Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists explain cancer cell metabolism changes

30.08.2006
Scientists at Jefferson Medical College and the Kimmel Cancer Center at Thomas Jefferson University in Philadelphia have found how a gene can dim the power production in the cell and in turn scale up its cancer-producing activities.

Two new studies provide stunning evidence suggesting that cyclin D1 – which is found in up to eight times normal amounts in half of all breast cancers – can cause a shift in the cancer cell's metabolism, changing its focus from energy production to proliferation. The findings, they say, may point to new therapeutic strategies against cancer.

Reporting last month in the journal Molecular and Cellular Biology, Kimmel Cancer Center director Richard G. Pestell, M.D., Ph.D., Professor and Chair of the Department of Cancer Biology at Jefferson Medical College, and colleagues showed for the first time that cyclin D1 – normally involved in promoting cell division – inhibits the size and activity of the cell's energy-making mitochondria.

In a separate report in August in the Proceedings of the National Academy of Sciences (PNAS), Dr. Pestell and a different team identified the mechanism behind cyclin D1's mitochondrial takeover. The research, taken together, shows that the inhibition leads to increased proliferation of cancer cells.

"From the cancer cell's point of view, the inhibition allows the cell to shift its biosynthetic priorities – it allows it to shift from making mitochondria themselves to synthesizing DNA and making the cell proliferate," says Dr. Pestell.

"Cyclin D1 shifts the individual cell's metabolism away from making mitochondria and towards cellular proliferation and the various genes involved in promoting such proliferation," he says.

The mitochondria often are called the "powerhouse" of the cell because they produce about 90 percent of the body's energy. They are located in the cytoplasm outside of each cell's nucleus.

Dr. Pestell notes that scientists have long suspected a link between mitochondrial malfunction and cancer, and since 1930 have known about such a change in metabolism when the cell turns cancerous. But the mechanisms haven't been well understood. When cells turn cancerous, they shift the way they metabolize glucose and other substrates. The researchers believe that their findings about cyclin D1 are part of such a mechanism. "These changes were observed previously," he says. "Now we know that the same factor that is involved in causing breast cancer also directly causes a metabolic shift."

I. Bernard Weinstein, M.D., Frode Jensen Professor of Medicine at Columbia University, notes that the 1930 discovery that the function of mitochondria is often impaired in cancer cells has remained unexplained and cancer research has been mainly focused on abnormalities in the function of genes in the nucleus of cells. The work by Dr. Pestell's group "provides novel insights into how these two types of abnormalities in cancer cells might be related."

In the PNAS publication, Dr. Pestell's team found that a protein, nuclear respiratory factor-1 (NRF-1), regulates a gene called mtTFA and is essential for mitochondrial

function. To make mitochondria, then, NRF-1 turns on mtTFA, which then activates genes that produce mitochondria. Cyclin D1 inactivates NRF-1, halting production.

"This discovery advances our understanding of the behavior of cancer cells and may suggest new types of cancer therapy," Dr. Weinstein says.

Dr. Pestell notes that such metabolic changes should leave the cancer cell vulnerable. "We'd like to link that change in metabolism to therapies," he says. "We've been able to prove that we can see changes in metabolism in the breast, and we should be able to target that change and kill the cancerous cells." He explains that specialists can image tumors based on changes in metabolism.

The results could also "provide a mechanism for targeting the mitochondria, rather than the nucleus," he says, noting that cancer drugs usually target nuclear genes. "Importantly, they provide a direct link between the mitochondria and the nucleus – one gene regulating both compartments of the cell. We didn't know what coordinated both functions. This shows both are functionally linked by a common gene."

"If we have therapies that target changes in metabolism, it allows us to develop therapies selective for the cancerous cells only," says Dr. Pestell.

Steve Benowitz | EurekAlert!
Further information:
http://www.jefferson.edu

Further reports about: Cyclin Pestell cyclin D1 metabolism mitochondria proliferation

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

Researchers invent tiny, light-powered wires to modulate brain's electrical signals

21.02.2018 | Life Sciences

The “Holy Grail” of peptide chemistry: Making peptide active agents available orally

21.02.2018 | Life Sciences

Atomic structure of ultrasound material not what anyone expected

21.02.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>