Fig 1: Bifidobacterium longum‐EVs promote p53 Ser15 phosphorylation to increase p53 accumulation in A2780‐CBP/R cells. (A) A2780‐CBP/R cells from different groups were treated with 10 μM carboplatin (CBP), 1 μg/mL of B. longum‐EVs, or the combination, whereas the cells treated with PBS were considered the control. After treatment for 24 h, cells from each group were harvested to analyze the expression levels of MRP1, ATP7A, ATP7B, and p53. (B) Extracts from A2780‐CBP/R cells from the B. longum‐EVs‐L, B. longum‐EVs‐M, and B. longum‐EVs‐H groups were immunoprecipitated with either control IgG or p53 antibodies, and the presence of p53 Ser15, Ser20, and Ser46 phosphorylation was determined by western blot analysis. (C) A2780‐CBP/R cells were transfected with p53S15D or p53wt or the combination with or without B. longum‐EVs. The cells were then treated with MG132 for an additional 6 h before collecting cell lysates for the ubiquitination assay. ***P < 0.001, versus the control group; ## P < 0.01, and ### P < 0.001, versus the CBP group.