Upregulation of phosphoserine phosphatase contributes to tumor progression and predicts poor prognosis in non-small cell lung cancer patients.

ABSTRACT

BACKGROUND: Growing evidence indicates that high phosphoserine phosphatase (PSPH) expression is associated with tumor prognosis in many types of cancers. However, the role of PSPH in non-small cell lung cancer (NSCLC) is unclear. The purpose of this study was to investigate the clinical significance of PSPH in NSCLC. METHODS: One hundred forty-three patients with histologically confirmed NSCLC who underwent surgery were included. Quantitative real-time PCR and Western blot were used to assess PSPH expression in paired tumor and corresponding adjacent non-tumorous tissues. The role of PSPH in invasion and cell growth was investigated in vitro. RESULTS: Compared to adjacent normal lung tissues, PSPH messenger RNA and protein levels were significantly higher in NSCLC tissues, and the PSPH expression level was positively related to clinical stage, metastasis, and recurrence. High PSPH expression was predictive of poor overall survival. A549 cells transfected with small interfering-PSPH showed inhibited cell migration, invasion, and proliferation. We further demonstrated that PSPH might promote the invasive capabilities of NSCLC cells through the AKT/AMPK signaling pathway. CONCLUSION: Our results indicate that PSPH may act as a putative oncogene in NSCLC, and may be a vital molecular marker for the metastasis and proliferation of NSCLC cells by regulating the AKT/AMPK signaling pathway.