The mTOR (mammalian Target of Rapamycin) pathway is constitutively activated in Diffuse Large B-Cell Lymphoma (DLBCL). mTOR inhibition has been shown to have clinical activity in patients with DLBCL, although overall response rates remain low. We therefore evaluated differences in the transcriptome between DLBCL cell lines with differential sensitivity to the mTOR inhibitor Rapamycin, to (A) identify gene-expression patterns(GEP) capable of identifying sensitivity to Rapamycin, (B) understand the underlying mechanisms of resistance to Rapamycin in DLBCL and (C) identify bioactive molecules likely to synergize with mTOR inhibitors. Using Affymetrix HuGene ST 1.0 microarrays, we were able to identify a gene expression signature capable of accurately predicting sensitivity and resistance to Rapamycin in DLBCL cell lines. Pathway analysis identified the serine/threonine kinase Akt as central to the differentially-expressed gene network. Connectivity mapping of our datasets identified compounds targeting the AKT pathway with a high likelihood of reversing the GEP associated with resistance to Rapamycin. Specifically, we evaluated the HIV protease inhibitor (PI) Nelfinavir, which is known to have anti-cancer and Akt-inhibitory properties, as well as the small molecule Akt inhibitor MK-2206, for their potential to synergize with to Rapamycin in DLBCL. Nelfinavir and MK-2206 caused profound inhibition of cell viability in combination with Rapamycin in DLBCL cell lines. Low nanomolar concentrations of Rapamycin inhibited phosphorylation of Akt and also downstream targets of activated mTOR when used in combination with these Akt inhibitors. These findings have the potential to significantly improve patient selection for mTOR inhibitor therapy, and to improve rates and depths of response. More broadly, they support the use of global RNA expression and connectivity mapping to improve patient selection and identify synergistic drug combinations for cancer therapy.
Akt inhibitors MK-2206 and nelfinavir overcome mTOR inhibitor resistance in diffuse large B-cell lymphoma.
Cell line
View SamplesMantle Cell Lymphoma (MCL) is a mostly incurable malignancy arising from nave B cells (NBC) in the mantle zone of lymph node follicles. We analyzed genome-wide methylation in MCL patients using the HELP (Hpa II tiny fragment Enrichment by Ligation mediated PCR) assay and found significant aberrancy in promoter methylation patterns as compared to normal NBCs. Using biological and stringent statistical criteria, we further identified four hypermethylated genes CDKN2B, MLF-1, PCDH8, HOXD8 and four hypomethylated genes CD37, HDAC1, NOTCH1 and CDK5 where aberrant methylation was associated with inverse changes in mRNA levels. MassArray Epityper analysis confirmed the presence of differential methylation at the promoter region of these genes. Immunohistochemical analysis of an independent cohort of 14 MCL patient samples, confirmed CD37 surface expression in 93% of patients, validating its selection as a target for MCL therapy. Treatment of MCL cell lines with a novel small modular immunopharmaceutical(CD37-SMIP) resulted in significant loss of viability in cell lines with intense surface CD37 expression. Treatment of MCL cell lines with the DNA methyltransferase inhibitor decitabine resulted in reversal of aberrant hypermethylation and synergized with the HDAC inhibitor SAHA in induction of the four hypermethylated genes CDKN2B, MLF-1, PCDH8 and HOXD8. The combination of Decitabine and SAHA also resulted in potent and synergistic anti-MCL cytotoxicity as compared to either drug alone. In conclusion, our analysis shows prominent and aberrant methylation of the MCL genome and identifies novel differentially methylated and expressed genes in MCL cell lines and patient samples. Furthermore, our data suggest that differentially methylated genes can be targeted for therapeutic benefit in MCL.
Genomewide DNA methylation analysis reveals novel targets for drug development in mantle cell lymphoma.
Disease, Cell line
View SamplesSOX11 (Sex determining region Y-box 11) expression is specific for MCL as compared to other Non-Hodgkin’s lymphomas. However, the function and direct binding targets of SOX11 in MCL are largely unknown. We used high-resolution ChIP-Seq to identify the direct target genes of SOX11 in a genome-wide, unbiased manner and elucidate its functional significance. Pathway analysis identified WNT, PKA and TGF-beta signaling pathways as significantly enriched by SOX11 target genes. qCHIP confirmed that SOX11 directly binds to individual genes in these pathways in both MCL cell lines and patients. Interrogation of an eighty-two patient gene-expression dataset demonstrated that SOX11 mRNA expression was inversely proportional to Ki-67, a marker of cell proliferation. Functional studies using RNA interference demonstrate that SOX11 directly regulates WNT signaling and modulates chemotherapy sensitivity to cytarabine in MCL. We analyzed SOX11 expression in three independent well-annotated tissue microarrays from the University of Wisconsin (UW), Karolina Institute and British Columbia Cancer Agency (BCCA). Our findings suggest that high SOX11 expression is associated with improved survival in a subset of MCL patients, particularly those treated with intensive chemotherapy incorporating cytarabine. Transcriptional regulation of WNT and other biological pathways affects by SOX11 target genes may help explain the impact of SOX11 expression on patient outcomes. Overall design: RNA-seq experiments studying SOX11-mediated regulation of gene transcription by examining genes differentially expressed following SOX11 depletion in 3 MCL cell lines, Granta-519, Z138 and JEKO-1
High-resolution chromatin immunoprecipitation (ChIP) sequencing reveals novel binding targets and prognostic role for SOX11 in mantle cell lymphoma.
No sample metadata fields
View SamplesWe performed RNA-Seq analysis of wildtype and three EPAS1-/- 786-O single cell clones generated by CRISPR/Cas9 to identify the HIF-2a-responsive genes in this cell line. Samples from wildtype 786-O cells treated with DMSO or HIF-2a antagonist compound C2 were also included in this analysis. Overall design: In this experiment, we analyzed the transcriptomic profiles of 2 replicates of wildtype (WT) EPAS1+/+ 786-O cells, 1 replicate for each of the three independent EPAS1-/- 786-O single cell clones, 1 replicate of WT-786-O cells treated with DMSO and 1 replicate of WT-786-O cells treated with 10uM HIF-2a antagonist C2.
A GPX4-dependent cancer cell state underlies the clear-cell morphology and confers sensitivity to ferroptosis.
Subject
View SamplesThe RNA splicing factor SF3B1 is recurrently mutated in chronic lymphocytic leukemia (CLL), but its functional role in the pathogenesis of this disease has not been firmly established. Here, we show that conditional expression of heterozygous Sf3b1-K700E mutation in mouse B lineage cells disrupts pre-mRNA splicing, alters B-cell development and function, and induces a state of cellular senescence. B-cell restricted expression of this mutation combined with Atm deletion led to the overcoming of cellular senescence, together with enhanced genome instability and the development of clonal B220+CD5+ CLL cells in elderly mice at low penetrance. Mice with CLL-like disease were found to have amplifications of chromosomes 15 and 17. Integrated transcriptome and proteome analysis of the CLL-like cells revealed coordinated dysregulation of multiple CLL-associated cellular processes. This included an unexpected signature of deregulated B-cell receptor (BCR) signaling, which we could also identify in SF3B1-mutated CLL samples from two independent patient cohorts. Notably, human CLLs harboring SF3B1 mutations exhibited greater sensitivity and altered response kinetics to BTK kinase ibrutinib. Our genetically faithful murine model of CLL thus reveals fresh insights regarding the impact of SF3B1 mutation on CLL pathogenesis and suggests a system for identifying vulnerabilities related to this mutation that can be further exploited for the treatment of CLLs with this common mutation. Overall design: RNA-seq of B cells from WT, Sf3b1 MT, Atm MT, DM and DM-CLL mice
A Murine Model of Chronic Lymphocytic Leukemia Based on B Cell-Restricted Expression of Sf3b1 Mutation and Atm Deletion.
Specimen part, Cell line, Subject
View SamplesWe undertook an integrative technological approach to compare miRNA detection capability of three high-throughput commercial platforms. Overall design: We artificially introduced human precursor, 2’-O-methyl modified and mature spiked-in miRNAs in a controlled fashion into native human placenta total RNA.
Differences in microRNA detection levels are technology and sequence dependent.
Subject
View SamplesWe examined the effects of TNFa and Spt5, the major DSIF subunit, on nascent and mature transcripts using RNA-Seq of chromatin-associated and cytoplasmic transcripts. Overall design: RNA was extracted from the cytosolic and chromatin fractions of control and Spt5 KD cells that were treated with TNFa for 1 hour
Analysis of Subcellular RNA Fractions Revealed a Transcription-Independent Effect of Tumor Necrosis Factor Alpha on Splicing, Mediated by Spt5.
No sample metadata fields
View SamplesPancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with limited treatment options. Familial predisposition to PDAC occurs in ~10% of cases, but causative genes have not been identified in most families. Uncovering the genetic basis for PDAC susceptibility has immediate prognostic implications for families and can provide mechanistic clues to PDAC pathogenesis. Here, we perform whole-genome sequence analysis in a family with multiple cases of PDAC and identify a germline nonsense mutation in the member of RAS oncogene family-like 3 (RABL3) gene never before directly associated with hereditary cancer. The truncated mutant allele (RABL3_p.S36*) co-segregates with cancer occurrence. To evaluate the contribution of the RABL3 mutant allele in hereditary cancer, we generated rabl3 heterozygous mutant zebrafish and found increased susceptibility to cancer formation in two independent cancer models. Unbiased approaches implicate RABL3 in RAS pathway regulation: the transcriptome of juvenile rabl3 mutants reveals a KRAS upregulation signature, and affinity-purification mass spectrometry for proteins associated with RABL3 or RABL3_p.S36* identifies Rap1 GTPase-GDP Dissociation Stimulator 1 (RAP1GDS1, SmgGDS), a chaperone that regulates prenylation of RAS GTPases. Indeed, we find that RABL3_p.S36* accelerates KRAS prenylation and requires RAS proteins to promote cell proliferation. Furthermore, rabl3 homozygous mutant zebrafish develop severe craniofacial, skeletal, and growth defects consistent with human RASopathies, and these defects are partially rescued with the MEK inhibitor trametinib. Finally, we identify additional germline mutations in RABL3 that impact RAS activity in vivo and have a significant burden in a cohort of patients with developmental disorders, suggesting a role in undiagnosed RASopathies. Moreover, RABL3 is upregulated in multiple human PDAC cell lines and knockdown abrogates proliferation, consistent with a broader role for RABL3 in PDAC. Our studies identify the RABL3 mutation as a new target for genetic testing in cancer families and uncover a novel mechanism for dysregulated RAS activity in development and cancer. Overall design: WT (4 replicates) and homozygous rabl3-TR41 mutant (3 replicates) larval zebrafish at 21 days of age.
Mutations in RABL3 alter KRAS prenylation and are associated with hereditary pancreatic cancer.
Age, Specimen part, Cell line, Subject
View SamplesRecently, a frequent chromosomal aberration fusing Androgen regulated TMPRSS2 promoter and the ERG gene (T/ERG) was discovered in prostate cancer. Several studies demonstrated cooperation between the T/ERG and other defective pathways in cancer progression however, the biological mechanism by which the T/ERG operates is yet to be determined. Using immortalized prostate epithelial cells (EP) model we were able to show that EP with the combination of androgen receptor(AR) and T/ERG(EP-AR T/ERG cell line) demonstrate an Epithelial to Mesenchymal Transition (EMT) manifested by a mesenchyme-like morphological appearance and behavior.
TMPRSS2/ERG promotes epithelial to mesenchymal transition through the ZEB1/ZEB2 axis in a prostate cancer model.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Runx3-mediated transcriptional program in cytotoxic lymphocytes.
Sex, Age, Specimen part, Treatment
View Samples