OBJECTIVETo inhibit the expression of beta-catenin and investigate the effect of the beta-catenin gene on Jurkat and K562 cells.

METHODSsiRNA specifically knocking down the expression of beta-catenin was used to testify the function of beta-catenin in Jurkat and K562 cells. Real time polymerase chain reaction and Western blot were performed respectively to testify the mRNA level and protein level of beta-catenin. Growth curve was determined by counting viable cells using trypan blue refusal-dyed method. The proliferation of cells was assayed by clonogenic counting and MTT method. The apoptotic cells were measured by Annexin V/PI staining. The cell cycle analysis was performed based on propidium iodide staining.

RESULTSCompared with the control group (transfected with siRNA directed against scramble gene), the survival, colonogenicity, and proliferation of the Jurkat and K562 cells were significantly decreased in experimental group transfected with beta-catenin siRNA. The colonogenicity was decreased from 31.9 +/- 5.55 (siRNA) to 25.0 +/- 5.13 (control) in Jurkat cells, and from 47.33 +/- 8.52 (siRNA) to 39.33 +/- 6.26 (control) in K562 cells (both P <0.05). The inhibition rate was (49.3 +/- 9.86)% (siRNA) and (15.1 +/- 6.55)% (control) respectively in Jurkat cells, and (39.4 +/- 7.56)% (siRNA) and (10.1 +/- 6.89)% (control) in K562 cells (both P <0.05). In addition, the apoptotic rate increased from (23.5 +/- 2.82)% (control group) to (55.9 +/- 2.22)% (experiment group) in Jurkat cells and from (14.9 +/- 8.54)% (control group) to (27.9 +/- 15.3)% (experiment group) in K562 cells. However, cell cycle analysis revealed no obvious phases change both in Jurkat and in K562 cells.

CONCLUSIONKnock-down of beta-catenin gene may decrease the proliferation, survival, and clonogenicity in Jurkat cells and K562 cells.