Heterogeneous nuclear ribonucleoprotein A2/B1 in association with hTERT is a potential biomarker for hepatocellular carcinoma
Heterogeneous nuclear ribonucleoprotein A2/B1 in association with hTERT is a potential biomarker for hepatocellular carcinoma
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DOI：
10.1111/j.1478-3231.2012.02778.x
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发表时间：
2012-08-01
影响因子：
6.7
通讯作者：
Kaneko, Shuichi
中科院分区：
文献类型：
--
作者：
Mizuno, Hideki;Honda, Masao;Kaneko, Shuichi
背景肝细胞癌（HCC）的异质性和缺乏适当的生物标志物阻碍了患者的预后和治疗分层。为了确定一个新的预后生物标志物，是相关的人端粒酶逆转录酶（hTERT）在肝癌，我们采用了一种独特的蛋白质组学方法，使用液相色谱-质谱/质谱（LC-MS/MS）凝胶过滤纯化后的肝组织。方法采用高效液相色谱法对肝癌和肝硬化组织的蛋白裂解液进行凝胶过滤。端粒酶复合物的分子量为350 kDa，与端粒酶活性平行。通过LC-MS/MS分析这些350kDa的分级裂解物。在手术切除的HCC患者中统计学检查鉴定的标志物和预后的关系。结果共鉴定出24个差异表达蛋白。这些蛋白质之一，异质核核糖核蛋白A2/B1（hnRNP A2/B1），进一步分析了免疫沉淀法使用组织和细胞系样品，并发现与hTERT相互作用。hnRNP A2/B1的小干扰RNA抑制端粒酶活性，免疫组化显示hnRNP A2/B1在HCC细胞核和胞浆的表达增强与HCC的分化程度和微血管浸润密切相关。此外，74例接受根治性手术治疗的HCC患者的生存分析表明，hnRNP A2/B1表达是患者生存的独立预后因素。结论hTERT相关蛋白核内不均一核糖核蛋白A2/B1是HCC患者潜在的预后标志物，可能成为HCC治疗的靶点。
Background The heterogeneous nature of hepatocellular carcinoma (HCC) and the lack of appropriate biomarkers have hampered patient prognosis and treatment stratification. To identify a new prognostic biomarker that is related to human telomerase reverse transcriptase (hTERT) in HCC, we employed a unique proteomics approach using liquid chromatograph-mass spectrometry/mass spectrometry (LC-MS/MS) after gel filtration purification of liver tissue. Methods Protein lysates from HCC and cirrhotic liver tissue were subjected to gel filtration using high performance liquid chromatography. The telomerase complex was identified at a molecular mass of 350kDa in parallel with telomerase activity. These fractionated lysates of 350kDa were analyzed by LC-MS/MS. The relation of the identified marker and prognosis was statistically examined in surgically resected HCC patients. Results We identified 24 differentially expressed proteins in HCC. One of these proteins, heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNP A2/B1), was further analyzed by immunoprecipitation assay using tissue and cell line samples and found to interact with hTERT. Moreover small interfering RNA against hnRNP A2/B1 suppressed telomerase activity, and immunohistochemical examination showed that the enhanced nuclear and cytoplasmic hnRNP A2/B1 expression in HCC was significantly associated with histological grade of tumor differentiation and microvascular invasion of HCC. Furthermore, survival analysis of 74 HCC patients who received curative surgical treatment showed that hnRNP A2/B1 expression is an independent prognostic factor for patient survival. Conclusions Heterogeneous nuclear ribonucleoprotein A2/B1, an hTERT-associated protein, is a potential prognostic biomarker for HCC patients and might be a therapeutic target of HCC.