Departments of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India.
Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India.
Sci Rep. 2019 Feb 26;9(1):2749. doi: 10.1038/s41598-019-39067-8.
Despite advances in biology and treatment modalities, the prognosis of glioblastoma (GBM) remains poor. Serum reflects disease macroenvironment and thus provides a less invasive means to diagnose and monitor a diseased condition. By employing 4-plex iTRAQ methodology, we identified 40 proteins with differential abundance in GBM sera. The high abundance of serum S100A8/S100A9 was verified by multiple reaction monitoring (MRM). ELISA and MRM-based quantitation showed a significant positive correlation. Further, an integrated investigation using stromal, tumor purity and cell type scores demonstrated an enrichment of myeloid cell lineage in the GBM tumor microenvironment. Transcript levels of S100A8/S100A9 were found to be independent poor prognostic indicators in GBM. Medium levels of pre-operative and three-month post-operative follow-up serum S100A8 levels predicted poor prognosis in GBM patients who lived beyond median survival. In vitro experiments showed that recombinant S100A8/S100A9 proteins promoted integrin signalling dependent glioma cell migration and invasion up to a threshold level of concentrations. Thus, we have discovered GBM serum marker by iTRAQ and verified by MRM. We also demonstrate interplay between tumor micro and macroenvironment and identified S100A8 as a potential marker with diagnostic and prognostic value in GBM.
尽管在生物学和治疗方式上取得了进展，但胶质母细胞瘤（GBM）的预后仍然很差。血清反映了疾病的宏观环境，因此提供了一种侵入性较小的方法来诊断和监测疾病状况。通过采用 4-plex iTRAQ 方法，我们在 GBM 血清中鉴定出 40 种具有差异丰度的蛋白质。通过多重反应监测（MRM）验证了血清 S100A8/S100A9 的高丰度。ELISA 和基于 MRM 的定量显示出显著的正相关。此外，通过对基质、肿瘤纯度和细胞类型评分进行综合研究，表明在 GBM 肿瘤微环境中存在髓样细胞谱系的富集。S100A8/S100A9 的转录水平被发现是 GBM 中独立的预后不良指标。术前和术后三个月随访的血清 S100A8 水平处于中等水平的患者，其生存时间超过了中位生存时间，预示着预后不良。体外实验表明，重组 S100A8/S100A9 蛋白在浓度达到阈值水平时，促进整合素信号依赖性神经胶质瘤细胞迁移和侵袭。因此，我们通过 iTRAQ 发现了 GBM 血清标志物，并通过 MRM 进行了验证。我们还证明了肿瘤微环境和宏观环境之间的相互作用，并确定 S100A8 作为一种具有诊断和预后价值的潜在标志物。
