Nav: Home

Fragmenting ions and radiation sensitizers

September 03, 2019

A new study using mass spectrometry is helping piece together what happens when DNA that has been sensitized by the oncology drug 5-fluorouracil is subjected to the ionising radiation used in radiotherapy.

The anti-cancer drug 5-fluorouracil (5FU) acts as a radiosensitizer: it is rapidly taken up into the DNA of cancer cells, making the cells more sensitive to radiotherapy. However, little is known about the precise mechanism through which radiation damages cells. A team of scientists led by Peter van der Burgt at the National University of Ireland in Maynooth, Ireland have now used mass spectrometry to shed some light on this process; their work was recently published in EPJ D. A full understanding of this process could ultimately lead to new ways of protecting normal tissues from the radiation damage caused by essential cancer treatments.

Radiotherapy involves delivering radiation, in the form of X-rays, to the cancer site. The X-rays or other high-energy particles collide with the molecules they encounter, knocking off electrons to form positively-charged ions, and these ions and electrons in turn react with other molecules in the cells: this can kill cancer cells, but can also cause short- and long-term damage to others.

5-fluorouracil resembles the bases in normal DNA but is more sensitive to radiation, both on its own and when incorporated into DNA. Van der Burgt and his colleagues investigated this sensitivity by producing a stream of 5FU particles in a mass spectrometer and colliding them with a beam of radiation. The spectrometer was then used to determine which ions were formed in the collisions by measuring their mass-to-charge ratio. Two sets of experiments were carried out: one using electrons as the radiation source, and the other using high-intensity photons.

Increasing the energy of the radiation increased the number and type of ions that were formed; the researchers identified many different fragment ions and determined the radiation level at which each was first formed. These included some ions that were absent from the spectrum of the natural base, uracil, and some that had not been observed in this type of experiment before. Undoubtedly, similar processes take place in the tissues of patients undergoing radiotherapy.
-end-
Reference:

P.J.M. van der Burgt, M.A. Brown, J. Bockova, A. Rebelo, M. Ryszka, J-C. Poully and S. Eden (2019) Fragmentation processes of ionized 5-fluorouracil in the gas phase and within clusters, European Physical Journal D 73: 184, DOI: 10.1140/epjd/e2019-100107-7

Contact:

Sabine Lehr
Springer Physics Editorial
Tel: +49-6221-4487-8336
Email: sabine.lehr@springer.com

Springer

Related Cancer Cells Articles:

New liver cancer research targets non-cancer cells to blunt tumor growth
'Senotherapy,' a treatment that uses small molecule drugs to target ''senescent'' cells, or those cells that no longer undergo cell division, blunts liver tumor progression in animal models according to new research from a team led by Celeste Simon, PhD, a professor of Cell and Developmental Biology in the Perelman School of Medicine at the University of Pennsylvania and scientific director of the Abramson Family Cancer Research Institute.
Drug that keeps surface receptors on cancer cells makes them more visible to immune cells
A drug that is already clinically available for the treatment of nausea and psychosis, called prochlorperazine (PCZ), inhibits the internalization of receptors on the surface of tumor cells, thereby increasing the ability of anticancer antibodies to bind to the receptors and mount more effective immune responses.
Engineered bone marrow cells slow growth of prostate and pancreatic cancer cells
In experiments with mice, researchers at the Johns Hopkins Kimmel Cancer Center say they have slowed the growth of transplanted human prostate and pancreatic cancer cells by introducing bone marrow cells with a specific gene deletion to induce a novel immune response.
First phase i clinical trial of CRISPR-edited cells for cancer shows cells safe and durable
Following the first US test of CRISPR gene editing in patients with advanced cancer, researchers report these patients experienced no negative side effects and that the engineered T cells persisted in their bodies -- for months.
Zika virus' key into brain cells ID'd, leveraged to block infection and kill cancer cells
Two different UC San Diego research teams identified the same molecule -- αvβ5 integrin -- as Zika virus' key to brain cell entry.
Plant-derived SVC112 hits cancer stem cells, leaves healthy cells alone
Study shows Colorado drug SVC112 stops production of proteins that cancer stem cells need to survive and grow.
Changes in the metabolism of normal cells promotes the metastasis of ovarian cancer cells
A systematic examination of the tumor and the tissue surrounding it -- particularly normal cells in that tissue, called fibroblasts -- has revealed a new treatment target that could potentially prevent the rapid dissemination and poor prognosis associated with high-grade serous carcinoma (HGSC), a tumor type that primarily originates in the fallopian tubes or ovaries and spreads throughout the abdominal cavity.
The development of brain stem cells into new nerve cells and why this can lead to cancer
Stem cells are true Jacks-of-all-trades of our bodies, as they can turn into the many different cell types of all organs.
White blood cells related to allergies may also be harnessed to destroy cancer cells
A new Tel Aviv University study finds that white blood cells which are responsible for chronic asthma and modern allergies may be used to eliminate malignant colon cancer cells.
Conversion of breast cancer cells into fat cells impedes the formation of metastases
An innovative combination therapy can force malignant breast cancer cells to turn into fat cells.
More Cancer Cells News and Cancer Cells Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Meditations on Loneliness
Original broadcast date: April 24, 2020. We're a social species now living in isolation. But loneliness was a problem well before this era of social distancing. This hour, TED speakers explore how we can live and make peace with loneliness. Guests on the show include author and illustrator Jonny Sun, psychologist Susan Pinker, architect Grace Kim, and writer Suleika Jaouad.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.