Dataset Information

Accelerated carcinogenesis following liver regeneration is associated with chronic inflammation-induced double-strand DNA breaks.

ABSTRACT: Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide and is considered to be the outcome of chronic liver inflammation. Currently, the main treatment for HCC is surgical resection. However, survival rates are suboptimal partially because of tumor recurrence in the remaining liver. Our aim was to understand the molecular mechanisms linking liver regeneration under chronic inflammation to hepatic tumorigenesis. Mdr2-KO mice, a model of inflammation-associated cancer, underwent partial hepatectomy (PHx), which led to enhanced hepatocarcinogenesis. Moreover, liver regeneration in these mice was severely attenuated. We demonstrate the activation of the DNA damage-response machinery and increased genomic instability during early liver inflammatory stages resulting in hepatocyte apoptosis, cell-cycle arrest, and senescence and suggest their involvement in tumor growth acceleration subsequent to PHx. We propose that under the regenerative proliferative stress induced by liver resection, the genomic unstable hepatocytes generated during chronic inflammation escape senescence and apoptosis and reenter the cell cycle, triggering the enhanced tumorigenesis. Thus, we clarify the immediate and long-term contributions of the DNA damage response to HCC development and recurrence.

SUBMITTER: Barash H

PROVIDER: S-EPMC2836653 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Accelerated carcinogenesis following liver regeneration is associated with chronic inflammation-induced double-strand DNA breaks.

Barash Hila H R Gross Eitan E Edrei Yifat Y Ella Ezra E Israel Ariel A Cohen Irit I Corchia Nathalie N Ben-Moshe Tehila T Pappo Orit O Pikarsky Eli E Goldenberg Daniel D Shiloh Yosef Y Galun Eithan E Abramovitch Rinat R

Proceedings of the National Academy of Sciences of the United States of America 20100125 5

Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide and is considered to be the outcome of chronic liver inflammation. Currently, the main treatment for HCC is surgical resection. However, survival rates are suboptimal partially because of tumor recurrence in the remaining liver. Our aim was to understand the molecular mechanisms linking liver regeneration under chronic inflammation to hepatic tumorigenesis. Mdr2-KO mice, a model of inflammation-associated can ...[more]

PMID: 20133864

Similar Datasets

Project description:Surgical resection is the preferred treatment for Hepatocellular carcinoma; however, it induces tumor recurrence. Our objective was to understand the molecular mechanisms linking liver regeneration under chronic-inflammation to tumorigenesis. Mdr2-knockout mice, a model of inflammation-associated cancer, underwent partial-hepatectomy which led to enhanced hepatocarcinogenesis. Yet, liver regeneration in these mice was severely attenuated. We demonstrate the activation of the DNA damage response machinery and altered genomic instability during early liver inflammatory stages resulting in hepatocyte apoptosis and cell-cycle arrest, and suggest their involvement in tumor recurrence subsequent to partial hepatectomy. We propose that under the regenerative proliferative stress induced by liver resection, the genomic unstable hepatocytes generated during chronic-inflammation, escape apoptosis and reenter the cell-cycle, triggering the enhanced tumorigenesis At present, there is a great organ shortage worldwide, thus the main treatment for Hepatocellular carcinoma (HCC) is liver resection. However, liver resection induces recurrence and mortality. In our study, we decipher, for the first time, the contribution of the DNA damage response in HCC development and recurrence, the immediate and long term effect. This is an important finding regarding the association between carcinogenesis and DNA damage response. Additionally, we demonstrate yet another link between inflammation, inducing DNA damage and genome instability, and carcinogenesis that has not been explored in the past. These results may assist in developing treatments that will reduce tumor recurrence and additionally, new prophylactic therapies during early inflammatory stages. Keywords: time course, regeneration RNA was isolated from liver samples of 9-month-old Mdr2-/- and control mice obtained on days 0 (the removed lobe), 2 and 6 following PHx. Samples of d0 were obtained from the same mice that were sacrificed on later days. As we were concerned by the variability in the KO group 6 samples were obtained for d0. All other time points and groups contained 3 samples each.

Project description:Mitochondrial dysfunction has been implicated in the pathophysiology of neurodegenerative disorders, including multiple sclerosis (MS). To date, the investigation of mitochondrial dysfunction in MS has focused exclusively on neurons, with no studies exploring whether dysregulation of mitochondrial bioenergetics and/or genetics in oligodendrocytes might be associated with the etiopathogenesis of MS and other demyelinating syndromes. To address this question, we established a mouse model where mitochondrial DNA (mtDNA) double-strand breaks (DSBs) were specifically induced in myelinating oligodendrocytes (PLP:mtPstI mice) by expressing a mitochondrial-targeted endonuclease, mtPstI, starting at 3 weeks of age. In both female and male mice, DSBs of oligodendroglial mtDNA caused impairment of locomotor function, chronic demyelination, glial activation, and axonal degeneration, which became more severe with time of induction. In addition, after short transient induction of mtDNA DSBs, PLP:mtPstI mice showed an exacerbated response to experimental autoimmune encephalomyelitis. Together, our data demonstrate that mtDNA damage can cause primary oligodendropathy, which in turn triggers demyelination, proving PLP:mtPstI mice to be a useful tool to study the pathological consequences of mitochondrial dysfunction in oligodendrocytes. In addition, the demyelination and axonal loss displayed by PLP:mtPstI mice recapitulate some of the key features of chronic demyelinating syndromes, including progressive MS forms, which are not accurately reproduced in the models currently available. For this reason, the PLP:mtPstI mouse represents a unique and much needed platform for testing remyelinating therapies.SIGNIFICANCE STATEMENT In this study, we show that oligodendrocyte-specific mitochondrial DNA double-strand breaks in PLP:mtPstI mice cause oligodendrocyte death and demyelination associated with axonal damage and glial activation. Hence, PLP:mtPstI mice represent a unique tool to study the pathological consequences of mitochondrial dysfunction in oligodendrocytes, as well as an ideal platform to test remyelinating and neuroprotective agents.

Dataset Information

Accelerated carcinogenesis following liver regeneration is associated with chronic inflammation-induced double-strand DNA breaks.

Publications

Accelerated carcinogenesis following liver regeneration is associated with chronic inflammation-induced double-strand DNA breaks.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets