STEM CELLS - Stem cells have the ability to change into other types of cells. Because stem cells can become bone, muscle, cartilage and other specialized types of cells, they have the potential to treat many diseases, including Parkinson's, Alzheimer's, diabetes and cancer. Stem cells are already being used to treat leukemia and some joint repairs. Stem cells are unprogrammed cells in the human body that can be described as "shape shifters." These cells have the ability to change into other types of cells. Stem cells are at the center of a new field of science called regenerative medicine. Because stem cells can become bone, muscle, cartilage and other specialized types of cells, they have the potential to treat many diseases, including Parkinson's, Alzheimer's, diabetes and cancer. They may also be used to regenerate organs, reducing the need for organ transplants and related surgeries. Stem cells are like little kids who, when they grow up, can enter a variety of professions. A child might become a fireman, a doctor or a plumber, depending on the influences in their life -- or environment. In the same way, these stem cells can become many tissues by making certain changes in their environment. Embryonic and fetal stem cells have the potential to morph into a greater variety of cells than adult stem cells do. Stem cells from fat have the ability to mature into other types of specific cells, including muscle, bone and cartilage.

..........................................................................................................................................................................................................................................................................................................

Stem Cells

What are stem cells and what are they used for?

.

Stem cells have the ability to change into other types of cells. Because stem cells can become bone, muscle, cartilage and other specialized types of cells, they have the potential to treat many diseases, including Parkinson's, Alzheimer's, diabetes and cancer. Stem cells are already being used to treat leukemia and some joint repairs.

HowStuffWorks

  

Stem cells are unprogrammed cells in the human body that can be described as "shape shifters."

These cells have the ability to change into other types of cells.

Stem cells are at the center of a new field of science called regenerative medicine.

Because stem cells can become bone, muscle, cartilage and other specialized types of cells, they have the potential to treat many diseases, including Parkinson's, Alzheimer's, diabetes and cancer.

Eventually, they may also be used to regenerate organs, reducing the need for organ transplants and related surgeries.

"Stem cells are like little kids who, when they grow up, can enter a variety of professions," Dr. Marc Hedrick of the UCLA School of Medicine says.

"A child might become a fireman, a doctor or a plumber, depending on the influences in their life -- or environment. In the same way, these stem cells can become many tissues by making certain changes in their environment."

Stem cells can typically be broken into four types:

·      Embryonic stem cells - Stem cells taken from human embryos

·      Fetal stem cells- Stem cells taken from aborted fetal tissue

·      Umbilical stem cells - Stem cells take from umbilical cords

·      Adult stem cells - Stem cells taken from adult tissue

Embryonic and fetal stem cells have the potential to morph into a greater variety of cells than adult stem cells do.

In April 2001, researchers at UCLA and the University of Pittsburgh found stem cells in fat sucked out of liposuction patients. Previously, stem cells were found only in bone marrow, brain tissue and fetal tissue -- sources that have caused both logistical and ethical problems.

Stem cells from fat have the ability to mature into other types of specific cells, including muscle, bone and cartilage, but how many other types is still unknown.

Prior to being transplanted into a person's tissue to begin regeneration of that tissue, stem cells have to go through differentiation.

Differentiation is the process by which scientists pre-specialize the stem cells, almost like preprogramming the stem cells to become specific cells.

These cells are then injected into the area of the body being targeted for tissue regeneration.

When stem cells come into contact with growth chemicals in the body, the chemicals program the stem cells to grow into the tissue surrounding it.

Stem cells are already being used to treat leukemia and some joint repairs.

For example, a bone-marrow transplant is accomplished by injecting stem cells from a donor into the bloodstream of the patient.

Stem cells from bone marrow also have the ability to repair the liver. Researchers are studying stem cells to find out if they could correct brain damage resulting from Parkinson's disease.

The next step will be to learn what influences stem cells to change into particular types of cells.

Once that's known, it will be possible to grow cells that perfectly match those of the patients.

HowStuffWorks got its start in 1998 at a college professor's kitchen table. From there, we quickly grew into an award-winning source of unbiased, reliable, easy-to-understand answers and explanations of how the world actually works. Today, our writers, editors, podcasters and video hosts share all the things we're most excited to learn about with nearly 30 million visitors to the site each month. Learn more about our authors, and maybe even become one yourself. You can learn more about us in our FAQ.

https://science.howstuffworks.com/life/cellular-microscopic/question621.htm

CHILDREN AND LEUKEMIA - Leukemia, which disrupts normal cell growth in the blood and bone marrow, accounts for nearly one-third of all childhood cancer cases. Certain forms of leukemia tend to strike early in life and affect far more children than adults. The disease manifests in various forms, and the subtypes that mostly affect children typically progress quickly and require immediate, aggressive treatment. Although similarities exist between childhood and adult leukemias, evidence suggests that the cancers don't share the same genetic roots. What has been known for some time is that there are clear genetic differences between childhood cancer and adult cancer. Important distinctions between childhood and adult leukemia may lie in how the bone marrow functions in people of different ages and how cancer commandeers that tissue for its own purposes.

................................................................................................................................................................

Children And Leukemia

Why Do Some Forms of Leukemia Affect Mostly Children?

By Nicoletta Lanese - Staff Writer 

Childhood leukemias may exploit specific vulnerabilities found only in immature cells.

Certain forms of leukemia tend to strike early in life and affect far more children than adults.          

Leukemia, which disrupts normal cell growth in the blood and bone marrow, accounts for nearly one-third of all childhood cancer cases, according to the American Cancer Society (ACS).

The disease manifests in various forms, and the subtypes that mostly affect children typically progress quickly and require immediate, aggressive treatment.

Although similarities exist between childhood and adult leukemias, evidence suggests that the cancers don't share the same genetic roots.                   

"What has been known for some time is that there are clear genetic differences between childhood cancer and adult cancer," said Dr. Thomas Mercher, a director of hematology-oncology research for the French National Institute of Health and Medical Research and the Gustave Roussy research institute in Villejuif, France.

Studies suggest that the specific genetic quirks seen in childhood leukemia cells may arise very early in life, or even in the womb, but how this happens step by step "is generally very unclear," Mercher said. 

Now, new research hints that childhood leukemia may be able to hijack only young, developing cells — like those found in fetuses and children — not the mature cells of full-grown adults. 
/
To investigate why certain leukemias may prey on immature cells, Mercher and his colleagues gathered genetic samples from young patients with a particularly aggressive form of acute myeloid leukemia (AML) and replicated the disease in mouse models.

The team's study, published Oct. 29 in the journal Cancer Discovery, hints at why the cancer appears early in life, often before the affected child reaches 2 years old.

"The genetic alterations that we studied here are only found in childhood leukemia," Mercher added. 

In general, AML is more prevalent in adults than children; the disease accounts for fewer than 25% of all childhood leukemia cases, according to the American Cancer Society.

However, a rare subtype called "acute myeloblastic leukemia type 7" (AML-M7) predominantly appears in infants under the age of 2.

Children with other forms of AML develop the disease later in life, around age 6, and show better survival rates than individuals with the more-aggressive subtype, the authors noted in a statement. 

Could the children's ages at the time of disease onset offer clues as to why these cancers have such different outcomes? To find out, the researchers looked to the children's genes.     

Frankenstein-style mutations 

Back in 2012, the team gathered leukemia cells from both children and adults who had AML-M7, discovering a key difference between the genetic material in the children versus the adults.

Many of the children's cells contained genes that had merged together, Frankenstein-style, to form new, hybrid genes.

Individually, the genes play important roles in blood cell development, but once stuck together, those genes may direct cells to build unusual proteins and ultimately transform into cancerous cells, the researchers theorized.

None of these "fusion genes" appeared in a single adult leukemia cell, which hinted that the team might be onto something.      

After the researchers published this initial finding, they and other scientists found ample evidence of fusion genes in AML-M7 leukemia.

But no one knew exactly what these hybrid genes did or why they appeared only in children. 

So, Mercher and his colleagues continued to investigate, focusing their research on a fusion gene known as ETO2–GLIS2.

Welding together two normally separate genes, ETO2 and GLIS2, the mutation appears in about 30% of children with AML-M7 and seems linked to poor responses to cancer treatment and low survival rates, the researchers wrote.

To learn how this mutation drives cancer, the team observed how the fusion gene seized control of hematopoietic stem cells, cells that normally give rise to healthy blood cells but can get hijacked by leukemia.          

The scientists developed a mouse model in which they could turn the ETO2–GLIS2 mutation "on" or "off" in a given tissue inside the mouse.

They ran their experiment in both fetal and adult-age mice to see if the fusion gene would affect cells differently depending on the cells' stage of development.

Turns out, that's exactly what happened. When the team activated ETO2–GLIS2 in fetal stem cells, the resulting proteins seemed to tamper with cellular pathways that normally turn the cells into healthy blood cells.

Basically, the fusion gene flipped a "molecular switch" that rapidly transformed the stem cells into aggressive leukemia.

Blocking ETO2–GLIS2 activation in the same fetal mice flipped the switch back, curbed the cancer growth and allowed stem cells to turn into normal blood once more. 

By comparison, the adult stem cells appeared "much less prone to give rise to leukemia" when ETO2–GLIS2 was activated, Mercher said.

In fact, the fusion gene did not appear to be a key driver of leukemia progression in adult mice. 

"The developmental stage of the cells in which the mutation arises determines the aggressiveness and the type of leukemia that you get," Mercher said. 
/
The results "show that more people should be paying attention to the fetal bone marrow environment," where hematopoietic stem cells can be found, said Dr. Mignon Loh, a pediatric hematologist-oncologist at the University of California, San Francisco, who was not involved in the study.

The immediate environment, or niche, where a fetal stem cell develops looks very different from the environment surrounding an adult cell, she said. 

"When you're a baby and have been incubating for 9 months, that niche is pretty pure," Loh said. Important distinctions between childhood and adult leukemia may lie in how the bone marrow functions in people of different ages and how cancer commandeers that tissue for its own purposes, she said. 

Research into ETO2–GLIS2 may also shed light on how other forms of childhood leukemia rely on fusion genes, provided that the team's findings in mice hold true in humans, Loh said.

More broadly, further research into the nature of fetal stem cells in general could reveal other avenues by which leukemia exploits developing cells, she said.

"There may be something permissive about a fetal-like stem cell" that allows it to transform into malignant cancer, Loh said.

If future research could pinpoint how child-specific mutations cause leukemia, drugs could be developed to stall or stop the disease, Mercher added. 

"That would be like [finding] the holy grail," Loh said.

Nicoletta Lanese is a science journalist and dancer who aims to bring science to new audiences, whether in print or on stage. She holds degrees in neuroscience and dance from the University of Florida and a graduate certificate in science communication from the University of California, Santa Cruz. Brains are her beat. Follow her on Twitter @NicolettaML. 

https://www.livescience.com/why-some-leukemia-mostly-affects-children.html?utm_source=notification

STEM CELLS - The term "stem cells" has become part of the mainstream lexicon, likely to be overheard in conversations anywhere from a baseball game to cocktail get-togethers. But what exactly are these cells? Along with phrases such as "that's just immoral" or "stem cells could be the end-all cure," one could easily weave in some technical tidbits about these microscopic, yet significant, cells. Stem cells are considered the "engine" cells of regeneration in that they are self-renewing and able to duplicate, or clone, themselves. These special cells are used in the rapidly growing field of regenerative medicine to halt or even reverse chronic diseases. Regenerative medicine seeks to repair or replace tissues or organs that have been damaged by trauma, disease or congenital defects. There are three types of stem cells: embryonic, umbilical cord (also known as mesenchymal, or MSC), and adult stem cells. Embryonic stem cells are considered pluripotent, meaning they can give rise to all of the cell types that make up the human body. Cord and adult stem cells are multipotent, which means that they are able to develop into more than one cell type, but they are more limited than pluripotent cells. In the United States, cord and adult stem cells are the only ones used in regenerative medical procedures. Due to ethical controversy, embryonic stem cells are not used in clinical practice but can be used for research purposes.

..........................................................................................................................................................................................................................................................................................................

Stem Cells

What Are Stem Cells?

By Jeanna Bryner - Live Science Managing Editor 

The term "stem cells" has become part of the mainstream lexicon, likely to be overheard in conversations anywhere from a baseball game to cocktail get-togethers.

But what exactly are these cells?

Along with phrases such as "that's just immoral" or "stem cells could be the end-all cure," one could easily weave in some technical tidbits about these microscopic, yet significant, cells.

Stem cells are considered the "engine" cells of regeneration in that they are self-renewing and able to duplicate, or clone, themselves.

These special cells are used in the rapidly growing field of regenerative medicine to halt or even reverse chronic diseases.

Regenerative medicine seeks to repair or replace tissues or organs that have been damaged by trauma, disease or congenital defects, according to the McGowan Institute for Regenerative Medicine at the University of Pittsburgh.

There are three types of stem cells: embryonic, umbilical cord (also known as mesenchymal, or MSC), and adult stem cells.

Embryonic stem cells are considered pluripotent, meaning they can give rise to all of the cell types that make up the human body.

Cord and adult stem cells are multipotent, which means that they are able to develop into more than one cell type, but they are more limited than pluripotent cells, according to NYSTEM (New York Stem Cell Science).

In the United States, cord and adult stem cells are the only ones used in regenerative medical procedures.

Due to ethical controversy, embryonic stem cells are not used in clinical practice but can be used for research purposes.

Adult stem cells

Adult stem cells — which can be taken from bone marrow, blood or fat — are mostly free of ethical controversy, but they have limited potential.

As we get older, not only do our stem cells lose functionality, but we have far fewer of them. Researchers estimate that newborns have 40 times more stem cells in their bone marrow compared to a 50-year old, according to a 2009 study in the Journal of Pathology.

In addition, adult stem cells may be subject to DNA abnormalities caused by sunlight, toxins and errors associated with making more DNA copies over the course of a lifetime, according to the National Institutes of Health (NIH).

Cord stem cells

Cord stem cells can be harvested from the umbilical cord after birth with the mother's permission.

This tissue, which is typically discarded, can be donated to science for use in research or medicine, or placed in a cord bank in case the mother or child may need it one day.

Cord stem cells are much more efficient at replicating once removed from the body compared to adult stem cells.

For example, when placed in a petri dish with the proper nutrients, one cord stem cell will multiply into 1 billion cells in 30 days, whereas one adult stem cell will multiply into only around 200 cells in 30 days, according to a 2011 study published in the journal Orthopedics.

Doctors use cord stem cells to treat autoimmune conditions, such as lupus, rheumatoid arthritis and multiple sclerosis, as well as chronic infections such as HIV, herpes and Lyme disease, according to AMA.

Embryonic stem cells

Embryonic stem cells hold the most promise for treating diseases, but heated debate abounds over the ethics of using them.

Human embryonic stem cells are derived from eggs fertilized in vitro (outside of the body) and are somewhat pristine.

These pluripotent stem cells are prized for their flexibility in being able to morph into any human cell.

When embryonic stem cells are grown in a laboratory under certain conditions for several months, they can remain unspecialized and produce millions of stem cells indefinitely.

The resulting batch of cells is referred to as a stem-cell line.

The NIH said 64 embryonic stem-cell lines existed as of August 2001 when President Bush announced the federal policy describing the constraints on funds for stem-cell research.

In March 2009, however, President Obama officially removed the restrictions placed by President Bush on federal funding for research on embryos.

Although it's been contested, the policy remains in effect with strict guidelines in place by the NIH.

Induced pluripotent stem cells

Scientists can now reprogram adult stem cells to become more like embryonic stem cells.

These are known as induced pluripotent stem cells (iPSCs). But since iPSCs are still adult stem cells, they carry the risk of having abnormalities.

Much more research is needed on iPSCs, but scientists hope to use them in transplantation medicine, according to the NIH.

Jeanna Bryner 

Live Science Editor-in-Chief

Jeanna is the editor-in-chief of Live Science. Prior to this role, she served as the site's managing editor, and before that a reporter for both Live Science and Space.com. Previously she was an assistant editor at Scholastic's Science World magazine. Jeanna has an English degree from Salisbury University, a Master's degree in biogeochemistry and environmental sciences from the University of Maryland, and a science journalism degree from New York University. 

https://www.livescience.com/32369-what-is-a-stem-cell.html