[Study on the biological activity and molecular mechanism of IFNalpha on human myeloma cell line Sko-007].
OBJECTIVE
To investigate the biological activity and molecular mechanism of interferon alpha (IFNalpha) on human myeloma cell line Sko-007.


METHODS
The effect of IFNalpha on the growth of Sko-007 cells was measured by MTT assay. Cells cycle distribution and the expression of two IL-6 receptor chains (IL-6R and gp130) on Sko-007 cell surface in the absence or presence of IFNalpha were monitored by FACS analysis. The activation state of protein kinase ERK, which is involved in Ras/MAPK signal transduction pathway mediating cell survival and proliferation, and the expression of anti-apoptotic Bcl-2 family proteins-Bcl-2, Bcl-x(L) and Mcl-1 in Sko-007 cells with or without IFNalpha were determined by immunoblot assay.


RESULTS
IFNalpha arrested Sko-007 cell cycle progression. After stimulation with IFNalpha, an obvious increase in G(0)/G(1) phase (41.1%-->84.1%) and decrease in S phase (57.1%-->13.3%) of Sko-007 cell cycle distribution can be observed. Moreover, the proliferation of Sko-007 cells was dramatically inhibited in the presence of IFNalpha, with a maximal inhibitory rate up to 88%. In addition, the expression of gp130 on cell surface, the activation of protein kinase ERK and the expression of Bcl-2 and Bcl-x(L) were all down-regualted in IFNalpha-stimulated Sko-007 cells.


CONCLUSIONS
The inhibitory effect of IFNalpha on the proliferation of Sko-007 cells was mediated by gp130 down-regulation, degradation of Bcl-2 family anti-apoptotic proteins and inhibition of ERK activation.
Song
Lun
L
Institute of Basic Medical Science, Academy of Military Medical Science, Beijing 100850, China.
Li
Yan
Y
Sun
Yingxun
Y
Shen
Beifen
B
D015703:Antigens, CD / Q000187:drug effects / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D050822:Cytokine Receptor gp130; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004789:Enzyme Activation / Q000187:drug effects; D016193:G1 Phase / Q000187:drug effects; D006801:Humans; D015151:Immunoblotting; D016898:Interferon-alpha / Q000494:pharmacology*; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009101:Multiple Myeloma / Q000378:metabolism / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D019947:Receptors, Interleukin-6 / Q000187:drug effects / Q000378:metabolism; D016192:Resting Phase, Cell Cycle / Q000187:drug effects; D016196:S Phase / Q000187:drug effects; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D051020:bcl-X Protein
D015703:Antigens, CD; C494811:BCL2L1 protein, human; C494199:IL6ST protein, human; D016898:Interferon-alpha; D008562:Membrane Glycoproteins; D019253:Proto-Oncogene Proteins c-bcl-2; D019947:Receptors, Interleukin-6; D051020:bcl-X Protein; D050822:Cytokine Receptor gp130; D020928:Mitogen-Activated Protein Kinases