Figure 3.

CD133 expression in CD133^neg and CD133^hi SW620 cell spheroids. (A) Within each cell line, spheroids were pooled and disrupted into single cell suspensions. CD133 reactivity was assessed by FACS. Solid purple, CD133; green overlay, negative control. (B) Immunohistochemical staining of CD133 in spheroids. Brown, CD133; blue, nuclear stain; magnification ×200. (C) CD133 protein expression in spheroids compared with cell monolayers by western blot analysis. Upper panel, CD133 reactivity; lower panel, β-tubulin reactivity. Lane 1, CD133^neg spheroids; lane 2, CD133^neg cell monolayers; lane 3, CD133^hi spheroids; lane 4, CD133^hi monolayers. (D) Expression of CD133 by qRT-PCR, standardized to CD133 expression of CD133^neg monolayer culture cells. ^*P<0.05 compared with CD133^neg monolayer culture cells. SP, spheroid; FACS, fluorescence-activated cell sorting; qRT-PCR, quantitative real time-PCR.