Glioma Essay

Malignant astrocytomas or Gliomas are the most frequent form of primary cancer that arise in the brain. The most malignant and aggressive type of glioma is glioblastoma multiforme(GBM). GBM ,which called grade IV astrocytoma, is one of the most common and deadly primary malignant brain tumor in adults with a high degree of morbidity and mortality and accounts for about 15% of all intracranial tumors in adults ages 40–75(2, 3)
Incidence rates of glioma in The United States yearly is about 5 in 100,000 persons (4)
Despite progress in chemotherapy, radiation oncology and surgical the prognosis of this cancer remains extremely poor (7-9)
On the other hand, Their anatomical localization, the penetration of the enviroment normal brain parenchyma
Among other pathways, The TGF-β pathway has been implicated to play a key function in glioma initiation and progression due to its effects on cell proliferation (20), tumor invasion (21), angiogenesis (22), immunosuppression (23) and the maintenance of stemness of glioma stem cells (GSCs) (24).
TGF-b has also been reported to induce matrix metalloproteinase (MMPs) expression and suppress tissue inhibitor of metalloproteinase (TIMP) expression, and increase the invasion of human glioma cells(19, 29) ligand-bound type II receptor activates and phosphorylates the type I receptor. Subsequently, Activated TbRI initiates cytoplasmic signaling pathways, which then phosphorylates Smad family proteins, Smad2 and Smad3 in the TGF-b subfamily, eventually that can pair with Smad4, a family member that is not phosphorylated by the type I receptor. also, The receptor complex recruits adaptor proteins and via post-translational modifications and activates several signaling proteins that transmit biological information (30,