In a study published online today in Nature Genetics, Carlo Maley, Ph.D., a researcher at The Wistar Institute, and his colleagues report that precancerous tumors containing a population of highly diverse cells were more likely to evolve into cancer than those containing genetically similar cells. The finding suggests that, in at least some forms of cancer, the more genetically diverse a precancerous tumor is, the more likely that tumor is to progress to full-blown cancer. If so, genetic diversity might act as a biomarker for cancer risk among patients with precancerous tissues.
"Although researchers first defined cancer in evolutionary terms in the 1970s, few researchers have actually studied the disease this way," says Maley, lead author on the study and an assistant professor in the molecular and cellular oncogenesis program at Wistar. "We wanted to know: If we measured a precancerous tumor’s genetic diversity at baseline, could we predict who would go on to get cancer?"
To find out, the scientists decided to analyze data on a precancerous condition called Barrett’s esophagus, in which cells lining the lower esophagus change due to repeated exposure to stomach acid from reflux, a condition often referred to as heartburn. Doctors typically adopt a "wait and watch" approach to treating patients with Barrett’s esophagus because the condition only rarely leads to cancer and is difficult to treat surgically.
In the study, Maley and colleagues analyzed precancerous tumor data from 268 patients, including multiple biopsies within each tumor. On average, these patients were followed for 4.4 years, during which time 37 developed cancerous tumors. Overall, the database used in the study represents more than 32,000 distinct genotypes of different cells within the tumors.
Using computational techniques to analyze the data, the researchers calculated measures of diversity inside the tumors. Essentially, they counted cell varieties and measured the genetic difference, or divergence, between those varieties. "Simply put, we took ecology measures of species diversity and translated them into measures of cell diversity within tumors," Maley says. The found a striking correlation between increased diversity of tumor cells and progression to cancer. For every additional cell variety detected in a tumor, the patient was twice as likely to progress to cancer.
Maley suggests that genetically diverse tumors have a high probability of generating mutant cells that will flourish and spread, allowing the tumor to transform and grow. In the future, in addition to serving as a biomarker for cancer risk, he adds, measures of genetic diversity might help doctors assess the success of cancer prevention therapies.
In fact, he speculates, genetic diversity among tumor cells might help explain why therapy sometimes fails. If a tumor contains a diverse population of cells, some of those cells are more likely to resist treatment, Maley says. Adapting to and surviving chemotherapy, these resistant cells could breed, leading to a cancer relapse. He hopes to pursue this hypothesis in the future. "More immediately," he adds, "we intend to validate the new study with other cohorts and other types of tumors."
Franklin Hoke | EurekAlert!
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences