Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Transparent zebrafish help researchers track breast cancer

23.10.2007
What if doctors could peer through a patient’s skin and see a cancer tumor growing? They’d be able to study how tumor cells migrate: how they look, how they interact with the blood system to find nourishment to grow and spread through the body.

Scientists at the University of California, San Diego (UCSD) School of Medicine can’t look through human skin. But a small, tropical minnow fish common to aquariums has given UCSD researchers a window for viewing live, human cancer cells in action. Working with transparent zebrafish to study one of the most aggressive forms of cancer, inflammatory breast cancer, has led to their discovery of how two proteins interact in the metastasis of breast cancer. The study led by Richard Klemke, Ph.D., professor of pathology at UCSD School of Medicine and the UCSD Moores Cancer Center, will be published in the Proceedings of the National Academy of Science online edition the week of October 22-26.

“By watching human breast cancer cells in real time in the live transgenic zebrafish, we were able to determine that two proteins are required in order for breast tumor cells to complete the most critical step of metastasis – entering the blood vessels,” said Konstantin Stoletov, Ph.D., of the department of pathology at the UC-San Diego School of Medicine, first author of the paper.

The scientists discovered that two proteins work together to allow cancerous breast tumors to enter the blood vessels, thus promoting metastasis. The first is vascular endothelial growth factor (VEGF), a protein made by cancerous cells that stimulates new blood vessel formation, or angiogenesis. The second is a small protein called RhoC that is involved in cell movement or migration, and is overexpressed in highly metastatic forms of breast cancer.

The researchers found that neither VEGF nor RhoC alone interact with blood vessels to allow the cancerous tumor to enter the blood vessels, or intravasate. “But together, they promote rapid intravasation,” said Stoletov.

Inflammatory breast cancer (IBC) is the deadliest form of human breast cancer, with fewer than half of those diagnosed today expected to live five years. The UCSD team developed an immuno-suppressed zebrafish that expresses green fluorescent protein (commonly known as GFP) only in its blood vessels, allowing scientists to view the tumor-induced blood vessel formation, or angiogenesis. They injected the fish with IBC cells that were tagged in different colors, in order to study the very rapid tumor progression.

The parental cancer cells were tagged in blue, and the migrating cells that overexpressed RhoC in red. Over several weeks, the researchers were able to watch the cancer’s progression using high-resolution, multi-color confocal microscopy.

The scientists discovered that RhoC induces an amoeboid-like mode of invasion, in which the cancerous cells move by means of temporary projections or ‘false feet.’ They also found that secretion of VEGF was required in order for the cancer cells to penetrate and enter the blood vessel.

“In later stages of the cancerous tumor, the VEGF induces rapid formation of irregular, leaky blood vessels,” said Stoletov. “We discovered that intravasation requires the secretion of VEGF, which disrupts the blood vessel wall, creating small openings that allow the tumor cells to penetrate and enter.”

Finding a way to suppress VEGF, thus inhibiting the growth of “leaky” blood vessels, could stop the movement of cancer cells into the blood vessels and the tumor’s subsequent metastasis, according to Klemke.

The results provide novel insight into mechanisms of cancer-cell invasion and intravasation, showing how RhoC and VEGF cooperate to facilitate cell metastasis in living tissues. The transparency of the fish also allowed the researchers to image and analyze, in three dimensions, images of a potential anti-cancer compound that inhibits the VEGF compound. They found that this inhibitor prevents formation of the vascular openings, thus inhibiting intravasation.

Debra Kain | EurekAlert!
Further information:
http://www.ucsd.edu

Further reports about: Researchers RhoC UCSD VEGF blood vessel breast cancerous formation intravasation metastasis vessel

More articles from Life Sciences:

nachricht BigH1 -- The key histone for male fertility
14.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Guardians of the Gate
14.12.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>