Colon cancer may begin when processes that regulate adult stem cells in the colon go awry. A handful of stem cells lie in the bottom of tiny tube-like "crypts" in the epithelium (or lining) of the colon. Stem cells produce daughter cells that proliferate, eventually making their way to the top of the crypt, where they become specialized colon cells. Simply put, mutations in the stem cells lead to mutant daughter cells and cancer.
To try to understand some of these processes, Bruce Boman, M.D., Ph.D., director of the Division of Genetic and Preventive Medicine at Jefferson Medical College of Thomas Jefferson University and at Jefferson’s Kimmel Cancer Center, and his co-workers used a microarray chip to analyze the expression of microRNAs (miRNAs). MiRNAs are tiny pieces of genetic material discovered in recent years that are thought to be important in regulating gene expression and in the development of cancer. The chip carried complementary genetic "probes" for most of the known miRNAs in human and mouse.
The researchers first compared miRNA expression in the bottom tenth of normal colon crypts, which is where stem cells are located, to the other nine-tenths of the crypt, where daughter cells were proliferating. This approach was designed to tell the difference between stem cell and non-stem cell activity.
They also examined miRNA gene expression in colon cancer tissue, finding changes in expression between normal tissue and cancer. More specifically, they found a pattern of 16 miRNA genes that characterizes the crypt bottom. The pattern accurately predicted which colon tissues were normal and which were cancerous.
Dr. Boman, professor of medicine and director of Jefferson’s Hereditary Cancer Center and Gastrointestinal Cancer Program at Jefferson’s Kimmel Cancer Center, presents the team’s findings April 4, 2006 at the annual meeting of the American Association for Cancer Research in Washington, D.C.
"This will not only give us insights into how tissue dynamics are regulated in normal colonic epithelium, but also in the development of cancer as well, where the normal steady state is disrupted," he says. "It might also help us better understand the stem cell origin of colon cancer.
"If a miRNA is binding to a gene product that is key to differentiation of a cell, and the miRNA is lost, maybe that cell won’t be able to undergo differentiation and will become a cancer cell," he says. "We’re now looking at the gene targets for the specific miRNAs.
"The exciting part," notes Dr. Boman, "is that by figuring out which of these molecules are lost in cancer, they can theoretically be replaced. This could have tremendous potential for the development of new drugs."
Steve Benowitz | EurekAlert!
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences