Figure 1. LiCl expands the population of stem-like cells in the Weri and Y79 retinoblastoma cell lines. A: LiCl significantly increased the number of ABCG2 and Musashi-1 (Msi-1) immunoreactive cells. Weri and Y79 human retinoblastoma cells were treated with 0, 20, and 40 mM LiCl for 48 h and then immunostained. The number of cells expressing ABCG2 (left) or Musashi-1 (Msi-1; right) were counted. The differences between 20 mM LiCl and control, and 40 mM LiCl and control, were significant at a p-value<0.001 (*). Each experiment was repeated eight times. B: LiCl increased the expression of stem cell marker genes Nanog and Oct3/4. QPCR was performed on Weri and Y79 cells treated with 20 mM or 40 mM LiCl. LiCl increased Nanog and Oct3/4 levels, and there was significantly greater expression with 40 mM LiCl treatment compared with 20 mM LiCl at a p-value<0.05, indicated by the asterisk. Each experiment was repeated three times.