Role of micro-RNA (miRNA) in pathogenesis of glioblastoma.

Glioblastoma (GBM) is a very lethal form of human brain cancer, which is characterized by rapid diffuse, infiltrative growth and high level of cellular heterogeneity. Such cancer patients usually survive for one year under treatment. Recently, the role of small non-coding RNA known as microRNAs (miRNA), have been suggested to be involved in the pathogenesis of glioblastoma, as miRNAs play a critical role in the tumor-forming processes. The change in expression levels of several miRNAs has been found in GBM patients within last 10 years. It is evident now that impairment of miRNA regulation is one of the key mechanisms in GBM pathogenesis. The miRNA deregulation is involved in many processes, such as cell proliferation, cell cycle regulation, apoptosis, invasion, glioma stem cell behavior, and angiogenesis. GBM is also known as Grade IV astrocytoma, a rare disease with an incidence of 2-3 cases per 100,000 people in Europe and North America, and 50% with GBM die within 1 year, while 90% within 3 years. The treatments of GBM involve chemotherapy, radiation and surgery. The median survival with standard radiation and chemotherapy with Temozolomide is 1 year and 3 months, and median survival without treatment is four and a half months. In this article, symptoms of GBM, treatments, the role of miRNAs, gene expressions, types of miRNAs, neoplasms and glioblastomas, the miRNA biogenesis pathways, deregulation of miRNAs, and care of GBM have been described.