Fig. 5

Retroviral mediated S100A16 over-expression inhibited proliferation, sphere formation and 3D-invasion abilities of OSCC cells in vitro. S100A16 was over-expressed in CaLH3 and H357 cell-lines and subsequent effect on malignant phenotype was examined. a Six thousands control or S100A16 over-expressing CaLH3 or H357 cells were seeded in duplicates in the microtiter E-plates and cell proliferation was measured in real time for 72 h with the xCELLigence system. S100A16 over-expressing cells proliferated significantly slower as compared to the control cells as demonstrated by the normalized cell index. Similarly, sphere formation abilities of S100A16-CaLH3 (b and d) and S100A16-H357 (c and e) cells were significantly reduced as compared to the corresponding controls. Error bars represent SEM of 6 replicates for each experiment. Student’s-t test was performed for statistical analysis. Expt., Experiment. S100A16 over-expression led to significant reduction in the invasive potential of CaLH3 cells in 3D-organotypic cultures (f, invasion quantified in g). Yellow dotted line represents the imaginary basement membrane. Black vertical lines with double arrowheads represent the depth of invasion of malignant keratinocytes. h–j S100A16 mediated functional effects on malignant phenotype were associated with concomitant down-regulation of proliferation/self-renewal markers (Bmi-1 and Oct4A) (h) and invasion-promoting molecules (MMP1 and MMP9 mRNA levels) in CaLH3 and H357 cell-lines (i and j). Error bars in (g) represent SEM of 4 repeated experiments where as in (i and j) represent 3 repeated experiments. Student’s-t test was performed for statistical analyses