Different p53 Genotypes Regulate PPARγ Post-Translational Modification in The Adipogenic Differentiation of Cancer Cells

Abstract Background: Our previous studies confirmed that high concentrations of cobalt chloride (CoCl2) can induce the formation of polyploid giant cancer cells (PGCCs). PGCCs have the properties of cancer stem cell. In this study, we demonstrate that PGCCs can be induced to differentiate into adipose in vitro and in vivo. In addition, the molecular mechanism of adipogenic differentiation of PGCCs with daughter cells was investigated by detecting the expression of adipocyte differentiation related proteins in mutant and wild-type p53 cancer cell lines. Methods: HEY and MDA-MB-231 control cells and PGCCs with daughter cells were cultured with adipogenic differentiation medium and the cell cycle was detected by flow cytometry. The expression of adipocyte differentiation related proteins, and P300 histone acetyltransferase activity were compared before and after adipogenic differentiation. Immunoprecipitation was used to analyze the post-translational modification of peroxisome proliferator-activator receptor-γ (PPARγ) and P53 in HEY and MDA-MB-231 control cells and PGCCs with daughter cells cultured with adipogenic differentiation medium. Animal xenograft models were used to study the adipogenic differentiation of PGCCs with daughter cells.Results: Dexamethasone, rosiglitazone, insulin, and 3-isobutyl-1-methylxanthine (IBMX) can force the trans-differentiation of PGCCs into post-mitotic and functional adipocytes. Activation of PPARγ is a critical step in the process of adipogenic differentiation. The expression levels of p-CREBser133, PPARγ, C/EBPα, C/EBPβ were higher in PGCCs with daughter cells after adipogenic differentiation compared with those without adipogenic differentiation in HEY and MDA-MB-231. P53 regulates the acetylation and phosphorylation of PPARγ and the expression of P300- Acetyl-PPARγ(Lys)- FABP4 and ERK- Phospho-PPARγ (Ser112)-FABP4 depended upon the genotype of p53 in HEY and MDA-MB-231 cells after cultured with adipogenic differentiation medium. The invasion and migration abilities of PGCCs with their daughter cells after adipogenic differentiation decreased compared with those cells without adipogenic differentiation.Conclusion: P300-P53-ERK-CREB-PPARγ-CEBPα/β-FABP4 pathway may participate in the adipogenic differentiation of HEY, MDA-MB-231 PGCCs with daughter cells, which associated with genotype of p53.