Expression and inhibitory effects of p53-upregulated modulator of apoptosis in gallbladder carcinoma

The p53-upregulated modulator of apoptosis (PUMA) has been reported to be involved in various types of cancer. However, its potential biological role in gallbladder carcinoma (GBC) has not been fully elucidated. The present study aimed to determine the expression levels of PUMA and its biological effects on GBC. The mRNA and protein expression levels of PUMA in GBC tissues and cell lines were measured using reverse transcription-quantitative PCR and western blotting, respectively. The effects of PUMA overexpression on cell viability, proliferation and invasive ability were determined in vitro using the MTT, colony formation and Transwell invasion assays, respectively. The apoptotic rates were detected using the Annexin V-FITC apoptosis detection kit. Furthermore, follow-up of patients with GBC was performed to identify the association between PUMA expression levels and GBC prognosis. The results of the present study demonstrated that the expression levels of PUMA were significantly lower in the GBC tissues and cell lines compared with those in adjacent normal gallbladder tissues and normal gallbladder cells, respectively. Further experiments indicated that overexpression of PUMA inhibited the viability, proliferation and invasive ability of GBC cells compared with those in the control-transfected GBC cells. In addition, overexpression of PUMA significantly promoted apoptosis in GBC cells. Furthermore, overexpression of PUMA inhibited epithelial-mesenchymal transition, and promoted Bax upregulation and Bcl-2 downregulation compared with those in the control group. Low PUMA expression levels were associated with a short overall survival time in patients with GBC. In conclusions, PUMA may act as a tumor suppressor in GBC and may serve as a potential novel treatment target for human GBC.