HBV相关性肝癌中Mig调控CD44+CD133+肝癌干细胞失巢凋亡的作用及其分子机制研究

Metastasis and recurrence for hepatocellular carcinoma is the most common cause of death ,Research shows that anoikis resistance is the precondition of it;Cancer stem cells(CSCs) are proposed to initiate tumor metastasis and propagation, both CD44 and CD133 are important liver cancer stem cell markers;CD44+CD133+ liver cancer stem cells own a stronger potential for self-renewal and differentiation;More and more evidence shows that tumor microenvironment(including chemokines) is of great importance in the dissemination and establishment of CSCs metastasis. Previous studies found that chemokine Mig in HBV-related liver cancer serum and liver tissue expressed higher than that in normal liver counterparts. HCC cell lines with different metastatic potentials was related with anoikis closely. Further,stimulated by Mig protein reduce the CD44 + CD133 + liver stem cell anoikis rate obviously, but no studies have reported its molecular mechanism. Therefore, based on the present theories and preliminary experiments ,this project intends to analyze the relationship between Mig、CD44+CD133+ liver cancer stem cells and the HCC prognosis,explore the effect and the molecular mechanisms of chemokine Mig in CD44 + CD133 + liver cancer stem cells anoikis in-depth, and animal experiments confirm that Mig can upregulate the anoikis resistance of CSCs,then promote their metastasis and invasion..Through these studies,we expect to find potential targets for intervention targets of HCC metastasis.

转移复发是肝癌最常见致死原因。研究表明，失巢凋亡抵抗是肝癌侵袭转移的前提；肿瘤干细胞与转移复发关系密切，CD44+CD133+肝癌干细胞具有更强的自我更新和分化潜能；肿瘤微环境中趋化因子对肿瘤干细胞的侵袭转移有重要的调控作用。前期研究发现，趋化因子Mig在乙肝相关性肝癌患者血清和肝癌组织高表达；不同转移潜能肝癌细胞系与失巢凋亡率明显相关；同时发现经Mig刺激后CD44+CD133+肝癌干细胞失巢凋亡率明显降低，但其具体分子机制尚无研究报道。因此，本课题组拟在前期实验基础上，从临床标本分析Mig、CD44+CD133+细胞表达比例与肝癌患者预后的联系；深入研究Mig调控CD44+CD133+肝癌干细胞失巢凋亡的分子机制；动物实验证实Mig可增强CD44+CD133+肝癌干细胞失巢凋亡抵抗，从而促进侵袭转移，以期寻找肝癌转移潜在的干预靶点。

原发性肝细胞癌（HCC）是常见的恶性肿瘤之一，在我国尤其高发，全球超过一半的病例发生在中国，肝癌易发生早期转移和复发，预后很差。研究表明，失巢凋亡抵抗是肝癌侵袭转移的前提，肿瘤干细胞与转移复发关系密切，CD133+为肝癌干细胞的重要标记物，而肿瘤微环境中趋化因子对肿瘤干细胞的侵袭转移也有重要的调控作用。我们前期研究发现，趋化因子Mig在乙肝相关性肝癌患者血清和肝癌组织表达升高，因此，本项目组拟在此基础上，从临床标本分析Mig表达与肝癌患者预后的联系，从细胞水平分析Mig对CD133+肝癌干细胞抵抗失巢凋亡能力及肝癌转移的影响，为肝癌细胞转移寻找潜在的干预靶点。研究结果显示：1）Mig在肝癌组织中高表达，并与肿瘤的分化程度、HBsAg(+)和转移密切相关，此外，Mig的高表达与肝癌患者不良预后有关。2）应用不同浓度的重组细胞因子Mig刺激以及Mig-siRNA、Mig过表达质粒转染CD133+肝癌干细胞后，流式细胞仪检测Mig对CD133+肝癌干细胞失巢凋亡的影响，结果表明，Mig可增强CD133+肝癌细胞的失巢凋亡抵抗能力。3）Transwell实验检测Mig对CD133+肝癌干细胞转移能力的影响，结果表明，Mig可增强CD133+肝癌干细胞的失巢凋亡抵抗，促进其转移。综上所述，Mig可增强CD133+肝癌干细胞的失巢凋亡抵抗并促进其转移，有助于为肝癌转移寻找潜在的干预靶点。