Rapamycin inhibiting Jurkat T cells viability through changing mRNA expression of serine/threonine protein phosphatase 2A

Aims: In this study, we analyzed the mRNA expression of serine/threonine (Ser/Thr) protein phosphatase 2A (PP2A) in the human leukemic T-cell line Jurkat cells treated with rapamycin, to determine whether rapamycin inhibiting cell viability is accompanied with the change of mRNA expression of PP2A. Methods and results: Jurkat cells were incubated with various concentrations of rapamycin and cultured for different hours. Cell viability was assessed by MIT assay. The mRNA expressions of PP2A subunits were measured by quantitative real-time polymerase chain reaction (PCR). We found that rapamycin had an inhibitory effect on cell viability. IC50 was 3433 nM at 48 h. We also found rapamycin had a dose and time-dependent effect on the gene expression of PP2A. When setting the concentration of rapamycin 500 nM, the mRNA expressions of PP2A subunits (Aa, A beta, PR55a, PR55 delta, PR61 gamma, PR70, Ca and C beta) were declined significantly at 48 h. When treated with various concentrations of rapamycin for 48 h, the mRNA expressions of PP2A subunits were down-regulated in the range from 10 nM to 500 nM. Conclusions: Rapamycin inhibiting Jurkat T cells viability may be related to the reduction of PP2A mRNA expressions. (C) 2011 Elsevier B.V. All rights reserved.