A study of tadpoles suggests that destructive molecules linked to ageing and cancer could play an important role in healing.
Scientists investigating how tadpoles regrow severed tails found an unexpected link to oxygen molecules normally considered highly harmful to health.
Without the molecules, known as reactive oxygen species (ROS), the tails would not regenerate.
Reactive oxygen molecules damage DNA and cell membranes and are associated with heart disease, cancer, and ageing.
Millions of people take antioxidant supplements to combat their effects. Health advice also encourages people to increase their consumption of antioxidant-rich fruits and vegetables.
But the new research suggests that ROS may have a previously unknown beneficial role in the healing process.
A number of animals, especially amphibians such as frogs and salamanders, have regenerative powers not shared by mammals.
If a tadpole loses its tail, it will grow a new one within a week.
Scientists know that regeneration of body parts involves a genetic pathway called Wnt, but many aspects of it remain a mystery.
Unravelling the secrets of tadpole regeneration could on one day lead to new healing treatments.
Researchers at the University of Manchester found that several metabolic genes were activated during tail regeneration in tadpoles. They included those involved in the production of ROS, in particular the powerfully destructive molecule hydrogen peroxide.
A marked increase in hydrogen peroxide levels occurred after tadpole tails were docked which remained throughout the regeneration process.
Lead scientist Professor Enrique Amaya, whose findings appear in the journal Nature Cell Biology, said: "When we decreased ROS levels, tissue growth and regeneration failed to occur.
"Our research suggests that ROS are essential to initiate and sustain the regeneration response. We also found that ROS production is essential to activate Wnt signalling, which has been implicated in essentially every studied regeneration system, including those found in humans. It was also striking that our study showed that antioxidants had such a negative impact on tissue regrowth, as we are often told that antioxidants should be beneficial to health."
Results of a massive gene analysis, published last month in the journal Nature, shows that there are four major classes of breast cancer, the Associated Press reported. "With this study, we're one giant step closer to understanding the genetic origins of the four major subtypes of breast cancer," study researcher Matthew Ellis, M.B., B.Chir., Ph.D., of the Washington University School of Medicine and the Siteman Cancer Center, said in a statement. "Now, we can investigate which drugs work best for patients based on the genetic profiles of their tumors," he added in the statement. "For basal-like breast tumors, it's clear they are genetically more similar to ovarian tumors than to other breast cancers. Whether they can be treated the same way is an intriguing possibility that needs to be explored."
Men are less likely to get breast cancer than women -- but when they do, it's often deadlier, according to a study presented earlier this year at the American Society of Breast Surgeons meeting. The Associated Press reported that men diagnosed with breast cancer live, on average, two fewer years than women who are diagnosed with breast cancer, and are also more likely to have the breast cancer spread, have larger tumors when the cancer is discovered, and be diagnosed later.
Cadmium -- a toxic metal that can be present in foods like shellfish, root vegetables, offal and cereals -- may raise risk of breast cancer, according to a March 2012 study in the journal Cancer Research. The research included 56,000 women. Researchers were able to analyze about how much cadmium each woman was consuming based on the cadmium-rich foods in her diet. They found that those who consumed the most cadmium had a 21 percent higher breast cancer risk, compared with those who consumed the least cadmium, HuffPost's Catherine Pearson reported.
Getting six or fewer hours of sleep may raise the risk of recurrent breast cancer among post-menopausal breast cancer patients, according to a study in the journal Breast Cancer Research and Treatment. However, this same link was not observed for pre-menopausal breast cancer patients. The findings suggest "that lack of sufficient sleep may cause more aggressive tumors, but more research will need to be done to verify this finding and understand the causes of this association," study researcher Cheryl Thompson, Ph.D. said in the statement.
A smallpox virus seems to be promising against a hard-to-treat form of breast cancer, called triple-negative breast cancer, according to a study in mice presented at the 2012 Annual Clinical Congress of the American College of Surgeons. "Based upon pathology, we could see that at least 60 percent of the tumors were completely regressed and the other 40 percent had very little areas of tumor cells present with a lot of necrosis, which is a sign that the tumor was responding to therapy," study researcher Dr. Sepideh Gholami, M.D., of Stanford University Medical Center, said in a statement. ABC News pointed out that this kind of breast cancer is notoriously hard to treat because it doesn't respond to other hormonal or immune treatments.
Working the night shift is linked to an increased risk of breast cancer, according to two different studies that came out this year. One of them, published in the journal Occupational and Environmental Medicine, showed that breast cancer risk went up among women who worked the night shift more than twice a week, with the risk being the highest among those who said that they are "morning people" instead of "night people." The Toronto Sun reported that the results of this study confirm the findings of the International Agency for Research on Cancer, which has a list of items and habits that may cause cancer. The IARC considers shift work "possibly carcinogenic." The other study, published in the International Journal of Cancer, showed that breast cancer risk is 30 percent higher for women who work the night shift, with the risk being especially clear among those working night-time jobs for four years, or those who worked the night shift for three or fewer nights a week.
The genes that help determine a woman's breast size may also be linked with her breast cancer risk, according to a study published earlier this year in the journal BMC Medical Genetics. Researchers examined the genetic data of 16,000 women to find that seven DNA variations, called single nucleotide polymorphisms (SNPs), seem to be linked with breast size -- and three of those SNPs are known to be associated with a person's risk of breast cancer, HuffPost's Catherine Pearson reported.
Just a little bit of exercise may help to reduce your risk of breast cancer, though the more you move, the better, according to a study in the journal CANCER. Researchers at the University of North Carolina in Chapel Hill found that postmenopausal or reproductive-age women in their study who exercised the most -- from 10 to 19 hours each week -- had a 30 percent lower risk of breast cancer, though exercising less than that was still linked with some protective benefits. "The observation of a reduced risk of breast cancer for women who engaged in exercise after menopause is particularly encouraging given the late age of onset for breast cancer," study researcher Lauren McCullough said in a statement.
For post-menopausal women, having Type 2 diabetes may raise the risk of breast cancer, according to a review conducted by the International Prevention Research Institute. "On the one hand, it's thought that being overweight, often associated with Type 2 diabetes, and the effect this has on hormone activity may be partly responsible for the processes that lead to cancer growth," study researcher Peter Boyle, the president of the International Prevention Research Institute, told The Telegraph. "But it's also impossible to rule out that some factors related to diabetes may be involved in the process."
Being overweight could lead to worse outcomes from breast cancer, according to a study published August in the journal Cancer. Specifically, the study showed that overweight women who have been treated for breast cancer have a higher risk of recurrence and death, NBC News reported. "Obesity seemed to carry a higher risk of breast cancer recurrence and death -- even in women who were healthy at the time that they were diagnosed, and despite the fact that they received the best available chemotherapy and hormone therapy," study researcher Dr. Joseph Sparano, associate chairman of medical oncology at the Montefiore Einstein Center for Cancer Care, told NBC News.
Marisa Weiss, MD, of breast cancer.org, explains the different breast cancer stages and what they mean.
The study follows controversial claims by Dr James Watson, co-discoverer of the structure of DNA, that antioxidants may be harmful to people with late-stage cancer.
Writing in the journal Open Biology, he said reactive oxygen species help clear dysfunctional and dangerous cells from the body. Antioxidants may hinder cancer recovery by blocking their effect, he argued.
Professor Amaya added: "It's very interesting that two papers suggesting that antioxidants may not always be beneficial have been published recently.
"Our findings and those of others are leading to a reversal in our thinking about the relative beneficial versus harmful effects that oxidants and antioxidants may have on human health, and indeed that oxidants, such as ROS, may play some important beneficial roles in healing and regeneration."
The team at the University of Manchester's Healing Foundation Centre now plans to study the role of ROS in healing and regeneration more closely.
Manipulating reactive oxygen species may improve the body's ability to heal and regenerate itself, the scientists believe.