Featured Research

from universities, journals, and other organizations

Physicists Join Fight Against Cancer, By Understanding How Best To Use Radiation To Kill Tumor Cells

Date:
June 28, 2001
Source:
Texas A&M University
Summary:
Physicists at Texas A&M University have joined the battle to fight cancer by studying collisions between particles. Professor John F. Reading and three graduate students are trying to understand how to make the best use of radiation to kill tumor cells.

COLLEGE STATION, June 11 - Physicists at Texas A&M University have joined the battle to fight cancer by studying collisions between particles. Professor John F. Reading and three graduate students are trying to understand how to make the best use of radiation to kill tumor cells. In current radiation treatments, only a portion of tumor cells die, while others are free to multiply and spread. By looking at the inner mechanisms of how radiation attacks tumor cells, the Texas A&M physicists think it might be possible to make radiation more effective.

Radiation is thought to kill tumor cells by damaging their DNA. In the form of a double helix with two strands, DNA is the part of the cell that carries the genetic code. Radiation may break either one or both of the DNA strands. If only one strand is broken, the cell can often repair the damage. If both strands are broken, the repair is more difficult and the cell is more likely to die.

Reading and graduate students Jun Fu, Mathew Fitzpatrick and Bill Smith, have been working for seven years on the mechanisms that occur when a particular type of radiation, made of a beam of ions, hits the living target cells.

"Once you understand the processes," says Reading, "you can act in a more informed manner, devise a more effective radiation, and therefore hopefully reduce the peripheral damage to healthy cells caused by radiation."

Working in collaboration with a group of physicists led by Annie Chetioui, professor of physics at the University of Pierre and Marie Curie of Paris in France, the Texas A&M physicists are developing computer programs to describe in detail the effects of beams of ions on tumors.

A focus of Chetioui's work is to explain the existence of an optimal ion speed associated with the highest killing rates. "As you slow the speed of the incoming ions, they have much more time to interact with the atoms on the DNA strand, so the killing rate increases" says Reading. "But past a critical point, even though the energy deposited still increases, the killing stops."

Chetioui theorizes that a special atomic reaction called an Auger process is the key to understanding this. As a projectile hits one DNA strand, it may cause an explosion of energetic electrons that scythe through the second DNA strand at an adjacent site causing the double break.

Further experiments conducted in France have led to some support for this mechanism but many free electrons with a wide range of speeds are always produced by the impact, not just the Auger electrons. All of these electrons eventually deposit their energy in the target and may also damage the cell. To show that fast Auger electrons are responsible for cell death, scientists need to accurately determine the distribution of electron speeds.

The Texas A&M group is now trying to provide these details. Graduate students Smith and Fitzpatrick have written Ph.D. theses that predict the onset of the Auger process. Fu's master's thesis builds on this work to determine the electron speeds. If the projectile is a fast proton and the target atom is hydrogen, the speeds can be measured. These experimental results are in good agreement with Fu's work. He will now go on to study DNA carbon and oxygen atoms.

"We successfully calculated the simplest case: the proton-hydrogen reaction with one ejected electron," Fu says. "We are now extending the calculation to many-electron cases, and we would need to consider reactions between a proton and carbon and oxygen atoms as well."

Although work is still ongoing, the Texas A&M physicists are well on their way to developing a tool that can help sort out precisely what happens when living cells are impacted by ion beams.

"If Chetioui is right, then by choosing the right beam energy, you could greatly enhance the effectiveness of radiotherapy," says Reading. "You could deliver much smaller doses directly to the cancer, cutting down on peripheral damage to healthy cells."


Story Source:

The above story is based on materials provided by Texas A&M University. Note: Materials may be edited for content and length.


Cite This Page:

Texas A&M University. "Physicists Join Fight Against Cancer, By Understanding How Best To Use Radiation To Kill Tumor Cells." ScienceDaily. ScienceDaily, 28 June 2001. <www.sciencedaily.com/releases/2001/06/010612070032.htm>.
Texas A&M University. (2001, June 28). Physicists Join Fight Against Cancer, By Understanding How Best To Use Radiation To Kill Tumor Cells. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2001/06/010612070032.htm
Texas A&M University. "Physicists Join Fight Against Cancer, By Understanding How Best To Use Radiation To Kill Tumor Cells." ScienceDaily. www.sciencedaily.com/releases/2001/06/010612070032.htm (accessed July 25, 2014).

Share This




More Health & Medicine News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
Can Watching TV Make You Feel Like A Failure?

Can Watching TV Make You Feel Like A Failure?

Newsy (July 24, 2014) A study by German researchers claims watching TV while you're stressed out can make you feel guilty and like a failure. 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:
from the past week

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