Martelli Claudia, Iavarone Federica, D'Angelo Luca, Arba Morena, Vincenzoni Federica, Inserra Ilaria, Delfino Daniela, Rossetti Diana Valeria, Caretto Marta, Massimi Luca, Tamburrini Gianpiero, Di Rocco Concezio, Caldarelli Massimo, Messana Irene, Castagnola Massimo, Sanna Maria Teresa, Desiderio Claudia
Istituto di Biochimica e Biochimica Clinica, Facoltà di Medicina, Università Cattolica del Sacro Cuore, Rome, Italy.
Mol Biosyst. 2015 Jun;11(6):1668-83. doi: 10.1039/c5mb00076a.
A top-down/bottom-up integrated proteomic approach based on LC-MS and 2-DE analysis was applied for comparative characterization of medulloblastoma and pilocytic astrocytoma posterior cranial fossa pediatric brain tumor tissues. Although rare, primary brain tumors are the most frequent solid tumors in the pediatric age. Among them the medulloblastoma is the prevalent malignant tumor in childhood while pilocytic astrocytoma is the most common, rarely showing a malignant progression. Due to the limited availability of this kind of sample, the study was applied to pooled tumor tissues for a preliminary investigation. The results showed different proteomic profiles of the two tumors and evidenced interesting differential expression of several proteins and peptides. Top-down proteomics of acid-soluble fractions of brain tumor homogenates ascribed a potential biomarker role of malignancy to β- and α-thymosins and their truncated proteoforms and to C-terminal truncated (des-GG) ubiquitin, resulting exclusively detected or over-expressed in the highly malignant medulloblastoma. The bottom-up proteomics of the acid-soluble fraction identified several proteins, some of them in common with 2-DE analysis of acid-insoluble pellets. Peroxiredoxin-1, peptidyl-prolyl cis-trans isomerase A, triosephosphate isomerase, pyruvate kinase PKM, tubulin beta and alpha chains, heat shock protein HSP-90-beta and different histones characterized the medulloblastoma while the Ig kappa chain C region, serotransferrin, tubulin beta 2A chain and vimentin the pilocytic astrocytoma. The two proteomic strategies, with their pros and cons, well complemented each other in characterizing the proteome of brain tumor tissues and in disclosing potential disease biomarkers to be validated in a future study on individual samples of both tumor histotypes.
一种基于液相色谱-质谱联用（LC-MS）和二维电泳（2-DE）分析的自上而下/自下而上的综合蛋白质组学方法，被应用于小儿后颅窝髓母细胞瘤和毛细胞型星形细胞瘤脑肿瘤组织的比较表征。尽管原发性脑肿瘤罕见，但却是儿童时期最常见的实体瘤。其中，髓母细胞瘤是儿童期最常见的恶性肿瘤，而毛细胞型星形细胞瘤是最常见的，很少发生恶性进展。由于这类样本的可用性有限，该研究应用于合并的肿瘤组织进行初步调查。结果显示了两种肿瘤不同的蛋白质组学图谱，并证明了几种蛋白质和肽的有趣差异表达。脑肿瘤匀浆酸溶性部分的自上而下蛋白质组学将β-和α-胸腺素及其截短的蛋白形式以及C末端截短的（去GG）泛素的恶性潜能生物标志物作用归因于它们，这些仅在高度恶性的髓母细胞瘤中被检测到或过度表达。酸溶性部分的自下而上蛋白质组学鉴定了几种蛋白质，其中一些与酸不溶性沉淀的二维电泳分析相同。过氧化物酶1、肽基脯氨酰顺反异构酶A、磷酸丙糖异构酶、丙酮酸激酶PKM、微管蛋白β和α链、热休克蛋白HSP-90-β以及不同的组蛋白是髓母细胞瘤的特征，而Igκ链C区、血清转铁蛋白、微管蛋白β2A链和波形蛋白是毛细胞型星形细胞瘤的特征。这两种蛋白质组学策略，各有优缺点，在表征脑肿瘤组织的蛋白质组和揭示潜在的疾病生物标志物方面相互补充良好，这些生物标志物将在未来对两种肿瘤组织学类型的个体样本进行的研究中得到验证。
