Intrinsic brain tumors, those that originate from neural cells within the brain and spinal cord, occur more frequently in older adults and children than they do in the general population. The main feature that makes intrinsic brain tumors different from cancers arising from other organs in the body is the fact that they rarely, if ever, metastasize outside the brain. Some cells in brain tumors do, however, stop dividing long enough to migrate a few millimeters away from the parent tumor to form new intracranial tumors. The most malignant of these is called glioblastoma multiforme (GBM).
Brain tumors are the second most common cause of cancer deaths in males and females under the age of 20. After leukemia, intrinsic brain tumors are the second leading cause of cancer deaths in men between the ages of 20 and 29. They are the fifth most frequent cause of cancer deaths among females between the ages of 20 and 39.
GBM is rare, with only two or three new cases per 100,000 population. They account for one-fifth of all tumors inside the cranium. Because of GBM cells' ability to break away from the main tumor, migrate a few millimeters within the brain and start dividing again to form new tumors, they are impossible to completely eradicate by surgery. It's is like trying to remove all the butter from a slice of toast.
GBM arises from cells in the brain called glial cells. Neurons, which are generally post-mitotic, meaning they lose the ability to divide once they have achieved terminal differentiation. Glial cells, on the other hand, may continue to divide and replicate throughout life. There is evidence from in vivo and in vitro studies to suggest that some, if not all, astrocytomas arise in utero.
There are three different types of glial cells in the brain, each with different functions. These are astrocytes, microglia and oligodendrocytes. Astrocytes are the most common neural cell type found in brain tumors. These are called astrocytomas. GBM is the most malignant of the astrocytomas, with median survival time of less than five months without treatment.
Astrocytes are characterized by their starry morphology and the presence of glial fibrillary acidic protein (GFAP). The normal function of astrocytes is to supply nutrients to nerve cells, support the vascular cells that comprise the blood brain barrier and repair damaged cells following trauma. New studies suggest that they communicate with neuronal cells by secreting glutamate, the brain's main excitatory neurotransmitter.
Oligodendrocytes have fewer spiny processes than astrocytes. Their main function is to produce the myelin sheath that surrounds nerve cell axons to insulate them and speed up nerve impulse transmission. A single oligodendrocyte can service as many as 50 different nerve cells. It is the myelin sheath that is attacked by the immune system in the autoimmune condition known as multiple sclerosis (MS).
Microglia are a special type of immune system cell resident within the central nervous system. These cells respond quickly to invasion from foreign bodies, embrace them through a process called phagocytosis and present them for destruction by T-cells. Resting microglia look very cute under the microscope, with tiny spines called processes. Activated microglia share more morphological characteristics with cells of the immune system, or leukocytes.
Brain tumors are the second most common cause of cancer deaths in males and females under the age of 20. After leukemia, intrinsic brain tumors are the second leading cause of cancer deaths in men between the ages of 20 and 29. They are the fifth most frequent cause of cancer deaths among females between the ages of 20 and 39.
GBM is rare, with only two or three new cases per 100,000 population. They account for one-fifth of all tumors inside the cranium. Because of GBM cells' ability to break away from the main tumor, migrate a few millimeters within the brain and start dividing again to form new tumors, they are impossible to completely eradicate by surgery. It's is like trying to remove all the butter from a slice of toast.
GBM arises from cells in the brain called glial cells. Neurons, which are generally post-mitotic, meaning they lose the ability to divide once they have achieved terminal differentiation. Glial cells, on the other hand, may continue to divide and replicate throughout life. There is evidence from in vivo and in vitro studies to suggest that some, if not all, astrocytomas arise in utero.
There are three different types of glial cells in the brain, each with different functions. These are astrocytes, microglia and oligodendrocytes. Astrocytes are the most common neural cell type found in brain tumors. These are called astrocytomas. GBM is the most malignant of the astrocytomas, with median survival time of less than five months without treatment.
Astrocytes are characterized by their starry morphology and the presence of glial fibrillary acidic protein (GFAP). The normal function of astrocytes is to supply nutrients to nerve cells, support the vascular cells that comprise the blood brain barrier and repair damaged cells following trauma. New studies suggest that they communicate with neuronal cells by secreting glutamate, the brain's main excitatory neurotransmitter.
Oligodendrocytes have fewer spiny processes than astrocytes. Their main function is to produce the myelin sheath that surrounds nerve cell axons to insulate them and speed up nerve impulse transmission. A single oligodendrocyte can service as many as 50 different nerve cells. It is the myelin sheath that is attacked by the immune system in the autoimmune condition known as multiple sclerosis (MS).
Microglia are a special type of immune system cell resident within the central nervous system. These cells respond quickly to invasion from foreign bodies, embrace them through a process called phagocytosis and present them for destruction by T-cells. Resting microglia look very cute under the microscope, with tiny spines called processes. Activated microglia share more morphological characteristics with cells of the immune system, or leukocytes.
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