Nav: Home

Promising cancer therapy advanced by chemical explanation

December 14, 2015

Radiation therapy: A chilling word that creates images of burn-injuries where the cancer killing ray went through the skin. For decades research hospitals have been investigating the alternative method Hadron therapy, or particle therapy, where runaway cells are bombarded with "naked" atomic nuclei or protons. When the particles pass through sick cells the collision creates chemical reactions preventing further cell division. Now researchers at the Department of Chemistry, University of Copenhagen, have discovered an unknown reaction caused by the therapy.

In the ten percent most important results of 2015

Birgitte Olai Milhøj is a PhD student at the Department of Chemistry. Her results have been published in the periodical Chemistry - A European Journal in an article entitled "Insight into the mechanism of the Initial reaction of a OH-Radical with DNA/RNA nucleobases: a Computational Investigation of Radiation Damage". The article received special mention as one of the ten percent most important results in 2015.

Correct dose imperative to avoid damage

On paper, particle therapy is less damaging than traditional radiation therapy but in order to determine the size of doses, it is imperative to understand the chemical as well as the physical and biological processes triggered by the subatomic particles, say Milhøj's supervisor Professor Stephan Sauer.

"The therapist obviously needs to shoot as many particles as necessary but preferably so few that there is no subsequent damage. As they are, our new results cannot be used to calculate the correct doses but we have provided new insights into how the treatment functions at the molecular level. It is our hope that physicians will be able to develop this into a dosis calculator", says Sauer and goes on: "In the long run, I really hope that cancer patients will receive better treatment thanks to our efforts".

"Hungry" molecules tear DNA to pieces

When atomic nuclei collide with structures inside the cancer cell, so called OH-radicals are created. OH-radicals are water molecules (H2O) lacking an Hydrogen-atom thus having transformed into a H1O. Molecules like these are extremely "hungry" to regain the missing hydrogen-atom, explains Sauer.

"To a water molecule, losing one of its hydrogen atoms is almost as bad as it would be for me to lose an arm. The OH-radical will do almost anything to steal a new hydrogen atom from anywhere. This might be from the cell's DNA-string, where there are abundant hydrogen atoms in the base pairs. If you destroy the base pairs, you prevent the cell from breeding. That is why it is so efficient to create these very aggressive OH-radicals inside the cancer cells", says Sauer.

Months of calculations for every possible reaction path

Milhøj and Sauer have uncovered the surprising reaction by pure computational chemistry but even in a computer, the calculations are extremely fiddly work. The further fate of the DNA base pairs is extremely dissimilar dependent on whether the OH-radical screeches in from above, below or from one of the sides. Consequently, Milhøj had to draw and animate the molecules in the computer and then switch on calculations lasting two to three months. All this in order to predict the consequences of just one single angle of attack, and she had to calculate 200 possible angles. The great breakthrough came to Milhøj when she developed a method of calculation reducing the time taken for each of the comprehensive simulations to two to three weeks for each of the 200 angles.

The first experiments with the new therapy go back as far as 1969 but not until the early noughts did hospitals throughout the world start adopting the therapy and invest in the machinery for it.
-end-


Faculty of Science - University of Copenhagen

Related Cell Division Articles:

Genetic signature boosts protein production during cell division
A research team has uncovered a genetic signature that enables cells to adapt their protein production according to their state.
Inner 'clockwork' sets the time for cell division in bacteria
Researchers at the Biozentrum of the University of Basel have discovered a 'clockwork' mechanism that controls cell division in bacteria.
Scientists detail how chromosomes reorganize after cell division
Researchers have discovered key mechanisms and structural details of a fundamental biological process--how a cell nucleus and its chromosomal material reorganizes itself after cell division.
Targeting cell division in pancreatic cancer
Study provides new evidence of synergistic effects of drugs that inhibit cell division and support for further clinical trials.
Scientists gain new insights into the mechanisms of cell division
Mitosis is the process by which the genetic information encoded on chromosomes is equally distributed to two daughter cells, a fundamental feature of all life on earth.
Cell division at high speed
When two proteins work together, this worsens the prognosis for lung cancer patients: their chances of survival are particularly poor in this case.
Cell biology: The complexity of division by two
Ludwig-Maximilians-Universitaet (LMU) in Munich researchers have identified a novel protein that plays a crucial role in the formation of the mitotic spindle, which is essential for correct segregation of a full set of chromosomes to each daughter cell during cell division.
Better together: Mitochondrial fusion supports cell division
New research from Washington University in St. Louis shows that when cells divide rapidly, their mitochondria are fused together.
Seeing is believing: Monitoring real time changes during cell division
Scientist have cast new light on the behaviour of tiny hair-like structures called cilia found on almost every cell in the body.
Exhaustive analysis reveals cell division's inner timing mechanisms
After exploring every possible correlation, researchers shed new light on a long-standing question about what triggers cell division.
More Cell Division News and Cell Division 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

Uncharted
There's so much we've yet to explore–from outer space to the deep ocean to our own brains. This hour, Manoush goes on a journey through those uncharted places, led by TED Science Curator David Biello.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Dispatch 1: Numbers
In a recent Radiolab group huddle, with coronavirus unraveling around us, the team found themselves grappling with all the numbers connected to COVID-19. Our new found 6 foot bubbles of personal space. Three percent mortality rate (or 1, or 2, or 4). 7,000 cases (now, much much more). So in the wake of that meeting, we reflect on the onslaught of numbers - what they reveal, and what they hide.  Support Radiolab today at Radiolab.org/donate.