[Targeted blockage of STAT5 by a decoy oligodeoxynucleotide inhibits the growth and proliferation of K562 cells]

Abstract

Objectives: To investigate targeted blockage of BCR/ABL oncoprotein mediated cell transformation by STAT5 decoy oligodeoxynucleotide (ODN), its effect on the growth and proliferation inhibition of K562 cells and the related molecular mechanisms.

Methods: STAT5 decoy ODN, designed and synthesized in vitro, was transfected into K562 cells by cationic lipid. The cell growth curve and colony formation assay were used to reflect the growth and proliferation capacity of K562 cells, RT-PCR to detect the expression of three genes downstream STAT5.

Results: Confocal microscopy demonstrated that STAT5 decoy ODN was successfully transfected into K562 cells (95.2% positive cells). STAT5 decoy ODN inhibited the growth of K562 cells (inhibition rate 77.7%) and their colony formation capacity (Decoy ODN treated group 8.3% vs control group 35.7%, P < 0.05) after the treatment with STAT5 decoy ODN, the expressions of c-myc, bcl-X(L), cyclin D1 mRNA were down-regulated by 15.4%, 30.8%, 29.1%, respectively in the K562 cells.

Conclusions: STAT5 decoy ODN inhibits the growth and proliferation of K562 cells. The mechanisms may be that decoy ODN blocks the transcriptional activation potent of STAT5 and down-regulates the expression of these tumor related genes downstream STAT5.