上调白血病骨髓基质细胞与耐药白血病细胞间GJIC功能逆转白血病细胞耐药的作用及机制研究

The function of gap junction protein ( Cx43 ) consists of gap junctional intercellular communication ( GJIC ) between leukemic bone marrow stroml cells is decrease, which took part in drug resistance of leukemia cells. But its channel function between leukemic bone marrow stromal cells and drug-fast leukemic cells and the impact on drug resistance in leukemia cells is still unclear. The previous studies by the Applicants found that the expression of drug resistance in leukemia cells Cx43 significantly decreased, that infers its ability to form effective channels with the marrow stromal cells also decreased, It might be an important factor that the leukemic cells acquired drug resistance,so,up-regulate the channel function can reverse the drug resistance in leukemia cells. To test this hypothesis, this study intends to establish a co-culture model using leukemic marrow stromal cells and leukemic cells, up-regulating the GJIC function between them by the gene transfection of Cx43, to observe its effect on drug resistance of leukemia cell apoptosis, cell cycle, cell co-culture of drug distribution in biological behavior, confirme the drug resistance of leukemic cells can be reversed by up-regulating the GJIC function between leukemic marrow stromal cells and drug-fast leukemic cells.and through the regulation of the resistance factors of -Ca2+ concentration by GJIC transfer, to clarify the possible mechanism of reversing the drug resistance in leukemia cells by up-regulatiing GJIC function, And Hope to reverse the drug resistance in leukemia cells by regulatiing GJIC function of the hematopoietic microenvironment.

白血病骨髓基质细胞间隙连接细胞间通讯（GJIC）功能缺失参与了白血病耐药的发生，但GJIC在白血病骨髓基质细胞与白血病细胞之间的功能状态如何及对白血病细胞耐药有何影响尚不明确。申请者前期研究发现耐药白血病细胞间隙连接蛋白43(Cx43)的表达明显下降，推测将减弱其与白血病基质细胞之间的GJIC功能，这可能是白血病细胞产生耐药的重要因素，上调两者间GJIC功能可逆转白血病细胞耐药。为验证此假设，本研究拟建立白血病骨髓基质细胞与耐药白血病细胞共培养模型，通过Cx43基因转染的方法上调两者间GJIC功能，检测共培养的耐药白血病细胞增殖、凋亡、药敏等生物学效应的改变，探讨上调骨髓基质细胞与耐药白血病细胞间GJIC功能对白血病细胞耐药的逆转作用；通过对经GJIC传递的Ca2+在白血病细胞内浓度的调控，阐明上调GJIC功能逆转白血病细胞耐药的机制，探索从改造GJIC功能角度逆转白血病细胞耐药的新方法。

白血病骨髓基质细胞间隙连接细胞间通讯（GJIC）功能缺失参与了白血病耐药的发生，但GJIC在白血病骨髓基质细胞与白血病细胞之间的功能状态如何及对白血病细胞耐药有何影响尚不明确。申请者前期研究发现耐药白血病细胞间隙连接蛋白43(Cx43)的表达明显下降，推测将减弱其与白血病基质细胞之间的GJIC功能，这可能是白血病细胞产生耐药的重要因素，上调两者间GJIC功能可逆转白血病细胞耐药。为验证此假设，本研究建立了白血病骨髓基质细胞与耐药白血病细胞共培养模型，通过Cx43基因转染的方法上调两者间GJIC功能，检测共培养的耐药白血病细胞增殖、凋亡、药敏等生物学效应的改变，结果发现：通过转染白血病骨髓基质细胞与耐药白血病细胞上Cx43的表达，上调二者之间的GJIC功能后，可以增加耐药白血病细胞对化疗药物的敏感性，增加凋亡，在一定程度上逆转白血病细胞耐药；进一步研究发现，上调GJIC功能后白血病细胞内钙离子浓度明显增加，这和其对白血病细胞耐药的逆转密切相关；上调白血病细胞内钙离子浓度通过调控BCL-2及P-gp等耐药相关蛋白的表达逆转白血病细胞耐药。研究结果初步阐明上调GJIC功能逆转白血病细胞耐药的机制，为从改造GJIC功能角度逆转白血病细胞耐药的提供了新的方法。