Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Stem cells may look malignant, not act it

Call it the cellular equivalent of big glasses, a funny nose and a fake mustache.

Bone marrow stem cells attracted to the site of a cancerous growth frequently take on the outward appearance of the malignant cells around them, University of Florida researchers report in a paper to be published in the August issue of Stem Cells.

But whether that enables them to fuel cancer's ability to develop and then spread, as some scientists suspect, is not entirely clear. The findings, available early in this month's online edition of the journal, actually contest the increasingly popular theory that bone marrow stem cells seed cancer. Instead, these cells might simply look like cancer, not act like it.

"They have the same kind of surface proteins," said study author Chris Cogle, M.D., an assistant professor of medicine at the UF's College of Medicine Program in Stem Cell Biology and Regenerative Medicine. "They have the same skin. The next question is 'Do they have the same guts"'

"Our results indicate these cells act as developmental mimics; they come in and look like the surrounding neoplastic tissue, but they aren't actually the seed of cancer," said Cogle, who also is affiliated with the UF Shands Cancer Center. "At the worst, these cells could help support cancerous tissue by providing it with growth factors or proteins that help the cancer grow and survive. At the very least, these marrow cells are just being tricked into coming into the cancerous environment and then made to walk and talk like they don't usually do."

The researchers have coined the term "developmental mimicry" to describe the phenomenon, which could have implications for the integrity of the cell lines scientists use to test new cancer drugs in the lab.

Up to 5 percent of cancerous tissue contains marrow-derived cells that look just like surrounding cancer. So when malignant tissue is grown in the laboratory for experiments that test the effects of new drugs, it's possible the results are muddied, Cogle said. Drugs, if effective, may be targeting the marrow cell mimics, not actual cancer cells.

"If there are bone marrow cells in this cancerous tissue, these cells may actually contaminate our cancer studies and could make a difference as to whether or not investigational drugs we're testing work or don't work," he said. "The significance of this is new treatments may work in the culture dish but may not translate to the clinic or the hospital room, and for many reasons. One of the reasons could be bone marrow contamination."

In their study, UF researchers evaluated two women who underwent bone marrow transplantation and subsequently developed colonic adenomas, four women who developed skin cancer and one who developed lung cancer.

"We questioned where the cancer was coming from — was it really from the patient or could it have been from the donor bone marrow that we transplanted in the patient?" Cogle said.

Each patient received infusions of bone marrow cells from a brother or an unrelated male donor. That enabled physicians to track the transplanted cells by screening for the Y male chromosome.

They found that the cancers were mostly of female origin, but the malignant tissue often contained small areas of male marrow cells.

"This led us to question the extent the donor marrow was participating in these cancers," Cogle said. "A tumor consists of a mixed bag of cells, not just one solid same-celled block of tissue. What we're trying to study is the role of these marrow-derived cells within the neighborhood of cancer."

The researchers then studied mice who underwent bone marrow transplant and developed the same cancers as the women. When they viewed the cancerous tissues under the microscope, they found marrow cells shared outward features of the cancer cells.

Cogle said research conducted elsewhere suggests marrow cells flock to a cancerous site to help set up a blood vessel-friendly environment that feeds the tumor. The current findings, supported by grants from the National Institutes of Health and the James & Esther King Biomedical Research Program, might be an aftereffect of this supporting role, he said.

UF researchers — who collaborated with scientists from Beth Israel Medical Center at New York's Albert Einstein College of Medicine, Yale University School of Medicine, St. Francis Hospital in Indianapolis and the Penn State Milton S. Hershey Medical Center — are now analyzing whether marrow cells that look like cancer are able to spawn tumors in animals, and whether they harbor the characteristic internal genetic defects of tumor cells.

Some patients who undergo bone marrow transplant later develop secondary cancers because of the high doses of radiation and chemotherapy they receive to prepare them for the procedure, said Mariusz Ratajczak, M.D., Ph.D., director of the Stem Cell Developmental Biology Program at the University of Louisville James Graham Brown Cancer Center and a member of the journal's editorial board.

"Transplanted cells which are derived initially from the bone marrow can include a population of stem cells which can on one hand do nice things and contribute to regeneration, and on the other hand if something goes wrong, these cells can also contribute to cancer development, of course in very rare cases," Ratajczak said. "This study has very nicely shown that that possibility exists, and it actually describes a new, novel mechanism. Somehow we know these cells contribute to growing tumor. They may not initiate it but they somehow contribute by developmental mimicry to these secondary malignancies."

Melanie Fridl Ross | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht Advanced analysis of brain structure shape may track progression to Alzheimer's disease
26.10.2016 | Massachusetts General Hospital

nachricht Indian roadside refuse fires produce toxic rainbow
26.10.2016 | Duke University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

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...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

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...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

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...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>