Linked Life Data

21380926

Source:http://linkedlifedata.com/resource/pubmed/id/21380926

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2011-3-22
pubmed:abstractText
Previous work from our laboratory demonstrated that glucosylceramide synthase (GCS) and multidrug resistance 1 gene (MDR1) are co-overexpressed in drug-resistant leukemia cells. We hypothesized that GCS and MDR1 may interact. In this study, we used RNA interference (RNAi) to silence the GCS or MDR1 gene in K562/AO2 drug-resistant cells. The sensitivity of cells to different treatments with doxorubicin was evaluated. We used Taqman probe fluorescence real-time quantitative PCR, and detected expression of GCS and MDR1 mRNAs in different interfering groups. Intracellular mean fluorescence intensity (MFI), which represents rhodamine123 (rh123) retention, was determined by flow cytometry (FCM). An MTT cytotoxicity assay showed that the 50% inhibition concentration (IC50) of doxorubicin of K562/AO2 cells (138.25 ± 3.75 µg/ml) was significantly higher than that of K562 drug-sensitive cells (2.125 ± 0.125 µg/ml), and that IC50 was evidently lower in K562/AO2 cells, whether it was transfected with a small interfering RNA (siRNA) targeting GCS (GCSsiRNA) or one targeting MDR1 (MDR1siRNA). Compared with untreated K562/AO2 cells, the inhibition rates of GCS mRNA in the cells transfected with GCSsiRNA for 9 and 36 h were 56.67 ± 9.29% (p < 0.05) and 74 ± 6.38% (p < 0.05), respectively. Interestingly, the expression of MDR1 mRNA was also inhibited to 51.7 ± 4.5% (p < 0.05) 36 h after transfection with GCSsiRNA, but there was no significant difference in MDR1 expression at 9 h post-transfection in cells treated with GCSsiRNA and a negative control. It is well known that rh123 retention in cells results from an efflux function of P-glycoprotein (P-gp). In K562 cells, rh123 retention was much higher than in K562/AO2 cells (p < 0.01). We also noted that rh123 retention in the K562/AO2 cells transfected with GCSsiRNA for 48 h was significantly higher than in the negative control group. In conclusion, we show in the present study that inhibition of the GCS gene affects the expression of MDR1 mRNA and P-gp function.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1865-3774
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
93
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
361-7
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
The effect of glucosylceramide synthase on P-glycoprotein function in K562/AO2 leukemia drug-resistance cell line.
pubmed:affiliation
Department of Pathophysiology, Soochow University, Suzhou 215123, China.
pubmed:publicationType
Journal Article