TY - JOUR
T1 - Nuclear chromatin patterns in 3 glucocorticoid-resistant RPMI 8226 human myeloma cell sub-lines
T2 - Correlations with cell growth and immunological phenotype
AU - Genty, Vincent
AU - El-Khoury, Victoria
AU - Liautaud-Roger, Françoise
AU - Dine, Gérard
AU - Dufer, Jean
PY - 2005/8
Y1 - 2005/8
N2 - Nuclear morphological alterations associated with glucocorticoid resistance in human myeloma were evaluated by image cytometry in three human myeloma RPMI 8226 cell sub-lines. Resistance was induced by drug selection using prednisone (8226p), methyl-prednisolone (8226m) and dexamethasone (8226d), respectively. All these three cell sublines displayed significant glucocorticoid-resistance without cross-resistance to doxorubicin. Nuclear geometry and texture were analyzed on G0/G1-selected cell nuclei and data compared with cell growth characteristics and membrane expression of CD23, CD38, CD44, and CD58 antigens. When compared to the parental RPMI 8226 cell line, glucocorticoid-resistant cells display a progressive chromatin condensation with heterogeneously distributed large chromatin clumps, a phenomenon not observed in the multidrug-resistant CEM-VLB cells. These alterations were correlated to the resistance index against glucocorticoids and to the expressions of CD38, and of CD44 variant forms CD44v5 and CD44v7-8 antigens. These data suggest that glucocorticoid resistance in RPMI 8226 cells could be associated with sub-visual specific higher-order chromatin organization changes. Furthermore, these alterations are correlated to the expression of membrane markers associated with tumors aggressiveness.
AB - Nuclear morphological alterations associated with glucocorticoid resistance in human myeloma were evaluated by image cytometry in three human myeloma RPMI 8226 cell sub-lines. Resistance was induced by drug selection using prednisone (8226p), methyl-prednisolone (8226m) and dexamethasone (8226d), respectively. All these three cell sublines displayed significant glucocorticoid-resistance without cross-resistance to doxorubicin. Nuclear geometry and texture were analyzed on G0/G1-selected cell nuclei and data compared with cell growth characteristics and membrane expression of CD23, CD38, CD44, and CD58 antigens. When compared to the parental RPMI 8226 cell line, glucocorticoid-resistant cells display a progressive chromatin condensation with heterogeneously distributed large chromatin clumps, a phenomenon not observed in the multidrug-resistant CEM-VLB cells. These alterations were correlated to the resistance index against glucocorticoids and to the expressions of CD38, and of CD44 variant forms CD44v5 and CD44v7-8 antigens. These data suggest that glucocorticoid resistance in RPMI 8226 cells could be associated with sub-visual specific higher-order chromatin organization changes. Furthermore, these alterations are correlated to the expression of membrane markers associated with tumors aggressiveness.
KW - CD38
KW - CD44
KW - Chromatin
KW - Glucocorticoids
KW - Image cytometry
KW - Myeloma cell line
KW - Nuclear texture
KW - Resistance
UR - http://www.scopus.com/inward/record.url?scp=25144438597&partnerID=8YFLogxK
U2 - 10.4161/cbt.4.8.1890
DO - 10.4161/cbt.4.8.1890
M3 - Article
C2 - 16210912
AN - SCOPUS:25144438597
SN - 1538-4047
VL - 4
SP - 832
EP - 839
JO - Cancer Biology and Therapy
JF - Cancer Biology and Therapy
IS - 8
ER -