Phosphoinositide-3-kinase (PI3K)-a inhibitors are clinically active in squamous carcinoma (SCC) of the head and neck (H&N) bearing mutations or amplification of PIK3CA. We aimed to identify potential mechanism of resistance and have observed that SCCs cells overcome the antitumor effects of the PI3Ka inhibitor BYL719 by maintaining PI3K-independent activation of the mammalian target of rapamycin (mTOR). The persistent mTOR activation is mediated by the tyrosine kinase receptor AXL. We found that AXL is overexpressed in resistant tumors, dimerizes with the epidermal growth factor receptor (EGFR), phosphorylates EGFR tyrosine 1173, resulting in activation of phospholipase C? (PLC?)- protein kinase C (PKC) that, in turn, activates mTOR. Finally, simultaneous treatment with PI3Ka and either EGFR, AXL or PKC inhibitors reverts this resistance. Overall design: RNAseq from acquired resistant cells CAL33B, K180B were compared to their parental counterpart CAL33 and K180, respectively. K180 is a shortcut of KYSE180, and B stands for BYL719. Duplicate of parental sensitive cells and K180B, and triplicate for CAL33B.
AXL mediates resistance to PI3Kα inhibition by activating the EGFR/PKC/mTOR axis in head and neck and esophageal squamous cell carcinomas.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Foxl2 functions in sex determination and histogenesis throughout mouse ovary development.
Sex, Subject
View SamplesComparison of Foxl2-null ovaries to wildtype ovaries, ovaries lacking Wnt4 or Kit, or testes, throughout mouse development.
Foxl2 functions in sex determination and histogenesis throughout mouse ovary development.
No sample metadata fields
View SamplesGene expression profiles of 8 samples of CD34+derived normal promyelocytes
Identification of a molecular signature for leukemic promyelocytes and their normal counterparts: Focus on DNA repair genes.
Specimen part
View SamplesHomeodomain interacting protein kinase 2 (Hipk2) has previously been implicated in control of several transcription factors involved in embryonic development, apoptosis, cell proliferation and tumour development13. Analysis of gene expression in tissues from genetically heterogeneous mouse or human populations can reveal motifs associated with the structural or functional components of the tissue, and may predict roles for genes of unknown function4,5. Here we have applied this network strategy to uncover a novel role for the Hipk2 gene in the transcriptional system controlling adipogenesis. Both in vitro and in vivo models were used to show that knockdown or loss of Hipk2 specifically inhibits white adipose cell differentiation and tissue development. In addition, loss of Hipk2 leads to induction of pockets of multilocular brown fat-like cells in remaining white adipose depots. These cells express markers of brown and beige fat such as uncoupling protein 1 (Ucp1) and transmembrane protein 26 (Tmem26), and thermogenic genes including PPAR- coactivator 1a (Ppargc1a), and cell death-inducing DFFA-like effector a (Cidea). These changes are accompanied by increased insulin sensitivity in Hipk2 knock-out mice and reduced high fat diet-induced weight gain, highlighting a potential role for this kinase in diseases such as diabetes and obesity. Our study underscores the versatility and power of a readily available tissue, such as skin, for network modelling of systemic transcriptional programs involved in multiple pathways, including lipid metabolism and adipogenesis.
Identification of Hipk2 as an essential regulator of white fat development.
Sex, Age, Specimen part
View SamplesGene expression in self-renewing epithelial tissues is controlled by cis- and trans-activating regulatory factors that mediate responses to exogenous agents capable of causing tissue damage, infection, inflammation, or tumorigenesis. We used network construction methods to analyze the genetic architecture of gene expression in normal mouse skin in a cross between tumor-susceptible Mus musculus and tumor-resistant Mus spretus. We demonstrate that gene expression motifs representing different constituent cell types within the skin such as hair follicle cells, haematopoietic cells, and melanocytes are under separate genetic control. Motifs associated with inflammation, epidermal barrier function and proliferation are differentially regulated in mice susceptible or resistant to tumor development. The intestinal stem cell marker Lgr5 is identified as a candidate master regulator of hair follicle gene expression, and the Vitamin D receptor (Vdr) links epidermal barrier function, inflammation, and tumor susceptibility.
Genetic architecture of mouse skin inflammation and tumour susceptibility.
No sample metadata fields
View SamplesGene expression levels in normal tissues can differ substantially between individuals, due to inherited polymorphisms acting in cis or trans. Analysis of this variation across a population of genetically distinct individuals allows us to visualize a network of co-expressed genes under normal homeostatic conditions, and the consequences of perturbation by tissue damage or disease development. Here, we explore gene expression networks in normal adult skin from 470 genetically unique mice, and demonstrate the dependence of the architecture of signaling pathways on skin tissue location (dorsal or tail skin) and perturbation by induction of inflammation or tumorigenesis. Gene networks related to specific cell types, as well as signaling pathways including Sonic Hedgehog (Shh), Wnt, Lgr family stem cell markers, and keratins differed at these tissue sites, suggesting mechanisms for the differential susceptibility of dorsal and tail skin to development of skin diseases and tumorigenesis. The Pten tumor suppressor gene network is extensively rewired in premalignant tumors compared to normal tissue, but this response to perturbation is lost during malignant progression. We present a software package for eQTL network analysis and demonstrate how network analysis of whole tissues provides insights into interactions between cell compartments and signaling molecules.
Gene Expression Architecture of Mouse Dorsal and Tail Skin Reveals Functional Differences in Inflammation and Cancer.
Sex, Age, Specimen part, Treatment
View SamplesGene expression levels in normal tissues can differ substantially between individuals, due to inherited polymorphisms acting in cis or trans. Analysis of this variation across a population of genetically distinct individuals allows us to visualize a network of co-expressed genes under normal homeostatic conditions, and the consequences of perturbation by tissue damage or disease development. Here, we explore gene expression networks in normal adult skin from 470 genetically unique mice, and demonstrate the dependence of the architecture of signaling pathways on skin tissue location (dorsal or tail skin) and perturbation by induction of inflammation or tumorigenesis. Gene networks related to specific cell types, as well as signaling pathways including Sonic Hedgehog (Shh), Wnt, Lgr family stem cell markers, and keratins differed at these tissue sites, suggesting mechanisms for the differential susceptibility of dorsal and tail skin to development of skin diseases and tumorigenesis. The Pten tumor suppressor gene network is extensively rewired in premalignant tumors compared to normal tissue, but this response to perturbation is lost during malignant progression. We present a software package for eQTL network analysis and demonstrate how network analysis of whole tissues provides insights into interactions between cell compartments and signaling molecules.
Gene Expression Architecture of Mouse Dorsal and Tail Skin Reveals Functional Differences in Inflammation and Cancer.
Sex, Specimen part
View SamplesGene expression levels in normal tissues can differ substantially between individuals, due to inherited polymorphisms acting in cis or trans. Analysis of this variation across a population of genetically distinct individuals allows us to visualize a network of co-expressed genes under normal homeostatic conditions, and the consequences of perturbation by tissue damage or disease development. Here, we explore gene expression networks in normal adult skin from 470 genetically unique mice, and demonstrate the dependence of the architecture of signaling pathways on skin tissue location (dorsal or tail skin) and perturbation by induction of inflammation or tumorigenesis. Gene networks related to specific cell types, as well as signaling pathways including Sonic Hedgehog (Shh), Wnt, Lgr family stem cell markers, and keratins differed at these tissue sites, suggesting mechanisms for the differential susceptibility of dorsal and tail skin to development of skin diseases and tumorigenesis. The Pten tumor suppressor gene network is extensively rewired in premalignant tumors compared to normal tissue, but this response to perturbation is lost during malignant progression. We present a software package for eQTL network analysis and demonstrate how network analysis of whole tissues provides insights into interactions between cell compartments and signaling molecules.
Gene Expression Architecture of Mouse Dorsal and Tail Skin Reveals Functional Differences in Inflammation and Cancer.
Sex
View SamplesHair follicles are self-renewing organs within the skin which cycle through periods of growth and destruction, with an intervening period of outward quiescence. The hair follicle cycle is driven by Hedgehog and Wnt signaling and affects epithelial thickness, melanin production, immune function, and tumor susceptibility. We have previously shown that somatic alterations to the genome affect the genetic architecture of the skin. This study examines how the hair follicle cycle affects gene the genetic architecture in vivo by genomic and genetic analysis of 343 genetically heterogeneous mice during the hair follicle growth phase (anagen) and quiescent phase (telogen). We use eQTL analysis and differential correlation to identify changes in metabolic and stem cell activity not detected by differential expression. Germline influence in gene expression is profoundly higher during anagen, but this increase is not a simple factor of higher levels of gene expression. The most strongly induced eQTLs were involved in cellular energy metabolism and melanogenesis rather than hair follicle growth or hedgehog signaling. We demonstrate that hair follicle and circadian rhythm pathways are sexually dimorphic, but do not find evidence for an effect of sex on eQTL networks. We also use eQTL gene network analysis to identify candidate causal relationships between expression of genes in the hair follicle and melanin pathways, identifying Mcoln3 as a candidate for the familial melanoma locus on 1p22. To lower the bioinformatic barriers to eQTL network analysis we produced CARMEN, a free open-source stand-alone software package. This study demonstrates how to perform a systems genetic analysis of a heterogeneous tissue studied in vivo under physiologically relevant growth signals.
Gene Expression Architecture of Mouse Dorsal and Tail Skin Reveals Functional Differences in Inflammation and Cancer.
Sex, Age, Specimen part
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