Figure 2.

α2δ1⁺ HGC-27 and α2δ1⁺ SGC-7901 cells displayed cancer stem cell properties. (A) Comparison of tumor formation frequency of purified α2δ1⁺ and α2δ1⁻ cells in NOD/SCID mice. α2δ1⁺ cells displayed significant tumorigenic capacity. (B) Comparison of sphere-formation frequency of purified α2δ1⁺ and α2δ1⁻ cells in vitro. α2δ1⁺ cells displayed significant sphere-forming capacity. α2δ1⁺ cells sorted from the sphere formed previously continued to display high sphere-forming capacity after subsequent propagation. (C) Comparison of differentiation potential of α2δ1⁺ and α2δ1⁻ cells in vitro. Purified α2δ1⁺ cells were cultured in vitro for 2 weeks, and the percentage of α2δ1⁺ cells decreased to the value similar to that of the unsorted parental cells. Purified α2δ1⁻ cells were cultured in vitro under the same condition for the same period, and the percentage of α2δ1⁺ cells remained extremely low in the post-cultured α2δ1⁻ cells. *p<0.05. Scale bar: 100 µm.

Abbreviation: FITC, fluorescein isothiocyanate.