This SuperSeries is composed of the SubSeries listed below.
Expression of microRNA and their gene targets are dysregulated in preinvasive breast cancer.
Sex, Age, Specimen part, Disease
View SamplesIntroduction: microRNAs (miRNAs) are short non-coding RNAs that negatively regulate gene expression and may play a causal role in invasive breast cancer. Since many genetic aberrations of invasive disease are detectable in earlier stages, we hypothesized that miRNA expression dysregulation and the predicted changes in gene expression would also be found in early breast neoplasias. Methods: Expression profiling of 365 miRNAs by RT-qPCR was combined with laser-capture microdissection to obtain an epithelial specific miRNA expression signature of normal breast epithelium (n=9) and of paired samples of histologically normal epithelium (HN) and ductal carcinoma in situ (DCIS) (n=16). To determine how miRNAs may control the expression of co-dysregulated mRNAs we also performed gene expression microarray analysis in the same paired HN and DCIS samples and integrated this with miRNA-target prediction. We further validated several target pairs by modulating the expression levels of miRNAs in MCF7 cells and measured the expression of target mRNAs and proteins. Results: Thirty-five miRNAs were aberrantly expressed between RM, HN and DCIS. Twenty-nine miRNAs and 420 mRNAs were aberrantly expressed between HN and DCIS. Combining these two datasets with miRNA-target prediction we identified two established target pairs (miR-195:CCND1 and miR-21:NFIB) and tested several novel miRNA:mRNA target pairs. Over-expression of the putative tumor-suppressor miR-125b, under-expressed in DCIS, repressed the expression of MEMO1, which is required for ErbB2-driven cell motility (also a target of miR-125b); and NRIP1/RIP140, which modulates the transcriptional activity of the estrogen receptor. Knockdown of the putative oncogenic miRNAs miR-182 and miR-183, both highly over-expressed in DCIS, increased the expression of CBX7 (which regulates E-cadherin expression), DOK4, NMT2, and EGR1. Augmentation of CBX7 by knockdown of miR-182 expression, in turn, positively regulated the expression of E-cadherin, a key protein involved in maintaining normal epithelial cell morphology which is commonly lost during neoplastic progression. Conclusions: These data provide the first miRNA expression profile of normal breast epithelium and of pre-invasive breast carcinoma. Further, we demonstrate that altered miRNA expression can modulate gene expression changes that characterize these early cancers. We conclude that miRNA dysregulation likely plays a substantial role in early breast cancer development.
Expression of microRNA and their gene targets are dysregulated in preinvasive breast cancer.
Sex, Age, Specimen part, Disease
View SamplesRNA was obtained from histologically normal bronchial epithelium of never, former, and current smokers undergoing fiberoptic bronchoscopy.
Reversible and permanent effects of tobacco smoke exposure on airway epithelial gene expression.
Age
View SamplesDynamic interaction between prostate cancer and the bone microenvironment is a major contributor to metastasis of prostate cancer to bone. In this study we utilized an in-vitro co-culture model of PC3 prostate cancer cells and osteoblasts followed by microarray based gene expression profiling to identify previously unrecognized prostate cancer-bone microenvironment interactions. Factors secreted by PC3 cells resulted in the up-regulation of many genes in osteoblasts associated with bone metabolism and cancer metastasis, including Mmp13, Il-6 and Tgfb2, and down-regulation of Wnt inhibitor Sost. To determine whether altered Sost expression in the bone microenvironment has an effect on prostate cancer metastasis, we co-cultured PC3 cells with Sost knockout (SostKO) osteoblasts and wildtype (WT) osteoblasts and identified several genes differentially regulated between PC3-SostKO osteoblast co-cultures and PC3-WT osteoblast co-cultures. Co-culturing PC3 cells with WT osteoblasts up-regulated cancer-associated long noncoding RNA (lncRNA) MALAT1 in PC3 cells. MALAT1 expression was further enhanced when PC3 cells were co-cultured with SostKO osteoblasts and treatment with recombinant Sost down-regulated MALAT1 expression in these cells. Our results suggest that reduced Sost expression in the tumor microenvironment may promote bone metastasis by up-regulating MALAT1 in prostate cancer.
Cancer-Osteoblast Interaction Reduces Sost Expression in Osteoblasts and Up-Regulates lncRNA MALAT1 in Prostate Cancer.
Cell line
View SamplesWe used heterokaryon cell fusion based reprogramming and identified the cytokine IL6 as a potential regulator of reprogramming to pluripotency. We generated iPS clones using the four reprogramming factors (4F) Oct4, Klf4, Sox2, and c-Myc. In addition, iPS clones were generated using only three factors (3F: Oct4, Klf4, amd Sox2) with the addition of the cytokine IL6 to reprogramming culture conditions. Global RNA-Seq of the 3F + IL6 derived iPS clones was done for comparison with 4F-derived iPS clones, mouse embryonic stem cells and mouse embryonic fibroblasts. Overall design: This study includes 8 samples: 2 independently derived 3F + IL6 iPS clones, 2 independently derived 4F iPS clones, 2 biological replicates of mouse D3-GFP ES cells, and 2 biological replicates of mouse embryonic fibroblasts (MEFs). The latter 6 samples are provided as references for the 3F + IL6 iPS clones. Poly-A RNA was isolated and prepared for sequencing using the Illumina TruSeq RNA kit (v2) to generate 50bp reads. Reads were aligned to mm10.
NKX3-1 is required for induced pluripotent stem cell reprogramming and can replace OCT4 in mouse and human iPSC induction.
Specimen part, Treatment, Subject
View SamplesInjuries to the anterior cruciate ligament (ACL) often result in post-traumatic osteoarthritis (PTOA). PTOA accounts for ~12% of all osteoarthritis (OA) cases, yet the mechanisms contributing to OA after joint injury are not well understood. To better understand the molecular mechanisms behind PTOA development following ACL injury, we profiled ACL injury-induced gene expression changes in knee joints of three mouse strains with varying susceptibility to PTOA: STR/ort (highly susceptible), C57BL/6 (moderately susceptible) and super-healer MRL/MpJ (not susceptible) and identified genes differentially expressed between these strains at 0-day [before injury], 1-day, 1-week, and 2-weeks post-injury. This study highlights many new potential therapeutic targets and OA biomarkers. Overall design: Comparative transcriptomics to understand the molecular changes associated with early stages of PTOA development in STR/ort, C57BL/6 and MRL/MpJ mice and to identify genes that contribute to increased OA susceptibility in STR/ort and resistance to PTOA in MRL/MpJ.
Comparative Transcriptomics Identifies Novel Genes and Pathways Involved in Post-Traumatic Osteoarthritis Development and Progression.
Age, Specimen part, Cell line, Treatment, Subject
View SamplesDensely ionizing radiation is a major component of the space radiation environment and has potentially greater carcinogenic effect compared to sparsely ionizing radiation that is prevalent in the terrestrial environment. It is unknown to what extent the irradiated microenvironment contributes to the differential carcinogenic potential of densely ionizing radiation. To address this gap, 10-week old BALB/c mice were irradiated with 100 cGy sparsely ionizing g-radiation or 10, 30, or 80 cGy of densely ionizing, 350 MeV/amu Si particles and transplanted 3 days later with syngeneic Trp53 null mammary fragments. Tumor appearance was monitored for 600 days. Tumors arising in Si-particle irradiated mice had a shorter median time to appearance, grew faster and were more likely to metastasize. Most tumors arising in sham-irradiated mice were ER-positive, pseudo-glandular and contained both basal keratin 14 and luminal keratin 8/18 cells (designated K14/18), while most tumors arising in irradiated hosts were K8/18 positive (designated K18) and ER negative. Comparison of K18 vs K14/18 tumor expression profiles showed that genes increased in K18 tumors were associated with ERBB2 and KRAS while decreased genes overlapped with those down regulated in metastasis and by loss of E-cadherin. Consistent with this, K18 tumors grew faster than K14/18 tumors and more mice with K18 tumors developed lung metastases compared to mice with K14/18 tumors. However, K18 tumors arising in Si-particle irradiated mice grew even faster and were more metastatic compared to control mice. A K18 Si-irradiated host profile was enriched in genes involved in mammary stem cells, stroma, and Notch signaling. Thus systemic responses to densely ionizing radiation enriches for a ER-negative, K18-positive tumor, whose biology is more aggressive compared to similar tumors arising in non-irradiated hosts.
Densely ionizing radiation acts via the microenvironment to promote aggressive Trp53-null mammary carcinomas.
No sample metadata fields
View SamplesReprogramming of somatic cells is a valuable tool to understand the mechanisms of regaining pluripotency and further opens up the possibility of generating patient-specific pluripotent stem cells. Reprogramming of mouse and human somatic cells into pluripotent stem cells, designated as induced pluripotent stem (iPS) cells, has been possible with the expression of the transcription factor quartet Oct4 (also known as Pou5f1), Sox2, c-Myc, and Klf4. Considering that ectopic expression of c-Myc causes tumourigenicity in offspring and retroviruses themselves can cause insertional mutagenesis, the generation of iPS cells with a minimal number of factors may hasten the clinical application of this approach. Here, we show that adult mouse neural stem cells express higher endogenous levels of Sox2 and c-Myc than embryonic stem cells, and that exogenous Oct4 together with either Klf4 or c-Myc are sufficient to generate iPS cells from neural stem cells. These two-factor (2F) iPS cells are similar to embryonic stem cells at the molecular level, contribute to development of the germ line, and form chimeras. We propose that, in inducing pluripotency, the number of reprogramming factors can be reduced when using somatic cells that endogenously express appropriate levels of complementing factors.
Pluripotent stem cells induced from adult neural stem cells by reprogramming with two factors.
No sample metadata fields
View SamplesC/EBPb is an auto-repressed protein that becomes posttranslationally activated by Ras-MEK-ERK signalling. C/EBPb is required for oncogene-induced senescence (OIS) of primary fibroblasts, but also displays pro-oncogenic functions in many tumour cells. Here, we show that C/EBPb activation by H-RasV12 is suppressed in immortalized/transformed cells, but not in primary cells, by its 30 untranslated region (30UTR). 30UTR sequences inhibited Ras-induced cytostatic activity of C/EBPb, DNA binding, transactivation, phosphorylation, and homodimerization, without significantly affecting protein expression. The 30UTR suppressed induction of senescence-associated C/EBPb target genes, while promoting expression of genes linked to cancers and TGFb signalling. An AU-rich element (ARE) and its cognate RNA-binding protein, HuR, were required for 30UTR inhibition. These components also excluded the Cebpb mRNA from a perinuclear cytoplasmic region that contains activated ERK1/2, indicating that the site of C/EBPb translation controls de-repression by Ras signalling. Notably, 30UTR inhibition and Cebpb mRNA compartmentalization were absent in primary fibroblasts, allowing Ras-induced C/EBPb activation and OIS to proceed. Our findings reveal a novel mechanism whereby non-coding mRNA sequences selectively regulate C/EBPb activity and suppress its anti-oncogenic functions.
3'UTR elements inhibit Ras-induced C/EBPβ post-translational activation and senescence in tumour cells.
Cell line
View SamplesWNT signaling is critical in most aspects of skeletal development and homeostasis, and antagonists of WNT signaling are emergning as key regulatory proteins with great promise as therapeutic agents for bone disorders. Until recently Sost and its paralog Sostdc1 have been described as growth factors with highly restricted expression in the adult where Sost was assumed 'osteocyte-' and Sostdc1 'kidney-' specific. Here we show that these two proteins emerged throgh ancestral genome duplication and their expression patterns have diverged to span complimentary domains in most organ systems including musculoskeletal, cardiovascular, nervous, digestive, reproductive and respiratory. In the developing limb, Sost and Sostdc1 display dynamic expression patterns with Sost being restricted to the distal ectoderm and Sostdc1 to the proximal ectoderm and the mesenchyme.
Sost and its paralog Sostdc1 coordinate digit number in a Gli3-dependent manner.
Specimen part
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