Navigation Links
St. Jude defines eye cancer gene's role in retinal development
Date:1/16/2008

A genetic discovery led by scientists at St. Jude Childrens 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 papers 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-oncogenesgenes 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-mycs 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.


'/>"/>

Contact: Summer Freeman
summer.freeman@stjude.org
901-495-3061
St. Jude Children's Research Hospital
Source:Eurekalert

Related biology news :

1. Genome update defines landscape of breast and colon cancers
2. New book defines promising young field of adult neurogenesis
3. Green tea boosts production of detox enzymes, rendering cancerous chemicals harmless
4. A study by the MUHC and McGill University opens a new door to understanding cancer
5. ESF EURYI award winner aims to stop cancer cells reading their own DNA
6. Protein chatter linked to cancer activation
7. Newly created cancer stem cells could aid breast cancer research
8. Western diet linked to increased risk of colon cancer recurrence
9. Obesity and lack of exercise could enhance the risk of pancreatic cancer
10. Low levels of key protein may indicate pancreatic cancer risk
11. Birth records hold pancreatic cancer clue
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/13/2016)... physicians supporting Medicaid patients in Central Florida ... telehealth thanks to a new partnership with higi.   ... can routinely track key health measurements, such as blood ... they opt in, share them with IMPOWER clinicians through ... location at no cost. By leveraging this data, IMPOWER ...
(Date:3/22/2016)... 2016 According to ... for Consumer Industry by Type (Image, Motion, Pressure, ... & IT, Entertainment, Home Appliances, & Wearable ... 2022", published by MarketsandMarkets, the market for ... USD 26.76 Billion by 2022, at a ...
(Date:3/15/2016)... , March 15, 2016 ... report published by Transparency Market Research "Digital Door Lock Systems ... Forecast 2015 - 2023," the global digital door lock systems ... Mn in 2014 and is forecast to grow at a ... of micro, small and medium enterprises (MSMEs) across the world ...
Breaking Biology News(10 mins):
(Date:5/25/2016)... ... May 25, 2016 , ... WEDI, the nation’s leading authority on the use ... W. Stellar has been named by the WEDI Board of Directors as WEDI’s president ... executive leader with more than 35 years of experience in healthcare, association management and ...
(Date:5/24/2016)... , May 24, 2016   MedyMatch Technology Ltd ... with artificial intelligence, real-time decision support tools in the emergency ... at the 2016 Israeli Advanced Technology Industries (IATI) BioMed Conference. ... Israel,s 15th National Life Sciences and Technology ... the David Intercontinental Hotel in Tel Aviv, Israel ...
(Date:5/23/2016)... ... May 23, 2016 , ... ... Precision Farming in 2017 and Beyond. The paper outlines the key trends that ... ag industry. , “We’ve witnessed a lot of highs and lows as the ...
(Date:5/23/2016)... Carolina (PRWEB) , ... May 23, 2016 , ... ... and building management solutions and services based in Aurora, Ohio, has broken ground ... established business in the Research Triangle Park area, this new location solidifies a ...
Breaking Biology Technology: