Navigation Links
St. Jude Defines Eye Cancer Gene's Role in Retinal Development
Date:1/16/2008

Study provides the foundation for improving understanding of N-myc gene's role in the eyes' growth during fetal development when retinoblastoma forms

MEMPHIS, Tenn., Jan. 16 /PRNewswire-USNewswire/ -- A genetic discovery led by scientists at St. Jude Children's Research Hospital helps answer a long-standing mystery about the eyes of vertebrates, and may translate into a deeper understanding of how genes coordinate the complex process of eye formation and how a rare pediatric eye cancer progresses.

"A series of complex developmental processes must be carefully orchestrated for the eye to form correctly," said Michael Dyer, Ph.D., associate member in the St. Jude Department of Developmental Neurobiology. "One important aspect of this coordination is that retinal thickness be the same, irrespective of eye size. For example, the mouse eye is about 5,000 times smaller than that of the elephant eye, but the retinal thickness in these two species is comparable."

Working with mice, the researchers found that a gene called N-myc coordinates the growth of the retina and other eye structures to ensure the retina has the proper thickness necessary to convert light from the lens into nerve impulses that the brain transforms into images. Until their study, reported in the Jan. 15 issue of "Genes & Development," almost nothing was known about the molecular mechanisms responsible for properly sizing the retina. Dyer is the paper's senior author.

"This represents the first example of a role for a Myc gene in retinal development," Dyer said. "On the basis of our data, we propose that N-myc plays a central role in coordinating retinal proliferation with eye growth during development."

Genes in the Myc family carry out vital roles during prenatal development by regulating the proliferation, size, differentiation and survival of cells. Myc genes are also proto-oncogenes--genes in which a mutation enables them to transform normal cells into cancerous ones. Malfunctioning N-myc genes are often associated with pediatric neural cancers, including neuroblastoma, medulloblastoma and retinoblastoma.

Recently, Dyer and his team identified the specific type of cell that gives rise to retinoblastoma, a potentially fatal malignant tumor in the retina that affects about 300 children in the United States annually. "The determination of N-myc target genes during retinal development may also contribute to the current understanding of retinoblastoma progression," he said.

In the course of their study, the researchers discovered that N-myc is not involved in regulating cell survival or neuronal differentiation in the developing retina. However, the gene is crucial for the proper proliferation of retinal cells. In mice in which the scientists inactivated N-myc, the volume of the retina was significantly smaller than in mice with normally functioning N-myc.

The team found no evidence of an increase in progenitor cell deaths between normal and N-myc-deficient retinas. The investigators then concluded the smaller retinas likely resulted from an N-myc-related proliferation defect in the progenitor retinal cells.

The researchers hypothesize that N-myc's activity occurs early in the cascade of reactions that control development of the retina and other eye components. Therefore, when something inactivates the gene, the result is both a reduction in retinal progenitor cell proliferation and a reduction in the signaling cues that coordinate the growth of the eye and retina.

"Importantly, for retinas to maintain nearly constant thickness across species that have different sizes of eyes, the total number of retinal cells must change several-fold," Dyer said. "The identification of N-myc as a key regulator of these processes allows us to begin to understand the coordination of complex developmental programs in the developing eye and how these processes have evolved."

Other authors of this paper include Rodrigo A.P. Martins, Frederique Zindy, Stacy Donovan, Jiakun Zhang, Stanley Pounds and Martine F. Roussel (St. Jude); Alice Wey and Paul S. Knoepfler (University of California at Davis and Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Sacramento, Calif.); and Robert N. Eisenman (Fred Hutchinson Cancer Research Center, Seattle).

This work was supported by grants from the National Institutes of Health, Cancer Center Support from the National Cancer Institute, Research to Prevent Blindness, the American Cancer Society, the Pearle Vision Foundation and ALSAC. Dyer is a Pew Scholar.

St. Jude Children's Research Hospital

St. Jude Children's Research Hospital is internationally recognized for its pioneering work in finding cures and saving children with cancer and other catastrophic diseases. Founded by late entertainer Danny Thomas and based in Memphis, Tenn., St. Jude freely shares its discoveries with scientific and medical communities around the world. No family ever pays for treatments not covered by insurance, and families without insurance are never asked to pay. St. Jude is financially supported by ALSAC, its fundraising organization. For more information, please visit http://www.stjude.org.


'/>"/>
SOURCE St. Jude Children's Research Hospital
Copyright©2008 PR Newswire.
All rights reserved

Related medicine technology :

1. Anesiva Defines Regulatory Pathway for Adlea with FDA
2. Childrens Hospital Cancer Study Finds Adolescents and Young Adults Dont Get Same Access to Cutting-Edge Treatment as Younger Patients
3. Kosan Initiates Phase 2 Trial of Alvespimycin, Second-Generation Hsp90 Inhibitor, in HER2-Positive Metastatic Breast Cancer
4. Interim Analysis Supports Continuation of Cell Genesys VITAL-1 Phase 3 Clinical Trial of GVAX Immunotherapy for Prostate Cancer
5. Nektar Commences Phase 2 Clinical Development Program for NKTR-102 (PEG-Irinotecan) in Colorectal Cancer
6. Exelixis Initiates Phase 1/2 Trial of XL184 in Patients With Non-Small Cell Lung Cancer
7. Marital Status Doesnt Affect Lung Cancer Survival
8. Northwest Biotherapeutics Conducting Ovarian Cancer Clinical Trial With DCVax(R)-L at University of Pennsylvania
9. Progen Provides Update on Phase 3 Clinical Program for PI-88 in Liver Cancer
10. Orion Genomics Announces the Discovery of Novel Breast Cancer Biomarkers
11. Video: New Results From One of the Worlds Largest Breast Cancer Trials Herald Hope for Thousands of Women
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/6/2016)... , May 6, 2016  Hill-Rom Holdings, Inc. (NYSE: ... of Directors declared a fiscal year 2016 third quarter ... percent increase over the amount paid a year ago. ... record as of the close of business on June 10, ...    Hill-Rom is a leading global medical technology ...
(Date:5/5/2016)... Ltd. today reported initial promising results in animal trials of its Zika vaccine candidates. ... ... ... ... Pubmed. The analysis identified the highest gene Replikin Counts in Zika history back to ...
(Date:5/5/2016)... , First quarter 2016 adjusted diluted earnings per share ... , First quarter reported diluted (GAAP) loss per share ... revises 2016 financial guidance; now expects 2016 revenues to range ... non-GAAP earnings per share to range from $4.50 to $4.80 ... and manufacturing facility restructuring , Company expands ...
Breaking Medicine Technology:
(Date:5/6/2016)... ... May 06, 2016 , ... The National Association of Chain ... in Puerto Rico. Radio messages set to debut on Monday, May 9, and ... about ways to protect themselves and their unborn children from the effects of ...
(Date:5/6/2016)... ... May 06, 2016 , ... DrugDev President and CEO Ibraheem ... pharmaceutical industry conducts clinical trials. This month Ibs was named No. 20 on The ... he was honored as a Tech Disruptor by the Philadelphia Business Journal. , Stephanie ...
(Date:5/6/2016)... (PRWEB) , ... May 06, 2016 , ... ... Bluvault's Integration Service, their latest implementation service offering for global clients of Coupa ... Appterra ). , Bluvault’s Integration Service is a key component in the ...
(Date:5/6/2016)... ... 06, 2016 , ... From May 4 to 6, EarQ and ... opportunity to learn more about Signia’s technology and the successful business and marketing techniques ... priority to see practices succeed in this highly competitive industry,” said Ed Keller, president ...
(Date:5/6/2016)... ... May 06, 2016 , ... Multiple award winning plumbing ... operated for over 35 years. Maintaining core values of exceptional customer service, quality work ... made them a leading name in San Diego plumbing, and other services including heating ...
Breaking Medicine News(10 mins):