scholarly journals MicroRNAomes of Cattle Intestinal Tissues Revealed Possible miRNA Regulated Mechanisms Involved in Escherichia coli O157 Fecal Shedding

Author(s):  
Ou Wang ◽  
Mi Zhou ◽  
Yanhong Chen ◽  
Tim A. McAllister ◽  
Graham Plastow ◽  
...  

Cattle have been suggested as the primary reservoirs of E. coli O157 mainly as a result of colonization of the recto-anal junction (RAJ) and subsequent shedding into the environment. Although a recent study reported different gene expression at RAJ between super-shedders (SS) and non-shedders (NS), the regulatory mechanisms of altered gene expression is unknown. This study aimed to investigate whether bovine non-coding RNAs play a role in regulating the differentially expressed (DE) genes between SS and NS, thus further influencing E. coli O157 shedding behavior in the animals through studying miRNAomes of the whole gastrointestinal tract including duodenum, proximal jejunum, distal jejunum, cecum, spiral colon, descending colon and rectum. The number of miRNAs detected in each intestinal region ranged from 390 ± 13 (duodenum) to 413 ± 49 (descending colon). Comparison between SS and NS revealed the number of differentially expressed (DE) miRNAs ranged from one (in descending colon) to eight (in distal jejunum), and through the whole gut, seven miRNAs were up-regulated and seven were down-regulated in SS. The distal jejunum and rectum were the regions where the most DE miRNAs were identified (eight and seven, respectively). The miRNAs, bta-miR-378b, bta-miR-2284j, and bta-miR-2284d were down-regulated in both distal jejunum and rectum of SS (log2fold-change: −2.7 to −3.8), bta-miR-2887 was down-regulated in the rectum of SS (log2fold-change: −3.2), and bta-miR-211 and bta-miR-29d-3p were up-regulated in the rectum of SS (log2fold-change: 4.5 and 2.2). Functional analysis of these miRNAs indicated their potential regulatory role in host immune functions, including hematological system development and immune cell trafficking. Our findings suggest that altered expression of miRNA in the gut of SS may lead to differential regulation of immune functions involved in E. coli O157 super-shedding in cattle.

2007 ◽  
Vol 29 (1) ◽  
pp. 76-83 ◽  
Author(s):  
Caroline Ojaimi ◽  
Khaled Qanud ◽  
Thomas H. Hintze ◽  
Fabio A. Recchia

Our aim was to determine the changes in the gene expression profile occurring during the transition from compensated dysfunction (CD) to decompensated heart failure (HF) in pacing-induced dilated cardiomyopathy. Twelve chronically instrumented dogs underwent left ventricular pacing at 210 beats/min for 3 wk and at 240 beats thereafter, and four normal dogs were used as control. The transition from CD to HF occurred between the 3rd and 4th wk of pacing, with end-stage HF at 28 ± 1 days. RNA was extracted from left ventricular tissue at control and 3 and 4 wk of pacing ( n = 4) and tested with the Affymetrix Canine Array. We found 509 genes differentially expressed in CD vs. control ( P ≤ 0.05, fold change ≥±2), with 362 increasing and 147 decreasing; 526 genes were differentially expressed in HF vs. control ( P ≤ 0.05; fold change ≥±2), with 439 increasing and 87 decreasing. To better understand the transition, we compared gene alterations at 3 vs. 4 wk pacing and found that only 30 genes differed ( P ≤ 0.05; fold change of ±2). We conclude that a number of processes including normalization of gene regulation during decompensation, appearance of new upregulated genes and maintenance of gene expression all contribute to the transition to overt heart failure with an unexpectedly small number of genes differentially regulated.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4118-4118
Author(s):  
Vibe Skov ◽  
Thomas Stauffer Larsen ◽  
Mads Thomassen ◽  
Caroline Riley ◽  
Morten Krogh Jensen ◽  
...  

Abstract Abstract 4118 Introduction: The polycomb repressive complex (PRC) 2 contains 3 core proteins, EZH2 (enhancer of zeste homolog 2), SUZ12, and EED, in which the SET (suppressor of vaegation-enhancer of zeste-trithorax) domain of EZH2 mediates the histone methyltransferase activity. This induces trimethylation of lysine 27 on histone H3, regulates the expression of HOX genes, and promotes proliferation and aggressiveness of neoplastic cells. EZH2, a known repressor of gene transcription, has been reported to be overexpressed in many cancers and correlates with poor prognosis. EZH2 may also be involved in disease progression in patients with the classical Philadelphia-negative chronic myeloproliferative neoplasms (CMPNs) encompassing essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF). Since the potential oncogenic role of EZH2 in CMPNs has never been investigated, we have assessed gene expression of EZH2 in a cohort of patients with CMPNs. Patients and Methods: Using Affymetrix HG-U133 2.0 Plus microarrays, recognizing 54675 probe sets (38500 genes), gene expression profiling has been performed on control subjects (n=21) and patients with ET (n =19), PV (n=41), and PMF (n=9). All patients were diagnosed according to the WHO criteria of a CMPN. Total RNA was purified from whole blood and amplified to biotin-labeled RNA and hybridized to microarray chips. Results: We identified 20439, 25307, 17417, and 25421 probe sets which were differentially expressed between controls and patients with ET, PV, PMF, and CPMNs as a whole, respectively (false discovery rate (FDR) adjusted p values < 0.05). These genes included EZH2, which was highly significantly upregulated in patients with PMF as compared to controls (2.3 fold upregulated; uncorrected p-value=1.09×10-8 and FDR=1.75×10-6, and between PMF and non-PMF patients (fold change=2.0, FDR < 0.0005). No significant differences in EZH2 gene expression were recorded between controls and ET patients, controls and PV patients, or controls and the CMPN group as a whole. Within patients, the EZH2 gene was also differentially expressed with the highest levels being recorded in patients with PMF compared to PV patients (fold change=2.4, FDR < 7.5 ×10-6). Discussion and Conclusions: Using global gene expression profiling we have found the EZH2 gene to be significantly upregulated in CMPN patients, with the highest expression levels being found in PMF. We hypothesize that an altered expression of EZH2 may be involved in the transformation of ET and PV into myelofibrosis. It remains to be clarified if deregulation of EZH2 occurs consequent to mutations in the EZH2-gene. Enhanced EZH2 expression may also be associated with silencing of differentiation genes during myelofibrotic and leukemic transformation. An increased expression of EZH2 may provide a proliferative advantage of the malignant clone through interaction with the pathways of key elements controlling cell growth arrest and differentiation, (e.g. nuclear factor kappa beta and - the proteasome pathway). Studies are in progress to elucidate if genomic loss of distinct microRNAs (microRNA 101 leads to overexpression of EZH2 in cancer is associated with overexpression of EZH2 in CMPNs. Highly expressed EZH2 may be a new marker of an aggressive clinical phenotype which might imply EZH2 as a novel biomarker for predicting prognosis. If so, EZH2-blockade might be a novel approach to be incorporated in the strategies for developing epigenetic therapies in patients with CMPNs. Disclosures: No relevant conflicts of interest to declare.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Giulia Pintarelli ◽  
Sara Noci ◽  
Davide Maspero ◽  
Angela Pettinicchio ◽  
Matteo Dugo ◽  
...  

Abstract Alterations in the gene expression of organs in contact with the environment may signal exposure to toxins. To identify genes in lung tissue whose expression levels are altered by cigarette smoking, we compared the transcriptomes of lung tissue between 118 ever smokers and 58 never smokers. In all cases, the tissue studied was non-involved lung tissue obtained at lobectomy from patients with lung adenocarcinoma. Of the 17,097 genes analyzed, 357 were differentially expressed between ever smokers and never smokers (FDR < 0.05), including 290 genes that were up-regulated and 67 down-regulated in ever smokers. For 85 genes, the absolute value of the fold change was ≥2. The gene with the smallest FDR was MYO1A (FDR = 6.9 × 10−4) while the gene with the largest difference between groups was FGG (fold change = 31.60). Overall, 100 of the genes identified in this study (38.6%) had previously been found to associate with smoking in at least one of four previously reported datasets of non-involved lung tissue. Seven genes (KMO, CD1A, SPINK5, TREM2, CYBB, DNASE2B, FGG) were differentially expressed between ever and never smokers in all five datasets, with concordant higher expression in ever smokers. Smoking-induced up-regulation of six of these genes was also observed in a transcription dataset from lung tissue of non-cancer patients. Among the three most significant gene networks, two are involved in immunity and inflammation and one in cell death. Overall, this study shows that the lung parenchyma transcriptome of smokers has altered gene expression and that these alterations are reproducible in different series of smokers across countries. Moreover, this study identified a seven-gene panel that reflects lung tissue exposure to cigarette smoke.


mSystems ◽  
2016 ◽  
Vol 1 (4) ◽  
Author(s):  
John D. Lippolis ◽  
Brian W. Brunelle ◽  
Timothy A. Reinhardt ◽  
Randy E. Sacco ◽  
Tyler C. Thacker ◽  
...  

ABSTRACT Bacteria can exhibit various types of motility. It is known that different types of motilities can be associated with virulence. In this work, we compare gene expression levels in bacteria that were grown under conditions that promoted three different types of E. coli motility. Better understanding of the mechanisms of how bacteria can cause an infection is an important first step to better diagnostics and therapeutics. Bacterial motility is thought to play an important role in virulence. We have previously shown that proficient bacterial swimming and swarming in vitro is correlated with the persistent intramammary infection phenotype observed in cattle. However, little is known about the gene regulation differences important for different motility phenotypes in Escherichia coli. In this work, three E. coli strains that cause persistent bovine mastitis infections were grown in three media that promote different types of motility (planktonic, swimming, and swarming). Using whole-transcriptome RNA sequencing, we identified a total of 935 genes (~21% of the total genome) that were differentially expressed in comparisons of the various motility-promoting conditions. We found that approximately 7% of the differentially expressed genes were associated with iron regulation. We show that motility assays using iron or iron chelators confirmed the importance of iron regulation to the observed motility phenotypes. Because of the observation that E. coli strains that cause persistent infections are more motile, we contend that better understanding of the genes that are differentially expressed due to the type of motility will yield important information about how bacteria can become established within a host. Elucidating the mechanisms that regulate bacterial motility may provide new approaches in the development of intervention strategies as well as facilitate the discovery of novel diagnostics and therapeutics. IMPORTANCE Bacteria can exhibit various types of motility. It is known that different types of motilities can be associated with virulence. In this work, we compare gene expression levels in bacteria that were grown under conditions that promoted three different types of E. coli motility. Better understanding of the mechanisms of how bacteria can cause an infection is an important first step to better diagnostics and therapeutics.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3562-3562
Author(s):  
Karel Fišer ◽  
Lucie Slámová ◽  
Alena Dobiášová ◽  
Júlia Starková ◽  
Eva Froňková ◽  
...  

Abstract We identified a subset of BCP-ALL with switch towards the monocytic lineage within the first month of treatment (swALL)[Slámová et al Leukemia 2014]. During the switch cells gradually lose CD19 and CD34 expression and acquire CD33 and CD14 positivity. We proved clonal relatedness of switched monocytic blasts with the diagnostic leukemic cells based on identical Ig-TCR rearrangements. SwALL cases are not associated with MLL or BCR/ABL1 aberrancies and lack any known genetic markers of lineage ambiguity (detected by FISH or MLPA). We analyzed transcriptomes of swALL samples at diagnosis (n=4) and at d8 (n=4) where the immunophenotypic switching was already apparent as well as control BCP-ALL (n=4). RNA was isolated form either FACS sorted cells or whole BM when blasts constituted >80% of cells. For RNA-Seq we used Illumina HiSeq 2000 paired-end or single end sequencing. Raw sequencing data were analyzed using adapted protocol from Anders at al [Anders et al Nature Protocols 2013] and custom scripts. For methylome analysis we used Enhanced Reduced Representation Bisulfite Sequencing (ERRBS)[Akalin et al PLoS Genetics 2012]. ERRBS quantitatively measures DNA methylation at ~3M CpGs genome-wide. Samples from swALL at diagnosis (n=7) and at d8 (n=4) and control BCP-ALL (n=4) were processed. Analysis was performed according to [Akalin et al Genome Biology 2012] and followed with custom analysis in R statistical language. Comparison (generalized exact binomial test) of transcriptomes of B-lineage blasts from diagnosis between swALLs and control BCP-ALLs revealed a number of differentially expressed genes. Among 300 most significantly differentially expressed were KLF4, CEBPD, CLEC12A and CLEC12B (upregulated in swALL) and ANXA5, VPREB1, CD9 and IGHG3 (downregulated in swALL). Hierarchical clustering separated not only swALL and control BCP-ALL, but also swALL cells before and during the monocytic switch. Changes in gene expression during lineage switch included downregulation of ITGA6, Id2, EBF1, CD19, CD34, FLT3, MYB, CD79a, BCR, PAX5, GATA3 and TCF3 genes and upregulation of S100A10, AIF1, CD14, CD33, LGALS1, RNF130 and MNDA. When comparing all three cell types (swALL B cell and monocytic blasts and control BCP-ALL blasts) we concentrated on 1) immunophenotype switch markers and 2) lineage related transcription factors (TF): 1) Both markers typical for B cell blasts (CD19, CD34) decreased during the switch. However while CD19 was expressed in swALL at diagnosis at same levels as in control BCP-ALL, CD34 was overexpressed in swALL compared to BCP-ALL at diagnosis. Both monocytic markers (CD33, CD14) increased their expression during the switch. CD14 showed no difference between swALL and control BCP-ALL at diagnosis. However CD33 was interestingly upregulated in swALL already at diagnosis and continued to rise during the switch. SwALL had therefore deregulated expression of lineage commitment markers already at diagnosis favoring stemness marker CD34 and myeloid marker CD33. 2) B lineage commitment related TFs (EBF1, TCF3, PAX5) were expressed in B lineage blasts in both swALL and control BCP-ALL. However they were all downregulated during the switch. On the other hand myeloid lineage related transcription factor CEBPA is overexpressed in diagnostic B lineage blasts in swALL compared to control BCP-ALL cases. Similarly CEBPD is overexpressed in swALL and its expression further rises during the switch. Other hematopoietic TFs upregulated in swALL cases include KLF4, NANOG and GATA3. To confirm some of the epigenetic markers of swALL cases (demethylation of CEBPA promoter) and to widen epigenetic screening we used ERRBS. While some of the upregulated genes had expectedly hypomethylated promoters in swALL (CEBPA, GATA3) other genes (TCF3, PAX5) had demethylated promoters in all cases. While the whole DNA methylation picture is still a challenge to draw both omics method could clearly separate swALL cases from control BCP-ALL using principal component analysis. In summary we show that immunophenotypic shift is associated with gene expression changes of surface markers, lineage specific transcription factors and other genes. Some of the genes have altered expression already at diagnosis. Expression of some key lineage genes is differentially regulated by DNA methylation. Supported by: GAUK 914613, GAČR P301/10/1877, UNCE 204012, IGA NT13462-4 Disclosures No relevant conflicts of interest to declare.


2014 ◽  
Vol 94 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Hrvoje Valpotić ◽  
Marcela Šperanda ◽  
Ana Kovšca-Janjatović ◽  
Mislav Ðidara ◽  
Gordana Lacković ◽  
...  

Valpotić, H., Šperanda, M., Kovšca-Janjatović, A., Ðidara, M., Lacković, G., Božić, F., Habrun, B., Srečec, S., Mataušić-Pišl, M. and Valpotić, I. 2014. Levamisole stimulates proliferation of circulating and intestinal immune cell subsets, gut health and performance in weaned pigs. Can. J. Anim. Sci. 94: 43–53. With the growing knowledge of the porcine immune system and its endogenous modulation, it has been clearly stated that exogenous modulation through the use of substances able to modulate immune functions represents an important prophylactic/therapeutic approach in prevention/treatment of both stress- and F4+ and F18+ enterotoxigenic E. coli (ETEC)-induced infections accompanied weaning. The aim of this study was to evaluate the effectiveness of levamisole (LEVA; 2.5 mg kg−1 BW in 10 mL) applied per os to weaned pigs in proliferation of circulating and intestinal immune cell subsets throughout a period of 5 wk. Changes in proportion or number of peripheral blood and ileal mucosal leukocytes tested were studied either weekly by flow cytometry or at the end of the experiment (day 35) by immunohistology/histomorphometry, respectively. Pigs treated with LEVA had increased proportions of peripheral blood CD45+ lymphoid cells, CD4+ and CD8+ T cells, and CD21+ B cells (P<0.01) between days 14 and 35 following the treatment. Also, LEVA stimulated the proliferation of CD45RA+ naïve lymphoid cells in interfollicular (P<0.001) and follicular areas (P<0.05) of ileal Peyer’s patches at day 35 of the experiment. These pigs had a significantly higher (P<0.05) average body weight (19.7 vs. 17.1 kg) and weight gain at the end of experiment compared with the control pigs (for 15%). We conclude that LEVA stimulated the proliferation of circulating and intestinal lymphoid cell subsets tested and improved performance in weaned pigs, and thus, the drug may nonspecifically enhance their immunity/resistance to F4+ and F18+ ETEC strains.


2021 ◽  
Author(s):  
Qi Zhou ◽  
Xin Xiong ◽  
Min Tang ◽  
Yingqing Lei ◽  
Hongbin Lv

Abstract BackgroundDiabetic retinopathy (DR), a severe complication of diabetes mellitus (DM), is a global social and economic burden. However, the pathological mechanisms mediating DR are not well-understood. This study aimed to identify differentially methylated and differentially expressed hub genes (DMGs and DEGs, respectively) and associated signaling pathways, and to evaluate immune cell infiltration involved in DR. MethodsTwo publicly available datasets were downloaded from the Gene Expression Omnibus database. Transcriptome and epigenome microarray data and multi-component weighted gene coexpression network analysis (WGCNA) were utilized to determine hub genes within DR. One dataset was utilized to screen DEGs and to further explore their potential biological functions using functional annotation analysis. A protein-protein interaction network was constructed. Gene set enrichment and variation analyses (GSVA and GSEA, respectively) were utilized to identify the potential mechanisms mediating the function of hub genes in DR. Infiltrating immune cells were evaluated in one dataset using CIBERSORT. The Connectivity Map (CMap) database was used to predict potential therapeutic agents. ResultsIn total, 673 DEGs (151 upregulated and 522 downregulated genes) were detected. Gene expression was significantly enriched in the extracellular matrix and sensory organ development, extracellular matrix organization, and glial cell differentiation pathways. Through WGCNA, one module was found to be significantly related with DR (r=0.34, P =0.002), and 979 hub genes were identified. By comparing DMGs, DEGs, and genes in WGCNA, we identified eight hub genes in DR ( AKAP13, BOC, ACSS1, ARNT2, TGFB2, LHFPL2, GFPT2, TNFRSF1A ), which were significantly enriched in critical pathways involving coagulation, angiogenesis, TGF-β, and TNF-α-NF-κB signaling via GSVA and GSEA. Immune cell infiltration analysis revealed that activated natural killer cells, M0 macrophages, resting mast cells, and CD8 + T cells may be involved in DR. ARNT2, TGFB2, LHFPL2 , and AKAP13 expression were correlated with immune cell processes, and ZG-10, JNK-9L, chromomycin-a3, and calyculin were identified as potential drugs against DR. Finally, TNFRSF1A , GFPT2 , and LHFPL2 expression levels were consistent with the bioinformatic analysis. ConclusionsOur results are informative with respect to correlations between differentially methylated and expressed hub genes and immune cell infiltration in DR, providing new insight towards DR drug development and treatment.


2019 ◽  
Author(s):  
Richard J. Fredendall ◽  
Jenny L. Stone ◽  
Michael J. Pehl ◽  
Paul M. Orwin

ABSTRACTWe used transcriptome analysis by paired-end strand specific RNA-seq to evaluate the specific changes in gene expression associated with the transition to static biofilm growth in the rhizosphere plant growth promoting bacterium Variovorax paradoxus EPS. Triplicate biological samples of exponential growth, stationary phase, and static biofilm samples were examined. DESeq2 and Rockhopper were used to identify robust and widespread shifts in gene expression the transcriptomic signals specific to each growth phase. Weidentified 1711 protein coding genes (28%) using DESeq2 that had altered expression greater than 2-fold specifically in biofilms compared to exponential growth. Fewer genes were specifically differentially expressed in stationary phase culture (757, 12%). A small set of genes (103/6020) were differentially expressed in opposing fashions in biofilm and stationary phase, indicating potentially substantial shifts in phenotype. Gene Ontology analysis showed that the only class of genes specifically upregulated in biofilms were associated with nutrient transport, highlighting the importance of nutrient uptake in the biofilm. The biofilm specific genes did not overlap substantially with the loci identified by mutagenesis studies, although some were present in both sets. The most highly upregulated biofilm specific gene is predicted to be a part of the RNA degradosome, which indicates that RNA stability is used to regulate the biofilm phenotype. Two small putative proteins, Varpa_0407 and Varpa_3832, are highly expressed specifically in biofilms and are predicted to be secreted DNA binding proteins, that may stabilize extracellular DNA as a component of the biofilm matrix. An flp/tad type IV pilus locus (Varpa_5148-60) is strongly downregulated in specifically in biofilms, in contrast with results from other systems for these pili. Mutagenesis confirms that this locus is important in surface motility rather than biofilm formation. These experimental results suggest that V. paradoxus EPS biofilms have substantial regulatory and structural novelty.


2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 654-654
Author(s):  
Raphael M Byrne ◽  
Rebecca Ruhl ◽  
Christian Lanciault ◽  
Sudarshan Anand ◽  
Abhinav Nellore ◽  
...  

654 Background: Colorectal cancer (CRC) in young patients is increasing in incidence and is associated with worse outcomes than CRC in older patients. While distinct molecular subtypes of CRC have been recently characterized, it is unclear whether there are molecular differences between the tumors of young and old patients. We sought to identify differences in gene expression of CRC between these two groups. Our discovery analysis identified a gene signature of several differentially expressed RNAs, from which we validated PEG10. The PEG10 gene on chromosome 7q21.3 has been implicated in liver, gallbladder, thyroid, and blood cancers, and is thought to play a role in cancer cell survival and regulation of apoptosis. In hepatocellular carcinoma, increased PEG10 expression has been associated with younger patient age. Methods: RNA sequencing data was obtained from The Cancer Genome Atlas (TCGA) and analyzed for differences in gene expression between patients ≤ 45 years old and those ≥ 65 years old. The identified differentially expressed genes were then validated with qPCR using human CRC tissue from patients ≤ 45 years old and those ≥ 65 years old. Results: RNA sequencing data from patients ≤ 45 years old (n = 29) and patients ≥ 65 years old (n = 299) identified seven genes with increased expression in younger patients: ZNF334 (log2 [fold change] = 2.30), DSC3 (1.78), PEG10 (1.67), CACNA1I (1.54), PKIA (1.33), MAP9 (1.27), and EPHX3 (1.17) (p < 0.07). Validation with qPCR for PEG10 was most promising, and was performed on both young (n = 10, mean age = 39) and old patient samples ( n= 8, mean age = 72). Two cancers (20%) in the young group received radiation treatment and five (50%) received chemotherapy. One cancer (12.5%) in the old group received radiation and two (25%) received chemotherapy. PEG10 had increased expression in the young group with log2 [fold change] = 3.16 (p < 0.02). Conclusions: We have identified a potentially unique gene expression signature for CRC in young patients, which includes PEG10. Functional analysis of PEG10 and other genes is underway using in vitro cell culture, archived human tumor tissue, and mouse tumor models.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3260-3260
Author(s):  
Rosana A Silveira ◽  
Angela A Fachel ◽  
Yuri B Moreira ◽  
Marcia T Delamain ◽  
Carmino Antonio De Souza ◽  
...  

Abstract Abstract 3260 Poster Board III-1 Background: CML treatment with tyrosine kinase inhibitors induces high and durable rates of complete cytogenetic response. Despite treatment efficacy, a significant proportion of patients develop resistance to these drugs. We measured gene expression profiles in an attempt to identify gene pathways that may be associated with dasatinib resistance. Patients and Methods: Mononuclear cells were separated from peripheral blood samples from seven CML patients resistant to imatinib, collected prior and after dasatinib treatment. Three patients who achieved partial cytogenetic response (Ph-positive cells: 1% - 35%) within twelve months were considered responders (R), whereas four patients who failed to achieve PCyR within 12 months of treatment were classified as non-responders. RNA samples prepared from peripheral mononuclear cells were hybridized to Agilent Technologies 4×44K Whole Human Genome Microarrays (WHGM) and 4×44K intronic-exonic custom oligoarrays. The latter was developed by Verjovski-Almeida's group (Nakaya et al, Genome Biology 2007, 8:R43) and contains sense and antisense probes that map to intronic regions in the human genome representing totally (TIN) and partially (PIN) intronic non-coding RNAs (ncRNAs), in addition to probes for the corresponding protein-coding genes of the same loci. Raw microarray data were normalized by the Affy package in statistical R language implemented in the Bioconductor platform. Each sample was labeled in replicate with Cy3 or Cy5 and the two were considered technical replicates. Two independent statistical approaches SAM (Significance Analysis of Microarrays) and Golub's discrimination score (SNR, Signal to Noise Ratio, with permutations) were performed to identify differentially expressed transcripts between responder and non-responder patients. For the intronic-exonic platform, the analysis parameters were FDR 10%, SNR>1.5 and p<0.01, and for WHGM platform parameters were FDR 5%, SNR>1.5 and p<0.001. For this latter platform, we also performed a patient leave-one-out analysis. Functions of transcripts differentially expressed were annotated and compared using GO Biological Process categories (www.genetools.microarray.ntu.no/egon). Results: We identified 34 ncRNAs with altered expression (26 over and 8 underexpressed in responders) in pre-treatment samples and 33 ncRNAs (20 over and 13 underexpressed in responders) in post-treatment samples. Functions associated with protein-coding genes from the same genomic loci as those of the intronic differentially expressed ncRNAs were: regulation of transcription (PRMT5, SOD2, SSBP3, BCL7A, MLL), signal transduction (PRKCB1, RASGRP2, NF1, PXN) and apoptosis (BCL2, PCSK6, TNFAIP8, EIF4G2). WHGM platform data analysis showed 63 and 250 protein-coding genes differentially expressed in pre and post-treatment samples, respectively. We observed a higher number of protein-coding genes with altered expression after treatment in the following functions: cell communication, immune response and metabolic process (p<0.02). Conclusions: Overall, these findings indicate that protein-coding genes and intronic ncRNAs may be related to dasatinib resistance and response to treatment. In particular, altered expression of ncRNAs transcribed from the introns of ‘regulation of transcription' genes could be part of an important alternative mechanism of gene expression control during emergence of resistance.Support: FAPESP (2005/60266-8) Disclosures: No relevant conflicts of interest to declare.


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