Interleukin-6 (IL-6) is an important growth factor for estrogen receptor-alpha (ER) positive breast cancer, and elevated serum IL-6 is associated with poor prognosis. We firstly demonstrated that pSTAT3 is the primary downstream IL-6 signaling pathway in ER-positive breast cancer, using ten different breast cancer cell lines. Three-dimensional cultures of these cell lines were also used to develop a 17-gene IL-6 specific gene signature that could be used to identify IL-6 driven disease. This signature included a variety of genes involved in immune cell function and migration, cell growth and apoptosis, and the tumor microenvironment. To further validate this IL-6 signature, we obtained 36 human ER-positive breast cancer tumor samples with matched serum for gene expression profiling and determination of an IL-6 pathway activation score (PAS). Patients with high IL-6 PAS were also enriched for elevated serum IL-6 (>=10 pg/ml). We then utilized a murine MCF-7 xenograft model to determine the role of IL-6 in ER-positive breast cancer and potential anti-IL-6 therapy in vivo. When IL-6 was administered in vivo, MCF-7 cells engrafted without the need for estrogen supplementation. Subsequently, we prophylactically treated mice at MCF-7 engraftment with an anti-IL-6 antibody (siltuximab), fulvestrant or combination therapy. Siltuximab alone was able to blunt MCF-7 engraftment. Similarly, when tumors were allowed to grow to 125 mm3 before treatment, siltuximab alone demonstrated tumor regressions in 90% (9/10) of tumors. Given the established role for IL-6 in ER+ breast cancer, this data demonstrates the potential for anti-IL-6 therapeutics.
Interleukin-6 is a potential therapeutic target in interleukin-6 dependent, estrogen receptor-α-positive breast cancer.
Specimen part
View SamplesWe found that a H3K4 specific histone methyltransferase MLL1, a mammalian homologue of Drosophila trithorax, is essential for circadian transcription. MLL1 is in a complex with CLOCK:BMAL1 and contributes to their rhythmic recruitment to circadian promoters and cyclic H3K4 tri-metylation. To analyze the function of MLL1 on circadian gene regulation, we performed comparative microarray analysis of global gene expression levels in WT and MLL1-deficient MEF, at two different circadian time points (CT18 and CT30). This analysis identified several genes whose expression levels were remarkably changed between CT18 and CT30 in WT and MLL1-KO MEF. Typical clock-regulated genes such as Per2, Per3, Bmal1, or Dbp were found to be changing in WT but not in MLL1-KO MEFs.
The histone methyltransferase MLL1 permits the oscillation of circadian gene expression.
Specimen part, Time
View SamplesProstate cancer (PCa) development and progression are associated with chronic inflammation. The cytokine interleukin (IL)-6 can influence progression, differentiation, survival, and angiogenesis of PCa. To identify novel pathways that are triggered by IL-6, we performed a gene expression profiling of two PCa cell lines, LNCaP and MDA PCa 2b, under treatment with 5 ng/ml IL-6. Interferon regulatory factor (IRF)9 was identified as one of the most prevalent IL-6 regulated genes in both cell lines. IRF9 is a mediator of type I interferon signaling and acts together with signal transduction and activator of transcription (STAT)1 and 2 to activate transcription of interferon responsive genes. The IL-6 regulation of IRF9 was confirmed at mRNA and protein levels by quantitative real-time PCR and Western blot, respectively, in both cell lines and could be blocked by the anti-IL-6 antibody Siltuximab. Three PCa cell lines with an autocrine IL-6 loop, PC3, DU145, and LNCaP-IL-6+, showed a high expression of IRF9. A tissue microarray with 36 malignant and adjacent 36 benign areas from prostate cancer specimens showed that IRF9 protein expression is moderately elevated in malignant areas and positively correlates with the tissue expression of IL-6. Downregulation and overexpression of IRF9 provided evidence for an interferon-independent role of IRF9 on cellular proliferation of different PCa cell lines. Furthermore, expression of IRF9 was essential to mediate the antiproliferative effects of IFN-2. We concluded that IL-6 is an inducer of IRF9 expression in prostate cancer and a sensitizer for the antiproliferative effects of IFN2.
IL6 sensitizes prostate cancer to the antiproliferative effect of IFNα2 through IRF9.
Cell line, Treatment
View SamplesMouse and human stem cells with features similar to those of embryonic stem cells have been derived from testicular cells. Although pluripotent stem cells have been obtained from defined germline stem cells (GSCs) of mouse neonatal testis, only multipotent stem cells have been obtained so far from defined cells of mouse adult testis. In this study we describe a robust and reproducible protocol for obtaining germline-derived pluripotent stem (gPS) cells from adult unipotent GSCs. Pluripotency of gPS cells was confirmed by in vitro and in vivo differentiation, including germ cell contribution and transmission. As determined by clonal analyses, gPS cells indeed originate from unipotent GSCs. We propose that the conversion process requires a GSC culture microenvironment that depends on the initial number of plated GSCs and the length of culture time.
Induction of pluripotency in adult unipotent germline stem cells.
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View SamplesMouse and human stem cells with features similar to those of embryonic stem cells have been derived from testicular cells. Although pluripotent stem cells have been obtained from defined germline stem cells (GSCs) of mouse neonatal testis, only multipotent stem cells have been obtained so far from defined cells of mouse adult testis. In this study we describe a robust and reproducible protocol for obtaining germline-derived pluripotent stem (gPS) cells from adult unipotent GSCs. Pluripotency of gPS cells was confirmed by in vitro and in vivo differentiation, including germ cell contribution and transmission. As determined by clonal analyses gPS cells indeed originate from unipotent GSCs. We propose that the conversion process requires a GSC culture microenvironment that depends on the initial number of plated GSCs and the length of culture time.
Induction of pluripotency in adult unipotent germline stem cells.
Specimen part
View SamplesThe satellite cell is considered the major tissue-resident stem cell underlying muscle regeneration, however, multiple non-satellite cell myogenic progenitors have been identified. PW1/Peg3 is expressed in satellite cells as well as a subset of interstitial cells with myogenic potential termed PICs (PW1+ Interstitial Cells). PICs differ from satellite cells by their anatomical location (satellite cells are sublaminal and PICs are interstitial), they do not express any myogenic marker and arise from a Pax3-independent lineage. Upon isolation from juvenile muscle (1 to 3 weeks old), PICs are capable to form both skeletal and smooth muscle suggesting they constitute a more plastic population compared to satellite cells. We used microarrays to gain insight into the relantionship between PICs and satellite cells.
Defining skeletal muscle resident progenitors and their cell fate potentials.
Age, Specimen part
View SamplesThe liver circadian clock is reprogrammed by nutritional challenge through the rewiring of specific transcriptional pathways. As the gut microbiota is tightly connected to host metabolism, whose coordination is governed by the circadian clock, we explored whether gut microbes influence circadian homeostasis and how they distally control the peripheral clock in the liver. Using fecal transplant procedures we reveal that, in response to high fat diet, the gut microbiota drives PPAR-mediated activation of newly oscillatory transcriptional programs in the liver. Moreover, antibiotics treatment prevents PPAR-driven transcription in the liver, underscoring the essential role of gut microbes in clock reprogramming and hepatic circadian homeostasis. Thus, a specific molecular signature characterizes the influence of the gut microbiome in the liver, leading to the transcriptional rewiring of hepatic metabolism.
Gut microbiota directs PPARγ-driven reprogramming of the liver circadian clock by nutritional challenge.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Cycles in spatial and temporal chromosomal organization driven by the circadian clock.
Specimen part, Disease, Time
View SamplesExpression profiles in WT MEF at different circadian time point after dexamethasone synchronyzation.
Cycles in spatial and temporal chromosomal organization driven by the circadian clock.
Specimen part, Time
View SamplesReduction in the cellular levels of the cyclin kinase inhibitor p27kip1 are frequently found in many human cancers and correlate directly with patient prognosis. Specifically ubiquitin dependent proteasomal turnover has been shown to cause reduced p27 expression in many human cancers. We recently demonstated that expression of a stabilized version of p27kip1 (p27kip1T187A) in a genetically modified mouse significantly reduced the number of intestinal adenomatous polyps which progressed to invasive carcinomas. Based on this work we set out to identify compounds which lead to a re-expression of p27 in cancer tissues. In this work we identify Argyrin A a compound derived from myxobacterium archangium gephyra as a potent inducer of p27kip1 expression. Argyrin A induces apoptosis in human colon cancer xenografts and tumor vasculature in vivo leading to a profound reduction in tumor size at well tolerated levels. Argyrin A functions are strictly dependent on the expression of p27kip1 as neither tumor cells nor endothelial cells which do not express p27kip1 respond to this compound. Surprisingly the molecular mechanism by which Argyrin A exerts its p27 dependent biological function is through a potent inhibition of the 20S proteasome.
Argyrin a reveals a critical role for the tumor suppressor protein p27(kip1) in mediating antitumor activities in response to proteasome inhibition.
Specimen part
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