Nucleostemin gene silencing by siRNA and growth inhibition, cell cycle arrest, and apoptosis induction of K562 leukemia cell line

Nucleostemin plays a critical role in controlling proliferation and self-renewal of stem cells and cancer cells. Thus, inhibition of nucleostemin expression could be a potent therapeutic approach in cancer treatment. In the present study, the effects of nucleostemin gene silencing in K562 cell line were studied.

In this experimental study, after transfecting NS-specific siRNA into K562 cells, changes in nucleostemin gene expression pattern were determined by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Trypan blue exclusion test, MTT assay, and fluorescent microscopy were used to evaluate the growth inhibition and apoptosis of K562 cells, respectively. Flow-cytometery was utilized for evaluating the effects of nucleostemin gene silencing on cell cycle.

The results showed the high expression of nucleostemin gene in K562 cells. NS-siRNA transfection into K562 cells at 200 nM inhibited the nucleostemin mRNA level up to 55% after 48 hours when compared to corresponding control cells. Forty eight hours after transfection, the cell growth decreased up to 33.7%. In addition, the silencing of nucleostemin induced G1 cell cycle arrest. Furthermore, fluorescent microscopy assays indicated that apoptosis occurred 48 hours after silencing nucleostemin gene expression.

Noticing the potent growth inhibitory and apoptotic effects of nucleostemin siRNA in human myeloid leukemia K562 cells, silencing this gene can be a potential target for inhibiting K562 cells as the stem cell model of chronic myeloid leukemia.