The brain tumor is the abnormal growth of heterogeneous cells around the central nervous system and spinal cord. Most clinically prominent brain tumors affecting both adult and pediatric are glioblastoma, medulloblastoma, and ependymoma and they are classified according to their origin of tissue. Chemotherapy, radiotherapy, and surgery are important treatments available to date. However, these treatments fail due to multiple reasons, including chemoresistance and radiation resistance of cancer cells. Thus, there is a need of new therapeutic designs to target cell signaling and molecular events which are responsible for this resistance. Recently epigenetic changes received increased attention because it helps in understanding chromatin-mediated disease mechanism. The epigenetic modification alters chromatin structure that affects the docking site of many drugs which cause chemo-resistance of cancer therapy. This review centers the mechanism of how epigenetic changes affect the transcription repression and activation of various genes including Polycomb gene, V-Myc avian myelocytomatosis viral oncogene (MYCN). This review also put forth the pathway of radiation-induced reactive oxygen species generation and its role in epigenetic changes in the cellular level and its impact on tissue physiology. Additionally, there is a strong relationship between the behavior of an individual and environment-induced epigenetic regulation of gene expression. The review also discusses Transcriptome heterogeneity and role of tumor microenvironment in glioblastoma. Overall, this review emphasis important and novel epigenetic targets that could be of therapeutic benefit, which helps in overcoming the unsolved chromatin alteration in brain cancer.

脑瘤是中枢神经系统和脊髓周围异质细胞的异常生长。影响成年和小儿的大多数临床上突出的脑肿瘤是胶质母细胞瘤，髓母细胞瘤和室管膜瘤，并且根据其组织来源对其进行分类。迄今为止，化学疗法，放射疗法和手术是重要的治疗方法。但是，这些治疗由于多种原因而失败，包括癌细胞的化学抗性和抗辐射性。因此，需要新的治疗设计以靶向引起这种抗性的细胞信号传导和分子事件。最近，表观遗传学的变化受到了越来越多的关注，因为它有助于理解染色质介导的疾病机制。表观遗传修饰会改变染色质结构，从而影响许多药物的对接位点，从而导致癌症治疗的化学耐药性。这篇综述集中于表观遗传变化如何影响各种基因（包括Polycomb基因，V-Myc禽骨髓细胞瘤病病毒致癌基因（MYCN））的转录抑制和激活的机制。这篇综述还提出了辐射诱导的活性氧物种生成的途径及其在细胞水平的表观遗传学变化中的作用及其对组织生理的影响。此外，个人行为与环境诱导的基因表达表观遗传调控之间存在密切关系。审查还讨论了转录组异质性和胶质母细胞瘤中肿瘤微环境的作用。总体，