Upregulated expression of NOP2 predicts worse prognosis of gastric adenocarcinoma by promoting tumor growth

BACKGROUND: NOP2 nucleolar protein plays a crucial role in early embryo development and cell proliferation. The role of NOP2 in human gastric adenocarcinoma has not been elucidated. In the present study, we aimed to examine the expression levels of NOP2 and dissected whether NOP2 expression was associated with aggressive clinicopathological outcomes of patients with gastric adenocarcinoma. METHODS: Clinicopathological analysis was performed in patients with gastric adenocarcinoma. Expression of NOP2 was tested by immunohistochemistry staining and quantitative RT-PCR. The prognostic role of NOP2 in gastric adenocarcinoma patients was assessed by univariate and multivariate analysis. The effect of NOP2 on cell proliferation was examined through cellular experiments and mice models. RESULTS: NOP2 expression was elevated in gastric adenocarcinoma tissues compared to normal gastric tissues. High expression of NOP2 was significantly correlated with tumor size, invasion depth, and lymph node metastasis. Moreover, patients with high NOP2 expression had poorer overall survival, and NOP2 was identified as an independent prognosis factor. Using the gastric adenocarcinoma cells, we found that NOP2 can promote tumor cell proliferation both in vitro and in vivo. CONCLUSIONS: Overexpression of NOP2 significantly correlates with a poorer prognosis of gastric adenocarcinoma patients and suggested the potential of NOP2, which may serve as a novel prognostic biomarker in gastric adenocarcinoma.