Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Tumor cells that border normal tissue are told to leave


The thin, single-cell boundary where a tumor meets normal tissue is the most dangerous part of a cancer according to a new study by scientists at Washington University School of Medicine in St. Louis. The researchers found that tumor cells bordering normal tissue receive signals that tell them to wander away from the tumor, allowing the cancer cells to establish deadly metastatic tumors elsewhere in the body.

The researchers say their discovery demonstrates the importance of the tumor’s environment and shows more precisely how the metastatic process occurs and might be stopped. Their study appears in the January 10 issue of Developmental Cell.

"What actually kills in cancer is not the primary tumor--it’s metastasis," says senior author Ross L. Cagan, Ph.D., associate professor of molecular biology and pharmacology and a researcher with the Siteman Cancer Center at Washington University School of Medicine and Barnes-Jewish Hospital. "You can’t study that in a laboratory dish. You have to look at the tumor cells in their natural environment--surrounded by normal tissues."

To do this, the research team created tumors in fruit fly eyes and wings that permitted them to study the behavior of individual tumor cells.

"We found that the tumor cells in direct contact with normal cells had a different behavior than cells further inside the tumor," says lead author Marcos Vidal, Ph.D., research associate in molecular biology and pharmacology. "They were exclusively the ones that tended to leave the tissue."

The tumors were generated by turning off an inhibitor of a major oncogene called Src (pronounced sarc), making the tumor cells high in Src oncogene activity. (An oncogene is a gene that increases the malignancy of a tumor cell.) This particular genetic change is common in human breast tumors.

Boundary tumor cells were shown to lose surface proteins that attach them to other cells and stabilize their position within tissues. The study demonstrated that it was the difference in Src activity that led to the change in the attachment proteins. When a high Src cell (tumor cell) was next to a low Src cell (normal cell) the attachment proteins changed their characteristics, and the high Src cell became "unglued."

In addition, this change sent a signal that activated several other proteins in the tumor cell, one of which was an enzyme that dissolves the matrix surrounding cells. This enzyme makes it possible for a cell to move through tissues.

"Even though all the cells in the tumors we created were genetically identical, the proximity of the boundary cells to normal cells--their interaction with normal cells--made them special," Vidal says. "This is the first time the epithelial environment has been shown to play a role in metastasis."

The cells that left the fruit fly tumors eventually succumbed to the natural process of programmed cell death and were eliminated. According to Cagan, that was not unexpected.

"In a tumor, probably 99.99 percent of the border cells are raining out of the edges and dying," Cagan says. "But as oncologists have found, cancer stems from an accumulation of genetic mutations. If one of these wandering cells acquires a second mutation that prevents cell death, it could go on to establish a metastatic tumor."

Having created a model for studying metastasis of tumor cells, the research team has begun to look for ways to manipulate boundary cells to prevent their metastatic behavior. They have seen that disabling some of the genes in the pathway activated in boundary cells stops the cells from leaving the tumor.

Cagan’s laboratory also has developed a robotic system for screening anticancer drugs, and they plan to use this system to look for drugs that will affect the metastatic process in their fruit fly model.

"A drug that can prevent metastasis would be an important adjunct for cancer treatments," Cagan says. "It could cut a patient’s risk of having tumor cells leave the area before the primary tumor was eradicated. That’s essential--metastatic cancer is far harder to treat than early-stage tumors."

Gwen Ericson | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences

nachricht Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>