CD20 positive cells are undetectable in the majority of multiple myeloma cell lines and are not associated with a cancer stem cell phenotype.
Although new therapies have doubled the survival of multiple myeloma patients, this remains an incurable disease. It has been postulated that the so-called myeloma cancer stem cells would be responsible for tumor initiation and relapse but their unequivocal identification remains unclear. Here, we investigated in a panel of myeloma cell lines the presence of CD20(+) cells harboring a stem-cell phenotype. Thus, only a small population of CD20(dim+) cells (0.3%) in the RPMI-8226 cell line was found. CD20(dim+) RPMI-8226 cells expressed the plasma cell markers CD38 and CD138 and were CD19(-)CD27(-). Additionally, CD20(dim+) RPMI-8226 cells did not exhibit stem-cell markers as shown by gene expression profiling and the aldehyde dehydrogenase assay. Furthermore, we demonstrated that CD20(dim+) 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 myeloma cancer stem cells.
Centro de Investigación del Cáncer, Instituto de Biología Molecular y Celular del Cáncer/Centro de Superior de Investigaciones Científicas-Universidad de Salamanca, Salamanca, Spain.
Teresa
T
Paíno
Enrique M
EM
Ocio
Bruno
B
Paiva
Laura
L
San-Segundo
Mercedes
M
Garayoa
Norma C
NC
Gutiérrez
M Eugenia
ME
Sarasquete
Atanasio
A
Pandiella
Alberto
A
Orfao
Jesús F
JF
San Miguel
D000444:Aldehyde Dehydrogenase / Q000032:analysis; D000818:Animals; D015703:Antigens, CD / Q000235:genetics; D018951:Antigens, CD20 / Q000235:genetics*; D014408:Biomarkers, Tumor / Q000235:genetics*; D045744:Cell Line, Tumor; D005434:Flow Cytometry; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D016130:Immunophenotyping; D051379:Mice; D016513:Mice, SCID; D009101:Multiple Myeloma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology; D010950:Plasma Cells / Q000378:metabolism / Q000473:pathology; D014183:Transplantation, Heterologous
D015703:Antigens, CD; D018951:Antigens, CD20; D014408:Biomarkers, Tumor; D000444:Aldehyde Dehydrogenase