Knockdown of nucleostemin can inhibit the proliferation of esophageal carcinoma cells in vitro through upregulating p21.

Background/aims: Esophageal squamous cell carcinoma is a common digestive tract cancer with poor prognosis. Nucleostemin is a nucleolar protein expressed in stem and cancer cells, involved in the regulation of cell proliferation. p21 plays an important role in negative regulation of the cell-cycle. We investigated the role of nucleostemin through regulating p21 expression in the occurrence and progression of human esophageal carcinoma.
Methodology: The expression of nucleostemin and p21 protein and of nucleostemin was knocked-down by means of RNA interference (RNAi) in Eca109 cells. Then, mRNA and protein expressions of nucleostemin and p21 were determined by reverse transcriptase polymerase chain reaction and Western blotting, respectively. In addition, the effect of nucleostemin RNAi on cell proliferation and cell cycle distribution of Eca109 cells were observed.
Results: Nucleostemin was high expressed, but p21 was low expressed in esophageal carcinoma tissues while increased level of nucleostemin protein was associated with reduced p21. inhibition of nucleostemin resulted in an increased expression of p21 and inhibition of cell proliferation, cause G1/G0 phase cells increased and S-phase cells reduced greatly in Eca109 cells.
Conclusion: Silence of nucleostemin inhibit cell proliferation through up-regulating p21 expression and nucleostemin may be involved in the pathogenesis of esophageal squamous cell carcinoma.