Korean scientists find key to producing cancer-killing cells
SEOUL
A team of South Korean scientists said they have found a way to produce the human body's own cancer-killing cells through gene therapy, offering new hope to cancer sufferers. The team said they had found that a gene called vitamin D3 upregulated protein 1 (VDUP1) plays a crucial role in directing stem cells to diversify into immune cells known as natural killer cells.
"Stem cells can develop into various cells and organs in the body," said the leader of the team, Inpyo Choi of the state-financed Korea Research Institute of Bioscience and Biotechnology in the central city of Daejeon. "We have found that when hematopoietic stem cells diversify into NK cells, VDUP1 plays a decisive role."
He said they have also developed the technology needed to induce stem cells obtained from a patient's bone marrow to diversify into immune cells and activate them. "This is the first step toward developing new treatments using our own immune system to fight cancers and other serious diseases," he said.
The results of the study--which come as scientists look for ways to supplement existing cancer treatments--were published in February in the journal Immunity.
The team investigated the role of the VDUP1 gene by breeding mice lacking the gene. These mice showed minimal changes in the development of other immune cells but there was a "profound reduction" in the numbers of natural killer cells and decreases in the activity of the cells, the researchers found.
In the VDUP1-deprived mice the expression of a protein called CD122--a precursor for NK cells--was reduced, showing that the gene was required for CD122 expression and the maturation of natural killer cells. "These results suggest that VDUP1 is a critical factor for the development and function of NK cells in vivo," the team said.
Yoon Suk-Ran, a member of the team, said they had extracted stem cells from mice and developed them into NK cells. They injected these cells into mice with skin cancers and confirmed the tumors were contained or killed.
"By developing this method, we may extract stem cells from a patient's bone marrow, culture NK cells, and inject them back into the patient's body to treat cancers," he said.
Diabetics twice as likely to develop liver cancer
PARIS
Older people with diabetes are between two and three times likelier to develop liver cancer than nondiabetics, says a study published in Gut, published by the British Medical Association.
Doctors led by Hashem El-Serag of the Houston Veteran Affairs Medical Center in Texas looked through a database of medical records of people aged over 65 compiled by the United States Medicare. Of 2,061 patients with liver cancer, 43 percent had diabetes. In a comparative group of 6,183 people whose health problems did not include liver cancer, the proportion of diabetics was only 19 percent.
The World Health Organization said around 3.2 million people die of diabetes each year. At least 171 million people have the disease, and the tally is likely to double by 2030.
Thalidomide: A second chance for a cursed drug?
PARIS
Thalidomide, involved in one of the pharmaceutical industry's most nightmarish episodes, may have a second life ahead of it as a drug to help cancer victims, researchers cautiously suggest. In a carefully monitored experiment, British doctors explored theories that thalidomide could combat cachexia, which occurs in around 50 percent of all patients with advanced cancer and is directly to blame for around one cancer death in five.
The British team recruited 50 patients with advanced pancreatic cancer and who were suffering from cachexia. Half of the vo-lunteers received thalidomide and the other a placebo. After two months, the thalidomide group was found to be stable, having lost only six grams in weight on average. Some in fact gained weight and felt better for it. Those who took placebo lost 3.63 kilos on average.
Thalidomide was "well tolerated and effective" in this particular case, the doctors said, adding that further research would show whether the benefits could apply to other kinds of cancer. In any case, it could never be used for pregnant women.
The study, which appears in Gut, was led by John Gordon of Southampton University Hospital School of Medicine in southern England.
Thalidomide was hauled off the shelves around the world in the early 1960s after it caused malformations among babies whose mothers had taken it as a morning-sickness drug during pregnancy.
30-minute cancer detector
TOKYO
A Japanese firm has developed a plastic chip half the size of a business card, which it said could detect a number of diseases, including cancer, within 30 minutes.
Conventional diagnostic chips are made of glass and can be used only after the blood samples are refined with separate equipment. But the chip by Toray Industries Inc., Japan's biggest maker of synthetic fibers, is made of synthetic resin and can find certain types of proteins in the blood.
"An early detection is very crucial in curing serious diseases such as cancer. We want to help people detect diseases at an early stage," Masashi Higasa, Toray's senior research associate, said. He explained how it works: "On the surface of the chip, there is a chemical-soaked 'corridor' where blood goes through for refinement. At the end of the corridor, only essential proteins in the blood remain for a diagnosis. The whole process takes about 30 minutes. It is the fastest medical diagnostic chip."
The company plans to market the chip in Japan within two years.
Benefits of experimental treatments
WASHINGTON
People with advanced cancer would benefit from submitting to experimental treatment since it has yielded better than expected results, according to a study published in March in the New England Journal of Medicine.
The US National Institutes of Health (NIH)
studied 11,935 cancer patients between 1991 and 2002 who did not respond to
traditional cancer treatment, finding that 11 percent of those who submitted
to experimental treatment saw significant improvement in their condition, with 34 percent showing some improvement. Other similar studies only showed positive results with four to six percent of patients who underwent experimental treatments.
The NIH analyzed 460 clinical tests conducted on 11,935 patients, but excluded those with children carried out by other pharmaceutical laboratories. Of the patients who took part in the NIH trials, three percent saw complete remission of their tumors, eight percent experienced a significant remission, while 34 percent showed some remission of their tumor. The death rate from the experimental cancer treatments was 0.5 percent, comparable to other anticancer treatments. Fourteen percent of the patients in the NIH tests developed secondary effects, at least one of which was serious.
Tests involving a single treatment with chemotherapy had a five-percent success rate, similar to earlier tests. A combination of drugs already approved by the US Food and Drug Administration together with experimental treatment yielded the best results.
Cancer linked to adult stem cells
PARIS
Excited talk about the use of stem cells to cure crippling diseases has been dampened by the discovery that ageing lab-dish cells pose a potential cancer threat. The concern focuses on adult stem cells, viewed as an uncontroversial alternative to stem cells from early embryos--the most versatile source of all.
Two new studies suggest that if adult stem cells replicate too many times in a lab dish, they risk becoming tumorous, said New Scientist in its report of the study. Cells that divided between 90 and 140 times in a lab formed cancers when they were transplanted into test animals, according research by a team at the Autonomous University of Madrid, Spain.
University Hospital of Odense doctors in Denmark suspect that after a certain number of divisions, genes get switched on in the cell that start making an enzyme called telomerase, and this eventually turns them cancerous. Further research is needed to determine what is a safe number of divisions before the ageing stem cell poses this risk.
Adult bone-marrow stem cells are currently being used in experimental treatment to repair damaged hearts. However, they should be safe because the cells are only briefly grown outside the body before being inserted back into human tissue, according to New Scientist.
Until now, only embryonic cells were believed to pose a cancer risk. At their very earliest stage, they can form aggressive cancers called teratomas if injected into a laboratory animal.
Stem cells are immature cells that are like blank slates. In this early state, they have yet to differentiate into the specific cells that make up the body's tissues. The goal among scientists is to harvest these cells and coax them into growing into fresh, replacement tissue that can then be transplanted into the body to reverse brain, nerve, muscle, and organ damage.
The most versatile stem cells come from embryos in their early stage, for they can differentiate into any part of the body. But embryonic cells have also ignited fierce objections from conservative religious groups who say that a cluster of embryonic cells has the same value as the life of a grown human being. As a result, many countries, including the United States, have imposed restrictions on the use and sources of embryonic stem cells and research funding.
Scientists are looking at potential stem cells from adult tissue, such as blood, bone marrow, and the liver, in order to skirt the problem.
Gene makes difference in hereditary colorectal cancer
WASHINGTON
Deficiencies in a gene allowing to avoid DNA reproductive problems considerably increases the risk of cancer in families that have a hereditary predisposition for colorectal cancer, according to a study in the Journal of the American Medical Association.
About 60 percent of families susceptible to this type of cancer known as HNPCC and Amsterdam-1 (AC-1) also have a defective repair gene called MMR. This combination often results in more frequent occurrences not only of this type of cancer but also of the cancer affecting small intestines, kidneys, ovaries, breasts, lungs, and other vital organs, said the study.
For families susceptible to AC-1 and also having a defective MMR gene, the prevalence of colorectal cancer is weak. Nor are they facing higher risks of other forms of cancer, according to the study conducted by Dr. Noralane Lindor of the Mayo Clinic in Rochester, Minnesota.
The discovery will help improve prognostication of cancer for families with hereditary predisposition for Lynch syndrome, which represents three percent of all cases of colorectal cancer, researchers explained. Hereditary colon cancer without polyps or HNPCC also increases the risk of stomach, kidney, small-intestine, and other types of cancer, they said.
Lung-cancer cases double in 30 years
LONDON
Worldwide cases of lung cancer have doubled in the past 30 years. Cancer Research UK said 1.4 million cases were diagnosed in 2002, compared with 600,000 in 1975. The number of all cases of cancer was also on the rise as the global population ages, with 10.9 million cases diagnosed and 6.7 million deaths in 2002.
In Britain, while the cancer diagnosis rate was up, the death rate was falling, it added. "Thanks to research, many more people diagnosed with cancer in 2005 will survive compared to 1975," Cancer Research UK's medical director John Toy said. Lung cancer is one of the most lethal forms of cancer with a survival rate of less than one in seven cases.
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