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Purpose: Our goal was to investigate the effect of SMYD3  on the biological behavior and histone 3 lysine-4 (H3K4) methylation of bladder cancer (BLAC).
Patients and methods: qRT-PCR identified that SMYD3  expression level in BLAC cell lines (T24, 5637, BUI-87 and J-82) and human normal uroepithelial cell line SV-HUC1. We also constructed green fluorescence protein lentiviral vector using the gene short hairpin RNA (shRNA) system. We used Western blot to analyze the SMYD3, H3K4me1, H3K4me2 and H3K4me3 expression levels in shRNA transfection lines. We also performed a colony-forming assay to determine colony-forming ability, cell counting kit-8 for cell proliferation detection, Transwell assay to determine cell migration and invasion and Annexin V-FITC/PI double staining to analyze cell apoptosis.
Results: The SMYD3  expression level was significantly higher in BLAC cell lines (T24, 5637, BUI-87 and J-82) than in human normal uroepithelial cell line SV-HUC1, and exhibited the highest expression level in T24 cells, among the cell lines tested. qRT-PCR and Western blot analysis results showed that SMYD3  was successfully suppressed in shRNA transfection lines, and identified that SMYD3  suppression resulted inhibited H3K4me2 and H3K4me3 but not H3K4me1. SMYD3  knockdown cells accelerated cell apoptosis and exhibited low cell colony-forming ability, proliferation ability, inhibition of cell migration and invasion compared with normal cells.
Conclusion: SMYD3  may be activated in BLAC cells to increase H3K4 activity to modulate cell proliferation, migration and invasion ability. The data will be a useful source for future therapy.
Keywords: SMYD3, H3K4 methylation, bladder cancer, cell proliferation