[Effect of GRK6 on Proliferation of Multiple Myeloma MM1R Cells and Its Mechanism].

OBJECTIVE: To explore the regulatory effect of GRK6 on the proliferation of multiple myeloma cells and its mechanism. METHODS: A lentivirus vector shRNA interfering in human GRK6 gene expression was constructed and trans-fected into multiple myeloma cells to obtain the cell line MM1R with stable down-regulation of GRK6 gene expression. The real-time quantitative PCR and Western blot were used to confirm the effectiveness of the GRK6 gene expression down-regulation mediated by lentivirus vector. The MM1R cells with most obvious down-regulation were selected to detect the effect of GRK6 gene on cell proliferation. RESULTS: The lentivirus vector GRK6-shRNA interfering in human GRK6 gene was constructed succesufully and transfected into multiple myeloma cells, thereby the MM1R cell line with stable down-regulation of GRK6 gene was obtained. The CCK-8 assay showed that the proliferative viability of MM1R cells in experimental group was significantly lower than that in control group (P<0.05); the flow cytometry showed that cells in experimental group were arrested in G0/G1 phase(P<0.05); the Western blot detection showed that the Cyclin D1 and CDK4 levels in experiment group obviously decreased as compared with control group. CONCLUSION: A lentivirus vector which can specifically interfere in GRK6 gene expression is constructed successfully, The MM1R cell line with stable down-regulation of GRK6 expression is obtained by transfection and screening. The down-regulation of GRK6 expression can arrest MM1R cells in G0/G1 phase, moreover inhibits the proliferation of MM1R cells by inhibition of Cyclin D1 and CDK4 levels.

[Effect of ADAM10 Inhibitor GI254023X on Proliferation and Apoptosis of Multiple Myeloma H929 Cells and Its Possible Mechanisms].

OBJECTIVE: To investigate the effect of ADAM10 inhibitor GI254023X on the proliferation and apoptosis of multiple myeloma H929 cell line and its mechanisms. METHODS: H929 cells were treated with different concentrations of GI254023X, the proliferation-inhibitive curve was assayed and plotted by CCK-8 method, the cell viability and apoptosis were detected by flow cytometry with Annexin V/7-AAD double staining. The cleavage of Notch1 protein (cleaved notch1) was determined by Western blot. The transcripts of Notch1 target gene Hes-1 were detected by real-time PCR. RESULTS: The GI254023X inhibited the proliferation of H929 cells in the time- and dose- dependent manners. As compared with the control group, the apoptosis of cells increased along with enhancement of GI254023X concentration; The expression of cleaved Notch1 was down-regulated after the treatment with GI254023X. The levels of Hes-1 mRNA transcripts in H929 cells was reduced in GI254023X treated group. CONCLUSION: GI254023X can remarkably inhibit the proliferation and induce the apoptosis of H929 cells. Its mechanism may be associated with inbihition of Notch1 activation.