Public release date: 12-Mar-2012 [ | E-mail | Share ]

Contact: Sarah Jackson press_releases@the-jci.org 919-684-0620 Journal of Clinical Investigation

EDITOR'S PICK Restoring what's lost: uncovering how liver tissue regenerates

The liver is unique among mammalian organs in its ability to regenerate after significant tissue damage or even partial surgical removal. Laurie DeLeve and her colleagues at the University of Southern California in Los Angeles wanted to better understand which cells are specifically responsible for driving liver regeneration. A specialized cell type, known as liver sinusoidal endothelial cells, has generally been thought to promote regeneration of liver tissue. However, the DeLeve team suspected that stem cells and progenitor cells, which have the capacity to differentiate into mature cell types, might be responsible for stimulating liver regeneration by generating hepatocyte growth factor. Using a rat model system, they first identified the presence of stem and progenitor cells that give rise to liver sinusoidal endothelial cells in both the liver and the bone marrow. They next sought to determine which population of stem and progenitor cells are required for regeneration. DeLeve and colleagues found that the bone marrow-derived cells were not required for liver cell proliferation in the absence of damage. In contrast, following surgical removal of a portion of the rat liver, an infusion of bone marrow-derived progenitor cells was required for liver regeneration. These results improve our understanding of how liver tissue can regenerate following damage and may shed light on liver complications in patients with suppressed bone marrow tissue.

TITLE: Liver sinusoidal endothelial cell progenitor cells promote liver regeneration in rats

AUTHOR CONTACT: Laurie D. DeLeve University of Southern California Keck School of Medicine, Los Angeles, CA, USA Phone: 323-442-3248; Fax: 323-442-3238; E-mail: deleve@usc.edu

View this article at: http://www.jci.org/articles/view/58789?key=21e2857b21106f232595

ONCOLOGY New Determinant of Human Breast Cancer Metastasis Discovered

Researchers at the University of Kentucky's Markey Cancer Center in Lexington, KY have provided new insight as to why the most severe subtype of breast cancer in humans frequently metastasizes. Tumor cells can exploit a cellular program that promotes cell migration and reduces adhesion between cells to spread to distant sites in the body (metastasis). This cellular program, known as the epithelial-mesenchymal transition, is normally restricted to wound healing, tissue remodeling and embryonic development. Increasing cell motility requires a decrease in E-cadherin, which functions to promote cell-cell adhesion. Led by Binhua Zhou, the research team identified G9a as a major repressor of E-cadherin expression. They found that G9a interacts with Snail, which can repress gene expression, to modify the E-cadherin promoter and block expression of the E-cadherin gene. Their findings establish that G9a is an important determinant of metastasis in the most severe sub-type of breast cancer, and suggest the development of new therapeutics targeting this pathway could potentially disrupt the metastatic disease.

TITLE: G9a interacts with Snail and is critical for Snail-mediated E-cadherin repression in human breast cancer

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JCI early table of contents for March 12, 2012