Tumor growth and metastasis is controlled by paracrine signaling between cells of the tumor microenvironment and malignant cells. Cancer-associated fibroblasts (CAFs), are functionally important components of the tumor microenvironment. Although some steps involved in the cross-talk between these cells are known, there is still a lot that is not clear. Thus, the addition of, the consideration of microenvironment in the development of the disease, to the clinical and pathological procedures (currently admitted as the consistent value cancer treatments) could lay the foundations for the development of new treatment strategies to control the disease.
Functional heterogeneity of cancer-associated fibroblasts from human colon tumors shows specific prognostic gene expression signature.
Specimen part
View SamplesSnail1 transcriptional factor is essential for triggering epithelial-to-mesenchymal transition (EMT) and inducing tumor cell invasion. We report here that Snail1 plays also a key role in tumor associated fibroblasts since is necessary for enhancement by these cells on epithelial cells tumor invasion. Snail1 expression in fibroblast requires signals derived from tumor cells such as TGF-b; reciprocally, in fibroblasts Snail1 organizes a complex program that favors collective invasion of epithelial cells at least in part by the secretion of diffusible signaling molecules, such as prostaglandin E2. The capability of human or murine tumor-derived cancer associated fibroblasts to promote tumor invasion is associated to Snail1 expression and obliterated by Snail1 depletion. In vivo experiments show that tumor cells co-transplanted with Snail1 depleted fibroblasts show lower invasion than those xenografted with control fibroblasts. Finally Snail1 depletion in mice prevents the formation of breast tumors and decreased their invasion. Therefore, these results demonstrate that the role of Snail1 in tumor invasion is not limited to its effect in EMT but dependent on its expression in stromal fibroblasts where it orchestrates its activation and the crosstalk with epithelial cells.
Snail1-Dependent Activation of Cancer-Associated Fibroblast Controls Epithelial Tumor Cell Invasion and Metastasis.
Specimen part
View SamplesAlthough heterochromatin is enriched with repressive traits, it is also actively transcribed, giving rise to large amounts of non-coding RNAs. Although these RNAs are responsible for the formation and maintenance of heterochromatin, little is known about how their transcription is regulated. Here we show that the Snail1 transcription factor represses pericentromeric transcription, acting through the H3K4 deaminase LOXL2. Since Snail1 plays a key role in the epithelial to mesenchymal transition (EMT), we analyzed the regulation of mouse heterochromatin transcription in this process. At the onset of EMT, one of the major structural heterochromatin proteins, HP1a, is transiently released from heterochromatin foci in a Snail1/LOXL2dependent manner during EMT, concomitantly with a down-regulation of major satellite transcription. Global transcriptome analysis indicated that ectopic expression of heterochromatin transcripts affects the transcription profile of EMT-related genes. Additionally, preventing the down-regulation of major satellite transcripts compromised the migratory and invasive behavior of mesenchymal cells. We propose that Snail1 regulates heterochromatin transcription through the histone-modifying enzyme, LOXL2, thus creating the favorable transcriptional state necessary for completing EMT.
Regulation of heterochromatin transcription by Snail1/LOXL2 during epithelial-to-mesenchymal transition.
Cell line, Treatment
View SamplesThe impact of specific p53 mutations on ovarian tumor development and response to therapeutic treatment remain limited. Here, using transgenic mouse models of epithelial ovarian cancer (EOC), we demonstrated that the Trp53R172H mutation promotes EOC progression compared to wild-type p53, but with different consequences between heterozygous and homozygous mutation status. EOC expressing heterozygous Trp53R172H mutation has enhanced responsiveness to steroid hormones and at late stage developed mucinous cystadenocarcinoma. These findings open new realms for exploring the interaction between p53 and steroid receptor, and the allelic status of p53 in EOC development and treatment.
Mutant p53 Promotes Epithelial Ovarian Cancer by Regulating Tumor Differentiation, Metastasis, and Responsiveness to Steroid Hormones.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Activation of MAPK pathways links LMNA mutations to cardiomyopathy in Emery-Dreifuss muscular dystrophy.
No sample metadata fields
View SamplesThe present research is devoted to the identification of gene(s) severely affected by LMNA mutations, leading to striated muscle laminopathies and more specifically the cardiomyopathy. For this purpose, we developped a large-scale gene expression approach on heart and skeletal tissues from Lmna H222P heterozygous Knock-In mouse model.
Activation of MAPK pathways links LMNA mutations to cardiomyopathy in Emery-Dreifuss muscular dystrophy.
No sample metadata fields
View SamplesThe present research is devoted to the identification of gene(s) severely affected by LMNA mutations, leading to striated muscle laminopathies and more specifically the cardiomyopathy. For this purpose, we developped a large-scale gene expression approach on heart and skeletal tissues from Lmna H222P heterozygous Knock-In mouse model.
Activation of MAPK pathways links LMNA mutations to cardiomyopathy in Emery-Dreifuss muscular dystrophy.
No sample metadata fields
View SamplesThe functional status of the tumor repressor protein (TP53 or TRP53) is a defining feature of ovarian cancer. Mutant or null alleles of TP53 are expressed in greater than 90% of all high-grade serous adenocarcinomas. Wild type TP53 is elevated in low-grade serous adenocarcinomas in women and in our Pten/Kras/Amhr2-Cre mutant mouse model. Disruption of the Trp53 gene in this mouse model did not lead to high-grade ovarian cancer but did increase expression of estrogen receptor alpha (ERalpha; ESR1) and markedly enhanced the responsiveness of these cells to estrogen. Specifically, when Trp53 positive and Trp53 null mutant mice were treated with estradiol or vehicle, only the Trp53 null and Esr1 positive tumors respond vigorously to estradiol in vivo and exhibit features characteristic of high-grade type ovarian cancer: invasive growth into the ovarian stroma, rampant metastases to the peritoneal cavity and signs of genomic instability. Estrogen promoted and progesterone suppressed the growth of Trp53 null ovarian tumors and tumor cells injected intraperitoneally (IP), subcutaneously (SC) or when grown in matrigel. Exposure of the Trp53 depleted cells to estrogen also has a profound impact on the tumor microenvironment and immune-related events. These results led to the new paradigm that TRP53 status is related to the susceptibility of transformed ovarian surface epithelial (OSE) cells to estradiol-induced metastases and genomic instability. This novel finding is relevant not only for women during their reproductive years but also for women on hormone (estradiol) replacement therapies.
Tumor repressor protein 53 and steroid hormones provide a new paradigm for ovarian cancer metastases.
Age, Specimen part
View SamplesGene expression from MDA-MB-231 cells shControl and shLOXL2.
Lysyl oxidase-like 2 (LOXL2) oxidizes trimethylated lysine 4 in histone H3.
Cell line
View SamplesA great number of studies have investigated changes induced by morphine exposure in gene expression using several experimental models. In this study, we examined gene expression changes during chronic exposure to morphine during maturation and differentiation of zebrafish CNS.
Whole-genome expression profile in zebrafish embryos after chronic exposure to morphine: identification of new genes associated with neuronal function and mu opioid receptor expression.
Treatment
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