Carcinoma of the colon and rectum with deregulation of insulin-like growth factor 2 signaling: clinical and molecular implications
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE66726 | GEO | 2016/07/04
SECONDARY ACCESSION(S): PRJNA277816
REPOSITORIES: GEO
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Project description:We here show that loss of imprinting (LOI) of IGF2 is a frequent and early event in the development of colon cancer and occurs throughout the large intestine. LOI leads to AKT1-dependent activation and suppression of a defined set of genes, many of which are cell cycle related. Our results further showed that IGF2 induces non-canonical wnt signaling. We hypothesize that IGF2 and Wnt5a cooperate in cancer progression. LOI is an attractive target for tumor prevention or targeted therapy. This is a comparison of colon cancer samples with (LOI) and without (ROI) loss of imprining of IGF2. All cases were from the sigmoid colon and were in UICC tumor stage pT2 N0 M0.
2016-07-04 | E-GEOD-66726 | biostudies-arrayexpress
Project description:To identify genes differentially expressed in the intestinal crypts between LOI(+) and LOI(-) mice, we performed microarray experiments using RNA extracted from laser capture microdissection, by microdissecting an average of 8,000 crypts from each of 3 LOI(+) and 3 LOI(-) mice. Keywords: genetic modification design H19 mutant mice with C57BL/6J background carrying a deletion in the H19 gene (3 kb) and 10 kb of the upstream region including differentially methylated region (DMR) were maintained without LOI phenotype by breeding female wild-type C57BL/6J and male H19+/-. Experimental crosses were performed between female H19+/- and male wild-type C57BL/6J to obtain LOI(+) mice and LOI(-) mice. Igf2 on the maternal allele is silenced in LOI(-), i.e. wild type, mice. But when H19 DMR deletion is inherited from mother, the normally silenced Igf2 on maternal allele is activated and LOI (loss of imprinting) of Igf2 occurs. LOI(+) and LOI(-) mice were sacrificed at 120 days, and the tissue pieces of the small intestine were collected from the middle (the third fifth) part and kept frozen at -80C. To detect gene expression change in intestinal progenitor cells clearly, Laser Capture Microdissection (LCM) was performed to collect intestinal crypt cells. The 10 um thick sections were prepared from the frozen small intestine pieces, and 8,000 intestinal crypts at average were dissected by LCM for each of three LOI(+) and LOI(-) mice, and 2 ug of total RNA at least were collected using RNeasy Kit (GIAGEN). 1.7 ug of total RNA for each sample were used for labeling to compare gene expressions in intestinal crypt between LOI(+) and LOI(-) mice.
2010-05-25 | E-GEOD-8583 | biostudies-arrayexpress
Project description:Imprinted genes occur in discrete clusters that are coordinately regulated by shared DNA elements. H19 and Igf2 are linked imprinted genes that play critical roles in development. Loss of imprinting at the IGF2/H19 locus is associated with Beckwith Wiedemann Syndrome (BWS). Here we use comprehensive genetic and genomic analyses to follow muscle development in a mouse model of BWS to dissect the separate and shared roles for Igf2 and H19 in the disease phenotype. We show that LOI results in defects in muscle differentiation and hypertrophy and we identify primary downstream targets of Igf2 (MAPK signaling) and of H19 (AKT/mTOR signaling). Moreover, we demonstrate instances where H19 and Igf2 misexpression work separately, cooperatively, and also antagonistically to establish the disease phenotype. This study underscores the fact that LOI phenotypes are multigenic and complex interactions contribute to disease outcomes.
2017-09-25 | GSE89136 | GEO
Project description:Numerous studies have described the critical role played by microRNAs (miRNAs) in cancer progression and the potential of these small non-coding RNAs for diagnostic or therapeutic applications. However, the mechanisms responsible for the altered expression of miRNAs in malignant cells remain poorly understood. Herein, via epigenetic unmasking, we identified a group of miRNAs located in the imprinted delta like non-canonical Notch ligand 1 (DLK1)-maternally expressed 3 (MEG3) locus that were repressed in hepatic tumor cells. Notably, miR-493-5p epigenetic silencing was correlated with hypermethylation of the MEG3-differentially regulated region (DMR) in liver cancer cell lines and tumor tissues from patients. Experimental rescue of miR-493-5p promoted an anti-cancer response by hindering hepatocellular carcinoma (HCC) cell growth in vitro and tumor progression in vivo. We found that miR-493-5p mediated part of its tumor-suppressor activity by abrogating overexpression of insulin-like growth factor 2 (IGF2) and the IGF2-derived intronic oncomir miR-483-3p in HCC cells characterized by IGF2 loss of imprinting (LOI). In summary, this study describes an unknown miRNA-dependent regulatory mechanism between two distinct imprinted loci and a possible therapeutic window for liver cancer patients exhibiting IGF2-miR-483 LOI and amplification.
2018-12-05 | GSE123313 | GEO
Project description:Numerous studies have described the critical role played by microRNAs (miRNAs) in cancer progression and the potential of these small non-coding RNAs for diagnostic or therapeutic applications. However, the mechanisms responsible for the altered expression of miRNAs in malignant cells remain poorly understood. Herein, via epigenetic unmasking, we identified a group of miRNAs located in the imprinted delta like non-canonical Notch ligand 1 (DLK1)-maternally expressed 3 (MEG3) locus that were repressed in hepatic tumor cells. Notably, miR-493-5p epigenetic silencing was correlated with hypermethylation of the MEG3-differentially regulated region (DMR) in liver cancer cell lines and tumor tissues from patients. Experimental rescue of miR-493-5p promoted an anti-cancer response by hindering hepatocellular carcinoma (HCC) cell growth in vitro and tumor progression in vivo. We found that miR-493-5p mediated part of its tumor-suppressor activity by abrogating overexpression of insulin-like growth factor 2 (IGF2) and the IGF2-derived intronic oncomir miR-483-3p in HCC cells characterized by IGF2 loss of imprinting (LOI). In summary, this study describes an unknown miRNA-dependent regulatory mechanism between two distinct imprinted loci and a possible therapeutic window for liver cancer patients exhibiting IGF2-miR-483 LOI and amplification.
2018-12-05 | GSE123314 | GEO
Project description:Genomic imprinting regulates parental origin-dependent mono-allelic gene expression. It is mediated by either germline differential methylation of DNA (canonical imprinting) or oocyte-derived H3K27me3 (non-canonical imprinting) in mice. Depletion of Eed, an essential component of Polycomb repressive complex 2, results in genome-wide loss of H3K27me3 in oocytes, which causes loss of non-canonical imprinting (LOI) in embryos. Although Eed maternal KO (matKO) embryos show partial lethality after implantation, it is unknown whether LOI itself contributes to the developmental phenotypes of these embryos, which makes it unclear whether non-canonical imprinting is developmentally relevant. Here, by combinatorial matKO of Xist, a non-canonical imprinted gene whose LOI causes aberrant transient maternal X chromosome inactivation (XCI) at preimplantation, we show that prevention of the transient maternal XCI greatly restores the development of Eed matKO embryos. Moreover, we find that the placentae of Eed matKO embryos are remarkably enlarged in a manner independent of Xist LOI. Heterozygous deletion screening of individual autosomal non-canonical imprinted genes suggests that LOI of the Sfmbt2 miRNA cluster-chromosome 2 miRNA cluster (C2MC), solute carrier family 38 member 4 (Slc38a4), and Gm32885 contributes to the placental enlargement. Taken together, our study provides evidence that Xist imprinting sustains embryonic development and autosomal non-canonical imprinting restrains placental overgrowth.
2022-06-30 | GSE199115 | GEO
Project description:Loss of imprinting (LOI), commonly observed in human tumors, refers to loss of monoallelic gene regulation normally conferred by parent-of-origin specific DNA methylation. To test the function of LOI in tumorigenesis, we developed a model using transient demethylation to generate imprint-free mouse embryonic stem (IF-ES) cells. To analyse the effect of LOI on gene expression, we compared gene expression profiles from embryonic fibroblasts derived from IF-ES cells (IF-MEFs) and wildtype MEFs.
2005-10-20 | E-MEXP-450 | biostudies-arrayexpress
Project description:Dysregulation of imprinted gene loci also referred to as loss of imprinting (LOI) can result in severe developmental defects and other diseases, but the molecular mechanisms that ensure imprint stability remain incompletely understood. Here, we dissect the functional components of the imprinting control region of the essential Dlk1-Dio3 locus (called IG-DMR) and the mechanism by which they ensure imprinting maintenance. Using pluripotent stem cells carrying an allele-specific reporter system, we demonstrate that the IG-DMR consists of two antagonistic regulatory elements: a paternally methylated CpG-island that prevents the activity of Tet dioxygenases and a maternally unmethylated regulatory element, which serves as a non-canonical enhancer and maintains expression of the maternal Gtl2 lncRNA by precluding de novo DNA methyltransferase function. Targeted genetic or epigenetic editing of these elements leads to LOI with either bi-paternal or bi-maternal expression patterns and respective allelic changes in DNA methylation and 3D chromatin topology of the entire Dlk1-Dio3 locus. Although the targeted repression of either IG-DMR or Gtl2 promoter is sufficient to cause LOI, the stability of LOI phenotype depends on the IG-DMR status, suggesting a functional hierarchy. These findings establish the IG-DMR as a novel type of bipartite control element and provide mechanistic insights into the control of Dlk1-Dio3 imprinting by allele-specific restriction of the active DNA (de)methylation machinery.
2021-09-14 | GSE148315 | GEO
Project description:Embryos generated with the use of assisted reproductive technologies (ART) can develop overgrowth syndromes. In ruminants, the condition is referred to as large offspring syndrome (LOS) and exhibits variable phenotypic abnormalities including overgrowth, enlarged tongue, and abdominal wall defects. These characteristics recapitulate those observed in the human loss-of-imprinting (LOI) overgrowth syndrome Beckwith-Wiedemann (BWS). We have recently shown LOI at the KCNQ1 locus in LOS, the most common epimutation in BWS. Although the first case of ART-induced LOS was reported in 1995, studies have not yet determined the extent of LOI in this condition. Here, we determined allele-specific expression of imprinted genes previously identified in human and/or mouse in day 105 Bos taurus indicus X Bos taurus taurus F1 hybrid control and LOS fetuses using RNAseq. Our analysis allowed us to determine the monoallelic expression of 20 genes in tissues of control fetuses. LOS fetuses displayed variable LOI when compared to controls. Biallelic expression of imprinted genes in LOS was associated with tissue-specific hypomethylation of the normally methylated parental allele. In addition, a positive correlation was observed between bodyweight and the number of biallelically expressed imprinted genes in LOS fetuses. Further, not only was there loss of allele-specific expression of imprinted genes in LOS, but we also observed differential transcript amounts of these genes between control and overgrown fetuses. In summary, we characterized previously unidentified imprinted genes in bovine and identified misregulation of imprinting at multiple loci in LOS. We concluded that LOS is a multi-locus loss-of-imprinting syndrome, as is BWS.
2015-03-06 | GSE63509 | GEO
Project description:Abnormal placentation in cloned animals remains an unsolved problem. We demonstrated the involvement of micro RNAs (miRNAs) in the abnormal enlargement (hyperplasia) of placentas in cloned mice. Using a comparative transcriptome analysis of cloned placentas, we noted the consistent upregulation of clustered miRNAs within Sfmbt2, a paternally expressed imprinted gene. This region was biallelically activated by loss of imprinting (LOI) in cloned placentas. Deletion of the maternal allele of the whole miRNA cluster resulted in the correction of their expression levels and upregulation of their putative target genes with antitumor or apoptotic functions. Consequently, the placental size was reduced to the normal level and histology was ameliorated. In contrast, correcting the expression of the LOI genes (Sfmbt2, Gab1, and Scl38a4) in cloned placentas had no impact on placental size. Thus, we identified that LOI of clustered miRNAs within Sfmbt2 in cloned placentas was the major cause of abnormal placental enlargement.
2020-02-29 | GSE129939 | GEO