brain tumor
The beneficial effects of anti-angiogenesis drugs in the treatment of the deadly brain tumors called glioblastomas appear to result primarily from reduction of edema - the swelling of brain tissue - and not from any direct anti-tumor effect, according to a study from Massachusetts General Hospital (MGH) researchers.
Scientists at The University of Nottingham have uncovered a vital new biological clue that could lead to more effective treatments for a children's brain tumour that currently kills more than 60 per cent of young sufferers.
A protein developed by scientists at Oregon Health & Science University blocks the growth of glioblastoma, an aggressive and deadly brain tumor, in laboratory rats, a new study shows. Herstatin inhibits the activation of a family of enzymes responsible for signaling inside tumor cells that tells the cells to proliferate and display other malignant properties, said Gail Clinton, Ph.D., professor of biochemistry and molecular biology in the OHSU School of Medicine who co-authored the study appearing this month in the journal Clinical Cancer Research.
A recently developed mouse model of brain tumors common in the genetic disorder neurofibromatosis 1 (NF1) successfully mimics the human condition and provides unique insight into tumor development, diagnosis and treatment, according to researchers at Washington University School of Medicine in St. Louis. After validating their animal model, the team made two important discoveries: New blood vessels and immune system cells may be essential to the initial formation of tumors and therefore may be promising drug targets; and brain images often used to determine the need for treatment may not actually be diagnostically informative.
Scientists have identified what may be the first nontoxic treatment for a subset of medulloblastoma, the most common type of malignant pediatric brain tumor. The finding is encouraging in that such precise, targeted therapies may someday replace traditional treatments that can have overwhelmingly negative side effects for pediatric cancer patients. ''Therapy for pediatric cancers of the central nervous system has not improved significantly in the last three decades. This is partly due to the absence of adequate model systems for testing novel therapies.''
Hotspots in two areas of a gene that encodes a specific signaling enzyme, or kinase, are vulnerable to a variety of mutations found in five types of brain cancers, according to a report published in the August 1 issue of the journal Cancer Research. Mutations in the gene PIK3CA occur spontaneously as part of the brain tumor development rather than being passed genetically between generations, said Hai Yan, M.D., Ph.D., the senior scientist of the studies. ''PIK3CA mutations are known to occur in as much as 30 percent of colorectal and gastric cancers and glioblastomas and they are also present, to a lesser extent, in breast and lung cancer,'' Yan noted. ''Our studies defined the association of mutant PIK3CA gene in a wider spectrum of adult and pediatric brain tumors as well.''
When molecules in cells are stimulated by light, they respond by becoming excited and re-emitting light of varying colors (fluorescence) that can be captured and measured by highly sensitive optical equipment. Now, researchers at Cedars-Sinai Medical Center and the University of Southern California are developing miniaturized spectroscopic instruments and computer software to take a real-time look at biochemical, functional and structural changes occurring within the cells and tissue of the brain. If the technology continues to progress as anticipated, neurosurgeons will be able to shine a light during surgery to diagnose brain tumors instantaneously and they will be able to discern the borders of tumors with greater precision than ever. Early studies appear to support these possibilities.
Researchers seeking to direct cancer-killing immune cells against the deadliest brain tumors have three new targets that show promise in laboratory studies and in a Phase I patient trial, according to two articles in the July 15 issue of the journal Cancer Research.
The antigens, previously associated with several other types of cancer cells, were recently found to be expressed in the most common and aggressive type of malignant brain tumor, glioblastoma multiforme (GBM).
Some day "night vision" goggles and beams of near infrared light may be able to detect tiny tumors and areas of cancerous tissue in the brain that surgeons can't normally see, say investigators at The University of Texas M. D. Anderson Cancer. They say their advance, successfully tested in animals, is designed to help neurosurgeons define tumor "margins" -- the area where a tumor ends and normal tissue begins -- when they operate on patients with brain tumors.
Researchers are working to develop a non-surgical approach to brain cancer that uses radiation and the injection of specially cultured bone marrow cells into the tumor. The combination sets in motion a local and systemic immune response to kill surviving tumor cells. The novel approach has provided promising results in a study on rats, described in the March 3 issue of the Journal of Immunotherapy. Human trials are expected to begin within the year.
Researchers in Los Angeles have combined a special protein that targets cancer cells with neural stem cells to track and attack malignant brain tumor cells. Glioblastoma multiforme, or gliomas, are a particularly deadly type of brain tumor. They are highly invasive with poorly defined borders that intermingle with healthy brain tissue, making them nearly impossible to remove surgically without catastrophic consequences. Furthermore, cells separate from the main tumor and migrate to form satellites that escape treatment and often lead to recurrence.
Using neural stem cells to hunt down and kill cancer cells, researchers have successfully tested a new treatment for brain cancer. They now hope the technique will lead to an effective treatment for glioma, the most aggressive form of primary brain tumor in humans. As the Cedars-Sianai researchers note, the prognosis has historically been extremely poor for patients diagnosed with malignant gliomas. The tumors have poorly defined margins, and glioma cells often spread deep into healthy brain tissue making their surgical removal difficult. Often, pockets of tumor cells break off from the main tumor and migrate deep into non-tumorous areas of the brain. Therefore, even if the original tumor is completely removed or destroyed, the risk of recurrence is high as cells in these distant "satellites" multiply and eventually re-form a new brain tumor. Due to these characteristics, treating brain cancer has been extremely difficult.
