This SuperSeries is composed of the SubSeries listed below.
Simultaneous analysis of miRNA-mRNA in human meningiomas by integrating transcriptome: A relationship between PTX3 and miR-29c.
Sex, Age, Specimen part
View SamplesAlthough meningioma is a common disease, there is a lack of understanding of the underlying molecular mechanisms behind its initiation and progression. We used combined miRNA-mRNA transcriptome analysis to discover novel genes and networks in meningiomas.
Simultaneous analysis of miRNA-mRNA in human meningiomas by integrating transcriptome: A relationship between PTX3 and miR-29c.
Sex, Age, Specimen part
View SamplesLeukemia Inhibitory Factor is an important cytokine of the IL family. Recent findings suggest it has a crucial role in cancer progression
Leukemia Inhibitory Factor Promotes Aggressiveness of Chordoma.
Cell line
View SamplesSphingosine 1-phosphate (S1P) is a bioactive lipid whose levels are tightly regulated by its synthesis and degradation. Intracellularly, S1P is dephosphoryled by the actions of two S1P-specific phosphatases, sphingosine 1-phosphate phosphatase 1 and 2. To identify the physiologic functions of S1P phosphatase 1, we have studied mice with its gene, Sgpp1, deleted. Sgpp1-/- mice appeared normal at birth but during the first week of life, they exhibited stunted growth, suffered desquamation, and most died before weaning. Interestingly, the epidermal permeability barrier developed normally during embryogenesis. Sgpp1 -/- pups and surviving adults exhibited epidermal hyperplasia and abnormal expression of keratinocyte differentiation markers. Keratinocytes isolated from Sgpp1 -/- skin had increased intracellular S1P levels, and expressed a gene expression profile that indicated enhanced differentiation. The results reveal S1P metabolism as a regulator of keratinocyte differentiation and epidermal homeostasis.
Sphingosine-1-phosphate phosphatase 1 regulates keratinocyte differentiation and epidermal homeostasis.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Placing the HIRA histone chaperone complex in the chromatin landscape.
Specimen part
View SamplesThe HIRA chaperone complex, comprised of HIRA, UBN1 and CABIN1, collaborates with histone-binding protein ASF1a to incorporate histone variant H3.3 into chromatin in a DNA replication-independent manner. To better understand its function and mechanism, we integrated HIRA, UBN1, ASF1a and histone H3.3 ChIP-seq and gene expression analyses. Most HIRA-binding sites co-localize with UBN1, ASF1a and H3.3 at active promoters and active and weak/poised enhancers. At promoters, binding of HIRA/UBN1/ASF1a correlates with the level of gene expression. HIRA is required for deposition of histone H3.3 at its binding sites. There are marked differences in nucleosome and co-regulator composition at different classes of HIRA-bound regulatory site. Underscoring this, we report novel physical interactions between the HIRA complex and transcription factors, a chromatin insulator and an ATP-dependent chromatin-remodelling complex. Our results map the distribution of the HIRA chaperone across the chromatin landscape and point to different interacting partners at functionally distinct regulatory sites.
Placing the HIRA histone chaperone complex in the chromatin landscape.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Wnt signaling potentiates nevogenesis.
Specimen part, Cell line
View SamplesSphingosine-1-phosphate (S1P) is a sphingolipid metabolite that regulates basic cell functions through metabolic and signaling pathways. Intracellular metabolism of S1P is controlled, in part, by two homologous S1P phosphatases, 1 and 2, which are encoded by Sgpp1 and Sgpp2, respectively. S1P phosphatase activity is needed for efficient recycling of sphingosine into the sphingolipid synthesis pathway. S1P phosphatase 1 is important for skin homeostasis, but little is known about the functional role of S1P phosphatase 2. To identify the functions of S1P phosphatase 2 in vivo, we studied mice with the Sgpp2 gene deleted. In contrast to Sgpp1-/- mice, Sgpp2-/- mice had normal skin and were viable into adulthood. Unexpectedly, WT mice expressed Sgpp2 mRNA at high levels in pancreatic islets when compared with other tissues. Sgpp2-/- mice had normal blood insulin levels and pancreatic islet size; however, Sgpp2-/- mice treated with a high-fat diet (HFD) had significantly lower blood insulin levels and smaller pancreatic islets compared with WT mice. The smaller islets in the HFD-treated Sgpp2-/- mice had a significantly lower adaptive -cell proliferation rate in response to the diet compared with HFD-treated WT mice. Importantly, -cells from Sgpp2-/- mice fed a normal diet showed significantly increased expression of proteins characteristic of the endoplasmic reticulum (ER) stress response compared with -cells from WT mice. Our results suggest that Sgpp2 deletion causes -cell ER stress, which is a known cause of -cell dysfunction, and reveal a novel juncture in the sphingolipid recycling pathway that could impact the development of diabetes.
Sphingosine-1-phosphate Phosphatase 2 Regulates Pancreatic Islet β-Cell Endoplasmic Reticulum Stress and Proliferation.
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View SamplesMelanocytes within benign human nevi are the paradigm for tumor suppressive senescent cells in a pre-malignant neoplasm. These cells typically contain mutations in either the BRAF or N-RAS oncogene and express markers of senescence, including p16. However, a nevus can contain 10s to 100s of thousands of clonal melanocytes and approximately 20-30% of melanoma are thought to arise in association with a pre-existing nevus. Neither observation is indicative of fail-safe senescence-associated proliferation arrest and tumor suppression. We set out to better understand the status of nevus melanocytes. Proliferation-promoting Wnt target genes, such as cyclin D1 and c-myc, were repressed in oncogene-induced senescent melanocytes in vitro, and repression of Wnt signaling in these cells induced a senescent-like state. In contrast, cyclin D1 and c-myc were expressed in many melanocytes of human benign nevi. Specifically, activated Wnt signalling in nevi correlated inversely with nevus maturation, an established dermatopathological correlate of clinical benignancy. Single cell analyses of lone epidermal melanocytes and nevus melanocytes showed that expression of proliferation-promoting Wnt targets correlates with prior proliferative expansion of p16-expressing nevus melanocytes. In a mouse model, activation of Wnt signaling delayed, but did not bypass, senescence of oncogene-expressing melanocytes, leading to massive accumulation of proliferation-arrested, p16-positive non-malignant melanocytes. We conclude that clonal hyperproliferation of oncogene-expressing melanocytes to form a nevus is facilitated by transient delay of senescence due to activated Wnt signaling. The observation that activation of Wnt signaling correlates inversely with nevus maturation, an indicator of clinical benignancy, supports the notion that persistent destabilization of senescence by Wnt signaling contributes to the malignant potential of nevi.
Wnt signaling potentiates nevogenesis.
Specimen part
View SamplesThe mammalian HIRA/UBN1/ASF1a complex is a histone chaperone complex that is conserved from yeast (Saccharomyces cerevisiae) to humans. This complex preferentially deposits the histone variant H3.3 into chromatin in a DNA replication-independent manner and is implicated in diverse chromatin regu- latory events from gene activation to heterochromatinization. In yeast, the orthologous complex consists of three Hir proteins (Hir1p, Hir2p, and Hir3p), Hpc2p, and Asf1p. Yeast Hir3p has weak homology to CABIN1, a fourth member of the human complex, suggesting that Hir3p and CABIN1 may be orthologs. Here we show that HIRA and CABIN1 interact at ectopic and endogenous levels of expression in cells, and we isolate the quaternary HIRA/UBN1/CABIN1/ASF1a (HUCA) complex, assembled from recombinant proteins. Mutational analyses support the view that HIRA acts as a scaffold to bring together UBN1, ASF1a, and CABIN1 into a quaternary complex. We show that, like HIRA, UBN1, and ASF1a, CABIN1 is involved in heterochromatinization of the genome of senescent human cells. Moreover, in proliferating cells, HIRA and CABIN1 regulate overlapping sets of genes, and these genes are enriched in the histone variant H3.3. In sum, these data demonstrate that CABIN1 is a functional member of the human HUCA complex and so is the likely ortholog of yeast Hir3p.
Human CABIN1 is a functional member of the human HIRA/UBN1/ASF1a histone H3.3 chaperone complex.
Specimen part
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