Inhibition of nm23-H1 gene expression in chronic myelogenous leukemia cells

For solid tumors of a malignant origin, the expression of the nm23-H1 gene is a positive prognostic factor. However, for chronic myeloid leukemia (CML), the prognostic role of nm23-H1 gene expression is unknown. The present study investigated the impact of nm23-H1 gene expression on the proliferation and migration of the CML K562 cell line to elucidate the association between nm23-H1 gene expression and CML cell survival. An RNAi lipo-recombinant plasmid of the nm23-H1 gene (pGCsi-nm23-H1) was constructed and transfected into the K562 cells. RT-PCR and western blotting were used to detect nm23-H1 mRNA and protein expression, respectively. The anchorage-independent growth ability of the transfected cells was observed in soft agar culture and the ability of the K562 cells to migrate was determined using a Transwell assay. Following the successful construction and transfection of the pGCsi-nm23-H1 plasmid into the K562 cells, nm23-H1 mRNA and protein expression levels were significantly lower compared with the control group. The stably-transfected pGCsi-nm23-H1 K562 cells exhibited a markedly increased ability to form colonies and the number and sizes of the colonies were significantly increased compared with those of the control. In vitro, the cells migrated through a Matrigel-coated membrane during incubation for 20 h. The Transwell assay revealed that the quantitative number of pGCsi-nm23-H1 K562 cells that migrated into the lower compartment of the invasion chamber was markedly increased compared with the control. In conclusion, nm23-H1 gene expression may inhibit K562 cell proliferation and migration. nm23-H1 may be a cancer suppressor gene and play a significant role in inhibiting the survival of CML cells.