Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New tool reveals molecular signature of cancer and HIV

27.10.2004


’LigAmp’ highly sensitive



Scientists have designed a new molecular tool, dubbed "LigAmp," to pinpoint DNA mutations among thousands of cells, the equivalent of searching for a single typo in an entire library of books. Preliminary studies in a small number of cell lines and body fluids show the ultra-sensitive test may help detect microscopic cancer and HIV drug resistance.
"Other molecular tests make it very difficult to locate a mutation in a particular cell surrounded by thousands of other cells that don’t have the mutation," says James Eshleman, M.D., Ph.D., who led the study with colleagues from the Johns Hopkins Department of Pathology and Kimmel Cancer Center. "LigAmp essentially filters background ’noise’ caused by normal cells and reveals specific mutations."

The researchers say that sensitive tests to locate mutations could identify cancer in patients at high-risk for the disease. Such tests could even help detect a recurrence of cancer by monitoring whether the number of mutations rises above a predetermined threshold value.



In addition to cancer detection, the Hopkins mutation-finder appears able to detect drug-resistant HIV. The team tested it on blood samples from a handful of patients with HIV and located DNA mistakes in the virus itself that make it resistant to certain antiretroviral drugs. Results of analyses of the new test are published in the November issue of Nature Methods.

"We designed LigAmp to improve how we look for extremely subtle variations in viral and cellular DNA," says Eshleman, an associate professor of pathology and oncology and associate director for the DNA Diagnostics Laboratory at Johns Hopkins. "The molecular code of normal cells may look identical to cancerous except for a single rung in the DNA ladder-structure."

The test works by creating a molecular "magnet" with an affinity for the DNA mistake, also known as a point mutation. If the mutation is found, the magnet binds to it and inserts a bacterial gene. The bacterial gene serves as a red flag and produces a fluorescent color visible to powerful computer programs.

In their studies, the Hopkins investigators tested LigAmp on colon cancer cell lines, blood from HIV patients, and fluid from cancer patients’ pancreatic ducts. Single mutations in colon cancer cells and drug-resistant HIV viruses were detected at dilutions of up to 1 in 10,000 molecules. Mutations of the KRAS2 gene were detected in duct fluid samples from three pancreatic cancer patients, which also corresponded to mutations found in their tumors. LigAmp also located a drug-resistance mutation, called K103N, in blood samples from three HIV patients.

Further analysis of LigAmp with larger sample sizes and blinded panels of clinical samples currently is under way. "Some initial studies show that we can simultaneously look for different mutations and quantify the number of mutated molecules present. This may help us build panels of cancer markers for screening and determine low or high levels of mutation."

Funding for this research was provided by the Maryland Cigarette Restitution Fund, the National Cancer Institute, and the National Institute of Allergy and Infectious Diseases.

Johns Hopkins colleagues working with Eshleman are Chanjuan Shi, Susan Eshleman, Dana Jones, Noriyoshi Fukushima, Li Hua, Antony Parker, Charles Yeo, Ralph Hruban, and Michael Goggins.

Vanessa Wasta | EurekAlert!
Further information:
http://www.jhmi.edu

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

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...

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

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>