The establishment of an interleukin-6-dependent myeloma cell line (FLAM-76) carrying t(11;14)(q13;q32) chromosome abnormality from an aggressive nonsecretory plasma cell leukemia.
A novel mature B-cell line (DOBIL-6) producing both parathyroid hormone-related protein and interleukin-6 from a myeloma patient presenting with hypercalcaemia.
We explored the molecular mechanisms involved in the establishement of CMA-03/06, an IL-6-independent variant of the multiple myeloma cell line CMA-03 previously generated in our Institution.
In addition, IFN treatment attenuated the interleukin 6 (IL-6)-dependent activation of signal transducer and activator of transcription 3 (Stat3), interfering with a known survival pathway in MM that has previously been linked with resistance to Fas-mediated apoptosis.
Although a reason for the overexpression in myeloma cells is not understood, very interestingly, the promoter region of the HM1.24 gene has a tandem repeat of three cis elements for a transcription factor, STAT3, which mediates interleukin-6 (IL-6) response gene expression.
Our results also demonstrated that APE1/Ref-1-specific siRNA significantly inhibited DNA binding activity of AP-1 and nuclear factor-κB (NF-κB), 2 important transcription factors in the regulation IL-6/8 secretion in MM BMSCs.
Taken together, these results delineate a key role for Hck-mediated phosphorylation of Gab1 and Gab2 docking proteins in IL-6-induced proliferation and survival of multiple myeloma cells and identify tyrosine kinases and downstream adapter proteins as potential new therapeutic targets in multiple myeloma.
A definitive separation of both putative sources for IL-6 may be difficult to achieve in fresh patient IL-6 growth requirement and production by pure myeloma cell populations using seven human myeloma cell lines (OCI-My 1 to 7) that were established from patients with advanced disease.
A crosstalk between myeloma cells and marrow stromal cells stimulates production of DKK1 and interleukin-6: a potential role in the development of lytic bone disease and tumor progression in multiple myeloma.
In this study we investigated myeloma cell apoptosis induced by IFN alpha using five human myeloma cell lines which were established without any additional supplementation of IL-6.
We identified both quantitative and qualitative changes in exosomes and exosomal miRNA, as well as inhibition of IL-6 trans-signaling, as molecular mechanisms mediating anti-MM activity.
To determine whether the receptor for IL-6 may exist as a soluble molecule, RNA was analysed from the transformed B-cell lines U266, CESS and Daudi, from bone marrow from two myeloma patients, and from normal leukocytes.