Does glioblastoma multiforme cause tumors?
37284#49
Glioblastoma multiforme (GBM) is the most aggressive (grade IV) and most common form of a malignant brain tumor. Even when aggressive multimodality therapy consisting of radiotherapy, chemotherapy, and surgical excision is used, median survival is only 12–17 months. Standard therapy for glioblastoma multiforme consists of maximal surgical resection of the tumor, followed by radiotherapy between two and four weeks after the surgical procedure to remove the cancer, then by chemotherapy, such as temozolomide. Most patients with glioblastoma take a corticosteroid, typically dexamethasone, during their illness to relieve symptoms. Experimental treatments include targeted therapy, gamma knife radiosurgery, boron neutron capture therapy and gene therapy.
Brain tumor
1023575#0
Glioblastoma, also known as glioblastoma multiforme (GBM), is the most aggressive cancer that begins within the brain. Initially, signs and symptoms of glioblastoma are non-specific. They may include headaches, personality changes, nausea, and symptoms similar to those of a stroke. Worsening of symptoms often is rapid. This may progress to unconsciousness.
The cause of most cases is unclear. Uncommon risk factors include genetic disorders such as neurofibromatosis and Li–Fraumeni syndrome, and previous radiation therapy. Glioblastomas represent 15% of brain tumors. They can either start from normal brain cells or develop from an existing low-grade astrocytoma. The diagnosis typically is made by a combination of CT scan, MRI scan, and tissue biopsy.
There is no clear way to prevent the disease. Typically, treatment involves surgery, after which chemotherapy and radiation therapy are used. The medication temozolomide is used frequently as part of chemotherapy. High dose steroids may be used to help reduce swelling and decrease symptoms. It is unclear whether trying to remove all or simply most of the cancer is better.
Despite maximum treatment, the cancer usually recurs. The most common length of survival following diagnosis is 12 to 15 months, with fewer than 3% to 5% of people surviving longer than five years. Without treatment, survival is typically three months. It is the most common cancer that begins within the brain and the second most common brain tumor, after meningioma. About 3 per 100,000 people develop the disease a year. It most often begins around 64 years of age and occurs more commonly in males than females. Immunotherapy is being studied.
Common symptoms include seizure, headaches, nausea and vomiting, memory loss, changes to personality, mood or concentration, and localized neurological problems.
Glioblastoma
1023575#38
The term glioblastoma multiforme was introduced in 1926 by Percival Bailey and Harvey Cushing, based on the idea that the tumor originates from primitive precursors of glial cells (glioblasts), and the highly variable appearance due to the presence of necrosis, hemorrhage and cysts (multiform).
Glioblastoma
1527537#11
Bevacizumab slows tumor growth but does not affect overall survival in people with glioblastoma multiforme.
Bevacizumab
1024090#12
Glioblastoma Multiforme is also a malignant tumor and classified as a grade IV. Glioblastomas can contain more than one cell type (i.e., astrocytes, oligodendrocytes). Also, while one cell type may die off in response to a particular treatment, the other cell types may continue to multiply. Glioblastomas are the most invasive type of glial tumors as they grow rapidly and spread to nearby tissue. Approximately 50% of astrocytomas are glioblastomas and are very difficult to treat.
Astrocyte
1023575#7
Glioblastoma multiforme tumors are characterized by the presence of small areas of necrotizing tissue that are surrounded by anaplastic cells. This characteristic, as well as the presence of hyperplastic blood vessels, differentiates the tumor from Grade 3 astrocytomas, which do not have these features.
Glioblastoma
36131613#6
SNAs packed gold nanoparticles are able to deliver small interfering RNA (siRNA) to treat glioblastoma multiforme in a proof-of-concept study using mouse model, reported by the research team led by Mirkin. The iRNA targets Bcl2Like12 gene overexpressed in glioblastoma tumors and silences the oncogene. The gold nanoparticles injected intravenously cross the blood-brain barrier and find their target in the brain. In the animal model, the treatment caused a 20% increase in survival rate and 3 to 4 fold reduction in tumor size. Mirkin indicated that this novel therapeutic approach establishes a platform for treating a wide range of diseases.
Spherical nucleic acid
14418619#0
Glial tumor is a general term for numerous tumors of the central nervous system, including astrocytomas, ependymal tumors, glioblastoma multiforme, and primitive neuroectodermal tumors.
Glial tumor
105038#44
Following a three-hour hearing on August 5, the Commission concluded that Chenar's finding had been in error. They found that the tumor had features of a glioblastoma multiforme, with widespread areas of necrosis, palisading of cells, and a "remarkable vascular component" described as having "the nature of a small congenital vascular malformation." Psychiatric contributors to the report concluded that "the relationship between the brain tumor and [...] Whitman's actions [...] cannot be established with clarity. However, the [...] tumor conceivably could have contributed to his inability to control his emotions and actions," while the neurologists and neuropathologists concluded: "The application of existing knowledge of organic brain function does not enable us to explain the actions of Whitman on August first."
Charles Whitman
1023575#15
Furthermore, glioblastoma multiforme exhibits numerous alterations in genes that encode for ion channels, including upregulation of gBK potassium channels and ClC-3 chloride channels. It has been hypothesized that by upregulating these ion channels, glioblastoma tumor cells can facilitate increased ion movement over the cell membrane, thereby increasing HO movement through osmosis, which aids glioblastoma cells in changing cellular volume very rapidly. This is helpful in their extremely aggressive invasive behavior, because quick adaptations in cellular volume can facilitate movement through the sinuous extracellular matrix of the brain.
Glioblastoma
13621537#10
Fyn overexpression has been studied in relation to the following cancers: prostate cancer, glioblastoma multiform, squamous cell carcinoma of the head and neck, pancreatic cancer, chronic melogenic leukemia, and melanoma. This overexpression triggers a promotion of “anti-apoptotic activity of Akt” in prostate cancer, meaning that these cells have gained the ability to avoid the normal cell death pathways (a common hallmark of cancer). Additionally, in glioblastoma multiform, Src and Fyn have been found to be “effectors of oncogenic EGFR signaling” which has led to tumor invasion and cancer cell survival.
FYN
1023575#3
Uncommon risk factors include genetic disorders such as neurofibromatosis, Li–Fraumeni syndrome, tuberous sclerosis, or Turcot syndrome. Previous radiation therapy is also a risk. For unknown reasons, GBM occurs more commonly in males.
Glioblastoma