Featured Research

from universities, journals, and other organizations

Tumor Cells Made More Sensitive To Radiation By Blocking A Key Cellular Molecule

Date:
October 25, 2000
Source:
University Of North Carolina School Of Medicine
Summary:
In recent years, cancer researchers have sought ways to make tumors more receptive to treatment. In a series of novel experiments, scientists at the University of North Carolina at Chapel Hill have succeeded in making tumor cells more sensitive to destruction by radiation therapy.

In recent years, cancer researchers have sought ways to make tumors more receptive to treatment. In a series of novel experiments, scientists at the University of North Carolina at Chapel Hill have succeeded in making tumor cells more sensitive to destruction by radiation therapy.

Related Articles


This was accomplished in colorectal tumor cells by two experimental interventions aimed at blocking activation of a cellular protein, NF-kappaB.

The findings will be detailed in Boston, Wednesday, October 25, at the annual meeting of the American Society for Therapeutic Radiation and Oncology.

Earlier research has shown that activation of the molecule in some tumor types inhibits the cellular self-destruction process called apoptosis. Moreover, ionizing radiation, which is used against malignancies, and some anti-cancer drugs, also may induce NF-kappaB activation.

"This can reduce the cell-killing effects of chemotherapy or radiation," said Joel E. Tepper, MD, head of radiation oncology at UNC-CH School of Medicine and a member of UNC Lineberger Comprehensive Cancer Center. "But it's also known you can inhibit the inhibition of apoptosis. And if you can do that, you may be able to do a more effective job of killing tumor cells with standard anticancer therapies."

The UNC experiments were aimed at determining if the effects of radiation would be enhanced against tumor cells in which NF-kappaB activation was inhibited. Suzanne M. Russo, MD, a former radiation oncology resident at UNC, and now a radiation oncologist at Wake Forest University led the study. Collaborators included Tepper and other Lineberger Center members Albert S. Baldwin, PhD, and James C. Cusack, MD.

The team investigated colorectal tumor cells in lab dishes and in tumors grown on mice. In carefully controlled experiments, they studied two methods of inhibiting NF-kappaB activation. One is the experimental drug PS-341, a proteosome inhibitor chemical that prevents the cell from degrading or breaking down another molecule, IkappaB. This molecule is attached to NF-kappaB and blocks it from activating. Much like a car's brakes, IkappaB stops NF-kappaB from moving into the nucleus, the cell's master control room.

The researchers also studied the effects of infusing tumor cells with a type of IkappaB that is a super-repressor of NF-kappaB. This super-repressor molecule when ferried into tumor cells via an inactivated cold virus creates a very stable attachment to NF-kappaB.

"We were able to determine that NF-kappaB inhibition by either method did in fact produce increased cell killing after radiation," Tepper said. "And we could document both increased cell killing and increased apoptosis."

Moreover, both Tepper and Russo point out that they also documented a decrease in "clonogenic survival." After treatment, tumor cells eventually ceased to divide and died. "This is the most important endpoint," Tepper said.

"We found that treatment with IkappaB super-repressor or PS-341 increased the radiation response," Russo said. "And when we went in vivo to look at mouse models and did the same interventions with tumors we grew on mice, we found the same thing.

"Potentially, agents that modify programmed cell death are exciting in that they may enhance the effects of our current anti-tumor therapies. As demonstrated by this study, radiation may work better in the presence of one of these agents."


Story Source:

The above story is based on materials provided by University Of North Carolina School Of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

University Of North Carolina School Of Medicine. "Tumor Cells Made More Sensitive To Radiation By Blocking A Key Cellular Molecule." ScienceDaily. ScienceDaily, 25 October 2000. <www.sciencedaily.com/releases/2000/10/001025072224.htm>.
University Of North Carolina School Of Medicine. (2000, October 25). Tumor Cells Made More Sensitive To Radiation By Blocking A Key Cellular Molecule. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2000/10/001025072224.htm
University Of North Carolina School Of Medicine. "Tumor Cells Made More Sensitive To Radiation By Blocking A Key Cellular Molecule." ScienceDaily. www.sciencedaily.com/releases/2000/10/001025072224.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. Video provided by Newsy
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins