The HMGB1 Knockout MCF-7 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt HMGB1 gene function in the MCF-7 human breast adenocarcinoma cell line. This knockout model eliminates the expression of HMGB1, a multifunctional protein that serves as a nuclear DNA chaperone and an extracellular damage-associated molecular pattern (DAMP). By employing a polyclonal knockout strategy, this cell population provides a robust and flexible tool for studying loss-of-function consequences in a well-characterized estrogen receptor-positive breast cancer background.
The MCF-7 host cell line is a well-established model of ER+/PR+ breast adenocarcinoma, originally derived from a pleural effusion metastasis. These adherent epithelial cells are pivotal for studying hormone-dependent proliferation and endocrine therapy resistance. Their extensive molecular and phenotypic characterization provides a consistent background for investigating how HMGB1 disruption alters cancer cell signaling and behavior in a receptor-driven context.
HMGB1 is a dual-function protein that acts as a nuclear DNA chaperone, facilitating chromatin remodeling and transcriptional regulation, and as a secreted DAMP that triggers innate immune responses. Its release is promoted by upstream signals such as TNF-??, IL-1??, LPS, and hypoxia, frequently mediated by NF-??B, p53, and HIF-1??. Once in the extracellular space, HMGB1 engages RAGE and TLR4 receptors, recruiting the adaptor MyD88 to activate NF-??B and MAPK pathways (including JNK, p38, and ERK), leading to the expression of pro-inflammatory cytokines like IL-6 and TNF-??, and adhesion molecules such as ICAM-1. Intracellularly, it interacts with p53, histone H1, and nucleosomes to modulate DNA repair and gene expression. CRISPR-mediated disruption of HMGB1 abolishes these dual functions, impairing chromatin architecture and dampening DAMP-driven inflammatory signaling.
In MCF-7 cells, HMGB1 knockout offers a robust model to dissect how DAMP signaling influences breast cancer proliferation, invasion, and metastasis. HMGB1 is strongly linked to inflammatory tumor microenvironments and hormone-independent growth, making this system valuable for studying endocrine therapy resistance and immune evasion. It also facilitates the exploration of autophagy and chromatin remodeling pathways that are often dysregulated in metastatic progression.
Researchers can employ this knockout cell population in a wide range of assays to examine phenotypic and molecular changes, including Western blotting, RT-qPCR, immunofluorescence, and ELISA for secreted HMGB1. Functional studies such as migration/invasion, proliferation, colony formation, and apoptosis assays can reveal HMGB1??s role in cancer cell behavior. Targeted pathway analyses, including NF-??B reporter assays and phospho-signaling profiling, as well as genome-wide approaches like RNA-seq and ChIP-qPCR, enable detailed mechanistic dissection. The model is also suitable for screening small molecule inhibitors targeting HMGB1 release or its downstream receptors. For additional information or to discuss specific experimental applications, please contact Ascent Research.
