Navigation Links
Study finds that cancer-causing gene crucial in stem cell development

Athens, Ga. Stem cells might be thought of as trunks in the tree of life. All multi-cellular organisms have them, and they can turn into a dazzling variety other cellskidney, brain, heart or skin, for example. One class, pluripotent stem cells, has the capacity to turn into virtually any cell type in the body, making them a focal point in the development of cell therapies, the conquering of age-old diseases or even regrowing defective body parts.

Now, a research team at the University of Georgia has shown for the first time that a gene called Myc (pronounced "mick") may be far more important in the development and persistence of stem cells than was known before. Myc is traditionally thought of as a cancer-causing gene, or oncogene, but recent studies from the UGA team have established critical roles for it in stem cell biology. The discovery has important implications for the basic understanding of developmental processes and how stem cells can be used for therapeutic purposes.

"This new research has uncovered a really unexpected role for Myc," said Stephen Dalton, GRA Eminent Scholar of Molecular Cell Biology and Georgia Cancer Coalition Distinguished Scientist at UGA. "Our work here represents the first mechanistic characterization of how Myc controls the pluripotent stem cell state."

The research was published today in the journal Cell Stem Cell. Other authors of the paper include Keriayn Smith and Amar Singh of the Dalton lab at UGA. Smith left recently to begin a postdoc at the University of North Carolina. Dalton also is a member of the department of biochemistry and molecular biology in the Franklin College of Arts and Sciences and is affiliated with the UGA Cancer Center and the Biomedical and Health Sciences Institute.

In previous work, Dalton and his colleagues showed that Myc is critical for stem cell maintenance and that it affects widespread changes in gene expression. This latter function is crucial when stem cells differentiate into more specific cell types. In the new research, Dalton's team showed that Myc sustains the important pluripotency process by repressing a "master regulator" gene called GATA6.

"Pluripotency is the inherent property of a cell to create all cell types, from an embryo to an adult organism," said Dalton. "It's an extremely important biological process, and knowing how it is controlled is crucial not only from a basic developmental perspective but also so that we can harness the potential of stem cells for the development of therapies, including those for diabetes, cardiovascular disease and a range of neurological disorders. Through a detailed understanding of early development, we hope to apply this information so that pluripotent stem cells can be differentiated into therapeutically useful cell types. These cells can then be used in a clinical setting to cure degenerative diseases and treat acute injury."

The finding that Myc inhibits GATA6 came as a big surprise to the Dalton team and points out that researchers have only seen the tip of the "molecular iceberg" in terms of what Myc does in stem cells. It now seems likely that understanding Myc's role in further detail will reshape current ideas about the basic biology of stem cells.

Dalton's new work addressed the uncertainty about how Myc maintains the pluripotency of stem cells by examining what happens when two forms of Mycc-Myc and N-Mycare inactivated in pluripotent stem cells. What he found was that either c- or N-Myc is sufficient to maintain pluripotency, but that the absence of both triggers the differentiation of pluripotent stem cells. Myc is therefore acting as a "brake" to restrain differentiation. When the "differentiation brake" is removed, cells lose their stem cell properties, and, potentially, they can become any one of over a hundred different cell types.

Pluripotent stem cells can now be made from skin fibroblasts and even from blood samples. (Fibroblasts are cells common in connective tissues of animals and play an important role in the healing of wounds, among many functions.) The conversion of mature fibroblast or blood cells back to pluripotent stem cells is called "reprogramming." Myc also has a critical role in this process. The ability to make stem cells from a patient's blood or skin is going to revolutionize medicine as it opens the way for patient-specific stem cells that would circumvent problems associated with immune rejection, said Dalton.

"During the reprogramming of cells, Myc represses genes associated with the differentiated state and primes them for the expression of stem cell genes," he said. "We now speculate that during the early reprogramming stage, Myc serves to change the cell cycle so that stem cells can divide for long periods of time without aging. This is also what Myc does in cancer cells."

Dalton said that there is an intriguing relationship between normal stem cells and cancer cells. Since Myc is crucial for maintenance of stem cells and for the development of cancer, pluripotent stem cells represent a good model for tumor biologists. Cancer is thought to be initiated by rogue stem cells found in different tissues, further highlighting the link between stem cell biology, cancer and Myc.

"This is clearly going to be a major area of research for many years to come," Dalton said.


Contact: Stephen Dalton
University of Georgia

Related medicine news :

1. Despite Treatment, Employees with Depression Generate Higher Absentee Costs, According to Thomson Reuters Study
2. American Council on Exercise (ACE) Study Reveals Kettlebells Provide Powerful Workout in Short Amount of Time
3. TV drama can be more persuasive than news program, study finds
4. Study carried out into biological risks of eating reptiles
5. Neuroimaging study may pave way for effective Alzheimers treatments
6. Study finds racial gaps continue in heart disease awareness
7. Luth Researchs IndicatorEDG(TM) Study Finds Americans Hopes of Achieving Their Dreams Are Fading
8. First blinded study of venous insufficiency prevalence in MS shows promising results
9. Soothing infants with food focus of childhood obesity study
10. People with anxiety disorder less able to regulate response to negative emotions, study shows
11. American Heart Association Rapid Access Journal Report: Study Finds Racial Gaps Continue in Heart Disease Awareness, Low Knowledge of Heart Attack Warning Signs Among Women
Post Your Comments:
(Date:11/28/2015)... ... November 28, 2015 , ... Safe storage for contraceptive devices may not ... from Lakewood, New Jersey and the other from Bradley Beach, New Jersey, there is ... the expense of having to replace NuvaRings more often than necessary. As such, it ...
(Date:11/28/2015)... Aliso Viejo, CA (PRWEB) , ... November 28, 2015 , ... ... 30 new fully customizable media panels to choose from, the possibilities are endless. Users ... angle, and more. With the ProPanel: Pulse masking effects, users are sure to get ...
(Date:11/27/2015)... Los Angeles, CA (PRWEB) , ... November 27, 2015 , ... ... new study carried out by the University of Toronto and the University of British ... number of hospitalizations for head injuries. The article explains that part of the reason ...
(Date:11/27/2015)... ... , ... A team of Swiss doctors has released a report on mesothelioma ... posted the findings on the website. Click here to read the details now. ... patients who were treated with chemotherapy followed by EPP surgery. Among the 106 patients ...
(Date:11/27/2015)... ... November 27, 2015 , ... Lizzie’s Lice Pickers just announced a ... customers 10% off of their purchase of lice treatment product. In addition, customers will ... to a company spokesperson. “Finding lice is a sure way to ruin the holidays, ...
Breaking Medicine News(10 mins):
(Date:11/25/2015)... Nov. 25, 2015  The American Academy of ... (ACOG), and the March of Dimes cheered today,s ... Our Infants Act of 2015 (S.799), which ... newborns born exposed to drugs, such as opioids, ... introduction, all three organizations have worked together leading ...
(Date:11/25/2015)... On Tuesday, November 24, 2015, the ... Wright Medical Technology, Inc. for product liability and ... implant device, awarded $11 million in favor of ... and three days of deliberations, the jury found ... designed and unreasonably dangerous, and that Wright Medical ...
(Date:11/25/2015)... , November 25, 2015 ... KTOV ) (TASE: KTOV), a biopharmaceutical company focused on ... of various clinical conditions, today announced the closing of ... Depository Shares ( ADSs ), each representing 20 ordinary ... to 3,158,900 ADSs. The ADSs and warrants were issued ...
Breaking Medicine Technology: