Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Texas scientists discover how a hepatitis C protein promotes liver cancer

06.12.2005


Texas--Scientists at the University of Texas Medical Branch at Galveston (UTMB) have identified a key biochemical connection between the hepatitis C virus and liver cancer.



The molecular mechanism is similar to the one that links the human papilloma virus (HPV), the cause of genital warts, and cervical cancer, according to Dr. Stanley M. Lemon, the senior author of a paper on the discovery that will be published this week in the online early edition of the Proceedings of the National Academy of Sciences.

"What we’ve found is that one of the hepatitis C virus proteins targets a cell protein that is crucial for suppressing the development of tumors, interfering with its ability to control cell proliferation," Lemon said. "By knocking out this ’tumor suppressor’ and promoting the proliferation of liver cells, this viral protein is setting up the liver for cancer."


According to the federal Centers for Disease Control and Prevention, about 85 percent of liver cancer cases in the United States occur in people infected by the hepatitis C virus. Approximately 200 million people worldwide suffer from chronic hepatitis C, which can persist in the body for decades after an initial infection, often causing so much liver damage that a transplant may be a patient’s only chance for survival. The most effective treatment available, interferon therapy, works only about half the time and often causes debilitating side effects. Those who fail treatment are at risk for fatal cirrhosis or developing liver cancer.

Researchers have known for a long time that hepatitis C virus infection can lead to liver cancer. But how the virus goes about this has been unclear.

The UTMB group discovered that the tumor-suppressing retinoblastoma protein is present at markedly reduced levels in cells containing a hepatitis C virus "replicon," a large piece of hepatitis C genetic material that is able to reproduce itself in cultured cells and also able to produce proteins made by hepatitis C viruses. "The replicon experiments enabled us to identify a protein known as NS5B that attaches to the retinoblastoma protein, a critical tumor suppressor, and accelerates its breakdown," Lemon said. He continued: "The way NS5B docks with the retinoblastoma protein is biochemically almost identical to the way a protein made by human papilloma virus does so to produce similar cancer-promoting results. That’s interesting, because the two viruses are so different --HPV is a DNA virus, while hepatitis C is composed of RNA."

Understanding just how hepatitis C infection leads to the development of cancer is of critical importance, Lemon said. With no one "silver bullet" cure for hepatitis C on the horizon, he explained, researchers must use new knowledge to maximize the effectiveness of various virus-fighting therapies now under development, managing the care of chronically infected patients in ways that will best help them avoid liver cancer.

Jim Kelly | EurekAlert!
Further information:
http://www.utmb.edu

More articles from Life Sciences:

nachricht Cells communicate in a dynamic code
19.02.2018 | California Institute of Technology

nachricht Studying mitosis' structure to understand the inside of cancer cells
19.02.2018 | Biophysical Society

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Contacting the molecular world through graphene nanoribbons

19.02.2018 | Materials Sciences

When Proteins Shake Hands

19.02.2018 | Materials Sciences

Cells communicate in a dynamic code

19.02.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>