Fat cells below the skin, known as adipocytes, can protect against infection They produce molecules called antimicrobial peptides that fend off bacteria Lack of antimicrobial peptides leaves people more prone to infections

By Madlen Davies for MailOnline

Published: 11:11 EST, 2 January 2015 | Updated: 16:58 EST, 2 January 2015

92 shares

21

View comments

Fat has been much maligned for promoting weight gain and raising cholesterol.

However, a new study has found fat is not all bad, helping people fight infections.

U.S. researchers made the surprising discovery that fat cells below the skin help protect against bacteria.

Professor Richard Gallo, of UC San Diego School of Medicine, uncovered the previously unknown role for fat cells known as adipocytes.

Originally posted here:
Fat below the skin 'helps protect against bacterial infections and blood poisoning'

Recommendation and review posted by Bethany Smith

Why are some types of cancer so much more common than others? Sometimes its due to faulty genes inherited from ones parents and sometimes to behaviors like smoking a pack of cigarettes every day. But in most cases, it comes down to something else stem cells.

This is the intriguing argument made by a pair of researchers from Johns Hopkins University. In a study published Friday in the journal Science, they found a very high correlation between the differences in risk for 31 kinds of cancer and the frequency with which different types of stem cells made copies of themselves.

Just how strong was this link? On a scale that goes from 0 (absolutely no correlation) to 1 (exact correlation), biostatistician Cristian Tomasetti and cancer geneticist Bert Vogelstein calculated that it was at least a 0.8. When it comes to cancer, thats high.

No other environmental or inherited factors are known to be correlated in this way across tumor types, Tomasetti and Vogelstein wrote.

Researchers have long recognized that when cells copy themselves, they sometimes make small errors in the billions of chemical letters that make up their DNA. Many of these mistakes are inconsequential, but others can cause cells to grow out of control. That is the beginning of cancer.

The odds of making a copying mistake are believed to be the same for all cells. But some kinds of cells copy themselves much more often than others. Tomasetti and Vogelstein hypothesized that the more frequently a type of cell made copies of itself, the greater the odds that it would develop cancer.

The pair focused on stem cells because of their outsized influence in the body. Stem cells can grow into many kinds of specialized cells, so if they contain damaged DNA, those mistakes can spread quickly.

The researchers combed through the scientific literature and found studies that described the frequency of stem cell division for 31 different tissue types. Then they used data from the National Cancer Institutes Surveillance, Epidemiology and End Results database to assess the lifetime cancer risk for each of those tissue types. When they plotted the total number of stem cell divisions against the lifetime cancer risk for each tissue, the result was 31 points clustered pretty tightly along a line.

To put this notion in concrete terms, consider the skin. The outermost layer of the skin is the epidermis, and the innermost layer of the epidermis contains a few types of cells. Basal epidermal cells are the ones that copy themselves frequently, with new cells pushing older ones to the skins surface. Melanocytes are charged with making melanin, the pigment that protects the skin from the suns damaging ultraviolet rays.

When sunlight hits bare skin, both basal epidermal cells and melanocytes get the same exposure to UV. But basal cell carcinoma is far more common than melanoma about 2.8 million Americans are diagnosed with basal cell carcinoma each year, compared with roughly 76,000 new cases of melanoma, according to the Skin Cancer Foundation. A major reason for this discrepancy, Tomasetti and Vogelstein wrote, is that epidermal stem cells divide once every 48 days, while melanocytes divide only once every 147 days.

Excerpt from:
Scientists explain how stem cells and 'bad luck' cause cancer

Recommendation and review posted by Bethany Smith

When it comes to skin infections, a healthy and robust immune response may depend greatly upon what lies beneath. In a new paper published in the January 2, 2015 issue ofScience, researchers at the University of California, San Diego School of Medicine report the surprising discovery that fat cells below the skin help protect us from bacteria.

Richard Gallo, MD, PhD, professor and chief of dermatology at UC San Diego School of Medicine, and colleagues have uncovered a previously unknown role for dermal fat cells, known as adipocytes: They produce antimicrobial peptides that help fend off invading bacteria and other pathogens.

"It was thought that once the skin barrier was broken, it was entirely the responsibility of circulating (white) blood cells like neutrophils and macrophages to protect us from getting sepsis," said Gallo, the study's principal investigator.

"But it takes time to recruit these cells (to the wound site). We now show that the fat stem cells are responsible for protecting us. That was totally unexpected. It was not known that adipocytes could produce antimicrobials, let alone that they make almost as much as a neutrophil."

The human body's defense against microbial infection is complex, multi-tiered and involves numerous cell types, culminating in the arrival of neutrophils and monocytes - specialized cells that literally devour targeted pathogens.

Skin graphic image via Shutterstock.

Read more at EurekAlert.

Go here to see the original:
The good role fat cells play in protecting us from disease

Recommendation and review posted by Bethany Smith

By Steven Reinberg HealthDay Reporter

WEDNESDAY, Dec. 31, 2014 (HealthDay News) -- Using stem cells derived from a patient's own bone marrow, researchers have repaired a fistula -- a potentially fatal tissue abnormality -- in the man's lower airway.

"This is another interesting new therapeutic approach for stem cells," said lead researcher Dr. Francesco Petrella, deputy director of thoracic surgery at the European Institute of Oncology in Milan, Italy.

The patient, a 42-year-old firefighter, developed the fistula after surgeons removed a lung as part of treatment for mesothelioma cancer. A fistula is abnormal tissue connecting an organ, blood vessel or intestine to another structure. In this case, the fistula developed between the lower airway and the tissue that surrounds the lungs.

"Our clinical experience supports the idea that stem cells could be effectively used to close some tissue defects developing after very complex surgical procedures, thus restoring a functioning airway," Petrella said.

A fistula that develops after chest surgery is serious and even deadly, Petrella said. Current treatments involve removing ribs and taking medications for months or years, he explained.

"Less invasive approaches like endoscopic glue injections have only poor results, so our proposed techniques could improve quality of life in these patients," Petrella said.

Sixty days after stem cell therapy, the firefighter's fistula was healed, the researchers said. The hole seen before stem cell therapy was no longer visible, having been replaced by new tissue created by the stem cell implant, they explained.

Some people are born with a fistula. Other causes of fistulas include complications from surgery, injury, infection and diseases, such as Crohn's disease or ulcerative colitis.

Petrella believes that this same stem cell technique could be used to treat fistulas that develop elsewhere in the body.

Read more:
Stem Cell Therapy Fixes Post-Surgical Airway Abnormality

Recommendation and review posted by Bethany Smith

The year in which a person was born may have an influence on their obesity risk, according to new research published in the Proceedings of the National Academy of Sciences.

Previously, research has linked a variant in the FTO gene to obesityrisk. Now, researchers from the Massachusetts General Hospital (MGH) Department of Psychiatry suggest in a new study that the impact of this variant on obesity risk depends largely on birth year.

The researchers noticed that most studies investigating the interactions of genes and the environment focused on differences within groups of people born during a particular span of years. The team realized that studies of these birth cohorts would not account for environmental changes occurring over time.

In an attempt to understand whether the environmental conditions experienced across different age groups affect the impact of a gene variant, the team analyzed data from the Framingham Offspring Study, which follows the children of participants from a long-term study that collected data from 1971-2008.

The body mass index (BMI) of the participants was measured eight times during the study period, which allowed the MGH team to examine the correlations between BMI and the FTO variants of the participants.

The researchers found no correlation between FTO variant and BMI for participants born before 1942. However, in participants born after 1942, the correlation between BMI and FTO was twice as strong as had been reported in previous studies.

Looking at participants in the Framingham Heart Study, we found that the correlation between the best known obesity-associated gene variant and body mass index increased significantly as the year of birth of participants increased, says lead author Dr. James Niels Rosenquist, of the MGH Department of Psychiatry. He adds:

These results to our knowledge the first of their kind suggest that this and perhaps other correlations between gene variants and physical traits may vary significantly depending on when individuals were born, even for those born into the same families.

Post-World War II lifestyle changes suggested as contributing factors

Although the environmental differences that caused this change in the association are not identified in the study, the authors hypothesize that the increased reliance on technology, rather than physical labor, and the availability of high-calorie processed foods both of which emerged following World War II are likely contributors.

Read the rest here:
Year of birth has an influence on genetic risk for obesity

Recommendation and review posted by Bethany Smith

IT was a wish that most teenagers take for granted.

Under-going gruelling treatment for a rare form of leukaemia in a hospital isolation chamber, Kitty Aplin-Haynes longed for the freedom to live life to the full like most girls her age.

But the cancer, which had spread to her brain and central nervous system, was so aggressive, her only hope of that freedom was a life-saving bone marrow transplant.

However, today the 18-year-old is at home and her wish has come true.

She can now look forward to laughing with friends and starting college after being told she is in remission thanks to the ultimate gift from a stranger, the gift of life.

Kitty is recovering after the bone marrow transplant plus a second procedure to boost her immune system from the same anonymous donor and she has another reason to smile.

Campaign Her family and friends desperate campaign to raise awareness of her plight will also save other lives as more than 130 people have signed up to the bone marrow register.

Kitty said: Many young people die waiting for a donor because only half of those who need a bone marrow transplant every year in the UK are lucky enough to find a match so I feel incredibly lucky.

Im overwhelmed my donor has donated his stem cells to me, not once, but twice.

Visit link:
Teenager celebrating New Year after being given the gift of life

Recommendation and review posted by Bethany Smith

When it comes to skin infections, a healthy and robust immune response may depend greatly upon what lies beneath. In a new paper published in the January 2, 2015 issue of Science, researchers at the University of California, San Diego School of Medicine report the surprising discovery that fat cells below the skin help protect us from bacteria.

Richard Gallo, MD, PhD, professor and chief of dermatology at UC San Diego School of Medicine, and colleagues have uncovered a previously unknown role for dermal fat cells, known as adipocytes: They produce antimicrobial peptides that help fend off invading bacteria and other pathogens.

"It was thought that once the skin barrier was broken, it was entirely the responsibility of circulating (white) blood cells like neutrophils and macrophages to protect us from getting sepsis," said Gallo, the study's principal investigator.

"But it takes time to recruit these cells (to the wound site). We now show that the fat stem cells are responsible for protecting us. That was totally unexpected. It was not known that adipocytes could produce antimicrobials, let alone that they make almost as much as a neutrophil."

The human body's defense against microbial infection is complex, multi-tiered and involves numerous cell types, culminating in the arrival of neutrophils and monocytes - specialized cells that literally devour targeted pathogens.

But before these circulating white blood cells arrive at the scene, the body requires a more immediate response to counter the ability of many microbes to rapidly increase in number. That work is typically done by epithelial cells, mast cells and leukocytes residing in the area of infection.

Staphylococcus aureus is a common bacterium and major cause of skin and soft tissue infections in humans. The emergence of antibiotic-resistant forms of S. aureus is a significant problem worldwide in clinical medicine.

Prior published work out of the Gallo lab had observed S. aureus in the fat layer of the skin, so researchers looked to see if the subcutaneous fat played a role in preventing skin infections.

Ling Zhang, PhD, the first author of the paper, exposed mice to S. aureus and within hours detected a major increase in both the number and size of fat cells at the site of infection. More importantly, these fat cells produced high levels of an antimicrobial peptide (AMP) called cathelicidin antimicrobial peptide or CAMP. AMPs are molecules used by the innate immune response to directly kill invasive bacteria, viruses, fungi and other pathogens.

"AMPs are our natural first line defense against infection. They are evolutionarily ancient and used by all living organisms to protect themselves," said Gallo.

Read the original:
Fat isn't all bad: Skin adipocytes help protect against infections

Recommendation and review posted by Bethany Smith

Cancers due to bad luck, left, and cancers due to a combination of bad luck, environmental factors, and inherited factors. Elizabeth Cook]

Cancers due to bad luck, left, and cancers due to a combination of bad luck, environmental factors, and inherited factors. / Elizabeth Cook]

Nearly two-thirds of all cancers are caused by random mutations of the body's stem cells, not by hereditary or environmental effects, according to a study released Jan. 1 by Johns Hopkins scientists.

Tissues with the most divisions of regenerative cells and hence the most chances for mutations tend to have the greatest rates of cancer, the study found.

This explains why skin cancers, for example, are far more common than bone cancers. Skin cells die constantly, so they must be replenished far more often than those that make bone, introducing more chances for errors that lead to cancer.

In effect, most cancers come down to "bad luck", the researchers say in the study.

The findings introduce new dimensions to the struggle against cancer, said two researchers who did not take part in the study.

The study was published Thursday in the journal Science. Cristian Tomasetti of the Johns Hopkins Kimmel Cancer Center at Johns Hopkins Medicine in Baltimore is first author. The study's senior author is Bert Vogelstein, also of the center, part of Johns Hopkins University.

Healthy diet and protection against carcinogens are still important, said Tomasetti, because the one-third variability is still substantial. And the proportion of randomness in each type of cancer varies. Some cancers tend to be greatly increased by environmental factors, such as lung cancer in smokers. The two-third average is a summary of the risk of cancer from all tissue types.

Strong relationship

Originally posted here:
Most cancer is bad luck, study finds

Recommendation and review posted by Bethany Smith

Dallas, Tx - SVF Stem Cell Therapy Testimonial - Neuropathy
http://www.innovationsstemcellcenter.com Call: 214.420.7970 Facebook: https://www.facebook.com/innovationsmedical Twitter: https://twitter.com/dallasdrj Inst...

By: dallasdrj

Read more here:
Dallas, Tx - SVF Stem Cell Therapy Testimonial - Neuropathy - Video

Recommendation and review posted by Bethany Smith

Cell biologists at UT Southwestern Medical Center have targeted telomeres with a small molecule called 6-thiodG that takes advantage of the cell's 'biological clock' to kill cancer cells and shrink tumor growth.

Dr. Jerry W. Shay, Professor and Vice Chairman of Cell Biology at UT Southwestern, and colleague, Dr. Woodring E. Wright, Professor of Cell Biology and Internal Medicine, found that 6-thio-2'-deoxyguanosine could stop the growth of cancer cells in culture and decrease the growth of tumors in mice.

"We observed broad efficacy against a range of cancer cell lines with very low concentrations of 6-thiodG, as well as tumor burden shrinkage in mice," said Dr. Shay, Associate Director of the Harold C. Simmons Comprehensive Cancer Center.

Dr. Shay and Dr. Wright, who hold The Southland Financial Corporation Distinguished Chair in Geriatrics, are co-senior authors of the paper appearing in the journal Cancer Discovery.

6-thiodG acts by targeting a unique mechanism that is thought to regulate how long cells can stay alive, a type of aging clock. This biological clock is defined by DNA structures known as telomeres, which cap the ends of the cell's chromosomes to protect them from damage, and which become shorter every time the cell divides. Once telomeres have shortened to a critical length, the cell can no longer divide and dies though a process known as apoptosis.

Cancer cells are protected from this death by an RNA protein complex called telomerase, which ensures that telomeres do not shorten with every division. Telomerase has therefore been the subject of intense research as a target for cancer therapy. Drugs that successfully block its action have been developed, but these drugs have to be administered for long periods of time to successfully trigger cell death and shrink tumors, leading to considerable toxicities. This outcome is partially because cells in any one tumor have chromosomes with different telomere lengths and any one cell's telomeres must be critically shortened to induce death.

6-thiodG is preferentially used as a substrate by telomerase and disrupts the normal way cells maintain telomere length. Because 6-thiodG is not normally used in telomeres, the presence of the compound acts as an 'alarm' signal that is recognized by the cell as damage. As a result, the cell stops dividing and dies.

Telomerase is an almost universal oncology target, yet there are few telomerase-directed therapies in human clinical trials, researchers noted.

"Using telomerase to incorporate toxic products into telomeres is remarkably encouraging at this point," said Dr. Wright.

Importantly, unlike many other telomerase-inhibiting compounds, the researchers did not observe serious side effects in the blood, liver and kidneys of the mice that were treated with 6-thiodG.

See the article here:
Researchers target the cell's 'biological clock' in promising new therapy to kill cancer cells

Recommendation and review posted by Bethany Smith

(CNN) -

In a mural from the year A.D. 79, a dog leads a blind man across a marketplace in Pompeii.

Dogs have lent their eyesight to people who need it, perhaps since the friendship between human and beast began. And now, mapping the genes of blind dogs could lead to treatments for the visually impaired.

By uncovering canine eye mutations, veterinary researchers are coming closer to understanding two of the most common diseases that cause blindness: glaucoma and retinitis pigmentosa.

It turns out that dogs' eyes are similar to humans', the veterinary researchers say, and what goes for theirs often goes for ours, too. So much so, that a U.S. foundation for research into blindness has funded some of their work.

A random phone call

Andras Komaromy's research journey began 10 years ago with a phone call from a breeder, who was watching dogs slowly go blind from a strange retinal disease.

"I drove more than 500 miles from Philadelphia to Michigan to examine the affected dogs," the research veterinarian said in a statement. He eventually moved there and researched the disease at Michigan State University.

The dogs were all of the same breed, Swedish Vallhunds. The hereditary disease appeared to be relatively new. Scandinavian veterinary eye examiners began seeing it in late 1990s.

The Swedish Vallhund is small, stocky and pointy-eared, with thick gray to red fur in a pattern resembling that of a German shepherd. Despite its compact size, it's tough and fearless, the American Kennel Club says -- a "big dog in a small body."

Read this article:
Research lending better understanding to common diseases

Recommendation and review posted by Bethany Smith

In a mural from the year A.D. 79, a dog leads a blind man across a marketplace in Pompeii.

Dogs have lent their eyesight to people who need it, perhaps since the friendship between human and beast began. And now, mapping the genes of blind dogs could lead to treatments for the visually impaired.

By uncovering canine eye mutations, veterinary researchers are coming closer to understanding two of the most common diseases that cause blindness: glaucoma and retinitis pigmentosa.

It turns out that dogs' eyes are similar to humans', the veterinary researchers say, and what goes for theirs often goes for ours, too. So much so, that a U.S. foundation for research into blindness has funded some of their work.

A random phone call

Andras Komaromy's research journey began 10 years ago with a phone call from a breeder, who was watching dogs slowly go blind from a strange retinal disease.

"I drove more than 500 miles from Philadelphia to Michigan to examine the affected dogs," the research veterinarian said in a statement. He eventually moved there and researched the disease at Michigan State University.

The dogs were all of the same breed, Swedish Vallhunds. The hereditary disease appeared to be relatively new. Scandinavian veterinary eye examiners began seeing it in late 1990s.

The Swedish Vallhund is small, stocky and pointy-eared, with thick gray to red fur in a pattern resembling that of a German shepherd. Despite its compact size, it's tough and fearless, the American Kennel Club says -- a "big dog in a small body."

It's an athletic herder and a friendly family dog. It impresses in show competitions -- dashing through "flyball" obstacle courses or walking through obedience drills.

Read this article:
Dog gene could lead to insight into blindness

Recommendation and review posted by Bethany Smith

TWO thirds of adult cancer cases were the result of genetic bad luck rather than unhealthy living, according to groundbreaking new research from the US.

Johns Hopkins University School of Medicine scientist Dr Bert Vogelstein said random mutations in DNA were the most common cause of cancer, with the rest caused by environment or inherited genes.

But he warned the finding should not be taken as a licence to drink or smoke to excess.

"This study shows that you can add to your risk of getting cancers by smoking or other poor lifestyle factors," Dr Vogelstein said.

"However, many forms of cancer are due largely to the bad luck of acquiring a mutation in a cancer driver gene regardless of lifestyle and heredity factors."

Researchers compared the number of times organ stem cells divided with the risk of cancer in the tissues.

Those with the most divisions were generally more prone to tumours.

They found 22 of 31 cancer types were caused by random cell mutations - really just genetic misfortune which scientists could not otherwise explain.

The remainder, including smoking-related lung cancer and skin cancer, were related to heredity and environmental factors like exposure to harmful chemicals.

"Cancer-free longevity in people exposed to cancer-causing agents, such as tobacco, is often attributed to their 'good genes', but the truth is that most of them simply had good luck," Dr Vogelstein said.

See original here:
Two thirds of cancer cases were genetic of bad luck: study

Recommendation and review posted by Bethany Smith

TrainingZone
VK.com : http://vk.com/id15662385 . : http://vk.com/wellnessfitness . : #TrainingZone #strength...

By: MrNim

Go here to see the original:
TrainingZone - Video

Recommendation and review posted by Bethany Smith

B3 14 Genetic Engineering and Gene Therapy Foundation Tier Summary
OCR Gateway Additional Science B3 Lesson 14 review on Genetic Engineering and Gene Therapy for the Foundation tier.

By: Westlands Science

Excerpt from:
B3 14 Genetic Engineering and Gene Therapy Foundation Tier Summary - Video

Recommendation and review posted by Bethany Smith

B3 14 Genetic Engineering and Gene Therapy Higher Tier Summary
OCR Gateway Additional Science B3 Lesson 14 review on Genetic Engineering and Gene Therapy for the Higher tier.

By: Westlands Science

Read the original here:
B3 14 Genetic Engineering and Gene Therapy Higher Tier Summary - Video

Recommendation and review posted by Bethany Smith

After surgery part eight quadriplegic artist stenosis C6 an
Robert Florio a quadriplegic artist. Started experiencing five years ago a lot of pain in the neck. Had my spinal cord injury when I was 14 I #39;m 32. Started experiencing loss of function in...

By: Rob Florio

See the article here:
After surgery part eight quadriplegic artist stenosis C6 an - Video

Recommendation and review posted by sam

Spinal Cord Injury myths
Spinal cord injury and myths : This video is from my experience as an spinal cord injury patient for 3 years. If you have any doubts regarding SCI and concerns regarding the content of the...

By: Spinal cord injury awareness

Read more here:
Spinal Cord Injury myths - Video

Recommendation and review posted by sam

WTOL: Regenerative Medicine - 12/24/14
Roger Kruse, MD, ProMedica Physicians, discuss regenerative medicine. Regenerative medicine uses stems cells and platelets to encourage your body #39;s natural healing processes to restore function...

By: ProMedica In The News

Visit link:
WTOL: Regenerative Medicine - 12/24/14 - Video

Recommendation and review posted by sam

Mayo Clinic #39;s Dr. Michael Yaszemski Speaking at #WSCS14
Dr. Michael J. Yaszemski, Mayo Clinic Center for Regenerative Medicine, speaking during the "US Military Investment in Regenerative Medicine" panel on December 3, 2014 at the 10th Annual World...

By: Mayo Clinic

Visit link:
Mayo Clinic's Dr. Michael Yaszemski Speaking at #WSCS14 - Video

Recommendation and review posted by sam

US Army #39;s LtCol Michael Davis Speaking at #WSCS14
Lt. Colonel, USAF Michael Davis, USAISR Deputy Commander and Chief of Reconstructive Surgery and Regenerative Medicine at the USAISR, speaking during the "US Military Investment in ...

By: Mayo Clinic

Go here to see the original:
US Army's LtCol Michael Davis Speaking at #WSCS14 - Video

Recommendation and review posted by sam

Mayo Clinic #39;s Abba Zubair Speaking at #WSCS14
Dr. Abba Zubair, Medical Director of the Transfusion Medicine and Stem Therapy Laboratory at Mayo Clinic in Florida speaking on his topic "Application of Microgravity Expanded Stem Cells in...

By: Mayo Clinic

More here:
Mayo Clinic's Abba Zubair Speaking at #WSCS14 - Video

Recommendation and review posted by sam

Mayo Clinic #39;s Dr. Timothy Nelson Discussing Regenerative Medicine Consult Service at #WSCS14
Mayo Clinic #39;s Dr. Timothy Nelson, Associate Professor of Medicine and Director of the Regenerative Medicine Consult Service discussing the regenerative medicine consult service, during the...

By: Mayo Clinic

More:
Mayo Clinic's Dr. Timothy Nelson Discussing Regenerative Medicine Consult Service at #WSCS14 - Video

Recommendation and review posted by sam

Released: 30-Dec-2014 1:50 PM EST Embargo expired: 1-Jan-2015 2:00 PM EST Source Newsroom: Johns Hopkins Medicine Contact Information

Available for logged-in reporters only

Newswise Scientists from the Johns Hopkins Kimmel Cancer Center have created a statistical model that measures the proportion of cancer incidence, across many tissue types, caused mainly by random mutations that occur when stem cells divide. By their measure, two-thirds of adult cancer incidence across tissues can be explained primarily by bad luck, when these random mutations occur in genes that can drive cancer growth, while the remaining third are due to environmental factors and inherited genes.

All cancers are caused by a combination of bad luck, the environment and heredity, and weve created a model that may help quantify how much of these three factors contribute to cancer development, says Bert Vogelstein, M.D., the Clayton Professor of Oncology at the Johns Hopkins University School of Medicine, co-director of the Ludwig Center at Johns Hopkins and an investigator at the Howard Hughes Medical Institute.

Cancer-free longevity in people exposed to cancer-causing agents, such as tobacco, is often attributed to their good genes, but the truth is that most of them simply had good luck, adds Vogelstein, who cautions that poor lifestyles can add to the bad luck factor in the development of cancer.

The implications of their model range from altering public perception about cancer risk factors to the funding of cancer research, they say. If two-thirds of cancer incidence across tissues is explained by random DNA mutations that occur when stem cells divide, then changing our lifestyle and habits will be a huge help in preventing certain cancers, but this may not be as effective for a variety of others, says biomathematician Cristian Tomasetti, Ph.D., an assistant professor of oncology at the Johns Hopkins University School of Medicine and Bloomberg School of Public Health. We should focus more resources on finding ways to detect such cancers at early, curable stages, he adds.

In a report on the statistical findings, published Jan. 2 in Science, Tomasetti and Vogelstein say they came to their conclusions by searching the scientific literature for information on the cumulative total number of divisions of stem cells among 31 tissue types during an average individuals lifetime. Stem cells self-renew, thus repopulating cells that die off in a specific organ.

It was well-known, Vogelstein notes, that cancer arises when tissue-specific stem cells make random mistakes, or mutations, when one chemical letter in DNA is incorrectly swapped for another during the replication process in cell division. The more these mutations accumulate, the higher the risk that cells will grow unchecked, a hallmark of cancer. The actual contribution of these random mistakes to cancer incidence, in comparison to the contribution of hereditary or environmental factors, was not previously known, says Vogelstein.

To sort out the role of such random mutations in cancer risk, the Johns Hopkins scientists charted the number of stem cell divisions in 31 tissues and compared these rates with the lifetime risks of cancer in the same tissues among Americans. From this so-called data scatterplot, Tomasetti and Vogelstein determined the correlation between the total number of stem cell divisions and cancer risk to be 0.804. Mathematically, the closer this value is to one, the more stem cell divisions and cancer risk are correlated.

Our study shows, in general, that a change in the number of stem cell divisions in a tissue type is highly correlated with a change in the incidence of cancer in that same tissue, says Vogelstein. One example, he says, is in colon tissue, which undergoes four times more stem cell divisions than small intestine tissue in humans. Likewise, colon cancer is much more prevalent than small intestinal cancer.

See the original post:
'Bad Luck' of Random Mutations Plays Predominant Role in Cancer, Study Shows

Recommendation and review posted by simmons

Chuck Bednar for redOrbit.com Your Universe Online

Two-thirds of all adult cancer cases are primarily the result of bad luck, according to the authors of a new study appearing in Fridays edition of the journal Science.

Dr. Bert Vogelstein, the Clayton Professor of Oncology at the Johns Hopkins University School of Medicine, and Dr. Cristian Tomasetti, an assistant professor of oncology at the Johns Hopkins University School of Medicine and Bloomberg School of Public Health, developed a statistical model that measured the proportion of cancer incidence across many different tissue types.

They found that two-thirds of adult cancer incidence across tissues occur when the random mutations that take place during stem cell division drive cancer through, while the remaining one-third of cases are the result of environmental factors and inherited genes.

All cancers are caused by a combination of bad luck, the environment and heredity, and weve created a model that may help quantify how much of these three factors contribute to cancer development, explained Dr. Vogelstein, who is also co-director of the Ludwig Center at Johns Hopkins and an investigator at the Howard Hughes Medical Institute.

Cancer-free longevity in people exposed to cancer-causing agents, such as tobacco, is often attributed to their good genes, but the truth is that most of them simply had good luck, he said, adding that that poor lifestyle choices can also contribute to this so-called bad luck factor.

The authors said that the implications of their model could alter the public perception about cancer risk factors, as well as impact the funding of research related to the disease.

If most cancer cases can be explained by random DNA mutations that occur as stem cells divide, explained Dr. Tomasetti, it means that lifestyle changes will be a tremendous help when it comes to preventing some forms of the disease, but will be less effective against other types.

As a result, the medical community should should focus more resources on finding ways to detect such cancers at early, curable stages, he added. He and Vogelstein said that they reached their conclusion by searching scientific literature for data on the cumulative number of total stem cell divisions among 31 tissue types that take place during a persons lifetime.

Stem cells renew themselves, repopulating cells that die off in specific organs, the researchers said. Cancer arises when tissue-specific stem cells experience mutations in which one chemical letter in DNA is erroneously swapped for another during the replication process.

Visit link:
Two-thirds of cancer cases are "bad luck," study says

Recommendation and review posted by simmons