TIP30在肝内胆管癌中的表达及意义

Expression of TIP30 in intrahepatic cholangiocarcinoma and its significance

摘要:

背景与目的：抑癌基因HIV-1 Tat相互作用蛋白2（TIP30）在人体多种肿瘤中存在表达下调或缺失，并与患者的不良预后相关。然而，在肝内胆管癌（ICC）中尚未见关于TIP30的研究。本研究旨在探讨TIP30在肝内胆管癌中的表达及临床意义。
方法：用免疫组化法检测51对ICC组织与癌旁组织中TIP30的表达，分析ICC组织中TIP30表达与ICC患者临床病理特征的关系，以及与ICC患者总生存率、累积复发率的关系。用软琼脂克隆法检测TIP30-shRNA转染后ICC细胞（ICC-9810、SSP-25和HuH-28）克隆形成能力的变化。通过数据库TargetScan和miRDB预测可能靶向TIP30的3'UTR的miRNA，用qRT-PCR进一步验证此结果。
结果：免疫组化结果显示，TIP30在ICC组织中的表达低于癌旁组织。临床数据分析提示，TIP30表达与淋巴结转移明显有关（P=0.008）；生存分析显示，TIP30高表达患者的5年总生存率明显高于TIP30低表达患者（P=0.041 2），而累积复发率明显低于TIP30低表达的患者（P=0.037 4）。
TIP30-shRNA转染后的ICC细胞（ICC-9810、SSP-25和HuH-28）形成的集落数均比阴性对照组明显增加（均P<0.001）。数据库预测结果显示，miR-124-3p可能识别并结合TIP30的3'UTR。qRT-PCR验证结果显示，ICC组织中miR-124-3p的相对含量明显高于癌旁组织（P<0.001）；在miR-124-3p转染后的ICC细胞（9810、SSP-25和HuH-28）中TIP30的表达低于阴性对照组（均P<0.05）。
结论：TIP30在ICC中的表达水平下调，且与ICC患者预后不良有关，机制可能与ICC中miR-124-3p介导的相关调控有关。本研究结果可能为今后ICC发病机制及分子靶向治疗的研究提供线索和依据。

Abstract:

Background and Aims: The tumor suppressor gene HIV-1 Tat interactive protein 2 (TIP30) is down-regulated or absent in many human tumors, and is related to the poor prognosis of patients. However, there is no report about TIP30 in intrahepatic cholangiocarcinoma (ICC). Therefore, this study was performed to investigate the expression of TIP30 in ICC and its clinical significance. 
Methods: The TIP30 expressions in 51 paired specimens of ICC tissue and tumor adjacent tissue were detected by immunohistochemical staining. The relations of TIP30 expression in ICC tissues with the clinicopathologic features as well as the overall survival rate and cumulative recurrence rate of ICC patients were analyzed. The change in colony-forming ability in ICC cells (ICC-9810, SSP-25 and HuH-28) after transfection with TIP30-shRNA were determined by soft agar colony formation assay. The potential miRNAs targeting the 3’UTR of TIP30 were predicted using TargetScan and miRDB databases, and then the results were further verified by qRT-PCR.
Results: The results of immunohistochemical staining demonstrated that the expression level of TIP30 in ICC tissue was lower than that in adjacent tissue. The results of clinical data analysis indicated that the TIP30 expression was significantly associated with lymph node metastasis (P=0.008). The survival analysis showed that the 5-year overall survival rate was significantly higher (P=0.041 2), while the cumulative recurrence rate was significantly lower (P=0.037 4) in patients with high TIP30 expression than those in patients with low TIP30 expression. The number of colony-forming units in ICC cells (ICC-9810, SSP-25 and HuH-28) transfected with TIP30-shRNA were significantly increased over the negative controls (all P<0.001). The results of database prediction suggested that miR-124-3p could recognize and bind to the 3' UTR of TIP30. The results of qRT-PCR verification revealed that the relative content of miR-124-3p in ICC tissue was significantly higher than that in adjacent tissue (P<0.001); the expressions of TIP30 in ICC cells (9810, SSP-25 and HuH-28) transfected with miR-124-3p were lower than those in their negative controls (all P<0.05).
Conclusion: The TIP30 expression is down-regulated in ICC, and is closely related to the poor prognosis of ICC patients. The mechanism may be associated with the regulation mediated by miR-124-3p. The results of this study may provide information and basis for future studies on the pathogenesis and molecular target therapy of ICC.