Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New avenue for treating colon cancer

10.02.2012
Research led by UC Riverside cell biologists describes mechanism by which some people may be more susceptible to colon cancer

An international research team led by cell biologists at the University of California, Riverside has uncovered a new insight into colon cancer, the third leading cause of cancer-related deaths in the United States. The research provides potential new avenues for diagnosing and treating the disease.

Led by Frances Sladek at UC Riverside and Graham Robertson at the University of Sydney, Australia, the team analyzed about 450 human colon cancer specimens and found that in nearly 80 percent of them the variants of a gene, HNF4A, are out of balance.

Human beings express several variants of the HNF4A gene, classified as P1 and P2 variants. Some tissues, like liver, have just one type of variant but the colon has both P1 and P2 variants. The P1 variant is found in the nuclei of cells in the normal colon but in the human colon cancer samples this variant is frequently either absent or located outside of the nucleus and, presumably, no longer functional.

Using human colon cancer cell lines and in vitro assays, the researchers found that the imbalance observed in the human tumor tissues seemed to be the result of a complex, multi-step process by an enzyme, Src kinase. Src kinase has been known to be activated in colon cancer but, until now, it was not known to act on the HNF4a protein (HNF4A is the gene, a stretch of DNA; HNF4a is the protein encoded by HNF4A). The UCR group found that activated Src modifies the P1 but not the P2 variant. The net result is loss of the P1 variant in the nuclei of cells in the colon.

Study results appeared online last week in the Proceedings of the National Academy of Sciences.

"Loss of nuclear P1 HNF4a protein in the colon may be an early sign of colon cancer," explained Sladek, a professor of cell biology and toxicologist. "A healthy colon has a good but delicate balance of the two HNF4a variants. If you could prevent the loss of the P1 variant via drugs, you might be able to maintain a normal colon and prevent colon cancer."

The researchers found another factor that increases a person's susceptibility to the disease: certain "single nucleotide polymorphisms" or SNPs located in the HNF4A gene. An SNP is a DNA sequence variation — a minor change in the genomic sequence that accounts for the variations we see between individuals. SNPs are the most common type of genetic variation among people.

"Individuals with certain SNPs may be more susceptible to colon cancer," said Karthikeyani Chellappa, a postdoctoral researcher in Sladek's lab and the first author of the research paper. "That's because these SNPs result in a greater amount of modification and a faster degradation of HNF4a by Src, at least in cell-based assays. It still needs to be investigated, though, whether individuals carrying these SNPs are indeed more susceptible to colon cancer."

Sladek noted that drugs are already available for inhibiting the activity of Src kinase.

"Some of these drugs are in clinical trials for colon cancer," she said. "It would be exciting to determine whether these drugs can maintain the P1 HNF4a protein levels, as well as inhibit the Src kinase activity."

A multifactorial disease influenced by genetics and the environment, colon cancer starts as a small polyp in the large intestine (colon) or the rectum (end of the colon). While most of the polyps are benign, some do turn cancerous. With proper screening, the disease can be detected early, when it is most curable.

Sladek, Chellappa and Robertson were joined in the research by Songqin Pan and Jake M. Schnabl at UCR; Lucy Jankova, Caroline L-S. Fung, Charles Chan, Owen F. Dent and Stephen J. Clarke at the University of Sydney, Australia; and Yann Brelivet of the Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France. Robertson and the Australian members of the team performed all the analysis of the human tumor samples.

The research was supported in part by a National Institutes of Health grant to Sladek.

The University of California, Riverside (http://www.ucr.edu) is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment has exceeded 20,500 students. The campus will open a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Center. The campus has an annual statewide economic impact of more than $1 billion. A broadcast studio with fiber cable to the AT&T Hollywood hub is available for live or taped interviews. UCR also has ISDN for radio interviews. To learn more, call 951-UCR-NEWS.

Iqbal Pittalwala | EurekAlert!
Further information:
http://www.ucr.edu

More articles from Life Sciences:

nachricht If Machines Could Smell ...
19.07.2019 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

nachricht Algae-killing viruses spur nutrient recycling in oceans
18.07.2019 | Rutgers University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Better thermal conductivity by adjusting the arrangement of atoms

Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.

In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...

Im Focus: First-ever visualizations of electrical gating effects on electronic structure

Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.

Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...

Im Focus: Megakaryocytes act as „bouncers“ restraining cell migration in the bone marrow

Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.

Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...

Im Focus: Artificial neural network resolves puzzles from condensed matter physics: Which is the perfect quantum theory?

For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.

Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...

Im Focus: Extremely hard yet metallically conductive: Bayreuth researchers develop novel material with high-tech prospects

An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".

The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

Heat flow through single molecules detected

19.07.2019 | Physics and Astronomy

Heat transport through single molecules

19.07.2019 | Physics and Astronomy

Welcome Committee for Comets

19.07.2019 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>