Figure 7. The effect of PNPO on the colony formation in breast cancer cells. (A) Detection of colonies in MCF-7 cells. (B) Detection of colonies in MDA-MB-231 cells. Upper panel, pictures of colony formation; lower panel, quantification of colony number. NC, negative control of shRNA; shPNPO, PNPO-shRNA. n = 3; * P < 0.05.