Starvation-induced Autophagy Promotes Apoptosis in p53-deficient Porcine Fibroblast Cells

PurposeTo investigate the effects of p53 gene on the morphology, proliferation, autophagy, and apoptosis in starvation-induced PFCs and to provide theoretical basis for further study on the molecular mechanism of p53 gene and tumorigenesis.

MethodThe p53^wt and p53^−/− PFCs were treated with EBSS, Baf A1 and EBSS+ Baf A1. The morphological changes were observed and cell proliferation, apoptosis, and the protein expression of ATG9A and Bcl-2 genes were detected.

ResultBoth of p53^wt and p53^−/− PFCs shrinkage and filamentous pseudopodia after EBSS or EBSS+ Baf A1 treatment when compared with the control. In p53^−/− PFCs, the proliferation rate was decreased obviously, and the expression level of ATG9A protein was significantly or extremely significantly up-regulated (P<0.05 or P<0.01), and the expression level of Bcl-2 protein had no significant difference (P>0.05). While in p53^wt PFCs, the expression level of Bcl-2 protein was significantly increased (P<0.05). In addition, the apoptosis rate of p53^−/− PFCs was significantly increased after EBSS treatment (P<0.05). Compared with p53^wt PFCs, p53^−/− PFCs showed the extremely significantly decreased the rate of morphology change (P<0.01), the significantly increased proliferation rate (P<0.05), the significantly or extremely significantly increased expression level of ATG9A protein (P<0.05 or P<0.01), and the significantly or extremely significantly decreased expression level of Bcl-2 protein (P<0.05 or P<0.01).

ConclusionIn starvation-induced condition, autophagy promoted apoptosis in p53^−/− PFCs, which provided an important theoretical basis for further study on the molecular mechanism of p53 gene regulating autophagy, apoptosis and tumorigenesis.