Objective: To further understand the interaction protein spectrum of heterogeneous ribonucleoprotein AB (hnRNP AB), and to investigate their clinical significance in hepatocellular carcinoma (HCC). Methods: We carried out mass spectrometry to reveal the specific peptides of KRAB-associated protein 1 (Kap1) and hnRNPAB, and verified their interaction by immunocoprecipitation and western blotting. Expression of hnRNPAB/Kap1 proteins were detected by immunohistochemical staining in the tissue microarrays. Categorical data were analyzed by the chi square test or Fisher exact test; enumeration data between groups were compared using Student t-test or Wilcocon signed rank test; the cumulative recurrence and survival rates were evaluated using the Kaplan-Meier method and the differences were assessed using the log-rank test. Results: We identified Kap1 as a molecular partner for hnRNPAB in HCCLM3 cells and HepG2 cells as well. We found that the 5-year survival rate of the Kap1high patients was significantly lower than the survival rate of those of the Kap1low group (36% vs 59% , HR = 1.67, P < 0.001). Similarly, Kap1high HCC patients had the poorest prognosis at 5-years, with higher cumulative recurrence rate than Kap1low patients (72% vs 54%, HR = 1.66, P = 0.001). Univariate and Multivariate analyses revealed that hnRNPAB /Kap1 alone (HR = 1.35 /1.28, P = 0.001) or in combination with Kap1 (HR =1.24 /1.27, P < 0.05) were independent prognostic indicators for overall survival and time to recurrence. Conclusion: In HCC cells, hnRNPAB and Kap1 form protein complexes. The expression levels of hnRNPAB alone or in combination with Kap1 in HCC patients are important because they provide not only a predictor for HCC prognosis but also a therapeutic target for future studies.
目的： 研究核不均一核糖核蛋白AB （hnRNPAB）在人肝癌细胞系中的互作蛋白谱，探讨hnRNPAB/KRAB相关蛋白1(Kap1)的共表达谱与肝癌患者临床病理特征之间的相关性及其在预测患者术后复发转移的临床价值。 方法： 质谱分析与多肽比对确定与hnRNPAB蛋白结合的Kap1蛋白肽段，免疫共沉淀验证两者的蛋白相互作用；免疫组织化学染色方法检测，hnRNPAB和互作蛋白Kap1在组织芯片中的表达谱，分析其与临床病理特征及预后的关联性。计数资料比较采用χ(2)或Fisher精确概率法；计量资料比较用两组间比较的t检验或wilcoxon符号秩检验；生存率的判定使用Kaplan-Meier方法，差异性使用Log-rank检验评估。 结果： 免疫共沉淀联合质谱技术鉴定出Kap1是hnRNPAB蛋白在人肝癌细胞中的结合蛋白之一，两者之间存在蛋白相互作用。生存分析结果显示Kap1高表达组肝癌患者术后5年总体生存率为36%，显著低于Kap1低表达组患者的59%，差异有统计学意义（HR = 1.67，P < 0.001）；其累计复发率为72%，显著高于Kap1低表达组患者的54%（HR = 1.66，P = 0.001）。单因素统计分析结果显示单独的hnRNP AB、Kap1以及两者联合均是肝癌患者术后生存和复发的独立预后影响因素，差异均有统计学意义（HR分别为1.35和1.28，P值均< 0.05）；联合hnRNPAB和Kap1对术后生存和复发的预测价值高于单个指标，差异均有统计学意义（HR分别为1.24和1.27，P值均< 0.05）。 结论： 在人肝癌细胞中hnRNPAB与Kap1形成蛋白复合体；HnRNPAB联合Kap1是非常好的独立预后指标，能准确预测肝癌患者术后的预后不良。.
Keywords: Expression profiling; Hepatic carcinoma; Heterogeneous ribonucleoprotein AB; KRAB-associated protein 1; Prognosis.