Figure 5.

p53 signaling pathway analysis by Western blot analysis (A) and clone formation assay (B). (A) Under the irradiation of ⁸⁹SrCl₂, the expression levels of pP53 (ser15), pP53 (ser20), acP53, and p21 in the MCF7-SMAR1 group were significantly increased, while the expression level of MDM2 was decreased compared with that in the MCF7 group or the MCF7-c group. However, after cells were treated with both ⁸⁹SrCl₂ and PFTα, the expression levels of p53 signaling pathway-related proteins in MCF7-SMAR1 group had no change compared with that in the MCF7 group or the MCF7-c group. (B) After cells were treated with both ⁸⁹SrCl₂ and PFTα, PFTα could reverse the SMAR1-enhanced radiosensitivity to ⁸⁹SrCl₂ in the MCF7-SMAR1 group.