Figure 5.
Impaired colony-forming ability and reduced tumor growth. A. Colony formation assay. MCF-7 cells were treated with siRNA1-3 or siGFP. 48 h after transfection cells were transferred to soft-agar plates for further incubation. 4 weeks later the colony numbers were scored with a microscope. The colony number of control cells was regarded as 100% for calculation. The data were expressed as mean ± SD (n = 3) and analysed by Student's t-test. *P < 0.05, **P < 0.01. B. Xenograft experiment in nude mice. 1 × 106 of HeLa cells treated with siRNA3 or control siGFP were subcutaneously injected into each flank of nude mice. Each group contained 4 mice. Tumor sizes were measured every 2–3 days and tumor volumes were calculated. The data were statistically analysed by Mann-Whitney U test. *P < 0.05, **P < 0.01.