PTTG3P promotes gastric tumour cell proliferation and invasion and is an indicator of poor prognosis.

Pseudogenes play a crucial role in cancer progression. However, the role of pituitary tumour-transforming 3, pseudogene (PTTG3P) in gastric cancer (GC) remains unknown. Here, we showed that PTTG3P expression was abnormally up-regulated in GC tissues compared with that in normal tissues both in our 198 cases of clinical samples and the cohort from The Cancer Genome Atlas (TCGA) database. High PTTG3P expression was correlated with increased tumour size and enhanced tumour invasiveness and served as an independent negative prognostic predictor. Moreover, up-regulation of PTTG3P in GC cells stimulated cell proliferation, migration and invasion both in vitro in cell experiments and in vivo in nude mouse models, and the pseudogene functioned independently of its parent genes. Overall, these results reveal that PTTG3P is a novel prognostic biomarker with independent oncogenic functions in GC.