Navigation Links
Common cancer gene sends death order to tiny killer

Scientists at Johns Hopkins have discovered one way the p53 gene does what it's known for—stopping the colon cancer cells. Their report will be published in the June 8 issue of Molecular Cell.

The research team identified a tiny bit of genetic code, a microRNA called miR-34a that participates in p53's uncanny ability to kill cells likely to become malignant because of damaged genes in their nuclei. MicroRNAs are small chains of ribonucleic acid (RNA) made by the same machinery that produces other types of RNA in the cell, such as the messenger RNAs that carry the instructions to make proteins. Once produced, microRNAs stick to messenger RNAs and, like crumpled paper jammed in a copy machine, prevent proteins from being made.

Josh Mendell, M.D., Ph.D., an assistant professor in the McKusick-Nathans Institute of Genetic Medicine, suspected that p53 activates microRNAs like miR-34a because a number of studies have demonstrated that these tiny RNA molecules are frequently abnormal in cancer cells.

"P53 is one of the most commonly mutated genes in human cancers," says Mendell. "And there is now a great deal of evidence that microRNAs themselves can act to either promote cancer or to stop cancer spread."

To test their idea, the team first chemically damaged the DNA of two sets of colon cancer cells, one missing p53 and the other containing healthy p53. They then looked for any of the 500 known human microRNAs that are activated only in cells containing p53.

It turned out that the miR-34a gene is turned on by p53, and in fact, experiments demonstrated that p53 binds directly to the genetic material near miR-34a to promote its activation.

Concluding that p53 controls miR-34a, they next teamed up with Charlie Lowenstein, M.D., and his colleagues in Hopkins's department of medicine to put miR-34a into colon cancer cells. Doing this killed cells that contained p53, but fewer were killed in cells lacking p53, furthe r suggesting that this microRNA gets its kill orders from p53.

When researchers examined pancreatic cancer cells known to contain damaged or missing p53, they found that those cells had limited or zero miR-34a.

"With no p53 gene or miR-34a to stem tumor development, there's no brake in pancreatic cells and uncontrolled growth leads to cancer," says Anirban Maitra, M.B.B.S., associate professor of pathology, oncology and genetic medicine.

Mendell and his team are looking for missing miR-34a in other cancers. If it's a widespread phenomenon, the work could lead to treatments that aim to restore the missing microRNA to cancer cells.


'"/>

Source:Johns Hopkins Medical Institutions


Related biology news :

1. Its not all genetic: Common epigenetic problem doubles cancer risk in mice
2. Harmful Bacterium Commonly Found in Poultry May Survive Refrigeration and Frozen Storage Combined
3. Men Estimate Mens Risks Of Common Disorders Higher Than Women Do, And Vice Versa
4. Use of Antibiotics for Acne May Increase Risk of Common Illness
5. Common viruses may cause cancer
6. Common alternative treatment for liver disease is found to be ineffective
7. Common molecular signature identified in solid tumors
8. Common bacteria pirate natural mechanism to get inside cells
9. Commonly used antidepressants may also affect human immune system
10. Common practices at petting zoos put visitors at risk
11. Common enzyme is a key player in DNA repair

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:5/16/2016)... YORK , May 16, 2016   EyeLock ... solutions, today announced the opening of an IoT Center ... to strengthen and expand the development of embedded iris ... an unprecedented level of convenience and security with unmatched ... authenticate one,s identity aside from DNA. EyeLock,s platform uses ...
(Date:4/28/2016)... -- First quarter 2016:   , Revenues ... first quarter of 2015 The gross margin was 49% ... and the operating margin was 40% (-13) Earnings per ... from operations was SEK 249.9 M (21.2) , Outlook ... 7,000-8,500 M. The operating margin for 2016 is estimated ...
(Date:4/15/2016)... , April 15, 2016 ... the,  "Global Gait Biometrics Market 2016-2020,"  report to ... http://photos.prnewswire.com/prnh/20160330/349511LOGO ) , ,The global gait biometrics ... of 13.98% during the period 2016-2020. ... angles, which can be used to compute factors ...
Breaking Biology News(10 mins):
(Date:6/27/2016)...  Liquid Biotech USA , ... Sponsored Research Agreement with The University of Pennsylvania ... cancer patients.  The funding will be used to ... clinical outcomes in cancer patients undergoing a variety ... employed to support the design of a therapeutic, ...
(Date:6/24/2016)... 24, 2016  Regular discussions on a range of subjects ... the two entities said Poloz. Speaking at a ... , he pointed to the country,s inflation target, which ... "In certain areas ... have common economic goals, why not sit down and address ...
(Date:6/24/2016)... (PRWEB) , ... June 24, 2016 , ... While the ... such as the Cary 5000 and the 6000i models are higher end machines that ... the height of the spectrophotometer’s light beam from the bottom of the cuvette holder. ...
(Date:6/23/2016)... ... June 23, 2016 , ... Mosio, a ... eBook, “Clinical Trials Patient Recruitment and Retention Tips.” Partnering with experienced clinical research ... by providing practical tips, tools, and strategies for clinical researchers. , “The landscape ...
Breaking Biology Technology: