FIGURE 3.

CD133 interacts with Src. A and B, HEK293T cells were transfected with CD133-StrepII plasmid or corresponding empty vector with StrepII tag. A, 48 h later, cells were harvested, and co-IP was done with Strep-Tactin-agarose. B, immunofluorescence assay was done to observe the co-localization of CD133 (green) and Src (red). C–G, SW620 cells were cultured in DMEM with or without FBS. C and D, co-IP analysis was performed to determine the interaction between endogenous CD133 and endogenous Src in SW620 cells. The band indicated by a red asterisk is CD133. E, an immunofluorescence assay was performed to examine the co-localization of CD133 (red) and Src (green). F, the relative mRNA level of CD133 was detected by quantitative PCR. Results are presented as the mean ± S.D. (error bars) (n = 3). Statistical analysis was performed by Student's t test (***, p < 0.001). G, flow cytometry was performed to examine the percentage of CD133-positive cells. The percentages shown in the graphs are the average percentages from the results obtained in three experiments. WCL, whole cell lysate; IB, immunoblotting.