Expression of human Jagged-1 protein on eukaryotic cells and establishment of stable transfectant cell line / 中国实验血液学杂志

Jagged-1 protein is one of the ligands belonging to Notch signaling pathway. Notch signaling pathway is one of the major signaling pathways mediated by contact between cells and plays an important role to regulate the process of proliferation and differentiation of hematopoietic cells in the hematopoietic microenvironment. To study the biological effect after the combination of receptor and ligand in Notch signaling pathway and the mechanism of Notch signaling pathway in bone marrow stromal cells mediated-drug resistance, a NIH-3T3 cell line over-expressing Jagged-1 protein was constructed for further research purposes. A full coding region of Jagged-1 gene was cloned and inserted into eukaryotic expression plasmid to construct pEGFP-IRES2-Jagged-1 eukaryotic expression vector, then transfected into NIH-3T3 cell line, a mammalian cells. As a result Western blot analysis confirmed that the transfectant NIH-3T3 cells highly expressed Jagged-1 protein and flow cytometry analysis confirmed that the NIH-3T3-pEGFP-IRES2-Jagged-1 cell line over-expressed Jagged-1 protein was monoclonal after screened by selective medium and limiting dilution analysis. It is concluded that the pEGFP-IRES2-Jagged-1 eukaryotic expression vector and a stable transfectant monoclonal NIH-3T3 cell line are successfully established. The construction of the stable transfectant monoclonal NIH-3T3 cell line which overexpressed Jagged-1 protein, provides the conditions to further study the mechanism of the bone marrow stromal cell-mediated drug resistance and to discover the new drug targets.

Notch signaling pathway and multiple myeloma / 中国实验血液学杂志

Notch signaling pathway is a main pathway through cell-cell interactions, which regulates the programmed cell death, cellular proliferation and differentiation in multiple cell systems, and also is an important signaling pathway to modulate the balance between proliferation and differentiation in hematopoietic environment, and is related with the incidence of multiple hematologic malignancies. Multiple myeloma (MM) is malignant in B cell lineage and characterized by clonal proliferative plasma cells. It is very difficult to cure MM patients with a low proliferation rate of the MM cell and drug resistance to the standard dosage of chemotherapy. In recent years, research has shown that in the malignant plasma cells of the patients with multiple myeloma (MM) and the cell lines, but not in normal plasma cells or tumor cells from patients with other malignancies, the Notch ligand Jagged2 was found to be overexpressed. Jagged2 can induce stromal cells to secrete IL-6, VEGF and IGF-1. Notch activation can interact with NF-kappaB and C-myc to promote the proliferation and to inhibit the apoptosis of MM cells, showing in the relationship between the incidence of myeloma and drug resistance. Inhibition of the Notch signaling pathway may induce the apoptosis of MM cells and enhance the effect of chemotherapy. Study indicated that the specific inhibition of Notch signaling by treatment with a gamma-secretase inhibitor (GSI) alone, a specific pharmacologic inhibitor of Notch signaling, induces the apoptosis of myeloma cells and improves sensitivity of myeloma cell to chemotherapy when combined. In this article the composition of Notch signalling pathway, the mechanism of Notch signalling pathway and the relation of Notch signalling pathway to multiple myeloma were reviewed.