Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Jefferson Researchers Develop Microchip to Track Genetic Signature of Cancer and Normal Tissue


MicroRNAs (miRNAs), tiny pieces of genetic material that can serve as stop signs for gene expression and protein synthesis, are thought to be important in the development of cancer. Now, researchers at Jefferson Medical College and the Kimmel Cancer Center of Thomas Jefferson University in Philadelphia have developed a technique that allows them to find which miRNA genes are expressed – and how – in both cancerous and normal tissue.

Scientists, led by Carlo Croce, M.D., director of Jefferson’s Kimmel Cancer Center and professor of microbiology and immunology at Jefferson Medical College, have developed a microarray chip onto which they were able to put all the known miRNA genes in both human and mouse. They found that each tissue they tested had its own characteristic pattern of miRNA gene expression.

The work might enable scientists to gain a better understanding of the roles of miRNAs in cancer and provide targets for future drug development. They reported their findings June 21, 2004 online in the Proceedings of the National Academy of Sciences.

Dr. Croce explains that miRNAs are thought to play important roles in regulating gene expression during development and cell differentiation. MiRNAs inhibit the function of their targets, typically messenger RNA, which is involved in gene expression. They either degrade the messenger RNA or block its translation. Cells in organisms from yeast to mammals make interfering RNA to shut off gene expression in development.

Dr. Croce and his colleagues had previously shown that deletions in miRNA genes were involved in B-cell chronic lymphocytic leukemia (CLL), the most common adult leukemia in the Western world. They also had reported that human miRNA genes are frequently located in “fragile” areas of the genome that are vulnerable to mutation. “We think the miRNA genes are in fact involved in many human cancers,” he says.

“As a result, we have a number of markers that allow us to characterize specific tissue in specific cells,” Dr. Croce says. “Now the chip allows us to compare normal tissue to malignant tissue.

“This kind of approach will give us important clues about the gene regulation in a number of cells in normal and cancer tissue,” he says. “It opens new avenues for treatment because these miRNA genes are so small, they can get into cells and be used as drugs. Characterizing their targets might help in understanding cancer phenotypes.”

MiRNA genes can function differently. Take miR-16, for example, which is one of the miRNA genes Dr. Croce has studied in CLL. It functions as a tumor suppressor, and probably some of its targets are oncogenes, he says. Tumor suppressor genes are normal genes that protect against the development of cancer. Oncogenes, on the other hand, promote excessive cell growth, the hallmark of cancer.

“If the miR is expressed at a high level, however, the RNA level of the targets would be low and the expression of the oncogene would be low,” he says. Conversely, “knocking out” the miR gene would mean the expression of the oncogene would be high.

“MiRNAs are a new mechanism involved in malignant transformation,” he says. “I think it will be found to be a very generalized mechanism and provide a lot of opportunities for treatment.

“The chip is an easy way to test for miRNA alterations,” he says. “When you look at a cancer, the chip will tell you which miRNAs are in fact there and which are not. Then you can study the targets and figure out their role in cancer.

“The next step is to continue to find out how these genes are regulated and what they regulate – their targets and their roles in cancers.”

Steven Benowitz | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht Molecular doorstop could be key to new tuberculosis drugs
20.03.2018 | Rockefeller University

nachricht Modified biomaterials self-assemble on temperature cues
20.03.2018 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Physicists made crystal lattice from polaritons

20.03.2018 | Physics and Astronomy

Mars' oceans formed early, possibly aided by massive volcanic eruptions

20.03.2018 | Physics and Astronomy

Thawing permafrost produces more methane than expected

20.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>