Wednesday, November 15, 2006

Nanotechnology promises new hope for Glioblastoma multiforme (a deadly brain cancer):

Glioblastoma multiforme (GBM) is the most aggressive form of the primary brain tumors known collectively as gliomas. These tumors arise from the supporting, glial (Glial cells provide physical and chemical support for neurons and make up about 90 percent of all the cells in the brain) cells of the brain during childhood and in adults. These growths do not spread throughout the body like other forms of cancer, but cause symptoms by invading the brain. Untreated, GMB’s are rapidly lethal and kill in about a year.

This is also known as "octopus tumors" because of the manner in which tendrils of malignant cells can extend into surrounding healthy brain tissue. As the term "multiforme" suggests, malignant cells can take on a wide variety of different shapes, making detection difficult until the tumors become quite large.

The area of the brain first involved by the tumor influences the first symptoms of GBMs. Progressive weakness, speech or visual loss occurs when "eloquent" brain regions are involved. More "silent" areas of the brain allow the tumors to become large before symptoms arise. In this case increased pressure in the head produces headache and rarely, visual loss from swelling of the optic nerves. The tumors also can irritate the brain, causing epileptic seizures. Rarely, spontaneous hemorrhage into the tumor yields a stroke syndrome, with the sudden development of a neurological deficit.

The tumor can be imaged by contrast-enhanced MRI scan. Progressive growth of the lesion on serial MR scans differentiates tumor from stroke. A PET scan showing increased uptake of glucose can also help separate a diagnosis of tumor from stroke. An open or needle biopsy provides tissue for microscopic diagnosis.

Striking some 18,000 new victims in the United States every year, the disease is always fatal, usually within six months of onset. Surgery and conventional radiation therapies may prolong life for up to a year, but cannot stop the tumors from continuing to spread throughout the brain. There are anticancer drugs that show promise against glioblastoma multiforme tumors, but getting these drugs past the blood-brain barrier has proven to be a major challenge.

A collaboration of researchers from the Lawrence Berkeley National Laboratory and the Children's Hospital of Oakland Research Institute (CHORI) have demonstrated, through in vitro studies, the potential for nanosized synthetic particles of low density lipoprotein, or LDL, to be used as a safe and effective means of delivering anticancer drugs to glioblastoma multiforme tumors.

The research team have now identified LDL receptors on glioblastoma multiforme tumor cells that can serve as specific molecular targets. In addition as the LDL receptors are sparse in normal human brain tissue but elevated on the tumor cells, the synthetic nano-LDLs can deliver drugs to the glioblastoma multiforme tumors while sparing healthy cells.

Read on more about this exciting new application where technology and neuroscience come together at

The related paper is here.

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