Natural Killer (NK) cells are primary effectors of innate immunity directed against transformed cells. In response, tumor cells have developed mechanisms to evade NK cell-mediated lysis but the molecular basis for target cell resistance is not well understood. In the present study, we used a lentiviral shRNA library targeting more than 1000 human genes to identify 83 genes that promote target cell resistance to human NK cells. Many of the genes identified in this genetic screen belong to common signaling pathways, however, none of these genes have previously been known to modulate susceptibility of human tumor cells to immunologic destruction. In particular, gene silencing of two members of the JAK family (JAK1 and JAK2) in a variety of tumor cell targets increased their susceptibility to NK-mediated lysis and induced increased secretion of interferon gamma (IFN-gamma by NK cells. Treatment of tumor cells with JAK inhibitors also induced increased susceptibility to NK cell activity. These findings may have important clinical implications and suggest that small molecule inhibitors of tyrosine kinases being developed as therapeutic anti-tumor agents may also have significant immunologic effects in vivo.
Tyrosine kinase pathways modulate tumor susceptibility to natural killer cells.
Cell line
View SamplesMany human oncogenes are challenging therapeutic targets. An alternative to direct targeting of oncogenes is to perform synthetic lethality screens for genes that are essential only in the context of specific cancer-causing mutations. We used high-throughput RNA interference (RNAi) to identify synthetic lethal interactions in cancer cells harboring mutant KRAS, the most commonly mutated human oncogene. We find that cells that are dependent on mutant KRAS exhibit sensitivity to suppression of the serine/threonine kinase STK33 irrespective of tissue origin, whereas STK33 is not required by KRAS-independent cells. STK33 promotes cancer cell viability in a kinase activity-dependent manner by regulating the suppression of mitochondrial apoptosis mediated through S6K1-induced inactivation of the death agonist BAD selectively in mutant KRAS-dependent cells. These observations identify STK33 as a target for treatment of the broad spectrum of mutant KRAS-driven cancers, and demonstrate the potential of RNAi screens for discovering critical functional dependencies created by oncogenic mutations that may enable therapeutic intervention for cancers associated with undruggable genetic alterations.
Synthetic lethal interaction between oncogenic KRAS dependency and STK33 suppression in human cancer cells.
Cell line
View SamplesThe rising incidence of obesity and related disorders such as diabetes and heart disease has focused considerable attention on the discovery of novel therapeutics. One promising approach has been to increase the number or activity of brown-like adipocytes in white adipose depots, as this has been shown to prevent diet-induced obesity and reduce the incidence and severity of type 2 diabetes. Thus, the conversion of fat-storing cells into metabolically active thermogenic cells has become an appealing therapeutic strategy to combat obesity. Here, we report a screening platform for the identification of small molecules capable of promoting a white-to-brown metabolic conversion in human adipocytes. We identified two inhibitors of Janus Kinase (JAK) activity with no precedent in adipose tissue biology that permanently confer brown-like metabolic activity to white adipocytes. Importantly, these metabolically converted adipocytes exhibit elevated UCP1 expression and increased mitochondrial activity. We further found that repression of interferon signalling and activation of hedgehog signalling in JAK-inactivated adipocytes contributes to the metabolic conversion observed in these cells. Our findings highlight a novel role for the JAK/STAT pathway in the control of adipocyte function and establish a platform to identify compounds for the treatment of obesity. Overall design: Human pluripotent stem-cell derived mesenchymal progenitor cells (PSC-MPCs), white adipose cells (PSC-WA), and brown adipose cells (PSC-BA) were treated with DMSO (as control), a JAK3-inhibitor compound, and a SYK-inhibitor compound respectively. Transcriptomic expression profiling was performed at 24 hours and 7 days respectively. Three biological replicates are available for each condition defined by cell type, compound, and time.
White-to-brown metabolic conversion of human adipocytes by JAK inhibition.
No sample metadata fields
View SamplesCancer cells that express oncogenic alleles of RAS typically require sustained expression of the mutant allele for survival, but the molecular basis of this oncogene dependency remains incompletely understood. To identify genes that can functionally substitute for oncogenic RAS, we systematically expressed 15,294 open reading frames in a human KRAS-dependent colon cancer cell line engineered to express an inducible KRAS-specific shRNA. We found 147 genes that promoted survival in the setting of KRAS suppression. In this model, the transcriptional co-activator YAP1 rescued cell viability in KRAS-dependent cells upon suppression of KRAS and was required for KRAS-induced cell transformation. Acquired resistance to Kras suppression in a Kras-driven murine lung cancer model also involved increased YAP1 signaling. KRAS and YAP1 converge on the transcription factor FOS and activate a transcriptional program involved in regulating the epithelial-mesenchymal transition (EMT). Together, these findings implicate transcriptional regulation of EMT by YAP1 as a significant component of oncogenic RAS signaling.
KRAS and YAP1 converge to regulate EMT and tumor survival.
Cell line
View SamplesCancer cells that express oncogenic alleles of RAS typically require sustained expression of the mutant allele for survival, but the molecular basis of this oncogene dependency remains incompletely understood. To identify genes that can functionally substitute for oncogenic RAS, we systematically expressed 15,294 open reading frames in a human KRAS-dependent colon cancer cell line engineered to express an inducible KRAS-specific shRNA. We found 147 genes that promoted survival in the setting of KRAS suppression. In this model, the transcriptional co-activator YAP1 rescued cell viability in KRAS-dependent cells upon suppression of KRAS and was required for KRAS-induced cell transformation. Acquired resistance to Kras suppression in a Kras-driven murine lung cancer model also involved increased YAP1 signaling. KRAS and YAP1 converge on the transcription factor FOS and activate a transcriptional program involved in regulating the epithelial-mesenchymal transition (EMT). Together, these findings implicate transcriptional regulation of EMT by YAP1 as a significant component of oncogenic RAS signaling Overall design: Three biological replicates of primary lung adenocarcinoma cells derived from the Kras Lox-STOP-Lox-G12D;p53flox/flox (KP) mouse lung cancer model into which a doxycycline-inducible shRNA targeting Kras expressed from the 3’UTR of GFP was introduced (KP-KrasA cells) were analyzed at timepoints (days) D0, D4, and D21.
KRAS and YAP1 converge to regulate EMT and tumor survival.
No sample metadata fields
View SamplesGene expression data from AML cell lines, MOLM-14, U937, THP-1 and HL-60, that were infected with a scrambled control hairpin (shControl), two shRNAs directed against GSK-3B (shGSK3B_1 and shGSK3B_2), or two shRNAs directed against GSK-3A (shGSK3A_5 and shGSK3A_6).
The intersection of genetic and chemical genomic screens identifies GSK-3α as a target in human acute myeloid leukemia.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Programming human pluripotent stem cells into white and brown adipocytes.
Specimen part, Disease
View SamplesThe utility of human pluripotent stem cells as a tool for understanding disease and as a renewable source of cells for transplantation therapies is dependent on efficient differentiation protocols that convert these cells into relevant adult cell types. Here we report the robust and efficient differentiation of human pluripotent stem cells into adipocytes. We found that inducible expression of PPARG2 in pluripotent stem cell-derived mesenchymal progenitor cells programmed their development towards an adipocyte cell fate. Using this approach, multiple human pluripotent cell lines were differentiated into adipocytes with efficiencies of 85% to 90%. These pluripotent stem cell-derived adipocytes retained their identity independent of transgene expression, could be maintained in culture for several weeks, expressed mature markers, and exhibited mature functional properties such as lipid catabolism in response to a beta-adrenergic stimulus. Global transcriptional and lipid metabolomic analyses further confirmed the identity and maturity of these pluripotent stem cell-derived adipocytes.
Programming human pluripotent stem cells into white and brown adipocytes.
Specimen part
View SamplesPathologic activation of c-Myc plays a central role in pathogenesis of several neoplasias, including multiple myeloma. However, therapeutic targeting of c-Myc has remained elusive due to its lack of a clear ligand-binding domain. We therefore targeted c-Myc transcriptional function by another means, namely the disruption of chromatin-dependent signal transduction. Members of the bromodomain and extra-terminal (BET) subfamily of human bromodomain proteins (BRD2, BRD3 and BRD4) associate with acetylated chromatin and facilitate transcriptional activation by increasing the effective molarity of recruited transcriptional activators. Notably, BRD4 marks select M/G1 genes in mitotic chromatin for transcriptional memory and direct post-mitotic transcription, via direct interaction with the positive transcription elongation factor complex b (P-TEFb). Because c-Myc is known to regulate promoter-proximal pause release of Pol II, also through the recruitment of P-TEFb, we evaluated the selective small-molecule inhibitor of BET bromodomains, JQ1, as a chemical probe to interrogate the role of BET bromodomains in Myc-dependent transcription and to explore their role as therapeutic targets in c-Myc-driven neoplasias.
BET bromodomain inhibition as a therapeutic strategy to target c-Myc.
Specimen part, Cell line, Treatment
View SamplesThe aim of this study was to investigate correlations between early subclinical findings (10 and 90 day histology and gene expression data) and late outcomes (transplant glomerulopathy and graft loss) in positive crossmatch kidney transplants (+XMKTx).
Early subclinical inflammation correlates with outcomes in positive crossmatch kidney allografts.
Specimen part
View Samples