Background: This study aimed to investigate the prognostic power of zinc-finger protein 418 (ZNF418 ) in gastric cancer (GC) and its potential role in GC development and progression.
Patients and methods: A total of 10 GC patients’ individual plasmas were collected and screened for dysregulated mRNA using human microarray. Among these dysregulated mRNAs, ZNF418  was found to be significantly downregulated in IIIA–IV stage GC patients compared to IA–IIA stage GC patients. Subsequently, the ZNF418  levels were detected by quantitative reverse transcription-polymerase chain reaction in both GC plasmas and tissues in a larger sample, and the association between ZNF418  expression level and clinicopathological features as well as overall survival (OS) of GC patients was further analyzed. Finally, a network of ZNF418  interactions with other molecules was predicated in STRING and GEPIA databases.
Results: Human mRNA microarray was performed to screen for abnormally expressed mRNAs between five IIIA–IV stage GC patients’ plasma and five IA–IIA stage GC patients’ plasma. A total of 662 mRNAs were differentially expressed in the IIIA–IV stage GC plasma vs IA–IIA stage GC plasma among all the candidate mRNAs according to the Student’s t -test. Results showed that a decrease in the ZNF418  expression level was associated with the presence of GC and also with higher tumor–node–metastasis stage and lower OS rates compared with that in adjacent noncancerous tissues. Cox regression analysis results demonstrated that the OS was independently correlated with ZNF418  expression. Finally, the prediction results showed that a total of eight mRNAs might have an interaction with ZNF418  in both STRING and GEPIA databases.
Conclusion: ZNF418  was first identified to be significantly downregulated in GC. Our study indicated that ZNF418  might serve as a novel biomarker for GC and was involved in GC development.
Keywords: plasma, diagnosis, prognosis, biomarker