Cooperative dependencies between mutant oncoproteins and wild-type proteins are critical in cancer pathogenesis and therapy resistance. Although spleen tyrosine kinase (SYK) has been implicated in hematologic malignancies, it is rarely mutated. We used kinase activity profiling to identify collaborators of SYK in acute myeloid leukemia (AML) and determined that FMS-like tyrosine kinase 3 (FLT3) is transactivated by SYK via direct binding. Highly activated SYK is predominantly found in FLT3-ITD positive AML and cooperates with FLT3-ITD to activate MYC transcriptional programs. FLT3-ITD AML cells are more vulnerable to SYK suppression than FLT3 wild-type counterparts. In a FLT3-ITD in vivo model, SYK is indispensable for myeloproliferative disease (MPD) development, and SYK overexpression promotes overt transformation to AML and resistance to FLT3-ITD-targeted therapy.
SYK is a critical regulator of FLT3 in acute myeloid leukemia.
Cell line, Treatment
View SamplesActivating signaling mutations are common in acute leukemia with KMT2A (previously MLL) rearrangements (KMT2A-R). These mutations are often subclonal and their biological impact remains unclear. Using a retroviral acute myeloid mouse leukemia model, we demonstrate that FLT3ITD, FLT3N676K, and NRAS G12D accelerate KMT2A-MLLT3 leukemia onset. Subclonal FLT3N676K mutations also accelerate disease, possibly by providing stimulatory factors such as Mif. Acquired de novo mutations in Braf, Cbl, Kras, and Ptpn11 were identified in KMT2A-MLLT3 leukemia cells and favored clonal expansion. During clonal evolution, serial genetic changes at the KrasG12D locus was observed, consistent with a strong selective advantage of additional KrasG12D. KMT2A-MLLT3 leukemias with signaling mutations enforced Myc- and Myb transcriptional modules. Our results provide new insight into the biology of KMT2A-R leukemia with subclonal signaling mutations and highlights the importance of activated signaling as a contributing driver in this disease. Overall design: mRNA sequencing of KMT2A-MLLT3 leukemias with or without activating mutations generated using Illumina NextSeq 500.
De novo activating mutations drive clonal evolution and enhance clonal fitness in KMT2A-rearranged leukemia.
Specimen part, Cell line, Subject
View SamplesIn this study, we have utilized microarray analysis to directly compare a subset of structurally distinct, clinically relevant SERMs in the presence and absence of estradiol, using a high replicate number (10) to ensure detection of modestly regulated genes.
Research resource: Transcriptional profiling in a cellular model of breast cancer reveals functional and mechanistic differences between clinically relevant SERM and between SERM/estrogen complexes.
Cell line
View SamplesThe goal is the characterization of the off-target activity of BKM120 observed in A2058 human melanoma cell line at IC90 concentration (3.606 M) but not at lower concentrations. Controls are BEZ235, GDC0941, showing no off-target activity.
Characterization of the mechanism of action of the pan class I PI3K inhibitor NVP-BKM120 across a broad range of concentrations.
Cell line
View SamplesThe Rac nucleotide Exchange Factor (Rac-GEF) P-Rex1 is highly expressed in breast cancer, specifically in the luminal subtype, and is an essential mediator of actin cytoskeleton reorganization and cell migratory responses induced by ErbB and other tyrosine-kinase receptors. Heregulin, a growth factor highly expressed in mammary tumors, causes the activation of P-Rex1 and Rac1 in breast cancer cells via ErbB3, leading to a motile response. Since there is limited information about P-Rex1 downstream effectors, we carried out a microarray analysis to identify genes regulated by P-Rex1 in the context of HRG stimulation. In T-47D breast cancer cells, HRG treatment caused major changes in gene expression, including genes associated with motility, adhesion, invasiveness and metastasis. Silencing P-Rex1 expression from T-47D cells using RNAi altered the induction and repression of a subset of HRG-regulated genes, among them genes associated with extracellular matrix organization, migration, and chemotaxis. HRG induction of MMP10, a gene encoding for metalloproteinase-10, was found to be highly sensitive both to P-Rex1 depletion as well as inhibition of Rac1 function by the GTPase Activating Protein (GAP) 2-chimaerin, suggesting the dependence of the P-Rex1/Rac1 pathway for the induction of genes critical for breast cancer invasiveness. Notably, there is a significant association in the expression of P-Rex1 and MMP10 in human luminal breast cancer, and their co-expression is indicative of poor prognosis.
Characterization of a P-Rex1 gene signature in breast cancer cells.
No sample metadata fields
View SamplesStaphylococcus aureus can cause serious skin, respiratory, and other life-threatening invasive infections in humans, and methicillin-resistant S. aureus (MRSA) strains have been acquiring increasing antibiotic resistance. While MRSA was once mainly considered a hospital-acquired infection, the emergence of new strains, some of which are pandemic, has resulted in community-acquired MRSA infections that often present as serious skin infections in otherwise healthy individuals. Accordingly, defining the mechanisms that govern the activation and regulation of the immune response to MRSA is clinically important and could lead to the discovery of much needed rational targets for therapeutic intervention. Because the cytokine thymic stromal lymphopoetin (TSLP) is highly expressed by keratinocytes of the skin3, we investigated its role in host-defense against MRSA. Here we demonstrate that TSLP acts on neutrophils to increase their killing of MRSA. In particular, we show that both mouse and human neutrophils express functional TSLP receptors. Strikingly, TSLP enhances mouse neutrophil killing of MRSA in both an in vitro whole blood killing assay and an in vivo skin infection model. Similarly, TSLP acts directly on purified human blood neutrophils to reduce MRSA burden. Unexpectedly, we demonstrate that TSLP mediates these effects both in vivo and in vitro by engaging the complement C5 system. Thus, TSLP increases MRSA killing in a neutrophil- and complement-dependent manner, revealing a key connection between TSLP and the innate complement system, with potentially important therapeutic implications for control of MRSA infection. Overall design: mRNA expression analysis. 16 samples are from 2 donors, 8 samples per donor, 2 time points (4hr and 16 hr), and 4 conditions (control, TSLP treated, Heat Killed MRSA treated, and TSLP+HKM treated) .
A TSLP-complement axis mediates neutrophil killing of methicillin-resistant <i>Staphylococcus aureus</i>.
No sample metadata fields
View SamplesWe report that decreased expression and activity of AhR exacerbates murine neovascular age-related macular degeneration, and increases cell migration and tube formation. The mechanism involves increased expression of pro-angiogenic mediators and altered matrix degradation. The results of our study suggest that the AhR signaling pathway may be important in multiple AMD related pathways. Overall design: Gene expression analysis in the retinal pigment epithelium (RPE)-choroid tissue from AhR knockout mice contrasted against wild-type age-matched controls.
Aryl hydrocarbon receptor knock-out exacerbates choroidal neovascularization via multiple pathogenic pathways.
No sample metadata fields
View SamplesMononuclear phagocytes play an important role in the removal of apoptotic cells by expressing cell surface receptors that recognize and remove apoptotic cells. Based on the knowledge that cigarette smoking is associated with increased lung cell turnover, we hypothesized that alveolar macrophages (AM) of normal cigarette smokers may exhibit enhanced expression of apoptotic cell removal receptor genes. AM obtained by bronchoalveolar lavage of normal non-smokers (n=11) and phenotypic normal smokers (n=13, 36 6 pack-yr) were screened for mRNA expression of all known apoptotic cell removal receptors using Affymetrix HG-U133 Plus 2.0 chips with TaqMan RT-PCR confirmation. Of the 14 known apoptotic receptors expressed, only MER Tyrosine Kinase (MERTK), a transmembrane tyrosine kinase receptor, was significantly up-regulated in smokers. MERTK expression was then assessed in AM of smokers vs nonsmokers by TaqMan RT-PCR, immunohistochemistry, Western and flow analysis. Smoker AM had up-regulation of MERTK mRNA levels (smoker vs non-smoker, 3.6-fold by microarray, p<0.003; 9.5-fold by TaqMan RT-PCR, p<0.02). Immunohistochemistry demonstrated a qualitative increase in MERTK protein expression on AM of smokers. Increased protein expression of MERTK on AM of smokers was confirmed by Western and flow analyses (p< 0.007 and p< 0.0002, respectively). MERTK, a cell surface receptor that recognizes apoptotic cells, is expressed on human AM, and its expression is up-regulated in AM of cigarette smokers. This may reflect an increased demand for removal of apoptotic cells in smokers, an observation with implications for the development of chronic obstructive pulmonary disease (COPD), a disorder associated with dysregulated apoptosis of lung parenchymal cells.
Overexpression of apoptotic cell removal receptor MERTK in alveolar macrophages of cigarette smokers.
Sex, Age
View SamplesThis dataset is part of the manuscript titled "The metabolic regulator ERRalpha, a downstream target of HER2/IGF1, as a therapeutic target in breast cancer" (in review). The expression data obtained in human mammary epithelial cells were used to generate a list of ERRalpha-regulated genes that was later refined in clinical breast cancer datasets to generate a clinically relevant signature of ERalpha activity (referred to as Cluster 3 signature). Using this signature of the estrogen-related receptor alpha (ERRa) to profile more than eight-hundred breast tumors, we found that patients with tumors exhibiting higher ERRa activity were predicted to have shorter disease free survival. Further, the ability of an ERRa antagonist, XCT790, to inhibit breast cancer cell proliferation correlates with the cells intrinsic ERRa activity. These findings highlight the potential of using the ERRa signature and antagonists in targeted therapy for breast cancer. Using a chemical genomic approach we determined that activation of the HER2/IGF1 signaling pathways upregulates the expression of PGC-1b, an obligate cofactor for ERRa activity. Knockdown of PGC-1b in HER2 positive breast cancer cells impaired ERRa signaling and reduced cell proliferation, implicating a functional role of PGC1b/ERRa in the pathogenesis HER2 positive breast cancer.
The metabolic regulator ERRα, a downstream target of HER2/IGF-1R, as a therapeutic target in breast cancer.
Specimen part
View SamplesPKCe, an oncogenic member of the PKC family, is aberrantly overexpressed in epithelial cancers. To date, little is known about functional interactions of PKCe with other genetic alterations and the effectors of this kinase that contribute to its tumorigenic and metastatic phenotype. Here we demonstrate that PKCe cooperates with the loss of the tumor suppressor Pten for the development of prostate cancer in a mouse model. Mechanistic analysis revealed that PKCe overexpression and Pten loss individually and synergically cause a remarkable up-regulation in the production of the chemokine CXCL13. Notably, targeted disruption of CXCL13 or its receptor CXCR5 in prostate cancer cells impaired their migratory and tumorigenic properties. In addition to providing evidence for an autonomous vicious cycle driven by PKCe, our studies identified a compelling rationale for targeting the CXCL13:CXCR5 axis for prostate cancer treatment.
Protein Kinase C Epsilon Cooperates with PTEN Loss for Prostate Tumorigenesis through the CXCL13-CXCR5 Pathway.
Cell line
View Samples