Ndt80, Cdc5 and Clb1, are drastically down-regulated. The study of the checkpoint response in zip1 htz1 has also allowed us to reveal the existence of an additional function of the Swe1 kinase, independent of CDK inhibitory phosphorylation, which is relevant to restrain meiotic cell cycle progression. In summary, our study shows that the H2A.Z histone variant impacts various aspects of meiotic development adding further insight into the relevance of chromatin dynamics for accurate gametogenesis.
No associated publication
No sample metadata fields
View SamplesAnalysis of the transcriptional profiles of mRNA and microRNA in Rasless fibroblasts. 4-Hydroxy-tamoxifen (4-OHT) treatment triggers removal of K-Ras expression in [H-Ras-/-;N-Ras-/-;K-Raslox/lox;RERTert/ert ] mouse fibroblasts (named K-Raslox) generating Rasless MEFs which are unable to proliferate, but recover proliferative ability after ectopic expression of constitutively active downstream kinases such as BRAF and MEK1.
Reversible, interrelated mRNA and miRNA expression patterns in the transcriptome of Rasless fibroblasts: functional and mechanistic implications.
Specimen part, Cell line, Treatment
View SamplesMultiple Myeloma (MM) remains incurable, and new drugs with novel mechanisms of action are still needed. In this report, we have analyzed the action of Zalypsis, an alkaloid analogous to certain natural marine compounds, in MM. Zalypsis turned out to be the most potent antimyeloma agent we have tested so far, with IC50s from picomolar to low nanomolar ranges. It also showed remarkable ex vivo potency in plasma cells from patients and in MM cells in vivo xenografted in mice. Besides the induction of apoptosis and cell cycle arrest, Zalypsis provoked DNA double-strand-breaks (DSB), evidenced by an increase in phospho-Histone-H2AX and phospho-CHK2, followed by a striking overexpression of p53 in p53-wild type cell lines. In addition, in those cell lines in which p53 was mutated, Zalypsis also provoked DSB and induced cell death, although higher concentrations were required. Immunohistochemical studies in tumours also demonstrated Histone-H2AX phosphorylation and p53 overexpression. Gene expression profile studies were concordant with these results, revealing an important deregulation of genes involved in DNA-damage response. The potent in vitro and in vivo antimyeloma activity of Zalypsis uncovers the high sensitivity of tumour plasma cells to DSB, and strongly supports the use of this compound in MM patients.
Zalypsis: a novel marine-derived compound with potent antimyeloma activity that reveals high sensitivity of malignant plasma cells to DNA double-strand breaks.
No sample metadata fields
View SamplesMicroarray expression profiling has currently failed to provide a consistent classification for human prostate cancer. Such classifications are important because they provide a framework for the identification of new biomarkers of clinical behavior and for the development of targeted therapies. We hypothesize that previous studies have been unsuccessful because of their failure to take into account the well documented occurrence of prostate cancer multifocality and genetic heterogeneity. We have invented a novel method for collecting whole RNALater preserved research slices from prostatectomy specimens that, for the first time, allows the mapping of multifocality and of genetic heterogeneity in prostate cancer to be integrated with the selection of samples for expression microarray analysis. For each specimen we will construct a map of the regions of cancer and of their ERG gene rearrangement status from whole mount formalin fixed sections immediately juxtaposed to the research slice. Only foci of cancers containing a homogeneous pattern of ERG gene alteration will be selected for study. A pilot study has already demonstrated the feasibility of this approach, and provides initial evidence that cancers may be stratified into at least two prognostically distinct categories. Novel biomarkers defining distinct prostate cancer categories will be verified and validated in future studies linked to clinical trials.
No associated publication
Sex, Specimen part, Subject
View SamplesBackground: Inter-patient prostate cancer (PrCa) heterogeneity results in highly variable patient outcomes. Multi-purpose biomarkers to dissect this heterogeneity are urgently required to improve treatment and accelerate drug development in PrCa. Circulating biomarkers are most practical for evaluating this disease. We pursued the analytical validation and clinical qualification of blood mRNA expression arrays.
Prognostic value of blood mRNA expression signatures in castration-resistant prostate cancer: a prospective, two-stage study.
Subject
View Samples