Fig. 5.

Silence of ST8SIA2 gene enhances the invasive ability and chemoresistance of MHCC97L cells both in vitro and in vivo. A, silencing of ST8SIA2 in MHCC97L cells was analyzed via the RNAi approach. ST8SIA2 transcripts were decreased apparently by shRNA treatment in MHCC97L cells. B, after shRNA transfection, a distinct reduction of ST8SIAII was observed at the protein level in Western blot analysis. C, differential FITC-Siglec7 binding profiles of MHCC97L, MHCC97L-control shRNA, and MHCC97L-ST8SIA2 shRNA1 cell lines using flow cytometry. Histograms of fluorescence intensities of cells with specific carbohydrate expression as determined. D, in vitro ECMatrix gel analysis was performed. The average number of cells that invaded through the filter was counted. MHCC97L-ST8SIA2 shRNA1 cells were significantly more invasive (*p < 0.05) than the MHCC97L and MHCC97L-control shRNA cells. E, cell chemosensitivity was assessed via MTT assay. The reported values were the IC₅₀ (mean ± S.D.) of three independent experiments (IC₅₀ represents the drug concentration producing a 50% decrease in cell growth). *p < 0.05 versus MHCC97L-control shRNA cells. F, an increase in mean tumor weight in mice with MHCC97L-ST8SIA2 shRNA1 tumors was observed relative to the control group (*p < 0.05). G, reduced regulation of ST8SIAII was also shown by IHC staining in xenograft tumors derived from MHCC97L-ST8SIA2 shRNA1 cells (400×). The data are means ± S.D. of three independent assays (*p < 0.05).