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Targeting fibroblast growth factor receptors blocks PI3K/AKT signaling, induces apoptosis, and impairs mammary tumor outgrowth and metastasis.
Specimen part
View Samples4T1 mouse mammary carcinoma cells have an autocrine FGFR active loop leading to constitutive activation of downstream signaling pathways. We found that FGFR inhibitors have a strong effect on the proliferation and survival of these cells.
Targeting fibroblast growth factor receptors blocks PI3K/AKT signaling, induces apoptosis, and impairs mammary tumor outgrowth and metastasis.
Specimen part
View Samples4T1 mouse mammary carcinoma cells have an autocrine FGFR active loop leading to constitutive activation of downstream signaling pathways. We found that FGFR inhibitors have a strong effect on 4T1 tumors in-vivo.
Targeting fibroblast growth factor receptors blocks PI3K/AKT signaling, induces apoptosis, and impairs mammary tumor outgrowth and metastasis.
Specimen part
View SamplesThe Epidermal Growth Factor Receptor 2 (ERBB2 or HER2) is amplified and overexpressed in approximately 20% of invasive breast cancers and is associated with metastasis and poor prognosis. Here we describe the role of a constitutively active splice variant of HER2 (Delta-HER2) in human mammary epithelial cells. Overexpression of Delta-HER2 in human mammary cells decreased apoptosis and increased proliferation and expression of epithelial-to-mesenchymal markers. It also induced invasion in three-dimensional cultures and promoted tumorigenicity and metastasis in vivo. In contrast, similar overexpression of wild-type HER2 failed to evoke the same effects. Unbiased protein-tyrosine phosphorylation profiling revealed a significant increase in phosphorylation of several key signaling proteins upon Delta-HER2 expression, some of which not previously shown to belong to the HER2 pathway. In addition, microarray analysis revealed the expression of a set of genes specifically associated with Delta-HER2 expression. We found those genes to be highly expressed in ER-negative, high grade and metastatic primary breast tumors. Altogether, these results provide new insights into the function of a tumorigenic splice variant of HER2 and the signaling cascade deriving from its activity
Mammary tumor formation and metastasis evoked by a HER2 splice variant.
Cell line
View SamplesCell fate perturbations underlie many human diseases, including breast cancer. However, the regulation of breast cell fate remains largely elusive. The mammary gland epithelium consists of differentiated luminal epithelial and basal myoepithelial cells, as well as undifferentiated stem cells and more restricted progenitors. Breast cancer originates from this epithelium but the molecular mechanisms underlying breast epithelial hierarchy remain ill-defined. Mouse and human luminal cells express keratins (K)18, 8, 19 and/or estrogen receptor (ER) and progesterone receptor (PR), their basal counterparts express K5, 14 and/or p63 and/or -smooth-muscle actin (-SMA)4-6. In this study, using a high-content confocal image-based shRNA screen for tumor suppressors regulating human breast cell fate, we discovered that ablation of the Hippo kinases large tumor suppressor (LATS) 1 and 2, promoted luminal fate and increased the number of bipotent and luminal progenitors, the proposed cell-of-origin of most human breast cancers. Mechanistically, we discovered a crosstalk between Hippo and ER signaling. In the presence of LATS, ER was targeted for ubiquitination and proteasomal degradation. Loss of LATS stabilized ER and Hippo effectors YAP/TAZ, which in concert control breast cell fate via intrinsic and paracrine mechanisms. Our findings uncover a novel non-canonical (i.e., YAP/TAZ-independent) effect of LATS in the regulation of human breast cell fate.
The Hippo kinases LATS1 and 2 control human breast cell fate via crosstalk with ERα.
Specimen part, Cell line
View SamplesPerturbation of the tightly regulated dynamic process of cell fate underlies many human diseases. The molecular mechanisms regulating breast cell fate in the hierarchically organized luminal and basal lineages of breast epithelium remain largely elusive. We performed a high-content confocal image-based shRNA screen for regulators of primary human breast cell fate. Inhibition of the Hippo kinases LATS was found to promote luminal fate and increase the number of progenitors, which is a paradox given that Hippo effectors YAP/TAZ have been associated with basal fate. Mechanistically, LATS loss increases the activities of YAP/TAZ and ER, which in concert control breast cell fate via intrinsic and paracrine effects. Reduced LATS expression is found in breast cancers with a poor prognosis; this diminishes the sensitivity of ER-positive- and increases the sensitivity of ER-negative cancers to endocrine therapy. Thus, in this study we have unraveled crosstalk between Hippo and estrogen signaling and shown that LATS loss triggers expansion of luminal progenitors, the highly suspected cell-of-origin in most breast cancers.
The Hippo kinases LATS1 and 2 control human breast cell fate via crosstalk with ERα.
Specimen part, Subject
View SamplesWe used microarrays to compare gene expression across different murine tissues.
Mice deficient in the respiratory chain gene Cox6a2 are protected against high-fat diet-induced obesity and insulin resistance.
Sex, Specimen part
View SamplesMyzus persicae (green peach aphid) feeding on Arabidopsis thaliana induces a defense response, quantified as reduced aphid progeny production, in infested leaves but not in other parts of the plant. Similarly, infiltration of aphid saliva into Arabidopsis leaves causes only a local increase in aphid resistance. Further characterization of the defense-eliciting salivary components indicates that Arabidopsis recognizes a proteinaceous elicitor with a size between 3 to 10 kD. Genetic analysis using well-characterized Arabidopsis mutant shows that saliva-induced resistance against M. persicae is independent of the known defense signaling pathways involving salicylic acid, jasmonate, and ethylene. Among 78 Arabidopsis genes that were induced by aphid saliva infiltration, 52 had been identified previously as aphid-induced, but few are responsive to the well-known plant defense signaling molecules salicylic acid and jasmonate. Quantitative PCR analysis confirms expression of saliva-induced genes. In particular, expression of a set of O-methyltransferases, which may be involved in the synthesis of aphid-repellent glucosinolates, was significantly up-regulated by both M. persicae feeding and treatment with aphid saliva. However, this did not correlate with increased production of 4-methoxyindol-3-ylmethylglucosinolate, suggesting that aphid salivary components trigger an Arabidopsis defense response that is independent of this aphid-deterrent glucosinolate.
Myzus persicae (green peach aphid) salivary components induce defence responses in Arabidopsis thaliana.
Specimen part, Treatment
View SamplesPlant respiration responses to elevated growth [CO2] are key uncertainties in predicting future crop and ecosystem function. In particular, the effects of elevated growth [CO2] on respiration over leaf development are poorly understood. This study tested the prediction that, due to greater whole-plant photoassimilate availability and growth, elevated [CO2] induces transcriptional reprogramming and a stimulation of nighttime respiration in leaf primordia, expanding leaves, and mature leaves of Arabidopsis thaliana. In primordia, elevated [CO2] altered transcript abundance, but not for genes encoding respiratory proteins. In expanding leaves, elevated [CO2] induced greater glucose content and transcript abundance for some respiratory genes, but did not alter respiratory CO2 efflux. In mature leaves, elevated [CO2] led to greater glucose, sucrose and starch content, plus greater transcript abundance for many components of the respiratory pathway, and greater respiratory CO2 efflux. Therefore, growth at elevated [CO2] stimulated dark respiration only after leaves transitioned from carbon sinks into carbon sources. This coincided with greater photoassimilate production by mature leaves under elevated [CO2] and peak respiratory transcriptional responses. It remains to be determined if biochemical and transcriptional responses to elevated [CO2] in primordial and expanding leaves are essential prerequisites for subsequent alterations of respiratory metabolism in mature leaves.
Developmental stage specificity of transcriptional, biochemical and CO2 efflux responses of leaf dark respiration to growth of Arabidopsis thaliana at elevated [CO2].
No sample metadata fields
View SamplesTranscriptional reprogramming and stimulation of leaf respiration by elevated CO2 concentration is diminished, but not eliminated, under limiting nitrogen supply.
Transcriptional reprogramming and stimulation of leaf respiration by elevated CO2 concentration is diminished, but not eliminated, under limiting nitrogen supply.
Age, Specimen part
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