[CEP192 overexpression is correlated with poor prognosis of gastric cancer and promotes gastric cancer cell proliferation by regulating PLK1/CDK1/Cyclin B1 signaling].

Objective: To investigate the correlation of CEP192 expression with prognosis of gastric cancer and biological behaviors of gastric cancer cells.

Methods: Public databases and clinical tissue samples were used to examine CEP192 expression level in gastric cancer. Kaplan-Meier survival curves, univariate and multivariate Cox regression analyses, ROC curves and bioinformatics analyses were used to explore the risk factors affecting the 5-year postoperative survival, the correlation of CEP192 expression level with the patients' survival, and its biological role in gastric cancer development. In gastric cancer MGC-803 cells with lentivirus-mediated CEP192 interference or overexpression, cell proliferation and expressions of PLK1, CDK1 and Cyclin B1 were examined with CCK-8 assay and Western blotting. The effects of CEP192 knockdown or overexpression on tumorigenesis of MGC-803 cells was observed in nude mice, and the expressions of PLK1, CDK1 and Cyclin B1 in the xenografts were detected.

Results: CEP192 was highly expressed in gastric cancer and associated with poor prognosis of the patients (P < 0.05). High expression of CEP192, CEA ≥5 ng/mL, CA199 ≥37 IU/mL, T3-4 stage, and N2-3 stage were independent risk factors affecting the patients' 5-year postoperative survival (P < 0.05). Bioinformatics analyses suggested that CEP192 was involved in several vital biological processes and positively regulated cell cycle progression. In MGC-803 cells, CEP192 knockdown significantly inhibited cell proliferation and lowered the expression levels of PLK1, CDK1, and Cyclin B1, while its overexpression produced the opposite effects. In the nude mouse models, CEP192 knockdown resulted in lowered tumorigenic potential of MGC-803 cells and decreased protein levels of PLK1, CDK1, and Cyclin B1 in the xenografts, while CEP192 overexpression in MGC-803 cells caused the opposite changes.

Conclusion: CEP192 overexpression is correlated with unfavorable outcomes of gastric cancer patients and promotes gastric cell proliferation by regulating the key proteins during G2/M phase transition.