Telling tumor. A genetic mutation could help doctors diagnose deadly tumors in the brain.
Credit: Photograph courtesy of Duke Photopath
Posted on 02/20/2009 11:12:35 AM PST by neverdem
Telling tumor. A genetic mutation could help doctors diagnose deadly tumors in the brain.
Credit: Photograph courtesy of Duke Photopath
While survival rates for many cancers have improved over the years, brain cancers often remain stubbornly unresponsive to treatment. Now, researchers are turning to genetics and have hit on a gene mutation that can be used to differentiate between the deadliest brain cancers. The find could help doctors more accurately diagnose these devastating tumors.
The most common brain tumor, glioblastoma, is also the deadliest. These tumors occur in two forms: primary, in which patients suddenly develop large and highly malignant tumors, and secondary glioblastomas, which begin as smaller, less aggressive tumors in the brain. Last fall, scientists reported an intriguing difference in the genetics of these two types of tumors. A particular mutation showed up in secondary tumors (Science, 4 September 2008, p. 1807). Patients with the mutation also seemed to have better prognoses than did those without it.
The researchers, led by D. Williams Parsons of Johns Hopkins University in Baltimore, Maryland, and Hai Yan of Duke University in Durham, North Carolina, were intrigued because the gene had not been previously implicated in cancer. The gene, called isocitrate dehydrogenase-1 (IDH1), codes for an important enzyme in cell metabolism. The researchers decided to sequence more brain tumors to verify what kinds of mutations occur in the IDH1 gene and how they impact cancer cells.
They sampled DNA from 445 brain tumors that had been removed from patients at various stages in development. Of these, 170 carried a mutated form of either IDH1 or its cousin gene, IDH2. Most of the mutated tumors were either secondary glioblastomas or other, less aggressive tumors, confirming last year's work, the researchers report online this week in The New England Journal of Medicine. Importantly, every tumor with a mutant gene had a single letter change in roughly the same location on the gene, which may make it easier to use as a biomarker because it's relatively easy to spot.
Then the researchers found that in brain cancer cells in the lab, enzymes that typically produce energy were virtually inactive in mutated cells compared with normal IDH cells--suggesting that these cells aren't metabolizing energy as efficiently and have less to grow on. Despite the results of the Science paper and this one, Yan says the mutation may not actually be protecting patients. It could just be signaling tumors to grow, albeit not as aggressively as in primary glioblastomas--but its function is far from clear right now. This is important because the two kinds of tumors can look very similar under the microscope, notes pathologist Roger McLendon of Duke, who also participated in the research. Testing for the IDH mutation could allow doctors to more accurately diagnose the disease, Yan says.
Whether the findings will lead to new treatments is unclear at this point, says cancer biologist William Hahn of the Dana-Farber Cancer Institute in Boston. But just using the mutation as a diagnostic tool would be a boon for brain cancer treatment, he says. "We're all hoping we'll have molecular markers to distinguish which tumors will do well or poorly."
Relate Site:
Whether it is a glioblastoma, also known as a glioma, or one of its subtypes, e.g. an astrocytoma or oligodendroglioma, it's referring to neoplasms, also known as tumors, of the supporting structure of nerve tissue, not individual neurons - the nerve cells that conduct the signals in the central nervous system.
P.S. That looks like a front(top) to rear(bottom) horizontal slice of a person's brain. The tumor appears to be the mess in the lower left part of the image. Any corrections are always appreciated.
Report: Fetal stem cells trigger tumors in ill boy It appears that the, "tumor is derived from at least two donors," (a problematic choice of words, BTW), that were obtained at 8–12 weeks of gestational age.
Flu: It's the Humidity. Absolutely
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Thanks for the comments. Is that an anteriorly displaced basal ganglia on the left?
Maybe... but then I’m just a cow vet pretending to speak pathologist :-(
Same with my father in law. Last October he suddenly started showing weird memory loss, and even weirder problems with semantics. He refused to go to the doctor, until he was forced to when he started falling in January. He was diagnosed with a stage four glioblastoma and died less than a month later.
Several MDs are now suggesting keeping the Vit D levels at a 90 to help reduce various cancer growths (including brain). Vit D helps startup many kinds of cancer enzymes called Phosphotases, which literally shut down the activities of other enzymes called Kinases, which are essential to the growth and reproduction of cancer cells. If you do not know what your Vit D level is....get it checked ASAP!!! Ask for test Vit D 25-OH, Total.
Resveratrol is another supplement many Docs are using as well for various cancers. This phytochemical blocks the actions of a number of cancer promoting genes thereby causing cancer cells to enter into apoptosis (cell death) and is included in the treatment of all cancers. I understand GSK has been buying up large amounts of the raw material for Resveratrol and conducting testing for a drug they want to put out. Use a pharmaceutically graded product by Xymogen, Biotics Research or Vitamin Research.
My mom died from a glioblastoma multiforme. She lived six months and one day from diagnosis (she fell, had a seizure...we initially thought she had a stroke). It was a living hell. She had grand mal seizures (dilantin(sp) didn’t help her at all) for the first couple of months and finally just went into a coma. I pray that medical science finds the answers to this cancer.
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