LONDON (Agence de Presse Medicale for Reuters Health) - British scientists said on Sunday they had discovered that Kaposi sarcoma first develops in the inner cell lining of lymphatic vessels. The cell type in which the sarcoma develops has been a mystery for more than a century, but a team at University College London (UCL) said genetic analysis showed that sarcoma cells are genetically similar to lymphatic endothelial cells.
The findings, reported in Nature Genetics, also show that the Kaposi sarcoma herpes virus can turn the endothelial cells that line blood vessels into cancerous lymphatic endothelial cells.
“We have shown for the first time that a virus can genetically reprogramme blood vessel endothelial cells into lymphatic endothelial cells, and that it is these lymphatic cells that develop into Kaposi sarcoma,” said Professor Chris Boshoff, joint director of the Cancer Research UK viral oncology group at UCL. “Now that we know in which type of cell Kaposi sarcoma originates, we should be able to identify new ways to treat the condition. The findings could also yield new clues about other cancers that are triggered by viruses, such as cervical cancer,” he added in a statement.
The team found that high levels of circulating growth factors that encourage lymphatic endothelial cells to proliferate were strongly associated with the development of Kaposi sarcoma.
Boshoff added: “Finding new cancers early is vital if treatment is to be successful. By testing blood for growth factors that encourage the cells lining lymph vessels to grow, doctors might be able to predict which high-risk patients - such as those with HIV or who have had an organ transplant - will subsequently develop Kaposi sarcoma.”
In another study in the same issue of Nature Genetics, Dr. Michael Detmar of Harvard Medical School, Boston, reports that he and colleagues infected differentiated blood vascular endothelial cells with the Kaposi-associated herpesvirus.
The infection, they found, “activates a developmental genetic program specifying lymphatic endothelial cell fate, including upregulation of PROX1 [a master regulator of lymphatic development] that is essential for the embryonic development of the mammalian lymphatic system.” The changes in expression, they conclude, shift the cells from the pattern typical of their original cell type and into one typical of lymph vessels.
Source: Nat Genet 2004. [ Google search on this article ]
MeSH Headings:Biological Sciences: Biology: Endothelium, Vascular: Gene Expression Regulation: Genetics: Genetics, Biochemical: Molecular Biology: Biological SciencesCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
