Drug resistance invariably limits the clinical efficacy of targeted therapy with kinase inhibitors against cancer. We found that targeted therapy with BRAF, ALK, or EGFR inhibitors induces a complex network of secreted signals in drug-stressed melanoma and lung adenocarcinoma cells. This therapy-induced secretome (TIS) stimulates the outgrowth, infiltration and metastasis of drug-resistant cancer clones in the tumour. Additionally, the TIS supports the survival of drug-sensitive cells, contributing to incomplete tumour regression. We used transcriptomic analysis of sensitive tumour cells and xenograft tumours treated with vehicle, vemurafenib, or crizotinib to identify the transcriptional drivers and to dissect the TIS in melanoma (A375, Colo800, UACC62) and lung adenocarcinoma (H3122). In addition, we utilize cell type–specific mRNA purification by translating ribosome affinity purification (TRAP) to identify pathways that are up-regulated in resistant cells (A375R) in response to the regressing tumour microenvironment. Overall design: Analysis of the response of drug sensitive melanoma and lung adenocarcinoma cells to pharmacological inhibition of their driver oncogene and gene expression analysis of drug resistant cancer cells responding to different tumor microenvironments.
Therapy-induced tumour secretomes promote resistance and tumour progression.
No sample metadata fields
View SamplesNumerous mammalian proto-oncogene and other growth-regulatory transcripts are upregulated in malignancy due to abnormal mRNA stabilization. In hepatoma cells expressing a hepatitis C virus (HCV) subgenomic replicon, we found that the viral nonstructural protein 5A (NS5A), a protein known to bind to viral RNA, also bound specifically to human cellular transcripts that encode regulators of cell growth and apoptosis, and this binding correlated with transcript stabilization. An important subset of human NS5A-target transcripts contained GU-rich elements, sequences known to destabilize mRNA. We found that NS5A bound to GU-rich elements in vitro and in cells. Mutation of the NS5A zinc finger abrogated its GU-rich element-binding and mRNA stabilizing activities. Overall, we identified a molecular mechanism whereby HCV manipulates host gene expression by stabilizing host transcripts in a manner that would promote growth and prevent death of virus-infected cells, allowing the virus to establish chronic infection and lead to the development of hepatocellular carcinoma. Overall design: Calculate mRNA decay rate by examining RNA-seq expression levels of 2 samples (Huh and Huh-HCV) at 3 time points (0h, 3h, and 6h) after transcription arrest. RNA-IP followed by RNA-seq on 2 samples (Huh and Huh-HCV).
The hepatitis C viral nonstructural protein 5A stabilizes growth-regulatory human transcripts.
No sample metadata fields
View SamplesComplex three-dimensional (3D) in vitro model systems that recapitulate human tumor biology are essential to better understand the pathophysiology of the disease and to aid in the discovery of novel anti-cancer therapies. 3D organotypic cultures exhibit intercellula communication, nutrient and oxygen gradients, and cell polarity that is lacking in traditional two-dimensional (2D) monolayer cultures. In the present study, we could demonstrate that 2D and 3D cancer models exhibit different drug sensitivities towards both targeted inhibitors of EGFR signaling and broad acting cytotoxic agents. Changes in the kinase activities of Erb family members and differential expression of apoptosis- and survival-associated genes before and after drug treatment may account for the differential drug sensitivities. Importantly, EGFR oncoprotein addiction was evident only in the 3D cultures mirroring the effect of EGFR inhibition in the clinic. Furthermore, targeted drug efficacy was strongly increased when incorporating cancer-associated fibroblasts into the 3D cultures. Taken together, we could provide conclusive evidence that complex 3D cultures are more predictive of the clinical outcome than their 2D counterparts. In the future, 3D cultures will be instrumental for understanding the mode of action of drugs, identifying genotype-drug response relationships and developing patient-specific and personalized cancer treatments.
Organotypic three-dimensional cancer cell cultures mirror drug responses <i>in vivo</i>: lessons learned from the inhibition of EGFR signaling.
Cell line
View SamplesRNA-seq of UPMM3 with restoration of BAP1 and BAP1 mutant proteins. Cell line UPMM3 contains a frameshift mutation in BAP1. Overall design: RNA-seq of UPMM3 with restoration of BAP1 and BAP1 mutant proteins
GNA11 Q209L Mouse Model Reveals RasGRP3 as an Essential Signaling Node in Uveal Melanoma.
Cell line, Subject
View SamplesObjective: To study if diabetic and insulin-resistant states lead to mitochondrial dysfunction in the liver, or alternatively, if there is adaption of mitochondrial function to these states in the long-term range.
Liver adapts mitochondrial function to insulin resistant and diabetic states in mice.
Sex, Specimen part, Treatment
View SamplesHuman primordial germ cells and mouse neonatal and adult germline stem cells are pluripotent and derive embryonic stem cell properties.
Generation of pluripotent stem cells from adult human testis.
No sample metadata fields
View SamplesIn most embryos, the mid-blastula transition is a complex process featuring maternal RNA degradation, cell cycle pause, zygotic transcriptional activation and morphological changes. The nucleocytoplasmic (N/C) ratio has been proposed to control the multiple events at MBT. To understand the global transcriptional response to the changes of the N/C ratio, we profiled wild type and haploid embryos using cDNA microarrays at three developmental stages.
Coupling of zygotic transcription to mitotic control at the Drosophila mid-blastula transition.
No sample metadata fields
View SamplesKaposis sarcoma-associated hepesvirus (KSHV) encodes four genes with homology to human interferon regulatory factors (IRFs). One of these IRFs, the viral interferon regulatory factor 3 (vIRF-3) is expressed in latently infected PEL cells and required for their continuous proliferation. Moreover, vIRF-3 is known to be involved in modulation of the type I interferon response.
Kaposi's sarcoma-associated herpesvirus viral interferon regulatory factor 3 inhibits gamma interferon and major histocompatibility complex class II expression.
Specimen part, Cell line
View SamplesThe Early Growth Response (Egr) family of transcription factors consists of 4 members (Egr1-4) that are expressed in a wide variety of cell types. A large body of evidence point to a role for Egr transcription factors in growth, survival, and differentiation. A major unanswered question is whether Egr transcription factors serve similar functions in diverse cell types by activating a common set of target genes. Signal transduction cascades in neurons and lymphocytes show striking parallels. Activation of either cell type activates the Ras-MAPK pathway and, in parallel, leads to increases in intracellular calcium stimulating the calcineurin-NFAT pathway. In both cell types, the strength of the activation signal affects the cellular outcomes and very strong stimuli lead to cell death. Notably both these pathways converge on the induction of Egr genes. We believe that downstream targets of Egr transcription factors in lymphocytes may also be activated by Egr factors in activated neurons. There is precedence for common target gene activation in these two cell types: apoptosis in both activated T cells and methamphetamine stimulated neurons occurs via FasL induction by NFAT transcription factors. We propose to use developing T lymphocytes (thymocytes) as a model system for discovery of Egr-dependent target genes for several reasons. First, we have observed a prominent survival defect in thymocytes from mice deficient in both Egr1 and Egr3 (1/3 DKO) and a partial differention block in the immature double negative (DN) stage. In addition, thymocytes are an easily manipulatable cell type, and the DN subpopulation affected in 1/3 DKO mice can be isolated to very high purity. We anticipate that 1/3 DKO thymocytes will provide an excellent experimental system that will provide insight into Egr-dependent transcription in neuronal development, activation, and death.
Redundant role for early growth response transcriptional regulators in thymocyte differentiation and survival.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Plasmacytoid dendritic cells and C1q differentially regulate inflammatory gene induction by lupus immune complexes.
Specimen part, Treatment, Subject
View Samples