Objectives: To investigate the effect of glycopeptide-preferring polypeptide GalNAc transferase 1 (ppGalNAcT1 ) targeted RNA interference (RNAi) on the growth and migration of human bladder carcinoma EJ cells invitro and in vivo. Methods: DNA microarray assays were performed to determine ppGalNAc Ts(ppGalNAc T1-9)expression in human bladder cancer and normal bladder tissues. We transfected the EJ bladder cancer cell linewith well-designed ppGalNAc T1 siRNA. Boyden chamber and Wound healing assays were used to investigatechanges of shppGalNAc T1-EJ cell migration. Proliferation of shppGalNAc T1-EJ cells in vitro was assessedusing [3H]-thymidine incorporation assay and soft agar colony formation assays. Subcutaneous bladder tumorsin BALB/c nude mice were induced by inoculation of shppGalNAc T1-EJ cells and after inoculation diametersof tumors were measured every 5 days to determine gross tumor volumes. Results: ppGalNAc T1 mRNA inbladder cancer tissues was 11.2-fold higher than in normal bladder tissues. When ppGalNAc T1 expressionin EJ cells was knocked down through transfection by pSUPER-shppGalNAc T1 vector, markedly reducedincorporation of [3H]-thymidine into DNA of EJ cells was observed at all time points compared with the emptyvector transfected control cells. However, ppGalNAc T1 knockdown did not significantly inhibited cell migration(only 12.3%). Silenced ppGalNAc T1 expression significantly inhibited subcutaneous tumor growth comparedwith the control groups injected with empty vector transfected control cells. At the end of observation course (40days), the inhibitory rate of cancerous growth for ppGalNAc T1 knockdown was 52.5%. Conclusion: ppGalNAcT1 might be a potential novel marker for human bladder cancer. Although ppGalNAc T1 knockdown caused noremarkable change in cell migration, silenced expression significantly inhibited proliferation and tumor growthof the bladder cancer EJ cell line.
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