Gene expression profiling of NB4 cells following knockdown of nucleostemin using DNA microarrays

Nucleostemin (NS) is mainly expressed in stem and tumor cells, and is necessary for the maintenance of their self-renewal and proliferation. Originally, NS was thought to exert its effects through inhibiting p53, while recent studies have revealed that NS is also able to function independently of p53. The present study performed a gene expression profiling analysis of p53-mutant NB4 leukeima cells following knockdown of NS in order to elucidate the p53-independent NS pathway. NS expression was silenced using lentivirus-mediated RNA interference technology, and gene expression profiling of NB4 cells was performed by DNA microarray analysis. A total of 1,953 genes were identified to be differentially expressed (fold change >= 2 or <= 0.5) following knockdown of NS expression. Furthermore, reverse-transcription quantitative polymerase chain reaction analysis was used to detect the expression of certain candidate genes, and the results were in agreement with the micaroarray data. Pathway analysis indicated that aberrant genes were enhanced in endoplasmic, c-Jun N-terminal kinase and mineral absorption pathways. The present study shed light on the mechanisms of the p54-independent NS pathway in NB4 cells and provided a foundation for the discovery of promising targets for the treatment of p53-mutant leukemia.