Figure 1.

Majority of cells in 4T1 TS are quiescent. (A) Images of TS generated from 4T1 cells. TS were cultured in non-adherent culture plates for 4 days. Scale bar, 100 µm. (B) TS exhibited slower cell proliferation rates than cells grown in monolayers (2D). Cell absorbances measured using WST-8 reagent after incubation for 4 days. (C) Cell cycle analysis of cells grown as 2D cultures or as TS showed accumulations of cells in the G0/G1 phase in TS. (D) mRNA expression of cyclin D1 was diminished in cells grown in TS. TS, tumorspheres.