Objective      To determine the expression of nucleostemin (NS)

Cyclin B1 and tumor suppressor gene

phosphatase and tensin homolog (PTEN) at mRNA and proteins levels in Shantou human embryonic esophageal epithelial cell line (SHEE) and Shantou human embryonic esophageal carcinoma epithelial cell line (SHEEC).       Methods      The SHEE and SHEEC cells were continuously subcultured

and the cells at the logarithmic growth phase were selected for the expression of NS

Cyclin B1 and PTEN at mRNA and proteins levels by RT-PCR and Western blotting. The levels were analyzed for correlation. Cell viability was detected by MTT assay after interference expression of NS.       Results      The mRNA expression of NS and Cyclin B1 were 2.047±0.507 and 2.214±0.213 times higher

while that of PTEN was 0.668±0.188 times lower in the SHEEC cells than the SHEE cells (P0.05). Significance differences were also seen in the protein levels of NS

Cyclin B1 and PTEN between the SHEE and SHEEC cells (1.142±0.113 vs 3.161±0.108

1.585±0.056 vs 2.173±0.058

1.894±0.341 vs 1.162±0.524

P0.05). The mRNA and protein expression levels of NS were positively correlated with those of Cyclin B1 (r=0.832

P0.01；r=0.991

P0.01)

and negatively correlated with PTEN (r=-0.924

P0.01；r=-0.769

P0.05). MTT assay showed that there were no significant difference in cell proliferation among NS RNAi group

MOCK group

and NC group at 12 h after RNA interference

but significant differences were seen in 24

36 and 48 h thereafter (P0.05).       Conclusion      The expression of NS and Cyclin B1 at mRNA and protein levels are higher

while those of PTEN is lower in SHEEC cells than SHEE cells. NS may affect the malignant progression of cells.