Characterization of neuroendocrine tumors in heterozygous mutant MENX rats: a novel model of invasive medullary thyroid carcinoma [pituitary]
Ontology highlight
ABSTRACT:
ORGANISM(S): Rattus norvegicus
PROVIDER: GSE29457 | GEO | 2017/11/15
SECONDARY ACCESSION(S): PRJNA141575
REPOSITORIES: GEO
Similar Datasets
Project description:As overwhelming evidence coming from transgenic mouse models but also from MEN4 patients seem to suggest that loss or inactivation of a single p27 allele plays an important role in neuroendocrine tumorigenesis, we decided to perform a detailed analysis of the phenotype of rats heterozygous for the MENX-associated germline Cdkn1b mutation. We here show that the reduction to a single functional p27 allele predisposes MENX heterozygous rats to the development of neuroendocrine malignancies.
2017-11-15 | GSE53365 | GEO
Project description:CDKN1B (p27) was formally established as a tumor suppressor gene (tsg) following the identification of inactivating germline mutations in rats (MENX syndrome) and patients (MEN4 syndrome) developing multiple neuroendocrine tumors (NETs). MENX-affected rats are homozygous for the predisposing p27 mutation, suggesting a canonical tsg function. In contrast, mice heterozygous for a defective Cdkn1b allele are already predisposed to tumor formation (haploinsufficiency). We here report that heterozygous mutant rats (p27+/mut) develop the same NETs seen in the homozygous (p27mut/mut) animals but with slower progression. In the tumors of p27+/mut rats, the wild-type allele is neither lost nor silenced, implying that p27 is haploinsufficient for tumor suppression also in this model. Transcriptome profiling of rat NETs having different p27 dosages revealed a tissue-specific, dose-dependent effect of p27 on gene expression. In p27+/mut rats, thyroid neoplasms progress to invasive and metastatic medullary thyroid carcinomas (MTCs) accompanied by increased calcitonin levels, as in humans. Comparison of expression signatures of late-stage versus early-stage MTCs from p27+/mut rats identified genes potentially involved in tumor aggressiveness. The expression of a subset of these genes was evaluated in human MTCs, and found associated with aggressive RET-M918T-positive tumors. Altogether, p27 haploinsufficiency in MENX rats uncovered a novel, representative model of invasive/metastatic MTC, exploitable for translational studies of this aggressive and often incurable cancer.
2017-11-15 | GSE98546 | GEO
Project description:MENX is a rat multiple endocrine neoplasia syndrome caused by a homozygous mutation of the Cdkn1b gene, encoding p27Kip1. Affected rats develop adrenomedullary hyperplasia which progresses to pheochromocytoma with time (incidence 100%), and to extra-adrenal pheochromocytoma (paraganglioma) (68%). We here report that hyperplasia and tumor have similar gene expression profiles, suggesting an early determination of the tumorigenic signature. Overexpressed genes in rat adrenal lesions are especially enriched in development/differentiation-associated genes.
2010-11-19 | GSE21006 | GEO
Project description:Emerging data indicate that breast epithelial stem cells and progenitors, particularly those in the luminal epithelial cell lineage, are the cells-of-origin of breast carcinomas, and factors that influence breast cancer risk may alter the number and/or properties of these cells. We hypothesize that a subset of p27+ cells represent hormone-responsive progenitors that are quiescent due to the high activity of TGFβ signaling in these cells. The Estrogen-induced mammary tumor model in ACI inbred rats is physiologically relevant rodent model of breast cancer. In the present study we successfully generated Cdkn1b knockout ACI rats and performed comprehensive phenotypic assessment and RNAseq profiling using FACS sorted basal (CD24+CD29high) and luminal (CD24+CD29low) cell populations to characterize Cdkn1b+/+ and Cdkn1b-/- females in prepubertal and adult cohorts. We found that p27KO rats exhibited mammary differentiation phenotype and reduced numbers of mammary epithelial progenitor pool, Interestingly, p27 ablation has the most pronounced effect on luminal progenitor cell gene expression, and milk protein genes and pStat5 were dramatically upregulated, while PR and FoxA1 were greatly downregulated in Cdkn1b-/- luminal cells. Further characterization of mammary glands of prepubertal Cdkn1b knockout rats by fat pad transplantation illustrated p27 deletion in the mammary cancer susceptible ACI rat strain induced mammary epithelial cell differentiation through cell non-autonomous mechanisms.
2019-02-11 | GSE116831 | GEO
Project description:Characterization of neuroendocrine tumors in heterozygous mutant MENX rats: a novel model of invasive medullary thyroid carcinoma [thyroid]
| PRJNA385488 | ENA
Project description:<p>The diagnosed incidence of small bowel neuroendocrine tumors (NETs) is increasing. While patients with localized disease can be treated surgically, those with metastatic disease currently have few treatment options. The success of biologically targeted therapies in other malignancies has led to interest in the molecular alterations underlying the pathogenesis of these NETs. To identify genetic aberrations in small intestine NETs, we generated copy number profiles from 31 primary and metastatic tumors and performed whole-exome sequencing on a subset of 29 primary small intestine NETs and 24 metastatic NETs in parallel with normal blood DNA. Whole-genome sequencing data was generated on 15 tumor/normal pairs and 5 primary/metastasis/normal trios. The global genetic landscape of small bowel NETs is relatively quiet. Consistent with previous studies, the overwhelming majority of tumors were characterized by loss of chromosome 18 and, to a lesser extent, other chromosome arm gains and losses. In stark contrast to arm-level alterations, recurrent high-level focal amplifications and deletions were much less prevalent in these tumors. High-throughput mutation screening and exome sequencing revealed similarly low rates of somatic mutation in NETs (median of 0.77 non-silent mutations per megabase (Mb) of coding DNA) compared to other recent cancer exome sequencing efforts. Our analysis of this cohort identified only a single, statistically significant recurrent somatic mutation targeting the cyclin-dependent kinase inhibitor gene, CDKN1B, encoding p27. </p>
| phs000579 | dbGaP
Project description:Background: Pseudohypoxic tumors activate pro-oncogenic pathways typically associated with severe hypoxia even when sufficient oxygen is present, leading to highly aggressive tumors. Prime examples are pseudohypoxic pheochromocytomas and paragangliomas (p-PPGLs), neuroendendocrine tumors currently orphan of effective therapy. Previous attempts to generate mouse models for p-PPGLs all failed. Here, we describe that the rat MENX line, carrying a Cdkn1b (p27) frameshift-mutation, spontaneously develops pseudohypoxic pheochromocytoma (p-PCC). Methods: We compared rat p-PCCs with their cognate human tumors at different levels: histology, immunohistochemistry, catecholamine profiling, electron microscopy, transcriptome and metabolome. Vessels architecture and angiogenic potential of PCCs was analyzed by light-sheet fluorescence microscopy ex vivo and multi-spectral optoacoustic tomography (MSOT) in vivo. Results: Analysis of tissues at various stages, from hyperplasia to advanced grades, allowed us to correlate tumor characteristics with progression. Pathological changes affecting mitochrondrial ultrastructure where present already in hyperplasias. Rat PCCs secreted high levels of norepinephrine and dopamine. Transcriptomic and metabolomic analysis revealed changes in oxidative phosphorylation that aggravated over time, leading to an accumulation of the oncometabolite 2-hydroxyglutarate, and to hypermethylation, evident by loss of the epigenetic mark 5-hmC. While rat PCC xenografts showed high oxygenation, induced by massive neoangiogenesis, rat PCC transcriptomes possessed a pseudohypoxic signature of high Hif2a, Vegfa, and low Pnmt expression, thereby clustering with human p-PPGL. Conclusion: Endogenous rat PCCs recapitulate key phenotypic features of human p-PPGLs. Thus, MENX rats emerge as the best available animal model of these aggressive tumors. Our study provides evidence of a link between cell cycle dysregulation and pseudohypoxia.
2021-01-13 | GSE162970 | GEO
Project description:Transcriptome analysis of effect of Lockd knockout on cells Many long non-coding (lnc) RNAs are reported to regulate gene expression and protein functions. However, the proportion of lncRNAs with biological activities among the thousands expressed in mammalian cells is controversial. We studied Lockd (Downstream of p27), a 434 bp polyadenylated lncRNA originating 4 kb 3’ to the Cdkn1b gene. Heterozygous and homozygous deletion of the 25 kb Lockd locus reduced Cdkn1b transcription by approximately 35 and 70% respectively in a mouse erythroid cell line. In contrast, homozygous insertion of a polyadenylation cassette 80 bp downstream of the Lockd transcription start site reduced the entire lncRNA transcript level by > 90%, but had no effect on Cdkn1b transcription. The 5’ region of the Lockd gene contains a DNase hypersensitive site, binds numerous transcription factors (TFs), and physically associates with the Cdkn1b promoter in chromosomal conformation capture (NG Capture-C) studies. Thus, the Lockd gene positively regulates Cdkn1b transcription through an enhancer-like cis element and not via the lncRNA transcript. These findings demonstrate that the biological functions of a lncRNA cannot be inferred simply from phenotypes that arise after deleting the corresponding genomic locus.
2016-06-01 | GSE75449 | GEO
Project description:Transcriptome analysis of effect of Lockd knockout on cells Many long non-coding (lnc) RNAs are reported to regulate gene expression and protein functions. However, the proportion of lncRNAs with biological activities among the thousands expressed in mammalian cells is controversial. We studied Lockd (Downstream of p27), a 434 bp polyadenylated lncRNA originating 4 kb 3â to the Cdkn1b gene. Heterozygous and homozygous deletion of the 25 kb Lockd locus reduced Cdkn1b transcription by approximately 35 and 70% respectively in a mouse erythroid cell line. In contrast, homozygous insertion of a polyadenylation cassette 80 bp downstream of the Lockd transcription start site reduced the entire lncRNA transcript level by > 90%, but had no effect on Cdkn1b transcription. The 5â region of the Lockd gene contains a DNase hypersensitive site, binds numerous transcription factors (TFs), and physically associates with the Cdkn1b promoter in chromosomal conformation capture (NG Capture-C) studies. Thus, the Lockd gene positively regulates Cdkn1b transcription through an enhancer-like cis element and not via the lncRNA transcript. These findings demonstrate that the biological functions of a lncRNA cannot be inferred simply from phenotypes that arise after deleting the corresponding genomic locus. We analyzed mouse G1E erythroid cell line clones with Control Lockd (C - 3 replicates) and with Lockd deletion with CRISPR (KO - 4 replicates) using Mouse Gene 2.0 ST Array platform (transcript version). Array data was processed by RMA algorithm.
2016-06-01 | E-GEOD-75449 | biostudies-arrayexpress
Project description:Cisplatin (CP) is a chemotherapeutic drug that is used to cure different types of cancer. CP induces DNA damage and leads to cell cycle arrest. The cyclin-dependent kinase inhibitor 1B (CDKN1B), also termed p27, plays an important role in the drug response ; and increased levels of p27 correlated with CP resistance. In HEK293 cells, we observed that p27 mRNAs levels increased whereas protein level drastically decreased in cells treated with CP; suggesting post-transcriptional regulatory events. To further understand the underlying mechanisms, we applied a biochemical approach combined with mass-spectrometry to systematically identify the RNA-binding proteins (RBPs) that are bound to the 3’UTR of p27 mRNAs in CP-treated versus non-treated cells in vivo. We found that 24 proteins, most of them known RBPs such HuR, hNRNPD, changed their association with p27 mRNA upon CP treatement. Furthermore, knock-down of a subset of the identified RBPs led to the inhibition of the CP-induced increase of p27 mRNA levels. In conclusion, these results highlight substantial rearrangement between RBPs and p27 mRNA upon CP treatment and corroborate the importance of post-transcriptional control in cellular drug response.
2019-09-27 | PXD008498 | Pride