Effects of interleukin-6 in epithelial-mesenchymal transition of Barrett's esophagus cells

Abstract

To explore whether the stimulation of interleukin-6 (IL-6) could induce Barrett's esophagus cells (CP-D) to undergo epithelial-mesenchymal transition (EMT). IL-6 was used to treat CP-D cell line at the concentrations of 0, 10, 20, 50 and 100 µg/L. The cell morphological changes were observed after 24 hour. Reverse transcription (RT)-PCR, wound healing assay and transwell assay was used to test the migratory potentials of CP-D cell. Western blot and immunofluorescence methods were performed to detect the expression of E-cadherin and vimentin. After 24-hour exposure of IL-6, CP-D cell lost its polarity and had reduced cell-to-cell adhesion connection. Wound healing assay showed the number of migrating cells was 131 ± 22 in 0 µg/L group, lesser than 10, 20, 50 and 100 µg/L group (328 ± 47, 347 ± 59, 483 ± 62, 492 ± 55, all P < 0.05). Transwell experiments indicated that IL-6 could enhance the invasiveness of CP-D (62 ± 11, 67 ± 15, 97 ± 12, 99 ± 13 vs 13 ± 5, all P < 0.05) . Real-time RT-PCR revealed that increasing concentrations of IL-6 led to a reduction of E-cadherin mRNA expression and an enhancement of vimentin mRNA expression. And significant differences were detected between 20 and 50 µg/L (0.79 ± 0.07 vs 0.47 ± 0.16, P = 0.012; 1.43 ± 0.15 vs 1.78 ± 0.37, P = 0.026). The results of Western blotting were consistent with those of real-time RT-PCR. It indicated that 50 µg/L was the most optimal concentration of IL-6 for inducing EMT in CP-D. IL-6 stimulation may induce CP-D to undergo EMT. As a result, its invasiveness and migration capacity becomes enhanced so as to lead to malignant transformation.