Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists discover key proteins linked to aging and cancer

04.01.2005


Fox Chase Cancer Center researchers have made new discoveries that shed new light on the mystery of why human tissues, such as skin, age. The findings focus on the composition and assembly of key chromosomal protein complexes involved in shutting down reproduction of aging cells. The report by molecular and cell biologist Peter D. Adams, Ph.D. and his colleagues appears in the January 2005 issue of Developmental Cell.



"In the lab, aging cells are called senescent cells. Senescent cells are no longer able to divide but remain metabolically active," Adams explained. "Accumulation of senescent cells over time appears to contribute to changes in tissue form and function commonly associated with aging, like the skin changes that occur between childhood and old age."

Most normal human cells undergo a limited number of cell divisions but are eventually arrested, either through final differentiation or senescence. Differentiation is the process whereby a proliferating cell stops growing and develops into a cell with a specific function, such as a liver cell or a neuron. Senescence is an irreversible stage in a cell’s life cycle and may underlie the human aging process and have an impact on diseases of aging, such as adult cancers.


"Most importantly, the failure of cells to stop growing through differentiation or senescence can lead to the uncontrolled growth of cancer," Adams emphasized. Both senescence and differentiation involve reorganization of chromatin structure --the complex of DNA, RNA and proteins, called histones, in the cell nucleus.

Previous research has shown that as cells reach senescence, a change in chromatin structure, called SAHF (senescence-associated heterochromatin foci), silences the genes that promote the cells’ growth. Adams’ discovery reveals the mechanism of SAHF formation. SAHF are domains of densely packed chromatin that repress activity of the genes that normally drive cell proliferation. Adams and coworkers have identified at least three proteins in the cell that contribute to formation of SAHF. These are called HIRA, ASF1a and PML. Of particular note, PML is named after acute promyelocytic leukemia, a cancer of white blood cells. Scientists have known for sometime that PML suppresses the formation of this cancer, but no one knew why.

Adams’ work suggests the possibility that this cancer arises because PML is unable to do its job in forming SAHF. If so, then extrapolating from recent findings in other cancers, inactivation of PML, HIRA, ASF1a and formation of SAHF may also contribute to other human cancers.

Future work in Adams’ lab will define the molecular details by which HIRA, ASF1a and PML make SAHF. Ultimately, this work might allow rationale design of therapeutics to treat cancer patients and even alleviate some aspects of human aging.

Adams’ co-authors on the new paper include postdoctoral associates Rugang Zhang, Ph.D., and Xiaofen Ye, Ph.D., graduate student Maxim V. Poustovoitov of Russian State Medical University in Moscow, scientific technicians Hidelita A. Santos and Wei Chen, staff scientist Ilya G. Serebriiskii, Ph.D., structural and computational biologist Roland L. Dunbrack, Ph.D., and staff scientist Adrian A. Canutescu, M.D., all at Fox Chase; Sally M. Daganzo, Ph.D., Jan P. Erzberger, Ph.D., James M. Berger, Ph.D., and Paul D. Kaufman, Ph.D., of Lawrence Berkeley National Laboratory; and John R. Pehrson, Ph.D., of the University of Pennsylvania School of Veterinary Medicine.

Poustovoitov is working in Adams’ laboratory as part of a novel partnership with the Russian medical and scientific institutions to provide training at Fox Chase for master’s- and doctoral-level students. Begun in 1998 with Russian State Medical University, the partnership has expanded over the years to include more students and more affiliations with premier Russian research institutions. Students typically intern at Fox Chase for about 18 months, although several have chosen to continue their studies and pursue doctoral research in their host laboratory.

Adams is a Leukemia and Lymphoma Society Scholar. Grants from the Department of Defense, the National Institutes of Health and the American Federation for Aging Research also helped support the new work on senescent cells.

Karen C. Mallet | EurekAlert!
Further information:
http://www.fccc.edu

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>