Microarray analysis of U87 Glioblastoma Multiforme cell line exposed to proton irradiation during acute hypoxia.

Glioblastoma multiforme (GBM), is the most malignant and common tumor among glial neoplasms. It is characterized by a peak of incidence between 45 and 70 years and a patient median survival time of 14.6 months. In addition, GBM undergoes malignant progression under hypoxic conditions that contributes to strong radioresistance and chemoresistance; alters the metabolism of the tumor cells; generates a strong genome instability, increases the angiogenesis, vasculogenesis, and contributes to the formation of the Cancer Stem Cells (CSCs) and the infamous Circulating Tumor Cells (CTCs) involved in metastasis formation. Moreover, GBMs have a poor prognosis due to treatment (such as surgical resection, conventional RT and chemotherapy) plan failures. In this sense, since standard GBM treatments are not effective, new promising strategies such as Proton Therapy (PT), are under investigation because supported by encouraging results. Considering these assumptions, the main aim of this study was to analyze GBM response to PT innovative treatment during induced acute hypoxia, by using a whole gene expression analysis. Thus, in this work we have reported in a descriptive way, the most statistically and biologically relevant pathways deregulated in U87 GBM cell line, according to specific PT plans during hypoxia condition, and in addition, some interesting biomarker networks were following discussed. Proton-induced gene expression changes in U87 GBM cell line after 2 and 10 Gy of proton doses during acute hypoxia, were analyzed as two-color hybridizations using Agilent Technologies whole human genome 4x44K microarrays. Samples were named as follow: U87 Hypoxia 2Gy and U87 Hypoxia 10Gy.