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
Finnish research group discovers a new immune system regulator
23.02.2018 | University of Turku
Minimising risks of transplants
22.02.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.
In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...
A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.
By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
23.02.2018 | Physics and Astronomy
23.02.2018 | Health and Medicine
23.02.2018 | Physics and Astronomy