TP53 Knockout Marc-145 Cell Line

The TP53 Knockout Marc-145 Cell Line is a CRISPR/Cas9-edited cell line with targeted disruption of the TP53 gene in the Marc-145 host background. This model provides a stable loss-of-function system to study p53 tumor suppressor functions in African green monkey kidney epithelial cells.

Marc-145 cells originated as a subclone of the MA-104 line and are derived from Cercopithecus aethiops kidney epithelium. These adherent cells retain epithelial characteristics and are highly permissive to porcine reproductive and respiratory syndrome virus (PRRSV) infection, making them a valuable model for investigating host-virus interactions and innate immune responses in kidney epithelia.

TP53 encodes the transcription factor p53, which governs cell cycle arrest, apoptosis, senescence, DNA repair, and metabolism in response to diverse stresses. p53 is constitutively targeted for degradation by MDM2; upon DNA damage or oncogenic signaling, upstream kinases ATM and ATR phosphorylate p53, stabilizing it. Activated p53 transcriptionally induces effectors such as CDKN1A (p21) to block cell cycle progression, and BAX and BBC3 (PUMA) to trigger apoptosis. p53 function is modulated through interactions with cofactors EP300 and CREBBP, and negative regulators MDM4 and HIPK2. Additional downstream mediators like GADD45A, RRM2B, and TIGAR link p53 to DNA repair, nucleotide metabolism, and glycolysis. Together, these components form a signaling network critical for tumor suppression and genomic fidelity.

In the TP53 knockout Marc-145 line, loss of p53 allows investigation of its role in kidney epithelial stress responses and antiviral defense. The PRRSV-permissive nature of Marc-145 cells enables studies on whether p53 influences viral replication or virus-induced apoptosis. This cell pair (wild-type vs. knockout) can be used to assess p53-dependent gene expression changes and to screen for pathway modulators in a primate epithelial context, relevant to both cancer and infectious disease research.

Researchers can utilize this line for a variety of assays. Western blotting and RT-qPCR detect p53 target gene expression (e.g., CDKN1A, BAX). Apoptosis can be quantified via caspase-3/7 activation, and cell cycle distribution by flow cytometry. Protein interactions with p53 (e.g., MDM2, EP300) are amenable to co-immunoprecipitation. ChIP-qPCR permits analysis of p53 promoter occupancy, while RNA-seq uncovers global transcriptional effects. For virology studies, PRRSV replication assays can measure viral titers. The cell line is well-suited for drug screening and functional genomics. For further information, please contact Ascent Research.