MSC介导的miR-34a/JAG-1/Notch信号通路调控MDS细胞恶性生物学行为的机制研究

Bone marrow microenvironment abnormality play an important role in the pathogenesis of MDS, the interaction between MDS-MSC and MDS malignant clone cells is the key factor, but the specific mechanism is unclear. In previous studies, we found that after co-culture with MDS-MSC, MDS-CD34+ exhibited increased cell proliferation; Microarray data revealed that Notch signals is abnormal in MDS CD34+ cells; MDS-MSC expressed lower miR-34a, the inhibition of target genes JAG-1 is decreased. We infer that MSC dependent JAG-1/Notch signals is a tumorigenesis signal, lack of miR-34a induced over-expression of JAG-1, which contributed to the formation of MDS malignant biological characteristics. To test this hypothesis, we will employ MDS cell lines, and primary cell to reveal the role of MSC in the regulation of the malignancy of MDS cells by miR-34a/JAG-1/NOTCH pathway, using the PCR, WB, FCM, adenovirus transfection /RNAi, et al. This study will lay the foundation for the pathogenesis of MDS from the interaction between MDS-MSC and MDS malignant clone cells, and provide new ideas for MDS treatment in the aspect of microenvironment.

骨髓微环境异常在MDS发病机制中发挥重要作用，MDS-MSC与MDS克隆细胞之间的相互作用是关键因素，但具体机制不明。申请人前期研究显示MDS-MSC与MDS细胞共培养后明显诱导CD34+细胞增殖；基因芯片显示MDS-CD34+细胞Notch信号存在异常，而MDS-MSC Notch信号的重要配体JAG-1高表达，对其可能有靶向调控关系的miR-34a明显低表达。因此，申请人推测MSC依赖的JAG-1/Notch信号是一个原癌信号，miR-34a的缺乏导致JAG-1过表达从而促进MDS细胞恶性增殖。为验证这一假说，我们将通过MDS细胞系、原代细胞，采用PCR、WB、FCM、病毒介导干扰/过表达等手段，探讨miR-34a通过JAG-1/Notch调控MSC介导的MDS细胞恶性生物学特征的分子机制，该项目将从微环境细胞相互作用角度揭示MDS发病机制，为MDS治疗在微环境方面提供新思路。

骨髓微环境异常是骨髓增生异常综合征（MDS)发病机制中的重要因素，其中骨髓间充质干细胞（BMMSC）对MDS细胞的恶性增殖起到重要支持作用。通过本项目我们发现MDS-BMMSC与MDS细胞共培养后可以明显诱导MDS细胞增殖，并且发现MDS-BMMSC中miR-34a低表达，可以负性调控Notch信号的重要配体JAG-1，而过表达miR-34a的BMMSC可以通过下调JAG-1来抑制MDS细胞增殖。另外，MDS-BMMSC中JAG-1高表达，并通过上调MDS细胞的Notch-1受体来促进MDS细胞增殖。这项研究验证了BMMSC介导的miR-34a/JAG-1/Notch-1信号通路调控MDS细胞恶性增殖的分子机制，有助于从微环境细胞相互作用角度揭示MDS发病机制。