Project description:Although new therapies have doubled the survival of multiple myeloma (MM) patients, this remains an incurable disease. It has been postulated that the so-called MM Cancer Stem Cells (MM-CSC) would be responsible for tumor initiation and relapse but their unequivocal identification remains unclear. Here, we investigated in a panel of MM cell lines the presence of CD20+ cells harboring a MM-CSC phenotype. Among the multiple cell lines investigated, only a small population of CD20dim+ cells (0.3%) in the RPMI-8226 cell line was found. CD20dim+ RPMI-8226 cells expressed the plasma cell markers CD38 and CD138 and were CD19-CD27-. Additionally, CD20dim+ RPMI-8226 cells did not exhibit stem-cell markers as shown by gene expression profiling and the aldehyde dehydrogenase (ALDH) assay. Moreover, we demonstrated that CD20dim+ RPMI-8226 cells are not essential for CB17-SCID mice engraftment and show lower self-renewal potential than the CD20- RPMI-8226 cells. These results do not support CD20+ expression for the identification of MM-CSC.
Project description:Multiple Myeloma (MM) is an hematological malignancy. MM cells are resistant to X-ray irradiations. We irradiated RPMI 8226 cancer cells with C-ions, which are more energetic than X-ray irradiations. We found that MM cells, RPMI 8226, are also resistant to C-ion irradiations. We used microarrays to investigate the mechanisms of MM cell resistance to C-ion irradiations.
Project description:Multiple Myeloma (MM) is an hematological malignancy. MM cells are resistant to X-ray irradiations. We irradiated RPMI 8226 cancer cells with C-ions, which are more energetic than X-ray irradiations. We found that MM cells, RPMI 8226, are also resistant to C-ion irradiations. We used microarrays to investigate the mechanisms of MM cell resistance to C-ion irradiations. MM cells, RPMI 8226, were subjected to 0 or 6 Gy doses of C-ion irradiations. RNA were extratred from each batch of cells one day after irradiations and subjected to microarray analysis.
Project description:We analyzed gene expression profiles of myeloma cells belonging to the group of bas prognosis RPMI 8226 and LP1 expressing either the GFP protein or a cyclin D1-GFP fusion protein
Project description:Although new therapies have doubled the survival of multiple myeloma (MM) patients, this remains an incurable disease. It has been postulated that the so-called MM Cancer Stem Cells (MM-CSC) would be responsible for tumor initiation and relapse but their unequivocal identification remains unclear. Here, we investigated in a panel of MM cell lines the presence of CD20+ cells harboring a MM-CSC phenotype. Among the multiple cell lines investigated, only a small population of CD20dim+ cells (0.3%) in the RPMI-8226 cell line was found. CD20dim+ RPMI-8226 cells expressed the plasma cell markers CD38 and CD138 and were CD19-CD27-. Additionally, CD20dim+ RPMI-8226 cells did not exhibit stem-cell markers as shown by gene expression profiling and the aldehyde dehydrogenase (ALDH) assay. Moreover, we demonstrated that CD20dim+ RPMI-8226 cells are not essential for CB17-SCID mice engraftment and show lower self-renewal potential than the CD20- RPMI-8226 cells. These results do not support CD20+ expression for the identification of MM-CSC. For detailed description of Material and Methods, see supplementary Methods. The human MM cell lines RPMI-8226, U266, MM1S, MM1R, NCI-H929, RPMI-LR5, U266-LR7 and U266-Dox4 were studied. Cells were cultured as previously described [Ocio, 2009, 3781]. MM cell lines were immunophenotyped using a 7-color immunofluorescence technique [Paiva, 2011, 697], with the following combination of monoclonal antibodies (Pacific Blue (PB)/ anemonia majano cyan (AmCyan)/ fluorescein isothiocyanate (FITC)/ peridinin chlorophyll protein-cyanin 5.5 (PerCP-Cy5.5)/ PE-cyanin 7 (PE-Cy7)/ allophycocyanin (APC)/ alexafluor 700 (AF700)): CD19/CD45/CD20/CD138/CD27/CD56/CD38. Data were stored for a minimum of 3x105 events. CD20dim+ and CD20- RPMI-8226 cells were sorted after incubation with CD20-APC/7AAD and acquisition on a FACSAria cytometer (Becton Dickison Biosciences). Sorting was performed only for viable cells (7AAD-) and debris were excluded by scatter properties. The CD20- and CD20dim+ RPMI-8266 sorted cells had a final purity of 98% and 88%, respectively. CD20dim+ and CD20- RPMI-8226 cells were extensively characterized. Morphological characterization was done with May-Grünwald-Giemsa staining. Characterization of VDJH and IGKappa rearrangements was performed as described elsewhere [BIOMED-2, BMH4-CT98-3936]. The expression of aldehyde dehydrogenase (ALDH) was assessed using the Aldefluor Kit (StemCell Technologies) following manufacturer’s instructions with further staining with a CD20-APC antibody. For gene expression profile studies, RNA was isolated, labeled and hybridized to Human Gene 1.0 ST array (Affymetrix) according to Affymetrix protocols [Gutiérrez, 2005, 402]. The arrays were analyzed using the DNA-Chip Analyzer software (DChip). Fold change ≥2 was considered significant.
Project description:We analyzed gene expression profiles of myeloma cells belonging to the group of bas prognosis RPMI 8226 and LP1 expressing either the GFP protein or a cyclin D1-GFP fusion protein Two cell lines RPMI 8226 and LP1. Two clones from each cell line GFP and cyclin D1-GFP. Four biological replicates independently grown and harvested. One replicate per array.
Project description:Gene expression of side population (SP) and major population (MP) of myeloma cell lines (RPMI-8226 and KMS-11) cultured under normoxic or hypoxic conditions for 48 h.
Project description:To determine the pharmacological mechanism of XYA1353 to MM, RNA-seq was performed to compare gene expression in RPMI-8226 cells treated by compound XYA1353 or not. We then performed gene expression profiling analysis using data obtained from RNA-seq of 2 cells.
