The relationship between the radioresistance of pancreatic cancer cell SW1990 and the induction of the Epithelial-Mesenchymal Transition: an in vitro study

Abstract

Objective: To investigate the relationship between the radioresistance of pancreatic cancer cell SW1990 and the induction of the Epithelial-Mesenchymal Transition (EMT). Methods: The radio-resistant pancreatic cancer cell SW1990-R were established by using the method of radiating pancreatic cancer cell SW1990 step by step and repeatedly. Then the changes of the morphology of the cell was observed by inverted phase contrast microscope, the radioresistance of SW1990-R was detected by colony-forming assay, and the apoptosis rate of the two cell lines after radiation were measured by flow cytometry. Then invasiveness and EMT-related genes was measured by trans-well test and qRT-PCR. Finally, the model of transplanted tumor on nude mouse was used to confirm the relationship between the radioresistance of pancreatic cancer cell SW1990 and the induction of EMT. Results: Compared with SW1990, SW1990-R had a lower radiosensitivity (survival fraction in 2 Gy, SF2: 0.326 3±0.007 3 vs 0.840 8±0.001 9, P<0.05) and lower apoptosis rate[(6.12±1.27) % vs (16.87±1.73)%, P<0.05]. Meanwhile, the invasive ability of SW1990-R were significant higher than that of SW1990 cell. According to the result of both in vivo and in vitro experiment, SW1990-R had a higher expression level of Vimentin and Snail, and lower expression level of E-cadherin when compared with SW1990. Conclusion: Compared with SW1990, the radio-resistant pancreatic cancer cell SW1990-R can induce the Epithelial-mesenchymal transition.