[Effect of hydroxyurea combined with interferon-alpha on growth and apoptosis-related oncogene expression of K562...

To observe the effect of hydroxyurea (HU) alone and in combination with interferon-alpha (IFN-alpha) on the cell growth and cell death, and the related oncogene expression of chronic myelogenous leukemia (CML) cell line, K562 cells. To further investigate the molecular basis of combination therapy on CML by chemotherapeutants combined with cytokines.

The proliferation and viability of K562 cells were detected by cell-counting and trypan blue dye exclusion test. The levels of bcr-abl, bax and c-myc gene expression in K562 cells incubated for 48 hours were examined using RT-PCR technique.

proliferation was suppressed and cell death process was accelerated by both HU and HU combined with IFN-alpha. HU significantly inhibited bcr-abl gene expression and increased bax gene expression level (both P < 0.05 as compared with that of control). Furthermore, IFN-alpha dose-dependently enhanced the regulatory effects of HU on bcr-abl and bax gene expression. HU alone and in combination with IFN-alpha suppressed slightly c-myc gene expression.

Both HU and HU combined with IFN-alpha can inhibit cell proliferation and promote cell death or apoptotic cell death by regulating the expression levels of the genes relating to cell proliferation and apoptosis. The molecular mechanism of HU and IFN-alpha synergistically acting on leukemic cells is further elucidated from the expression level of the related genes which control the balance of survival and death or apoptosis of the cells.