Psf3 is a prognostic biomarker in lung adenocarcinoma

Psf3 is a member of the evolutionarily conserved heterotetrameric complex GINS (Go-Ichi-Ni-San), which consists of Sld5, Psf1, Psf2, and Psf3. Previous studies have suggested that some GINS complex members are upregulated in cancer, but the status of Psf3 expression in lung adenocarcinoma has not been investigated. The objective of the current study was to determine whether Psf3 plays a role in lung adenocarcinoma by investigating clinical samples. We investigated the status of Psf3 expression in cancer cells of 125 consecutive resected lung adenocarcinomas by immunohistochemistry. Increased Psf3 expression was observed in 27 (21.6%) of the 125 cases. Further, univariate analysis and log-rank test indicated a significant association between Psf3 expression and lower overall survival rate (P = 0.0001 and P < 0.0001, respectively). Multivariate analysis also indicated a statistically significant association between increased Psf3 expression and lower overall survival rate (hazard ratio, 5.2; P = 0.0027). In a subgroup analysis of only stage I patients, increased Psf3 expression was also significantly associated with a lower overall survival rate (P = 0.0008, log-rank test). Moreover, the Ki67 index level was higher in the Psf3-positive group than in the Psf3-low positive group (P < 0.0001, Mann-Whitney U-test). Our results indicated that Psf3 can serve as a prognostic biomarker in lung adenocarcinoma.