Different roles of C/EBP-alpha in chromosome conformation during lung injury of young and old mice

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DNA sequence specific binding protein such as p53 regulation is critical for gene expression and homeostasis. The p53 protein is a quick stress response protein in the cells and activates a unique transcriptome which determines cellular fate. To prepare a background for animal studies, in this year, I investigated transcriptional regulation by p53 protein using in vitro cell lines, Raji and A549 cells. I identified that Raji cells harbor a p53 p72R missense mutation, the lung adenocarcinoma cell line, A549 cells contain the wild type p53. To understand the p53 P72R regulation in cell cycle dependent manner, I synchronized the Raji cells with HU treatment which allows synchronization of cells in G1-S phase while inducing a replication stress. I also synchronized Raji cells in G2-M phase by Thymidine and Nocodazole treatment. In addition, Nutlin-3a treatment was used to activate p53 in the Raji cells and A549 cells.In summary, I could confirm that 1. In Raji cells, Nutlin-3a treatment fails to upregulate the MDM2 expression, this suggesting a loss of function of p53 P72R in the gene expression of its target genes, MDM2. In the A549 containing the wild type p53, Nutlin-3 treatment can induce p53 activation and MDM2 expression. 2. The protein and qPCR analysis suggested p53 p72R regulation is deviated than wild type p53 for regulation of genes subsets including of metastatic receptors, CXCR5, CCR7, RAC1, RHOA and proliferation gene subsets HLA-DQ genes. This regulation is not observed in wild type p53 activation in A549 cells.