PML Knockout THP-1 Cell Line

The PML Knockout THP-1 Cell Line is a CRISPR/Cas9-mediated gene-edited knockout cell line derived from the human THP-1 monocytic cell line. This product provides a loss-of-function model of the PML gene, enabling researchers to dissect its roles in tumor suppression, apoptosis, senescence, and innate antiviral immunity. By permanently disrupting PML expression, this cell line serves as a defined in vitro system for studying PML-dependent molecular mechanisms without the confounding effects of prior gene knockdown approaches.

THP-1 is a human monocytic cell line established from the peripheral blood of a 1-year-old male with acute monocytic leukemia. It is widely used as a model for monocyte and macrophage differentiation and function. Upon treatment with phorbol esters like PMA, THP-1 cells differentiate into macrophage-like cells, allowing studies of macrophage biology, innate immunity, and inflammatory responses. The parental THP-1 line retains oncogenic mutations typical of acute leukemia, providing a relevant context for studying tumor suppressor genes like PML. This knockout line thus combines the well-characterized THP-1 background with specific ablation of PML, facilitating focused investigations into its roles in monocytic cell biology and leukemogenesis.

PML is a tumor suppressor protein that serves as the essential organizer of PML nuclear bodies, subnuclear structures that sequester and post-translationally modify partner proteins via SUMOylation. Through these nuclear bodies, PML activates p53 by promoting its phosphorylation and acetylation, leading to transcriptional induction of pro-apoptotic and cell-cycle arrest genes such as BAX, PUMA, NOXA, and p21 (CDKN1A). PML also potentiates interferon signaling by facilitating the assembly of transcriptional complexes involving STAT1, IRF7, and other interferon-stimulated transcription factors. Additionally, PML interacts with SP100, DAXX, ATRX, HIPK2, and SUMO proteins to modulate DNA damage responses, senescence, and antiviral defenses. Upstream, PML is transcriptionally induced by interferons (IFN-??/??/??), p53, retinoic acid, and oncogenic stress signals, while viral proteins often target PML to evade innate immunity. Loss of PML disrupts these pathways, impairing p53-dependent apoptosis and weakening interferon-mediated antiviral responses.

In the THP-1 monocytic leukemia background, PML knockout provides a powerful tool to dissect how this tumor suppressor governs monocyte/macrophage biology and contributes to leukemogenesis. The THP-1 line, as a model for acute monocytic leukemia, allows exploration of PML’s role in hematological malignancies, particularly in the context of acute promyelocytic leukemia where PML-RAR?? fusions drive disease. PML loss in THP-1 cells may accelerate proliferation, impair differentiation, and reduce sensitivity to apoptosis-inducing agents such as arsenic trioxide, which directly targets PML. Moreover, this knockout line enables the study of PML-dependent innate immune signaling pathways in a monocytic environment, including interferon responses to viral challenge. The interaction of PML with key immune factors like STAT1 and IRF7 can be functionally tested, and the role of PML nuclear bodies in monocyte-to-macrophage differentiation can be elucidated using PMA-induced maturation protocols.

Researchers can employ this knockout line in a wide range of assays to investigate PML function. Western blotting and immunofluorescence can verify PML ablation and assess the assembly of nuclear bodies. Apoptosis induction monitored by Annexin V/PI flow cytometry can evaluate the role of PML in intrinsic and extrinsic death pathways. RT-qPCR of downstream targets such as BAX, p21, and interferon-stimulated genes under various stimuli reveals PML-mediated transcriptional regulation. Co-immunoprecipitation experiments can probe interactions with DAXX, SP100, or SUMO-modified partners. Drug sensitivity testing with retinoic acid, arsenic trioxide, or interferons can assess therapeutic vulnerabilities. Finally, PMA-induced macrophage differentiation followed by phenotypic profiling can uncover PML functions in innate immune cell biology. For further inquiries or to request a quotation, please contact Ascent Research.