Navigation Links
Scientists discover how cancer may take hold
Date:9/24/2007

Stanford, CA-- A team, led by researchers at the Carnegie Institution,* has found a key biochemical cycle that suppresses the immune response, thereby allowing cancer cells to multiply unabated. The research shows how the biomolecules responsible for healthy T-cells, the bodys first defenders against hostile invaders, are quashed, permitting the invading cancer to spread. The same cycle could also be involved in autoimmune diseases such as multiple sclerosis. The work is published in the September 25, 2007, issue of PLoS Biology.

The scientists used special molecular nanosensors for the work. We used a technique called fluorescence resonance energy transfer, or FRET, to monitor the levels of, tryptophan, one of the essential amino acids human cells need for viability, explained lead author Thijs Kaper. Humans get tryptophan from foods such as grains, legumes, fruits, and meat. Tryptophan is essential for normal growth and development in children and nitrogen balance in adults. T-cells also depend on it for their immune response after invading cells have been recognized. If they dont get enough tryptophan, the T-cells die and the invaders remain undetected.

The scientists looked at the chemical transformations that tryptophan undergoes as it is processed in live human cancer cells. When tryptophan is broken down in the cancer cells, an enzyme (dubbed IDO) forms molecules called kynurenines. This reduces the concentration of tryptophan in the local tissues and starves T-cells for tryptophan. A key finding of the research was that a transporter protein (LAT1), present in certain types of cancer cells, exchanges tryptophan from the outside of the cell with kynurenine inside the cell, resulting in an excess of kynurenine in the body fluids, which is toxic to T-cells.

Its double trouble for T-cells, remarked Wolf Frommer. Not only do they starve from lack of tryptophan in their surroundings, but it is replaced by the toxic kynurenines, which wipes T-cells out.

The scientists think that this cycle may be also be involved in cells involved in certain autoimmune diseases. In these cases the cells may not be able to take up or convert enough tryptophan. Without enough of the amino acid or the IDO enzyme to convert tryptophan, the cells cannot produce enough kynurenine. Lacking kynurenine, the bodys own T-cells cannot be kept in check, so they rebel and attack the body.

The FRET system detects metabolites such as sugars and amino acids using a biosensor tag. A protein is genetically fused to tags at opposite ends of a molecule. The tags are made from different colors of the jellyfish green fluorescent protein (GFP). When a metabolite binds to the biosensor, it changes the shape of the sensors backbone, altering the position of the fluorescent tags. When a specific wavelength of light activates one tag, it fluoresces. When the metabolite causes the tags to move close together, the other tag will also fluoresceresonating like a tuning fork. This system allows the scientists to visually track the location and concentration of certain biochemicals.

Our FRET technology with the novel tryptophan nanosensor has an added bonus, said Thijs. It can be used to identify new drugs that could reduce the ability of cancer cells to uptake tryptophan or their ability to degrade it. We believe that this technology could be a huge boost to cancer treatment.


'/>"/>

Contact: Wolf Frommer
wfrommer@stanford.edu
650-325-1521 x208
Carnegie Institution
Source:Eurekalert

Related biology technology :

1. UW computer scientists fighting computer virus "Cold War"
2. Scientists find way to make human collagen in lab
3. Wisconsin scientists to be recognized for innovative biofuel technology
4. UW-Madison scientists to mimic nature for newest cancer drugs
5. UW scientists study strange material with communications potential
6. Scientists find nanotech method for examining cells
7. UW space scientists use Keck telescope to study wild weather of Uranus
8. UW computer scientists tout achievements and explain industry shortcomings
9. Facing shortage of U.S. scientists, UW wants to boost math enrollment
10. UW-Madison scientists find a key to cell division
11. TIP/UW Scientists Provide Mars Rover Commentary
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/27/2016)... 2016  Sequenom, Inc. (NASDAQ: SQNM ), ... through the development of innovative products and services, announced ... United States denied its petition to review ... Sequenom,s U.S. Patent No. 6,258,540 (",540 Patent") are not ... the Supreme Court,s Mayo Collaborative Services v. Prometheus Laboratories ...
(Date:6/27/2016)... Raleigh, NC (PRWEB) , ... June 27, 2016 ... ... a mission to bring innovative medical technologies, services and solutions to the healthcare ... development and implementation of various distribution, manufacturing, sales and marketing strategies that are ...
(Date:6/27/2016)... Ginkgo Bioworks , a leading organism design company ... as one of the World Economic Forum,s Technology ... companies. Ginkgo Bioworks is engineering biology to manufacture ... the nutrition, health and consumer goods sectors. The ... Fortune 500 companies to design microbes for their ...
(Date:6/24/2016)... ... June 24, 2016 , ... While the majority of commercial spectrophotometers and ... and the 6000i models are higher end machines that use the more unconventional z-dimension ... light beam from the bottom of the cuvette holder. , FireflySci has developed ...
Breaking Biology Technology:
(Date:4/26/2016)... and LONDON , April ... part of EdgeVerve Systems, a product subsidiary of ... today announced a partnership to integrate the Onegini ...      (Logo: http://photos.prnewswire.com/prnh/20151104/283829LOGO ) ... their customers enhanced security to access and transact ...
(Date:4/14/2016)... 14, 2016 BioCatch ™, ... today announced the appointment of Eyal Goldwerger ... Goldwerger,s leadership appointment comes at a time ... the deployment of its platform at several of the ... which discerns unique cognitive and physiological factors, is a ...
(Date:3/23/2016)... , March 23, 2016 ... erhöhter Sicherheit Gesichts- und Stimmerkennung mit Passwörtern ... (NASDAQ: MESG ), ein führender ... das Unternehmen mit SpeechPro zusammenarbeitet, um erstmals ... Finanzdienstleistungsbranche, wird die Möglichkeit angeboten, im Rahmen ...
Breaking Biology News(10 mins):