Aspirin's Anti-Colon Cancer Effect May Depend on Genes

Tumors with a key mutation seemed unaffected by daily use of the drug, study found

By Robert Preidt

HealthDay Reporter

TUESDAY, June 25 (HealthDay News) -- Numerous studies have found that daily low-dose aspirin might help shield against colon cancer. But new research suggests that gene mutations found in different colon tumors may influence that relationship.

This study of data from more than 127,000 people in the Nurses' Health Study and the Health Professionals Follow-Up Study in the United States found that the benefits of aspirin used were affected by mutation of a gene called BRAF.

Specifically, regular aspirin use was associated with a lower risk of colorectal cancers characterized by the "typical" form of BRAF, but not with the risk of colon cancers with mutated forms of BRAF.

These findings suggest that BRAF-mutant colon tumor cells may be less sensitive to the effects of aspirin, according to the study in the June 26 issue of the Journal of the American Medical Association.

The researchers also found that taking a higher number of aspirin tablets a week -- more than 14 tablets -- was associated with a lower risk of colorectal cancer with typical BRAF, but this was not seen with BRAF-mutated cancers, according to a journal news release.

The research was led by Reiko Nishihara of the Dana-Farber Cancer Institute in Boston.

Importantly, regular aspirin use after a diagnosis of either type of colorectal cancer did not improve patients' survival, the team said.

"This suggests that the potential protective effect of aspirin may differ by BRAF status in the early phase of tumor evolution before clinical detection but not during later phases of tumor progression," the study authors wrote.

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Supreme Court Rules That Human Genes Can't Be Patented

Decision should have profound impact on medicine, gene-testing industry

By EJ Mundell

HealthDay Reporter

THURSDAY, June 13 (HealthDay News) -- In a decision that could have far-reaching implications for medicine, the U.S. Supreme Court on Thursday ruled that human genes cannot be patented.

The ruling could be a blow to drug companies such as Myriad Genetics, whose effort to patent an isolated form of a gene that might foretell cancer risk was at the center of the case. The high court decided that, unlike drugs or medical devices, human genes are not "created" by companies and therefore cannot be patented, USA Today reported.

"Myriad did not create anything," Justice Clarence Thomas wrote in the unanimous decision. "To be sure, it found an important and useful gene, but separating that gene from its surrounding genetic material is not an act of invention."

Still, the justices did say that Myriad or companies like it might be able to patent forms of DNA that were not simply extracted from genes taken from the human body.

According to USA Today, the judges' nine-to-zero decision was in line with past decisions that have ruled that forces of nature are not patent-eligible, while products of human invention are.

The decision may have a profound impact on the bottom line of companies that sell genetic tests. According to USA Today, more than 40,000 patents linked to genetic material have been issued by the U.S. Patent and Trademark Office since 1984. Myriad's gene tests for breast and ovarian cancer risk have been used by almost 1 million women since the late 1990s.

But the newspaper noted that these tests aren't cheap: it costs $3,340 for the breast cancer gene analysis, for example.

As is usual in cases over patents, Myriad and industry representatives have long argued that losing patent protection would lead to less investment in research and development.

On the other side, doctors and patient advocacy groups say loss of patent protection for gene-based products would free up competition, drive prices down and lead to more research and development, not less.

In a statement released earlier this week, the National Society of Genetic Counselors, argued against the patenting of genes.

"Exclusive licenses on patents create barriers that could stifle the development of innovative tests by restricting the access of researchers to gene sequences," the group said, "or requiring researchers to pay exorbitant licensure costs that will ultimately be passed on to the consumer."

An advocacy group for patients with ovarian cancer agreed.

"Many women we work with are concerned about their genetic risk of developing ovarian cancer, especially in the wake of Angelina's Jolie's announcement that she carries the BRCA1 mutation," Calaneet Balas, CEO of the Ovarian Cancer National Alliance, said in a statement. "Myriad's patent limited women's options for learning about their genetic risk."

The Supreme Court agreed that a gene is a preexisting entity that is not subject to patent.

"In isolation, it has no value, it's just nature sitting there," Justice Sonia Sotamayor said, USA Today reported.

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Weight-Loss Surgery May Affect Fat-Related Genes

Swedish researchers found better body-fat control in people who had procedure

By Robert Preidt

HealthDay Reporter

THURSDAY, April 11 (HealthDay News) -- Weight-loss surgery changes the levels of genes involved in burning and storing fat, a new study says.

The findings may help lead to the development of new drugs that mimic this weight-loss-associated control of gene regulation, said the authors of the study published online April 11 in the journal Cell Reports.

"We provide evidence that in severely obese people, the levels of specific genes that control how fat is burned and stored in the body are changed to reflect poor metabolic health," senior author Juleen Zierath, a professor with the Karolinska Institute in Sweden, said in a journal news release.

"After [weight-loss] surgery, the levels of these genes are restored to a healthy state, which mirrors weight loss and coincides with overall improvement in metabolism," Zierath explained.

Weight-loss surgery -- also called bariatric surgery -- can help obese people lose large amounts of weight in a short time. The surgery also leads to early remission of type 2 diabetes in many patients.

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Weight-Loss Surgery May Affect Fat-Related Genes

THURSDAY, April 11 (HealthDay News) -- Weight-loss surgery changes the levels of genes involved in burning and storing fat, a new study says.

The findings may help lead to the development of new drugs that mimic this weight-loss-associated control of gene regulation, said the authors of the study published online April 11 in the journal Cell Reports.

"We provide evidence that in severely obese people, the levels of specific genes that control how fat is burned and stored in the body are changed to reflect poor metabolic health," senior author Juleen Zierath, a professor with the Karolinska Institute in Sweden, said in a journal news release.

"After [weight-loss] surgery, the levels of these genes are restored to a healthy state, which mirrors weight loss and coincides with overall improvement in metabolism," Zierath explained.

Weight-loss surgery -- also called bariatric surgery -- can help obese people lose large amounts of weight in a short time. The surgery also leads to early remission of type 2 diabetes in many patients.

-- Robert Preidt
Copyright © 2013 HealthDay. All rights reserved. SOURCE: Cell Reports, news release, April 11, 2013

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Genes and Early Wheezing Tied to Childhood Asthma Risk

Common cold symptom increased odds for asthma in study

By Robert Preidt

HealthDay Reporter

WEDNESDAY, March 27 (HealthDay News) -- Certain genetic factors and wheezing early in life are associated with a greatly increased risk of asthma in children, a new study says.

Researchers examined data from nearly 500 children and found that about 90 percent of those who had two copies of a common genetic variation and who also experienced wheezing when they had a cold early in life developed asthma by age 6.

These children, all from families with a history of asthma or allergies, were nearly four times more likely to develop asthma than those who did not have the genetic variation and did not wheeze, according the study in the March 28 issue of the New England Journal of Medicine.

The genetic variation is found on chromosome 17 and is common. Half of the children in the study had one copy and 25 percent had two copies. The researchers also noted that colds are extremely common and affect nearly all infants.

The increased risk is associated with wheezing during colds caused by a human rhinovirus infection, the University of Chicago Medical Center researchers said.

"We found that the interaction between this specific wheezing illness and a gene or genes on a region of chromosome 17 determines childhood asthma risk," study author Carole Ober, a professor of human genetics at the University of Chicago, said in a medical center news release. "The combination of genetic predisposition and the child's response to this infection has a huge effect."

The researchers said it is not clear how this gene variation and wheezing interact to increase the risk of developing asthma. It also should be noted that the research showed only an association between them, and not a cause-and-effect relationship.

About 25 percent of children who had no wheezing from a human rhinovirus infection developed asthma, and 40 percent of those who experienced wheezing in the first three years of life but lacked the risk-related gene variants developed asthma.

That rose to nearly 60 percent among those with one copy of the gene variant and to 90 percent for those with two copies.

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Picky Eating in Youngsters Might Be Largely Caused by Genes

Title: Picky Eating in Youngsters Might Be Largely Caused by Genes
Category: Health News
Created: 3/22/2013 12:36:00 PM
Last Editorial Review: 3/25/2013 12:00:00 AM

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Tots' Sleep Differences Due to Genes, Environment, Study Suggests

But parents should still try to correct bad sleep habits, expert says

By Amy Norton

HealthDay Reporter

MONDAY, May 27 (HealthDay News) -- A new study of twins suggests that genes may play a big role in how long babies and toddlers sleep at night, while environment is key during nap time.

Researchers found that among nearly 1,000 twins they followed to age 4, genes seemed to explain much of the difference among youngsters' nighttime sleep habits. In contrast, napping seemed mainly dependent on the environmental setting -- especially for toddlers and preschoolers.

So does this mean the amount of sleep your little one gets at night is out of your control?

No, said the lead researcher on the study, which was published online May 27 in the journal Pediatrics.

"[Parents] should not give up on trying to correct inadequate sleep duration or bad sleep habits early in childhood," said Evelyne Touchette, of Laval University in Quebec, Canada.

For one, the study found that environment did matter in babies' and toddlers' nighttime sleep -- and even seemed to overshadow genes by the age of 18 months.

The reasons for the findings are unclear, Touchette said. But she said it makes sense that environment would matter more at the age of 18 months versus 6 months, when the maturation of the brain may be key in infants' ability to sleep for longer stretches at night.

There's no clear explanation, though, for why genetic influences became stronger again after the age of 18 months, Touchette said.

A sleep researcher not involved in the study said it's not really possible to break down children's sleep into "nature or nurture" questions.

"Everything is a complex interaction between genes and environment," said Hawley Montgomery-Downs, an associate professor of psychology at West Virginia University in Morgantown.

It's not possible, she said, to parse out what proportion of young children's sleep duration is due to genes, and what proportion is environment.

For the study, Touchette's team followed nearly 1,000 Canadian twins whose mothers reported on their sleep habits from the ages of 6 months through 4 years. About 400 children were identical twins, which means both twins share all of the same genes; the rest were fraternal twins, who are no more genetically similar than non-twin siblings.

In general, such studies can help researchers sort out the influences of genes versus "shared environment," which could include anything from a mom's diet during pregnancy to family income.

When it came to hours slept at night, genes seemed to explain more than half of the variance among children at the ages of 30 months and 4 years. Genes were nearly as important at the age of 6 months.

The exception was the age of 18 months, when environment seemed to account for about half of the variance among the children.

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Genes May Boost Woman's Risk of Postpartum Depression

Test found specific changes to two genes predicted problem with 85 percent accuracy

By Amy Norton

HealthDay Reporter

TUESDAY, May 21 (HealthDay News) -- Pregnant women with specific alterations in two genes may be at increased risk of suffering depression after giving birth, a small new study suggests.

The researchers hope they can use the findings to develop a blood test that could help spot pregnant women who are vulnerable to postpartum depression, which affects around 15 percent of new mothers.

Their study, reported in the May 21 issue of the journal Molecular Psychiatry, uncovered specific chemical changes in two genes that predicted which women would develop postpartum depression with 85 percent accuracy.

Little is known about the genes, called TTC9B and HP1BP3, but they are somehow involved in activity in the brain's hippocampus, which regulates mood. Based on animal research, both genes seem to be "reactive to estrogen," said Zachary Kaminsky, a researcher at Johns Hopkins University School of Medicine in Baltimore who worked on the study.

The findings offer clues as to what makes some women susceptible to postpartum depression. But there is still a lot of work to be done before a screening test becomes available, according to an expert not involved in the research.

"This is a first step, but I think we're pretty far off from having a blood test," said Dr. Kimberly Yonkers, a professor of psychiatry and obstetrics and gynecology at Yale School of Medicine in New Haven, Conn.

She said the study was small -- involving only 51 women, about a dozen of whom developed depression within a month of giving birth -- so the results need to be validated in larger studies.

But beyond that, Yonkers said, there's the larger, "dicey" issue of how much benefit there would be from telling pregnant women their genes put them at heightened risk of postpartum depression.

"You may unnecessarily worry some women," Yonkers said.

"Information is power," Kaminsky said, and for some women, knowing they are at risk of postpartum depression can offer a chance to minimize that risk: Their partner, family or friends could be especially attentive and step in to ease some of the stress of being a new mom, for example.

Kaminsky acknowledged that if a blood test result actually caused distress for an expectant mom, it would not be good. But, he said, having a blood test as an option for women who want an idea of their risk could be valuable.

Kaminsky and two of his co-researchers have filed for a patent on testing for the genetic markers.

The findings are based on 51 pregnant women with a history of depression or bipolar disorder, which raises the risk of suffering depression during or after pregnancy. One group of 19 women had major depression during their pregnancies, and 12 continued to have symptoms in the first month after giving birth.

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Genes vs. Lifestyle: What Matters Most for Health?

Does an illness like heart disease or cancer run in your family? Don't assume that your genes control your destiny. Experts say the lifestyle choices you make every day can help keep you healthy.

There's no doubt that some genes do lead inevitably to disease. "But for most people, a healthy lifestyle trumps inherited risk," says cardiologist Donald Lloyd-Jones, MD. He is chair of preventive medicine at Northwestern University Feinberg School of Medicine. "Even if a disease runs in your family, there's a lot you can do to avoid it."

Here's a look at how lifestyle changes can cut your risk of disease.

About 25% of colon cancers are in people with some family history of the disease. In the rest of people who get colon cancer, genetics doesn't seem to play a role.

But lifestyle may be a factor. Studies show that most people can dramatically lower their colon cancer risk by taking these steps:

Eat very little red or processed meat.Exercise.Keep a healthy weight.Drink alcohol in moderation or not at all.

Other cancers are even more influenced by the choices we make. A good example is lung cancer.

80% to 90% of lung cancers are caused by smoking.Men who smoke are 23 times more likely to develop lung cancer than nonsmokers.Women who smoke are 13 times more likely to get lung cancer.

The longer you smoke and the more cigarettes you smoke, the greater your risk.

Still, genes do play some role. Some people who get lung cancer never smoked. Other people smoke and don't get lung cancer. But the biggest risk factor by far is smoking.

With heart disease, more than 100 types of genes may play a small role in a person's risk, Lloyd-Jones says. "But by far the biggest factor is lifestyle."

Lloyd-Jones and colleagues analyzed data from the Framingham Heart Study. The study followed three generations of families. The researchers found that:

Family history made up only 17% of a person's heart disease risk.Poor lifestyle choices, such as lack of exercise, made up a whopping 83% of the risk.

A heart-healthy lifestyle can lower your risk of heart disease.

For example, one type of gene strongly linked to heart disease is called 9p21. On average, it raises your risk of having a heart attack by about 20%.

But if people who carry this gene eat a diet with lots of fruits and vegetables, research shows, they cut their risk back down to normal. People with that type of gene who eat a poor diet, on the other hand, have two times the normal risk of having a heart attack.

Type 2 diabetes is influenced by a combination of genes and lifestyle. Between 30% and 70% of the risk of developing type 2 diabetes is shaped by inherited genes.

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Shared Genes May Link ADHD, Autism and Depression

By Steven Reinberg

HealthDay Reporter

WEDNESDAY, Feb. 27 (HealthDay News) -- Autism, attention-deficit/hyperactivity disorder (ADHD), major depression, bipolar disorder and schizophrenia may all share common genetic risk factors, a new study says.

In this largest study of its kind, researchers spotted gene variations governing brain function that may raise the risk for these often devastating mental woes. In the future, these gene variants might become key targets for prevention or treatment, the scientists said.

"This study, for the first time, shows that there are specific genetic variants that influence a range of childhood and adult-onset psychiatric disorders that we think of as clinically different," said lead researcher Dr. Jordan Smoller, a professor of psychiatry at Harvard Medical School in Boston.

"We also found that there was significant overlap in the genetic components of several disorders, especially schizophrenia with bipolar disorder and depression, and to a lesser extent autism with schizophrenia and bipolar disorder," he said.

The researchers don't yet understand exactly how these variants are involved in the disorders, he noted. "This is the first clue that specific genes and pathways may cause a broader susceptibility to a number of disorders. Now the important work will be to figure out how this actually happens," said Smoller, who is also associate vice chair of the department of psychiatry at Massachusetts General Hospital.

Dr. Alessandro Serretti, from the Psychiatry Institute at the University of Bologna in Italy, wrote an accompanying journal editorial on the study. He believes that "we are now able to understand what are the pathways to [these] psychiatric disorders."

There are potential clinical applications, both in the classification of disorders, predicting who's most at risk, and perhaps new and better drug therapies, Serretti said. However, there's no immediate clinical application for these findings, he added.

The report was published Feb. 28 in the online edition of The Lancet.

To look for common genetic markers, called nucleotide polymorphisms, that might be risk factors for the five disorders, the Psychiatric Genomics Consortium scanned the genes of more than 33,000 people suffering from these disorders and nearly 28,000 people without such issues. This is the largest study of the genetics of psychiatric illness yet conducted, the researchers said.

Smoller's group found four gene areas that all overlapped with the five disorders, two of which regulate calcium balance in the brain.

These overlapping gene variants appear to increase the risk for bipolar disorder, major depressive disorder and schizophrenia in adults, the researchers said.

Further analysis found that genes governing calcium channel activity in the brain might also be important in the development of all five disorders, autism and ADHD included.

Smoller noted these genetic risk factors may only account for a very small part of the risk driving these disorders, and just how big a share they account for isn't yet known.

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Lack of Sleep Disrupts Genes

By Peter Russell
WebMD Health News

March 1, 2013 -- Sleeping fewer than six hours for several nights in a row affects hundreds of genes responsible for keeping us in good health, says a new study.

Research led by the U.K.'s Surrey Sleep Research Centre found that people who were subjected to sleep deprivation for a week underwent changes at a molecular level that could affect their well-being.

Sleep disorders are common in industrialized countries, with about 10% to 20% of the U.S. and European population reporting they often don’t get a good night’s sleep. Lack of sleep and disrupting the sleep-wake cycle are known to have a damaging effect on health, but the reasons behind this remain largely unexplored.

The small study involved 14 healthy men and 12 healthy women who were allowed to sleep under laboratory conditions for 5.7 hours one week and 8.5 hours another week.

After each seven-day period, researchers collected and looked at blood samples that included RNA, or ribonucleic acid, from each person. The major type of RNA is called messenger RNA, and this plays a vital role in making proteins. These samples allowed the researchers to examine what happens to the RNA in the blood, brain, and liver.

Professor Derk-Jan Dijk and his colleagues found that volunteers who got less than six hours of sleep each night over the course of a week had changes to 711 RNA genes linked to inflammation, the ability to fight disease, and stress. These changes might have an impact on obesity, diabetes, heart disease, and brain function.

The findings appear in the journal PNAS.

Professor Jim Horne from the Sleep Research Centre at Loughborough University says people shouldn’t be alarmed by the study results. 

"The potential perils of 'sleep debt' in today’s society and the need for 'eight hours of sleep a night’ are overplayed and can cause undue concern," Horne says. "Although this important study seems to support this concern, the participants had their sleep suddenly restricted to an unusually low level, which must have been somewhat stressful." 

"We must be careful not to generalize such findings to, say, habitual six-hour sleepers who are happy with their sleep,” he says.  “Besides, sleep can adapt to some change, and should also be judged on its quality, not simply on its total amount."

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