Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Low oxygen levels could drive cancer growth

04.05.2012
Low oxygen levels in cells may be a primary cause of uncontrollable tumor growth in some cancers, according to a new University of Georgia study. The authors' findings run counter to widely accepted beliefs that genetic mutations are responsible for cancer growth.

If hypoxia, or low oxygen levels in cells, is proven to be a key driver of certain types of cancer, treatment plans for curing the malignant growth could change in significant ways, said Ying Xu, Regents-Georgia Research Alliance Eminent Scholar and professor of bioinformatics and computational biology in the Franklin College of Arts and Sciences.

The research team analyzed samples of messenger RNA data—also called transcriptomic data—from seven different cancer types in a publicly available database. They found that long-term lack of oxygen in cells may be a key driver of cancer growth. The study was published in the early online edition of the Journal of Molecular Cell Biology.

Previous studies have linked low oxygen levels in cells as a contributing factor in cancer development, but not as the driving force for cancer growth. High incidence rates of cancer around the world cannot be explained by chance genetic mutations alone, Xu said. He added that bioinformatics, which melds biology and computational science, has allowed researchers to see cancer in a new light. Gene-level mutations may give cancer cells a competitive edge over healthy cells, but the proposed new cancer growth model does not require the presence of common malfunctions such as a sudden proliferation of oncogenes, precursors to cancer cells.

"Cancer drugs try to get to the root—at the molecular level—of a particular mutation, but the cancer often bypasses it," Xu said. "So we think that possibly genetic mutations may not be the main driver of cancer."

Much of cancer research so far has focused on designing drug treatments that counteract genetic mutations associated with a particular type of cancer. In their study, the researchers analyzed data downloaded from the Stanford Microarray Database via a software program to detect abnormal gene expression patterns in seven cancers: breast, kidney, liver, lung, ovary, pancreatic and stomach. The online database allows scientists to examine information from microarray chips, which are small glass slides containing large amounts of gene material.

Xu relied on the gene HIF1A as a biomarker of the amount of molecular oxygen in a cell. All seven cancers showed increasing amounts of HIF1A, indicating decreasing oxygen levels in the cancer cells.

Low oxygen levels in a cell interrupt the activity of oxidative phosphorylation, a term for the highly efficient way that cells normally use to convert food to energy. As oxygen decreases, the cells switch to glycolysis to produce their energy units, called ATP. Glycolysis is a drastically less efficient way to obtain energy, and so the cancer cells must work even harder to obtain even more food, specifically glucose, to survive. When oxygen levels dip dangerously low, angiogenesis, or the process of creating new blood vessels, begins. The new blood vessels provide fresh oxygen, thus improving oxygen levels in the cell and tumor and slowing the cancer growth—but only temporarily.

"When a cancer cell gets more food, it grows; this makes the tumor biomass bigger and even more hypoxic. In turn, the energy-conversion efficiency goes further down, making the cells even more hungry and triggering the cells to get more food from blood circulation, creating a vicious cycle. This could be a key driver of cancer," Xu said.

Xu explained that this new cancer-growth model could help explain why many cancers become drug resistant so quickly—often within three to six months. He stressed the importance of testing the new model through future experimental cancer research. If the model holds, researchers will need to search for methods to prevent hypoxia in cells in the first place, which could result in a sea change in cancer treatment.

Additional authors of this study include Juan Cui, Xizeng Mao and Victor Olman, all of UGA, and Phil Hastings of Baylor College of Medicine. Xu also has a joint appointment with Jilin University in China.

Ying Xu | EurekAlert!
Further information:
http://www.uga.edu

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>