Figure 7.

Overexpressed p21 inhibits ferroptosis.A and B, NARF2 pBpuro and NARF2 K2/D expressing constitutive CDK2-cyclin D were transduced with p21or CMV (empty) recombinant adenoviruses at different MOIs as indicated. Forty-eight hours later, the cells were treated with CETZOLE 1 (C1) and cell viability was determined after 48 h by methylene blue staining. ∗p < 0.05 when compared with CMV infected cells. C and D, lipid peroxidation as assessed using BODIPY-C11. NARF2-pBpuro cells in the absence of IPTG were infected with adenoviral vectors to overexpress p21 (MOI-100). CETZOLE 1 was added 48 h later along with BODIPY-C11 dye. Flow cytometry was used to assess BODIPY oxidation after 48 h. These p21 overexpression experiments were done simultaneously with CDK2/cyclin E experiments shown earlier. Therefore, in (C), the two left-most panels (CMV, DMSO, and C1) are identical to those in Figure 5G. The mean fluorescence intensity ratios from triplicate samples are shown in (D). p value from a Student's t test is shown. E, Western blot analysis depicts the protein levels of p21, p-RB (ser780), total RB, and actin as a loading control after infection with adenovirus to overexpress p21. CDK, cyclin-dependent kinase; RB, retinoblastoma.