ABSTRACT
Over the past decade, next generation sequencing (NGS) has become the standard method in research of cancer genomics; currently NGS is entering a new stage - direct usage in clinical oncology to improve diagnostics and establish personalized tumor treatments. NGS allows to read the genome and it is successfully applied to detect mutations and other somatic changes (translocations, inversions, insertions and deletions, copy number variants) leading to the development of a tumor. With a focus on transcriptome sequencing allows to clearly identify differences in gene expression, improve the classification of tumors and detect somatic chimeras. All these possibilities are especially relevant for pediatric neurooncology filed in view of the existing limitations in treatment and the need for the most accurate identification of the key factors of tumor development. In this article, we describe sequencing technology basis, its application on brain tumor materials to improve diagnostics, and other relevant possibilities that can be considered for direct usage in medicine.
Subject(s)
Brain Neoplasms , Neoplasms , Brain Neoplasms/diagnosis , Brain Neoplasms/genetics , Child , DNA Copy Number Variations , High-Throughput Nucleotide Sequencing/methods , Humans , Mutation , Neoplasms/pathology , Sequence Analysis, DNA/methodsABSTRACT
DnA methylation has recently been accepted as the most reliable and effective method of diagnosing central nervous system (CNS) tumors. Healthy organs and tumors of different localizations have their own unique methylation structure. Determination of total tumor DNA methylome is the detection of all methylated nucleotides in a tumor. The "gold standard" for analyzing the methylation state of individual cytosines is bisulfite conversion, in which unmethylated cytosines are converted to uracils and read as thymines, while methylated cytosines are protected from conversion.
