Gollapalli Kishore, Ghantasala Saicharan, Atak Apurva, Rapole Srikanth, Moiyadi Aliasgar, Epari Sridhar, Srivastava Sanjeeva
1 Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay , Mumbai, India .
2 Proteomics Laboratory, National Centre for Cell Science , Pune, India .
OMICS. 2017 May;21(5):275-284. doi: 10.1089/omi.2017.0028.
Gliomas are heterogeneous and most commonly occurring brain tumors. Blood-brain barrier restricts the entry of brain tumor proteins into blood stream thus limiting the usage of serum or plasma for proteomic analysis. Our study aimed at understanding the molecular basis of aggressiveness of various grades of brain tumors using isobaric tagging for relative and absolute quantification (iTRAQ) based mass spectrometry. Tissue proteomic analysis of various grades of gliomas was performed using four-plex iTRAQ. We labeled five sets (each set consists of control, grade-II, III, and IV tumor samples) of individual glioma patients using iTRAQ reagents. Significantly altered proteins were subjected to bioinformatics analysis using Database for Annotation, Visualization and Integrated Discovery (DAVID). Various metabolic pathways like glycolysis, TCA-cycle, electron transport chain, lactate metabolism, and blood coagulation pathways were majorly observed to be perturbed in gliomas. Most of the identified proteins involved in redox reactions, protein folding, pre-messenger RNA (mRNA) processing, antiapoptosis, and blood coagulation were found to be upregulated in gliomas. Transcriptomics data of glioblastoma multiforme (GBM), low-grade gliomas (LGGs), and controls were downloaded from The Cancer Genome Atlas (TCGA) data portal and further analyzed using BRB-Array tools. Expression levels of a few significantly altered proteins like lactate dehydrogenase, alpha-1 antitrypsin, fibrinogen alpha chain, nucleophosmin, annexin A5, thioredoxin, ferritin light chain, thymosin beta-4-like protein 3, superoxide dismutase-2, and peroxiredoxin-1 and 6 showed a positive correlation with increasing grade of gliomas thereby offering an insight into molecular basis behind their aggressive nature. Several proteins identified in different grades of gliomas are potential grade-specific markers, and perturbed pathways provide comprehensive overview of molecular cues involved in glioma pathogenesis.
胶质瘤是异质性且最常见的脑肿瘤。血脑屏障限制脑肿瘤蛋白进入血流，从而限制了血清或血浆用于蛋白质组学分析。我们的研究旨在利用基于等压标签相对和绝对定量（iTRAQ）的质谱法了解不同级别脑肿瘤侵袭性的分子基础。使用四通道iTRAQ对不同级别的胶质瘤进行组织蛋白质组学分析。我们使用iTRAQ试剂标记了五组（每组包括对照、二级、三级和四级肿瘤样本）个体胶质瘤患者。对显著改变的蛋白质使用注释、可视化和综合发现数据库（DAVID）进行生物信息学分析。观察到多种代谢途径，如糖酵解、三羧酸循环、电子传递链、乳酸代谢和凝血途径在胶质瘤中主要受到干扰。在胶质瘤中发现，大多数参与氧化还原反应、蛋白质折叠、信使前体RNA（mRNA）加工、抗凋亡和凝血的已鉴定蛋白质上调。从癌症基因组图谱（TCGA）数据门户下载多形性胶质母细胞瘤（GBM）、低级别胶质瘤（LGG）和对照的转录组学数据，并使用BRB-Array工具进一步分析。一些显著改变的蛋白质，如乳酸脱氢酶、α-1抗胰蛋白酶、纤维蛋白原α链、核磷蛋白、膜联蛋白A5、硫氧还蛋白、铁蛋白轻链、胸腺素β-4样蛋白3、超氧化物歧化酶-2以及过氧化物酶1和6的表达水平与胶质瘤级别的增加呈正相关，从而深入了解其侵袭性本质背后的分子基础。在不同级别胶质瘤中鉴定出的几种蛋白质是潜在的级别特异性标志物，而受到干扰的途径提供了胶质瘤发病机制中涉及的分子线索的全面概述。
