我们曾研究提出复发性肝癌（RHCC）具有单克隆和多克隆两种起源模式特征，用以指导临床个体化治疗和判断预后，但目前仍缺乏RHCC克隆分型适用的分子标志物及发生机制的研究。我们在近期研究中发现，let-7g在肝癌与配对RHCC组织之间呈显著差异表达。为此，我们拟采用miRNAs芯片技术，扩大优化不同克隆型RHCC差异表达的miRNAs，在60对原发和RHCC配对病例中进行验证，建立起评估RHCC克隆型与发生风险的miRNAs检测谱系及临床实验室适用性检测技术流程；通过靶基因数据库，预测并验证目的miRNAs的靶基因，构建携带目的miRNAs和shRNA的慢病毒载体，检测人肝癌细胞系感染后在靶基因功能调控、癌细胞的增殖、侵袭和凋亡及裸鼠成瘤能力上的变化特点，阐明目的miRNAs在RHCC克隆型发生中的作用机制，为临床评估RHCC克隆类型、判断预后及制定个体化治疗策略提供理论依据和有效的诊断方法。

Supported by the last National Natural Science Foundation of China, we put forward a new concept of six molecular subtypes of clonal origins of postoperative recurrent hepatocellular carcinoma (RHCC).Briefly,PHCC derived from monoclonal model is considered to be derived from intrahepatic residual cancer cells of the last resected tumor. Clinically, more attention should be paied on the comprehensive treatment for patients with monoclonal RHCC,including, interferon-based therapy, ablation therapy as well as transhepatic arterial chemoembolization for anti-tumor metastasis.Whereas RHCC of polyclonal origin means in nature a newborn of primary tumor.The first choice of treatment for patients with polyclonal RHCC is of still surgical resection,and their opstoperative prognoses are also better than the patients with RHCC from monoclonal origin. .However, it still remains a hot issue in looking for more applied molecular diagnostic markers and detection techniques for determing the patterns of clonal origin of RHCC in clinical lab. Recently,by using quantitative reverse transcriptase PCR (qRT-PCR),we find that let-7g, a microRNA(miRNA), shows a significantly differential expression in paired primary and RHCC tissues.No similar researches on the relationship between miRNA expression profiles and clonal models of RHCC have ever been reported before. .Therefore, for objective evaluation of different clonal patterns of RHCC, we plan using the miRNA chip technology for screening,validation and optimization of clonotype-specific and sensitive miRNA differential expression profiles between primary and RHCC, which are further verified in 60 paired RHCC tissues. We also design to predict the target genes of key miRNAs by public microRNA target prediction databases,and study the functional regulations of key miRNAs to their target genes, including the changes in proliferation,invasion and apoptosis in human hepatoma cell lines of MHCC97-L and MHCC97-H,which are transfected with targeted miRNAs and shRNA based on lentiviral vectors,including let-7g,and the tumorigenic ability was also tested by the tumor formation in nude mice after the vector transfection. We aim to provide theoretical basis and diagnostic tool for clinic to correctly diagnose clonal origins, establish individualized treatment,as well as to evaluate the long-term survival for patients with RHCC.