Clinicopathological significance and prognostic value of polypyrimidine tract binding protein 1 (PTBP1) in gastric cancer

BACKGROUND: Polypyrimidine tract binding protein 1 (PTBP1) is a member of heterogeneous nuclear ribonucleoprotein (hnRNP) family and has recently been reported to contribute to development and progression of various tumors. However, the clinicopathological significance and prognostic value of PTBP1 in gastric cancer have not been sufficiently elucidated. METHODS: Bioinformatic analysis of The Cancer Genome Atlas (TCGA) data were employed to analyze the expression of PTBP1 mRNA and its prognostic value in gastric cancer. The expression type of PTBP1 in gastric cancer cells was further confirmed through reverse transcription polymerase chain reaction (RT-PCR) and western blot assay. Then, the association between PTBP1 protein expression and clinicopathological features was analyzed based on immunohistochemical staining results in gastric cancer tissue microarray including 311 cases. The prognostic value of PTBP1 protein was explored through univariate and multivariate analyses. Additionally, cell count and transwell assay were performed to detect the biological role of PTBP1 in gastric cancer cells in vitro. RESULTS: PTBP1 was highly expressed in gastric cancer cells and tissues at mRNA and protein level. High expression of PTBP1 was closely related to several clinicopathological features, including gender, age at surgery, histological type, TNM stage and lymph node metastasis. Moreover, high expression PTBP1 predicts poor prognosis, and may be an independent prognostic factor for overall survival in gastric cancer patients. Knockdown of PTBP1 substantially suppressed the proliferation, migration and invasion of gastric cancer cells in vitro. CONCLUSIONS: PTBP1 is up-regulated and predicts poor prognosis in gastric cancer. PTBP1 may serve as a biomarker of poor prognosis and a novel target in treating gastric cancer.