Any tumor that arises from the supportive tissue or glial cell, of the brain is called a “glioma” [8]. Astrocytoma is the one type of glyoma. It is named after astrocytes. Astrocytes are star-shaped cells from which they grow.According to the degree of abnormality Astrocytomas are graded in to I to IV classes [8] .These classes are Pilocytic Astrocytomas (PA) , Diffuse Astrocytoma, Anaplastic Astrocytomas(AA) and Glioblastoma Multiformeor( GBM) .
Pilocytic Astrocytomas are generally slow growing, non-infiltrative pediatric tumors [9] and rarely fatal. Pilocytic astrocytoma appears most commonly in young adults and children, with most cases (75%) indicating in the first 2 decades of life [10,11,12].
Diffuse Astrocytoma may be arises anywhere in the brain, but are most common in the cerebral hemispheres the “thinking” part of the …show more content…
Grade IV astrocytomas are two types i.e Primary and secondary tumors , as we know that primary tumors are very aggressive and the most common form of astrocytoma grade IV [19] and the secondary tumors are those which originate as a lower-grade tumor and evolve into a grade IV tumor. It is distinguished histopathologically from diffuse lower-grade astrocytomas by the presence of necrosis or micro vascular proli-feration[20].Among several tumor suppressor genes, p53 reveal to play a key role in the pathogenesis of many prevalent malignancies [21] including brain cancer. p53 has been displayed to exert tumor suppressor activity by impelling apoptosis , initiating the cell cycle [22], stimulating cell differentiation [23], and being involved in DNA repair pathways [24]. Mutations in the p53 gene are identified in about 28% of de novo GBM and 65% of secondary [25], thus indicating that p53 abnormalities are common in the progression from a low grade lesion to a high grade lesion
Pilocytic Astrocytomas are generally slow growing, non-infiltrative pediatric tumors [9] and rarely fatal. Pilocytic astrocytoma appears most commonly in young adults and children, with most cases (75%) indicating in the first 2 decades of life [10,11,12].
Diffuse Astrocytoma may be arises anywhere in the brain, but are most common in the cerebral hemispheres the “thinking” part of the …show more content…
Grade IV astrocytomas are two types i.e Primary and secondary tumors , as we know that primary tumors are very aggressive and the most common form of astrocytoma grade IV [19] and the secondary tumors are those which originate as a lower-grade tumor and evolve into a grade IV tumor. It is distinguished histopathologically from diffuse lower-grade astrocytomas by the presence of necrosis or micro vascular proli-feration[20].Among several tumor suppressor genes, p53 reveal to play a key role in the pathogenesis of many prevalent malignancies [21] including brain cancer. p53 has been displayed to exert tumor suppressor activity by impelling apoptosis , initiating the cell cycle [22], stimulating cell differentiation [23], and being involved in DNA repair pathways [24]. Mutations in the p53 gene are identified in about 28% of de novo GBM and 65% of secondary [25], thus indicating that p53 abnormalities are common in the progression from a low grade lesion to a high grade lesion