Overexpression of GP73 promotes cell invasion, migration and metastasis by inducing epithelial-mesenchymal transition in pancreatic cancer

Pancreatic cancer is one of the most difficult clinical cases to diagnose with a very low 5-year survival rate of 5%, regardless of the advances made in both the medical and surgical treatment of the disease. One of the contributing factors for the high mortality rate seen of pancreatic cancer patients is the lack of effective chemotherapies, which is believed to be due to drug-resistance. Based on recent evidence, epithelial-mesenchymal transition (ETM) of pancreatic cancer cells has been found to be associated with the development of drug resistance and an increase in cell invasion. Therefore, we conducted the present study in order to investigate the regulatory effects of Golgi protein-73 (GP73) on PC. GP73 and EMT-related gene expressions in PC, along with the adjacent and chronic pancreatitis tissues were determined by means of RT-qPCR and Western blot analysis. Cultured PC cells were treated with pAdTrack-CMV, si-NC, GP73 overexpression, Si-GP73, Snail-siRNA and GP73 + Snail-siRNA. Cell invasion, migration and metastasis were measured in vitro and in vivo. The results revealed that the PC tissues and chronic pancreatitis tissues exhibited diminished E-cadherin expression and amplified GP73, N-cadherin, Vimentin and Snail expression. In response to GP73 gene silencing, PC cells presented with increased E-cadherin expression and decreased N-cadherin, Vimentin, Snail expression in addition to the inhibition of the number of invasive cells, tumor volume and number of liver lesions. These findings highly indicated that the overexpression of GP73 promotes cell invasion, migration and metastasis by inducing EMT in PC.