Featured Research

from universities, journals, and other organizations

Lack Of Key Enzyme Associated With Development Of Rare Tumor

Date:
June 12, 2006
Source:
NIH/National Institute of Child Health and Human Development
Summary:
Researchers at the National Institutes of Health have discovered that a rare tumor of the adrenal glands appears to result from a genetic deficiency of an important enzyme. The enzyme is one of a class of enzymes involved in halting a cell's response to hormones and appears to stop cells from dividing.

Researchers at the National Institutes of Health have discovered that a rare tumor of the adrenal glands appears to result from a genetic deficiency of an important enzyme. The enzyme is one of a class of enzymes involved in halting a cell's response to hormones and appears to stop cells from dividing.

The study, published in Nature Genetics, was conducted by researchers in NIH's National Institute of Child Health and Human Development. The NIH group collaborated with scientists from the Mayo Clinic, the Cochin Institute in Paris, the University of Paris, Ohio State University in Columbus, and the Universitaire Vaudois in Lausanne, Switzerland, in collecting samples from patients with rare adrenal disorders. Scientists from Sapio Sciences in York, Pennsylvania, assisted in the analysis of the data.

In conducting the study, the researchers used gene arrays to analyze the DNA of patients with a rare tumor of the adrenal glands, known as micronodular adrenocortical hyperplasia, explained the study's senior author, Constantine Stratakis, M.D., D(Med)Sc, Chief of NICHD's Section on Endocrinology and Genetics. The researchers also used the technology to analyze samples of the patients' tumors.

The researchers found four patients who had mutant copies of a gene that contains the information for Phosphodiesterase 11A (PDE11A). Phosphodiesterases are a family of enzymes involved in "switching off" a cell's response to hormones, Dr. Stratakis explained.

For a hormone to affect the cell, it must first bind to a molecule, or receptor, on the cell's surface, analogous to how a key fits into a lock. This action triggers the cell to produce substances known as cyclic nucleotides. These function as "second messengers," often stimulating the cell to begin an activity. In the case of adrenal cells, cyclic nucleotides, such as cyclic AMP and cyclic GMP, may stimulate cell growth or other activities. Once the activity has ended, phosphodiesterases degrade the cyclic nucleotides, thereby halting the cell's response to the hormone.

In the study, the patients' tumors were made up of cells that were deficient in the enzyme PDE11A. This enzyme halts cyclic nucleotide production in adrenal cells as well as in other kinds of cells in the body. Because they lacked PDE11A, the patients' adrenal cells had higher levels of cyclic nucleotides. The researchers believe that these higher cyclic nucleotide levels led to the formation of tumors.

The gene for PDE11A contains the information needed to make 4 slightly different forms of the enzyme. The form of the enzyme that was mutated in the patients who took part in the study was found in large amounts in normal adrenal glands and in even larger amounts in normal prostate glands, Dr. Stratakis added. Other forms of PDE11A are found in several other tissues, including the testes, skeletal muscle, and the heart.

Dr. Stratakis noted that although the evidence associating the mutation in the gene for PDE11A to the development of adrenal tumors was very strong, the study was not capable of proving that the mutation actually caused the tumors.

In their article, the researchers wrote that drugs used to treat erectile dysfunction interfere with the functioning of PDE11A. The researchers noted that PDE11A "is partially inhibited" by the drug tadalafil and "weakly" inhibited by sildenafil. They added that there are no reports in the medical literature of malfunctioning adrenal glands or increased adrenal cell growth in users of these drugs.

"However, detailed clinical studies addressing this potential complication are currently lacking," they wrote.

Dr. Stratakis and his colleagues are currently planning studies to determine if differences in the gene for PDE11A might influence an individual's cancer risk.


Story Source:

The above story is based on materials provided by NIH/National Institute of Child Health and Human Development. Note: Materials may be edited for content and length.


Cite This Page:

NIH/National Institute of Child Health and Human Development. "Lack Of Key Enzyme Associated With Development Of Rare Tumor." ScienceDaily. ScienceDaily, 12 June 2006. <www.sciencedaily.com/releases/2006/06/060612083315.htm>.
NIH/National Institute of Child Health and Human Development. (2006, June 12). Lack Of Key Enzyme Associated With Development Of Rare Tumor. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2006/06/060612083315.htm
NIH/National Institute of Child Health and Human Development. "Lack Of Key Enzyme Associated With Development Of Rare Tumor." ScienceDaily. www.sciencedaily.com/releases/2006/06/060612083315.htm (accessed September 23, 2014).

Share This



More Health & Medicine News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Liberia Pleads for Help to Fight Ebola

Liberia Pleads for Help to Fight Ebola

AP (Sep. 22, 2014) Liberia's finance minister is urging the international community to quickly follow through on pledges of cash to battle Ebola. Bodies are piling up in the capital Monrovia as the nation awaits more help. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Ebola Doctor Says Border Controls Critical

Ebola Doctor Says Border Controls Critical

AP (Sep. 22, 2014) A Florida doctor who helped fight the expanding Ebola outbreak in West Africa says the disease can be stopped, but only if nations quickly step up their response and make border control a priority. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Global Ebola Aid Increasing But Critics Say It's Late

Global Ebola Aid Increasing But Critics Say It's Late

Newsy (Sep. 21, 2014) More than 100 tons of medical supplies were sent to West Africa on Saturday, but aid workers say the global response is still sluggish. Video provided by Newsy
Powered by NewsLook.com
Sierra Leone in Lockdown to Control Ebola

Sierra Leone in Lockdown to Control Ebola

AP (Sep. 21, 2014) Sierra Leone residents remained in lockdown on Saturday as part of a massive effort to confine millions of people to their homes in a bid to stem the biggest Ebola outbreak in history. (Sept. 20) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins