Furthermore, IFNAR1 expression level positively correlated to overall survival of patients with multiple myeloma (MM), and the IFN-α level in patient bone marrow was significantly lower than that in marrow of healthy individuals.
We discovered that among several myeloma growth/survival factors tested (including IL6, oncostatin M, insulin-like growth factor 1, tumor necrosis factor α and IFNα) IFNγ was the strongest inducer of BCL6 mRNA and protein expression in MM cell lines.
In MM cells undergoing IFN-induced sensitization to Fas-mediated apoptosis, the repression of telomerase was increased as compared to IFN-alpha treatment alone.
Also, treatment of the IgE-producing human myeloma cell line U266BL with IFN-tau-reduced IgE production and inhibited cell proliferation compared with media controls.
Furthermore, the study demonstrates that MM cell lines are not simultaneously sensitive to IFN-gamma and alpha, indicating that the mechanisms of action of the two types of IFN are distinct.