[Effect of glucosylceramide synthase on P-gp expression by ERK signal transduction pathway in leukemia multi-drug resistance cell line].
OBJECTIVE
To investigate the effect of glucosylceramide synthase (GCS) on P-glycoprotein (P-gp) expression via extracellular signal-regulated kinase (ERK) pathways in leukemia K562/A02 cell line.


METHODS
K562/A02 multidrug resistance cells were treated with GCS siRNA and U0126, respectively. Expression of multidrug resistance protein 1 (MDR1) mRNA was analyzed with qRT-PCR. Phosphorylated ERK1/2, total ERK1/2 protein and P-gp in different groups were measured with Western blotting.


RESULTS
After treated with U0126, P-ERK1/2 was decreased along with the increased U0126 concentration. P-ERK1/2 and P-gp were apparently down-regulated by U0126 at the concentrations of 20 μmol/L, 40 μmol/L and 60 μmol/L. After being transfected with GCS siRNA, GCS mRNA was inhibited by 70.50% (58.00%-76.00%) in K562/A02 cells. Compared with the negative control, both P-ERK1/2 and P-gp were inhibited significantly after RNAi for 72 hours (P<0.01 and P<0.05, respectively.


CONCLUSIONS
GCS may affect the expression of P-gp by ERK signal transduction pathway in leukemia cells.
Department of Pathophysiology, Medical College, Soochow University, Suzhou, Jiangsu 215123, P.R. China.
Yu-ling
YL
Li
Ke-ming
KM
Xie
Yang-yang
YY
Zhang
Hui-jun
HJ
Mu
Bin
B
Zhang
Jian
J
Zou
Ping
P
Xie
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D005964:Glucosyltransferases / Q000378:metabolism*; D006801:Humans; D020014:K562 Cells; D007938:Leukemia / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D005964:Glucosyltransferases; C023246:ceramide glucosyltransferase