The generation of induced pluripotent stem cells (iPSCs) often results in aberrant silencing of the imprinted Dlk1-Dio3 gene cluster, which compromises their ability to generate entirely iPSC-derived mice (all-iPSC mice). Here, we show that reprogramming in the presence of ascorbic acid attenuates hypermethylation of Dlk1-Dio3 by enabling a chromatin configuration at its imprint control region that interferes with abnormal binding of the DNA methyltransferase Dnmt3a. This approach allowed us to generate adult all-iPSC mice from mature B cells, which have thus far failed to support the development of exclusively iPSC-derived postnatal mice. Our data demonstrate that factor-mediated reprogramming can endow a defined, terminally differentiated cell type with a developmental potential equivalent to that of embryonic stem cells. More generally, these findings indicate that the choice of culture conditions used for transcription factor-mediated reprogramming can strongly influence the epigenetic and biological properties of resultant iPSCs.
No associated publication
Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Aberrant silencing of imprinted genes on chromosome 12qF1 in mouse induced pluripotent stem cells.
Specimen part
View SamplesVariant late-infantile (vLINCL) and juvenile neuronal ceroid lipofuscinosis (JNCL) share clinical and pathological features, including lysosomal accumulation of mitochondrial ATP synthase subunit c, but the unrelated CLN6 and CLN3 genes may initiate disease via similar or distinct cellular processes. To gain insight into the NCL pathways, we established murine wild-type and vLINCL CbCln6nclf cerebellar cells and compared them to wild-type and JNCL CbCln3ex7/8 cerebellar cells. CbCln6nclf/nclf cells and CbCln3ex7/8/ex7/8 cells both displayed abnormally elongated mitochondria and reduced cellular ATP levels and, as cells aged to confluence, exhibited accumulation of subunit c protein in Lamp 1-positive organelles. However, at sub-confluence, endoplasmic reticulum PDI immunostain was decreased only in CbCln6nclf/nclf cells, while fluid-phase endocytosis and LysoTracker labeled vesicles were decreased in both CbCln6nclf/nclf and CbCln3ex7/8/ex7/8 cells, though only the latter cells exhibited abnormal vesicle subcellular distribution. Furthermore, unbiased gene expression analyses revealed only partial overlap in the cerebellar cell genes and pathways that were altered by the Cln3ex7/8 and Cln6nclf mutations. Thus, these data support the hypothesis that vLINCL and JNCL mutations trigger distinct processes that converge on a shared pathway, which is responsible for proper subunit c protein turnover and neuronal cell survival.
Distinct early molecular responses to mutations causing vLINCL and JNCL presage ATP synthase subunit C accumulation in cerebellar cells.
Specimen part
View SamplesOur testis transplantation data demonstrate that only Sox2-GFP+c-kit- cells contain testis-repopulating potential and we wondered whether a molecular comparison of the Sox2-GFP+c-kit+ and Sox2-GFP+c-kit- spermatogonial cells would uncover genes that could explain the exclusive repopulation potential of the latter cell population. To this end, we sorted individual testis cell populations and subjected extracted and amplified RNA to array analysis.
No associated publication
Age
View SamplesThe RB and p53 tumor suppressor pathways regulate the transcription of genes involved in cell cycle progression, DNA replication, DNA repair, and apoptosis. These tumor suppressors are critical modulators of the response to genotoxic damage and both pathways are frequently inactivated in human cancers.
No associated publication
Specimen part
View SamplesTumors engender an environment dominated by M2 differentiated tumor macrophages that support tumor invasion, metastases and escape from immune control. In this study, we demonstrate that following radiation therapy of tumors in mice there is an influx of tumor macrophages that polarize towards wound repair and immune suppression.
Expression of NF-κB p50 in tumor stroma limits the control of tumors by radiation therapy.
Specimen part, Treatment, Time
View SamplesOur previous investigation indicated that high-virulence C. gattii (C. gattii TIMM 4097) tend to reside in the alveoli, whereas low-virulence C. gattii (C. gattii TIMM 4903) tend to be washed out from the alveoli and move into the central side of the respiratory system. To test this hypothesis, we performed microarray assay.
How histopathology can contribute to an understanding of defense mechanisms against cryptococci.
Sex, Specimen part
View SamplesThe maintenance of advanced malignancies relies on continued activity of driver oncogenes, although their rate-limiting role is highly context-dependent with respect to tumor types and associated genetic alterations. Oncogenic Kras mutation is the signature event in human pancreatic ductal adenocarcinoma (PDAC), serving a critical role in tumor initiation. Here, an inducible KrasG12D-driven p53 mutant PDAC mouse model establishes that advanced PDAC remains strictly dependent on continued KrasG12D expression and that KrasG12D serves a vital role in the control of tumor metabolism, through stimulation of glucose uptake and channeling of glucose intermediates through the hexosamine biosynthesis pathway (HBP) and the pentose phosphate pathway (PPP). Notably, these studies reveal that oncogenic Kras regulates ribose biogenesis. Unlike canonical models of PPP-mediated ribose biogenesis, we demonstrate that oncogenic Kras drives intermediates from enhanced glycolytic flux into the non-oxidative arm of the PPP, thereby decoupling ribose biogenesis from NADPNADPH-mediated redox control. Together, this work provides in vivo mechanistic insights into how oncogenic Kras promotes metabolic reprogramming in native tumors and illuminates potential metabolic targets that can be exploited for therapeutic benefit in Kras-driven PDAC.
Oncogenic Kras maintains pancreatic tumors through regulation of anabolic glucose metabolism.
Specimen part, Treatment
View SamplesThe cancer-risk associated rs6983267 single nucleotide polymorphism (SNP) and the accompanying long non-coding RNA CCAT2 in the highly amplified 8q24.21 region has been implicated in cancer predisposition, though causality has not been established. Here, using allele-specific CCAT2 transgenic mice, we demonstrate that CCAT2 overexpression leads to spontaneous myeloid malignancies. CCAT2 is overexpressed in bone marrow and peripheral blood of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) patients. CCAT2 induces global deregulation of gene expression by downregulating EZH2 in vitro and in vivo in an allele-specific manner. We also identified a novel disease-specific RNA mutation (named DNA-to-RNA allelic imbalance, DRAI) at the SNP locus in MDS/MPN patients and CCAT2-transgenic mice. The RNA transcribed from the SNP locus in malignant hematopoietic cells have different allelic composition from the corresponding genomic DNA, a phenomenon rarely observed in normal cells. Our findings provide fundamental insights into the functional role of rs6983267 SNP and CCAT2 in myeloid malignancies.
Cancer-associated rs6983267 SNP and its accompanying long noncoding RNA <i>CCAT2</i> induce myeloid malignancies via unique SNP-specific RNA mutations.
Specimen part
View SamplesThe p53 gain of function p53R172H promotes accelerated tumor growth and progression to carcinoma. To identify gene expression changes associated with the oncogenic function of mutant p53 we compared the expression profiles of oral tumors induced by activation of oncogenic K-ras and p53 gain- or loss-of-function mutations
No associated publication
Age, Specimen part
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