Researchers say the findings provide new information about how tumors develop blood vessels, and why new drugs designed to block tumor blood-vessel growth are often less effective than expected.
The study by scientists at the Ohio State University Comprehensive Cancer Center and Department of Pathology is to be published Feb. 20 in the journal PLoS ONE. “These findings suggest that tumor blood vessels are derived mainly from tumor cells, with a smaller number coming from normal blood-vessel cells,” says principal investigator Jian-Xin Gao, assistant professor of pathology.
“This may explain why many anti-angiogenic drugs fail to block tumor growth.”
Gao notes that potential anti-angiogenic drugs are usually screened using normal blood-vessel cells, also called endothelial cells, or their progenitors.
“The screened drugs may be very good at blocking the formation of blood vessels made by normal endothelial cells, but have little effect on blood-vessel formation by precancerous stem cells or other blood-vessel-forming cancer cells,” Gao says. “Our findings suggest that screening of these agents should include precancerous stem cells.”
Normal stem cells are unspecialized cells that can give rise to other types of cells. Recent evidence suggests that tumors consist of a small number of cancerous stem cells, or cancer-propagating cells with some features of stem cells, and a large number of their malignant progeny.
Precancerous stem cells are thought to be cells that can remain noncancerous or progress to cancer, depending on subsequent environmental influences.
For this study, Gao and his colleagues used mouse precancerous stem cells grown in the laboratory and transplanted into immune-deficient mice. The researchers removed the resulting tumors from the mice and, using tests for various molecular markers, observed that the tumor blood vessels were largely derived from precancerous stem cells.
“The tumor blood-vessel cells were abnormal and highly variable in appearance compared with normal cells,” Gao says.
The precancerous stem cells also produced similar levels of substances that stimulate blood-vessel growth (i.e., angiogenic factors), but they were much more potent in forming new blood vessels and larger tumor masses compared with tumors grown from typical tumor cells.
The researchers examined new blood vessel formation in human tumors transplanted into mice, and observed changes similar to those previously seen in the mouse tumors.
Lastly, the researchers examined the appearance of blood vessels in human cervical and breast tumors and observed that the blood-vessel cells displayed similar abnormalities and aberrant patterns of molecular markers.
“This suggests that the ability of these tumors to form blood vessels is likely linked to precancerous stem cells or other blood-vessel-forming tumor cells,” Gao says.
Citation: Shen R, Ye Y, Chen L, Yan Q, Barsky SH, et al (2008) Precancerous Stem Cells Can Serve As Tumor Vasculogenic Progenitors. PLoS ONE 3(2): e1652.doi:10.1371/journal.pone.0001652
Microgel powder fights infection and helps wounds heal
14.11.2018 | Michigan Technological University
Spread of deadly eye cancer halted in cells and animals
13.11.2018 | Johns Hopkins Medicine
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly
The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
14.11.2018 | Materials Sciences
14.11.2018 | Health and Medicine
14.11.2018 | Life Sciences