Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Synergistic Tumor Suppressor Activity of E-cadherin and p53 in a Conditional Mouse Model for Diffuse-Type Gastric Cancer

ABSTRACT: BACKGROUND & AIMS: Gastric cancer is the second most frequent cause of death from cancer in the world, diffuse-type gastric cancer (DGC) exhibiting a poor prognosis. Germline mutations of CDH1, encoding E-cadherin, have been reported in hereditary DGCs, and genetic and/or epigenetic alterations of CDH1 are frequently detected in sporadic DGCs. Genetic alterations of TP53 are also frequently found in DGCs. To examine the synergistic effect of loss of E-cadherin and p53 on gastric carcinogenesis, we established a mouse line in which E-cadherin and p53 are specifically inactivated in the stomach parietal cell lineage. METHODS: We crossed Atp4b-Cre mice with Cdh1loxP/loxP and Trp53loxP/loxP mice, and examined the gastric phenotype of Atp4b-Cre+;Cdh1loxP/loxP;Trp53loxP/loxP mice. RESULTS: Non-polarization of E-cadherin-negative parietal cells and proton pump-negative atypical foci were observed in the transgenic mice. Intramucosal cancers and invasive cancers composed of poorly differentiated carcinoma cells and signet ring cells, which were histologically very similar to those in humans, were found from 6 and 9 months, respectively. Fatal DGCs developed at 100% penetrance within a year, frequently metastasized to lymph nodes, and had tumorigenic activity in immunodeficient mice. Gene expression profiling analyses also revealed that DGCs in the E-cadherin/p53-deficient mice resembled human DGCs. CONCLUSIONS: Our mouse line is the first genetically modified mouse model of DGC and very useful for clarifying the mechanism underlying gastric carcinogenesis, and provides a new approach to the treatment and prevention of DGC because of morphological and biochemical similarities with human DGC. Two-condition experiment, Gastric cancer vs. normal gastric mucosal tissues. Biological replicates: pooled control sample from five normal gastric mucosal tissues, three replicates from diffuse-type gastric cancer.

ORGANISM(S): Mus musculus

SUBMITTER: Kaoru Mogushi

PROVIDER: E-GEOD-25302 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Publications

Synergistic tumour suppressor activity of E-cadherin and p53 in a conditional mouse model for metastatic diffuse-type gastric cancer.

Shimada Shu S Mimata Ayako A Sekine Masaki M Mogushi Kaoru K Akiyama Yoshimitsu Y Fukamachi Hiroshi H Jonkers Jos J Tanaka Hiroshi H Eishi Yoshinobu Y Yuasa Yasuhito Y

Gut 20110824 3

<h4>Background</h4>Gastric cancer is the second most frequent cause of death from cancer in the world, diffuse-type gastric cancer (DGC) exhibiting a poor prognosis. Germline mutations of CDH1, encoding E-cadherin, have been reported in hereditary DGC, and genetic and/or epigenetic alterations of CDH1 are frequently detected in sporadic DGC. Genetic alterations of TP53 are also frequently found in DGC. To examine the synergistic effect of the loss of E-cadherin and p53 on gastric carcinogenesis, ...[more]

PMID: 21865403

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Project description:Background & Aims: E-cadherin expression disruption is commonly observed in epithelial cancers and metastasis. Such event is also recognized as a crucial step in gastric cancer (GC) initiation and progression. As aberrant expression of microRNAs often perturb the normal expression and function of pivotal cancer-related genes, we characterized and dissected a pathway initiated by loss of microRNA-101 that causes E-cadherin dysfunction through upregulation of EZH2 expression in GC. Methods: Microarrays were used to profile the expression of microRNAs in human GC. Array-CGH revealed DNA copy number changes that were validated by genomic quantitative PCR and Snapshot. Expression levels of microRNAs, mRNA and protein were determined by quantitative-real time PCR and western-blot/co-immunofluorescence. CDH1 inactivating mechanisms were analyzed. Gain and loss of function experiments were done in KatoIII cells. E-cadherin functionality was assessed by immunofluorescence and flow cytometry. Results: MiR-101 expression was significantly decreased in tumors in comparison with normal gastric mucosas (P<.0001). In 65% of the analyzed GC cases, miR-101 downregulation was caused by deletions and/or microdeletions at miR-101-2 locus. EZH2 overexpression and consequent loss/aberrant E-cadherin expression was found in concomitance with miR-101 downregulation in 41% of the analyzed GC cases. This occurred preferentially in cases retaining allele(s) untargeted by classical CDH1 inactivating mechanisms. MiR-101 gain of function experiments or direct inhibition of EZH2, led to a strong depletion of endogenous EZH2 protein and consequent rescue of functional E-cadherin at the cell membrane, mimicking results obtained with clinical GC samples. Conclusions: Deletions and/or microdeletions at miR-101-2 locus underlying mature miR-101 downregulation and consequent EZH2 overexpression represented a novel cascade of genetic events leading to E-cadherin disruption, preferentially affecting the intestinal-type of GC. In the present study, 37 primary GCs and a pool of 10 normal gastric mucosas were used to acquire the expression of 703 known human mature miRNAs deposited in the Sanger miRBase Sequence Database, Release 10.0 (http://microrna.sanger.ac.uk), as well as 393 novel human miRNAs discovered through deep sequencing and validated by qRT-PCR and array profiling (NCodeM-bM-^DM-" Human miRNA microarray probe set V3 from Invitrogen). The 10 normal gastric mucosa RNA samples were pooled to obtain the normal gastric reference sample, which was labelled and hybridised four times to check arrays' reproducibility.

Dataset Information

Synergistic Tumor Suppressor Activity of E-cadherin and p53 in a Conditional Mouse Model for Diffuse-Type Gastric Cancer

Publications

Synergistic tumour suppressor activity of E-cadherin and p53 in a conditional mouse model for metastatic diffuse-type gastric cancer.

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