Unknown,Transcriptomics,Genomics,Proteomics

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Loss of p53 in enterocytes generates an inflammatory microenvironment enabling invasion and metastasis of carcinogen-induced colorectal tumors

ABSTRACT: Loss of p53 is considered to allow progression of colorectal tumors from the adenoma to the carcinoma stage. Using mice with an intestinal epithelial cell (IEC) specific deletion of p53, we demonstrate that single loss of p53 is not sufficient to initiate intestinal tumorigenesis, but markedly enhances carcinogen-induced tumor incidence and leads to invasive cancer and lymph node metastasis. While during the initiation stage p53 controls DNA damage and IEC survival, during tumor progression, loss of p53 is associated with the formation of an inflammatory microenvironment and activation of NF-kB and Stat3. Thus, we propose a novel p53 controlled tumor suppressive function that is independent of its well-established role in cell cycle regulation, apoptosis and senescence. 4 AOM induced cancers derived from Tp53DEIC mice were isolated and DNA was extracted. These were compared to genomic DNA isolated from healthy littermate control animals. Agilent Mouse 4x180K arrays were used (Design ID 27411).

ORGANISM(S): Mus musculus

SUBMITTER: André Lechel

PROVIDER: E-GEOD-28129 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Project description:Histone deacetylases (Hdac) remove acetyl groups from proteins, influencing global and specific gene expression. Hdacs control inflammation, as shown by Hdac inhibitor-dependent protection from DSS-induced murine colitis. While tissue-specific Hdac knockouts show redundant and specific functions, little is known of their intestinal epithelial cell (IEC) role. We have shown previously that dual Hdac1/Hdac2 IEC-specific loss disrupts cell proliferation and determination, with decreased secretory cell numbers and altered barrier function. We thus investigated how compound Hdac1/Hdac2 or Hdac2 IEC-specific deficiency alters the inflammatory response. Floxed Hdac1 and Hdac2 and villin-Cre mice were interbred. Compound Hdac1/Hdac2 IEC-deficient mice showed chronic basal inflammation, with increased basal Disease Activity Index (DAI) and deregulated Reg gene colonic expression. DSS-treated dual Hdac1/Hdac2 IEC-deficient mice displayed increased DAI, histological score, intestinal permeability and inflammatory gene expression. In contrast to double knockouts, Hdac2 IEC-specific loss did not affect IEC determination and growth, nor result in chronic inflammation. However, Hdac2 disruption protected against DSS colitis, as shown by decreased DAI, intestinal permeability and caspase-3 cleavage. Hdac2 IEC-specific deficient mice displayed increased expression of IEC gene subsets, such as colonic antimicrobial Reg3b and Reg3g mRNAs, and decreased expression of immune cell function-related genes. Our data show that Hdac1 and Hdac2 are essential IEC homeostasis regulators. IEC-specific Hdac1 and Hdac2 may act as epigenetic sensors and transmitters of environmental cues and regulate IEC-mediated mucosal homeostatic and inflammatory responses. Different levels of IEC Hdac activity may lead to positive or negative outcomes on intestinal homeostasis during inflammation Total RNAs from the colon of three control and three Hdac2 IEC-specific knockout mice were isolated with the Rneasy kit (Qiagen, Mississauga, ON, Canada).

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Loss of p53 in enterocytes generates an inflammatory microenvironment enabling invasion and metastasis of carcinogen-induced colorectal tumors

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