Mcl-1 mediates cytokine deprivation induced apoptosis of human myeloma cell line XG-7 / 中华医学杂志(英文版)

ABSTRACT

<p><b>OBJECTIVE</b>To investigate apoptosis in XG-7, a human myeloma cell line, induced by IL-6 deprivation and the function of three anti-apoptotic Bcl-2 proteins (Bcl-2, Bcl-kappa(L), Mcl-1) in the apoptotic process.</p><p><b>METHODS</b>Apoptosis in XG-7 myeloma cells induced by IL-6 withdrawal was determined by flow cytometry with propidium iodide (PI) nuclear staining. Expressions of three Bcl-2 proteins in XG-7 cells were monitored by immunoblotting assay.</p><p><b>RESULTS</b>In the absence of IL-6 for a certain time, a significant percentage of apoptiotic XG-7 cells can be observed, as well as down-regulated expression of one of the three anti-apoptotic proteins (Mcl-1) in XG-7 cells. IL-6 re-stimulation in XG-7 cells following cytokine removal up-regulated the expression of Mcl-1 and inhibited cell apoptosis.</p><p><b>CONCLUSION</b>Mcl-1,instead of Bcl-2 and Bcl-kappa(L), plays an important role in IL-6 deprivation induced apoptosis in XG-7 human myeloma cells.</p>