Biological and molecular characterization of CMA03/06, a newly established interleukin-6 independent variant of the CMA03 human myeloma cell line.

ABSTRACT: We performed a biological and molecular characterization of the novel human multiple myeloma cell line CMA03/06, an IL-6-independent variant of CMA03 cell line previously established in our Institution. We showed that the CMA03/06 cells grows in the absence of IL-6 with a doubling time comparable to CMA03; the addition of IL-6 to the culture medium or co-culture with multipotent mesenchymal stromal cells does not induce an increase in proliferation rate. Interestingly, we provided evidence that IL-6 independence of CMA03/06 cells is not a consequence of the development of an autocrine IL-6 loop, even though the cells maintain the IL-6 signaling pathway responsiveness as demonstrated by STAT1 and STAT3 induction by IL-6. A slight constitutive activation of STAT3 has been observed in CMA03/06 cell line; however STAT3 silencing in CMA03/06 cells did not affect their viability and proliferation suggesting that this pathway is not the only responsible for the IL-6 independency of CMA03/06 cell line. The new cell line showed a lower susceptibility to camptothecin-induced apoptosis compared to CMA03 cells, whereas an increased induction of apoptosis was observed in CMA03/06 cell line after Bortezomib treatment which may suggest the involvement NF-kB pathway in the IL-6 independent growth and survival of CMA03/06 cells. Finally, global gene expression profiling analysis allowed the identification of a list of 308 modulated genes in CMA03/06 versus CMA03 cells, many of which particularly relevant for MM biology. Overall, the novel CMA03/06 cell line may represent a suitable model for studies investigating molecular mechanisms involved in clonal evolution towards IL-6 and/or stroma-independent growth and survival of myeloma cells. This series of microarray experiments contains the gene expression profiles of 3 independent replicas of CMA03 grown in in normal culture conditions and in absence of IL-6, respectively, and 3 independent replicas of CMA03/06 in normal culture conditions. Cell pellets were resuspended in TRIzol Reagent (Life Technologies, Inc., Rockville, MD, USA), total RNA was then purified using the RNeasy® total RNA Isolation Kit (Qiagen, Valencia, CA).5.5 micrograms of single-stranded DNA target obtained from 100 ng of purified total RNA was fragmented and then labeled using the WT Terminal Labeling Kit according to the standard Affymetrix protocol (GeneChip® Whole Transcript (WT) Sense Target Labeling Assay Manual).The fragmented labeled single-stranded DNA target was hybridized for 16 hr 30 minutes at 45°C on GeneChip® Gene 1.0 ST array according to the standard Affymetrix protocol. The arrays were washed and stained in the Affymetrix Fluidics Station 450.

ORGANISM(S): Homo sapiens

SUBMITTER: Antonino Neri 

PROVIDER: E-GEOD-39685 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress