The identifcation of alternatively spliced transcript variants specific to particular biological processes in tumours should increase our understanding of cancer. Hypoxia is an important factor in cancer biology and associated splice variants may present new markers to help with planning treatment. A method was developed to analyse alternative splicing in exon array data, using probeset multiplicity to identify genes with changes in expression across their loci, and a combination of the splicing index and a new metric based on the variation of reliability weighted fold changes to detect changes in the splicing patterns. The approach was validated on a cancer/normal sample dataset in which alternative splicing events had been confirmed using RT-PCR. We then analysed ten head and neck squamous cell carcinomas using exon arrays and identified differentially expressed splice variants in five samples with high versus five with low levels of hypoxia-associated genes (Winter et al, 2007; Cancer Res 67:3441-9). The analysis identified a splice variant of LAMA3 (Laminin 3), LAMA3-A, known to be involved in tumour cell invasion and progression. The full-length transcript of the gene (LAMA3-B) did not appear to be hypoxia-associated. The results were confirmed using qualitative real time PCR. In a series of 59 prospectively-collected head and neck tumours (Winter et al, 2007; Cancer Res 67:3441-9), expression of LAMA3-A had prognostic significance whereas LAMA3-B did not. This work illustrates the potential for alternatively spliced transcripts to act as biomarkers of disease prognosis with improved specificity for particular tissues or conditions over assays which do not discriminate between splice variants.
Exon array analysis of head and neck cancers identifies a hypoxia related splice variant of LAMA3 associated with a poor prognosis.
No sample metadata fields
View SamplesPurpose: The goal of this study is to analyze the transcriptional pathways regulated by Fbxo22 and Keap1 in mouse lung adeno carcinoma cells. Methods: mouse lung adeno carcinoma cells either Keap1 wild type (KP) or mutant (KPK), have been transfected for 3 days with siRNA targeting Fbxo22. Knock down efficiency has been evaluated by western blot (using specific antibody for Fbxo22) and qPCR (using specific oligos for Fbxo22) . Results: The transcriptomic analysis helps us to support our finding that loss of either Keap1 or Fbxo22 induces metastases Overall design: All 12 samples generated by deep sequencing in triplicate
Nrf2 Activation Promotes Lung Cancer Metastasis by Inhibiting the Degradation of Bach1.
Specimen part, Subject
View SamplesBACKGROUND & AIMS- More frequent interaction of bacteria with the colonic epithelium is associated with ulcerative colitis (UC). The identities of all proteins which promote bacterial clearance in colonic epithelial cells are unknown. Previously, we discovered that dCAP-D3 (Chromosome Associated Protein-D3), regulates responses to bacterial infection. We examined whether CAP-D3 promotes bacterial clearance in human colonic epithelium. METHODS- Clearance of Salmonella or adherent-invasive Escherichia coli LF82 was assessed by gentamycin protection assays in HT-29 and Caco-2 cells expressing CAP-D3 shRNA. CAP-D3 levels in colonic epithelial cells from healthy and UC patient tissues were analyzed by immunoblot. RNA-sequencing identified bacterially-induced CAP-D3 target genes. The role of CAP-D3 target genes in bacterial clearance was analyzed by gentamycin protection assays, immunofluorescent staining, and by using pharmacologic inhibitors. RESULTS- CAP-D3 expression was reduced in colonic epithelial cells from UC patients with active disease. Reduction of CAP-D3 expression inhibited autophagy and decreased intracellular bacterial clearance. The components of the heterodimeric SLC7A5/SLC3A2 amino acid transporter were identified as CAP-D3 target genes; their levels increased in infected, CAP-D3 deficient cell lines and in cells from UC patients. In HT-29 cells, this resulted in earlier SLC7A5 recruitment to Salmonella-containing vacuoles, increased mTOR activity, and enhanced bacterial survival. Inhibition of SLC7A5/SLC3A2 or mTOR activity rescued the bacterial clearance defect in CAP-D3 deficient cells. CONCLUSIONS- CAP-D3 attenuates amino acid transporter transcription to promote bacterial autophagy in colon epithelial cells. CAP-D3 protein levels are decreased in patients with active UC, suggesting that CAP-D3 is a potential therapeutic target to restore mucosal homeostasis in UC patients. Overall design: Three RNA samples from 3 independent experiments including timepoints taken at 0, 0.5 and 7 hours post-infection were analyzed on a bioanalyzer for quality; one of the 0.5 hour post-infection samples was excluded at this time due to poor RNA purity. Directional, cDNA libraries made from cellular mRNAs were generated from the other 8 samples and sequenced (paired-end sequencing of 100 bp reads) in the Genomics Core at the University of Chicago on an Illumina HiSeq2000.
Chromosome-associated protein D3 promotes bacterial clearance in human intestinal epithelial cells by repressing expression of amino acid transporters.
No sample metadata fields
View SamplesOncogene-induced DNA methylation-mediated transcriptional silencing of tumor suppressors frequently occurs in cancer, but the mechanism and functional role of this silencing in oncogenesis is not fully understood. Here, we show that oncogenic epidermal growth factor receptor (EGFR) induces silencing of multiple unrelated tumor suppressors in lung adenocarcinomas and glioblastomas by inhibiting DNA demethylase TET oncogene family member 1 (TET1) via the C/EBP transcription factor. After oncogenic EGFR inhibition, TET1 binds to tumor suppressor promoters and induces their re-expression via active DNA demethylation. Ectopic expression of TET1 potently inhibits lung and glioblastoma tumor growth, and TET1 knockdown confers resistance to EGFR inhibitors in lung cancer cells. Lung cancer samples exhibited reduced TET1 expression or TET1 cytoplasmic localization in a majority of cases. Collectively, these results identify a conserved pathway of oncogenic EGFR-induced DNA methylation-mediated transcriptional silencing of tumor suppressors, which may have therapeutic benefit for oncogenic EGFR-mediated lung cancers and glioblastomas.
Oncogenic EGFR Represses the TET1 DNA Demethylase to Induce Silencing of Tumor Suppressors in Cancer Cells.
Cell line
View SamplesAffymetrix Microarrays were used to analyse gene expression in aortas and circulating CD115+ cells of ApoE- and ApoE/Lymphotoxin beta receptor (LTbR)-double-deficent mice fed a Western diet from 8 to 12 weeks of age in order to identify regulated genes and pathways leading to reduced atherosclerosis in ApoE-/-/LTbR-/- mice compared to ApoE-/- littermate controls.
Deficiency in lymphotoxin β receptor protects from atherosclerosis in apoE-deficient mice.
Sex, Age
View SamplesThe first clinical trial testing the combination of targeted therapy with a BRAF inhibitor vemurafenib and immunotherapy with a CTLA-4 antibody ipilimumab was terminated early due to significant liver toxicities, possibly due to paradoxical activation of the MAPK pathway by BRAF inhibitors in tumors with wild type BRAF. MEK inhibitors can potentiate the MAPK inhibition in tumor, while potentially alleviating the unwanted paradoxical MAPK activation. With a mouse model of syngeneic BRAFV600E driven melanoma (SM1), we tested whether the addition of the MEK inhibitor trametinib would enhance the immunosensitization effects of the BRAF inhibitor dabrafenib. Combination of dabrafenib and trametinib with pmel-1 adoptive cell transfer (ACT) showed complete tumor regression. Bioluminescent imaging and tumor infiltrating lymphocyte (TIL) phenotyping showed increased effector infiltration to tumors with dabrafenib, trametinib or dabrafenib plus trametinib with pmel-1 ACT combination. Intracellular IFN gamma staining of the TILs and in vivo cytotoxicity studies showed trametinib was not detrimental to the effector functions in vivo. Dabrafenib increased tumor associated macrophages and T regulatory cells (Tregs) in the tumors, which can be overcome by addition of trametinib. Microarray analysis revealed increased melanoma antigen, MHC expression, and global immune-related gene upregulation with the triple combination therapy. Given the up-regulation of PD-L1 seen with dabrafenib and/or trametinib combined with antigen specific ACT, we tested the triple combination of dabrafenib, trametinib with anti-PD1 therapy, and observed superior anti-tumor effect to SM1 tumors. Our findings support the testing of these combinations in patients with BRAFV600E mutant metastatic melanoma.
Improved antitumor activity of immunotherapy with BRAF and MEK inhibitors in BRAF(V600E) melanoma.
Specimen part, Treatment, Compound
View SamplesGamma-secretase inhibitors (GSIs), which block the activation of NOTCH receptors, are being tested in the treatment of T-cell acute lymphoblastic leukemia (T-ALL). Thus far, limited antileukemic cytotoxicity and severe gastrointestinal toxicity have restricted the clinical application of these targeted drugs. Here we show that combination therapy with GSIs plus glucocorticoids can improve the antileukemic effects of GSIs and reduce their gut toxicity in vivo. Inhibition of NOTCH1 signaling in glucocorticoid-resistant T-ALL restored glucocorticoid receptor auto-up-regulation and induced apoptotic cell death through induction of BIM expression. Additionally, cotreatment with glucocorticoids induced Ccnd2 upregulation in the gut which protected mice from the intestinal secretory metaplasia typically induced by loss of NOTCH signaling. These results support a role for glucocorticoids plus GSIs in the treatment of glucocorticoid-resistant T-ALL.
Gamma-secretase inhibitors reverse glucocorticoid resistance in T cell acute lymphoblastic leukemia.
Specimen part
View SamplesGlucocorticoids are an essential component of the treatment of lymphoid malignancies and resistance to glucocorticoid therapy constitutes a prominent clinical problem in relapsed and refractory lymphoblastic leukemias. Constitutively active NOTCH signaling is involved in the pathogenesis of over 50% of T-cell lymphoblastic leukemia (T-ALL) which harbor activating mutations in the NOTCH1 gene. Aberrant NOTCH1 signaling has been shown to protect normal thymocytes from glucocorticoid induced cell death. Here we analyzed the interaction of glucocorticoid therapy with inhibition of NOTCH signaling in the treatment of T-ALL. Gamma-secretase inhibitors (GSI), which block the activation of NOTCH receptors, amplified the transcriptional changes induced by glucocorticoid treatment, including glucocorticoid receptor autoinduction and restored sensitivity to dexamethasone in glucocorticoid-resistant T-ALL cells. Apoptosis induction upon inhibition of NOTCH signaling and activation of the glucocorticoid receptor was dependent on transcriptional upregulation of BIM and subsequent activation of the mitochondrial/intrinsic cell death pathway. Finally, we used a mouse xenograft model of T-ALL to demonstrate that combined treatment with dexamethasone and a GSI results in improved antileukemic effects in vivo. These studies provide insight in the mechanisms of glucocorticoid resistance and serve as rationale for the use of glucocorticoid and GSIs in combination in the treatment of T-ALL.
Gamma-secretase inhibitors reverse glucocorticoid resistance in T cell acute lymphoblastic leukemia.
No sample metadata fields
View SamplesWe obtained gene expression data and HD-SNP6.0 copy number data from PTL, PCNSL and PMLBCL samples and performed an integrative analysis on them. RNA was whole genome amplified using Nugen.
Targetable genetic features of primary testicular and primary central nervous system lymphomas.
Disease, Disease stage
View SamplesTo identify novel oncogenic pathways in T-cell acute lymphoblastic leukemia (T-ALL), we combined expression profiling of 117 pediatric patient samples and detailed molecular cytogenetic analyses including the Chromosome Conformation Capture on Chip (4C) method. Two T-ALL subtypes were identified that lacked rearrangements of known oncogenes. One subtype associated with cortical arrest, expression of cell cycle genes and ectopic NKX2-1 or NKX2-2 expression for which rearrangements were identified. The second subtype associated with immature T-cell development and high expression of the MEF2C transcription factor as consequence of rearrangements of MEF2C, transcription factors that target MEF2C or MEF2C-associated cofactors. We propose NKX2-1, NKX2-2 and MEF2C as T-ALL oncogenes that are activated by various rearrangements.
Integrated transcript and genome analyses reveal NKX2-1 and MEF2C as potential oncogenes in T cell acute lymphoblastic leukemia.
Specimen part
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