Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researcher explores tumors’ survival strategy

21.02.2003


Dr. Kouros Motamed is studying endothelial cells where they live, in the complex environment that provides, not only support and structure, but regulation and direction.


Dr. Kouros Motamed, vascular biologist at the Medical College of Georgia, is studying angiogenesis, the formation of new blood vessels, and how some tumors pirate this mechanism in order to survive.



As he studies these cells that line blood vessels, this vascular biologist at the Medical College of Georgia focuses on the proteins and growth factors that regulate their normal processes, including proliferation, differentiation, migration and death.

He wants to better understand how these cells interact with their environment because there are still many unanswered questions.


But he also wants to know because tumors sometimes commandeer these cells’ ability to grow new blood vessels that bring life-sustaining nutrients and oxygen. "For most tumors to become any larger than 2 to 3 millimeters (a small fraction of an inch) in diameter, they have to recruit blood vessels," said Dr. Motamed.

This new vessel growth, called angiogenesis, can be beneficial. An injury can throw an angiogenic switch, activating a previously quiet endothelial cell. "As a result of activation, the endothelial cell loses its contact with the matrix (the milieu cells live in), elongates and invades the surrounding, stromal tissue," Dr. Motamed said. The cell then begins to proliferate, forming the lumen through which blood will eventually flow, and recruits supporting cell types and matrix components to form a new, functional vascular bed that is believed to accelerate wound healing.

The fact that many tumors also activate angiogenesis to survive has helped make it a hot topic in science. Dr. Motamed, who came to MCG in September from The Hope Heart Institute in Seattle, has his eye on the role of basic fibroblast growth factor in promoting angiogenesis and a protein called SPARC, which seems to have multiple roles in cancer and new blood vessel formation.

"SPARC is a protein most abundant during tissue remodeling and repair," said Dr. Motamed. The protein has many functions including regulating the activity of growth factors. His studies are helping delineate the exact molecular mechanism through which SPARC inhibits basic fibroblast growth factor and vascular endothelial growth factor, both important to angiogenesis. Most tumor cells also express high levels of these growth factors. "In addition to making a host of factors themselves, cancer cells can also manipulate the cells of the host to facilitate their own proliferation and migration," Dr. Motamed said.

SPARC - secreted protein acidic and rich in cysteine - is commonly expressed in the healthy remodeling of tissue, such as during embryonic development and wound- healing. It also is expressed in varying degrees by different cancers; expression is increased in breast cancer, prostate cancer and melanoma and decreased in ovarian cancer. "The bottom line is that the environment that supports the growth of cancer cells and their development into tumors is regulated by a multitude of factors. One of these factors is SPARC or a class of proteins like it," Dr. Motamed said. Although the exact role(s) of SPARC in this complex process remains unclear - and may vary depending on the tissue in which it’s expressed - Dr. Motamed believes it’s an important role that takes him back to the cell matrix.

He’s looking at the SPARC expressed by prostate, breast and ovarian cancers to distinguish the role of SPARC expressed by these cancers and their supporting cells. Dr. Motamed, in collaboration with investigators at The Hope Heart Institute and the University of Texas Southwestern, will use the SPARC-less mouse model and a normal, control counterpart for these studies at MCG. He’ll also be looking at how the different tumors fare in the varying SPARC environments.

One of his many goals is to find the contribution of SPARC endogenous to the mouse, including exploring its potential for inhibiting and promoting tumors. It could be that SPARC’s more common role in inhibiting blood vessel formation is changed when tumors express yet another protein that cuts or cleaves SPARC, turning it into a promoter. It also could be that still other proteins cleave the cell matrix, releasing its previously dormant store of growth factors and, consequently, a huge burst of factors that can induce new blood vessel formation, he said.

"The school of thought is that there is a constant dialogue between the cancer cells and their so-called stromal cells, which are the supporting, non-cancerous cells within a tumor environment," Dr. Motamed said. "It’s very obvious that you have to find out the players that regulate tumor cells or, the opposite, inhibit the growth of tumor cells, in this milieu that contains the cancer cells and supporting cells. The more you find out about all of these regulatory elements, the better off you are in battling tumors and cancer."


###
Support for Dr. Motamed’s research includes a four-year Howard Temin Award from the National Cancer Institute.

The Medical College of Georgia is the state’s health sciences university and includes the Schools of Allied Health Sciences, Dentistry, Graduate Studies, Medicine and Nursing, MCG Hospital and Clinics and the Children’s Medical Center.

Toni Baker | EurekAlert!
Further information:
http://www.mcg.edu/

More articles from Health and Medicine:

nachricht Laser activated gold pyramids could deliver drugs, DNA into cells without harm
24.03.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

nachricht What does congenital Zika syndrome look like?
24.03.2017 | University of California - San Diego

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>