Prognostic Significance of PTTG1 and Its Methylation in Lung Adenocarcinoma

Pituitary tumor-transforming gene-1 (PTTG1), one type of DNA repair-related gene, has been reported to be dysregulated in several tumors and serve as a tumor promotor. Previously, the oncogenic roles of PTTG1 were also reported in lung adenocarcinoma (LUAD). However, the prognostic values of PTTG1 in LUAD and the possible mechanism of its dysregulation have not been clarified. We analyzed TCGA datasets and reported that PTTG1 expression showed a distinct increase within LUAD specimens in comparison with nontumor specimens. Further survival study revealed that patients containing a great PTTG1 level had noticeably less overall survival and progression-free survival as compared with patients containing a low PTTG1 level. Multivariate analyses confirmed that PTTG1 expression was a factor of prognosis that is independent in terms of LUAD patients. Besides, PTTG1 methylation had a negative regulation on PTTG1, so PTTG1 had a high expressing level in LUAD tissues. However, the relation between hypermethylation and overall survival was not demonstrated using TCGA datasets. In addition, we observed that LUAD specimens with advanced stages exhibited a higher level of PTTG1. Finally, the dysregulated genes related to PTTG1 expression were screened, and KEGG assays revealed that the above genes were involved in the p53 signaling pathway, indicating the possible regulatory function of PTTG1 in the p53 signaling pathway. Overall, our findings suggest that PTTG1 may serve as an efficient clinical biomarker and a therapeutic target for patients suffering from LUAD.