The HMOX1 Knockout 143B Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal population of 143B human osteosarcoma cells in which the HMOX1 gene has been functionally disrupted. This heterogeneous knockout cell product provides a versatile loss-of-function model for investigating the role of heme oxygenase-1 (HO-1) in bone cancer biology without the clonal homogeneity of single-cell-derived lines.
The 143B cell line is a highly tumorigenic human osteosarcoma model derived from the HOS line, featuring mutant TP53 and an epithelial-like adherent morphology. These cells form osteoid matrix and aggressive tumors in xenograft models, making them widely used for studying bone cancer proliferation, metastasis, and therapy.
HMOX1 encodes heme oxygenase-1, the rate-limiting enzyme in heme catabolism that degrades pro-oxidant heme into biliverdin, carbon monoxide, and free iron. Under oxidative stress, the transcription factor NRF2 (NFE2L2) escapes KEAP1-mediated degradation, translocates to the nucleus, and induces HMOX1 expression. HO-1-derived carbon monoxide activates soluble guanylyl cyclase (sGC) to produce cGMP and stimulate PKG signaling, while biliverdin is reduced by biliverdin reductase A (BLVRA) to the antioxidant bilirubin. The released iron promotes ferritin heavy chain (FTH1) synthesis, mitigating labile iron toxicity. These products collectively confer cytoprotective, anti-inflammatory, and antioxidant effects that influence ferroptosis sensitivity. HO-1 is regulated by upstream factors such as NRF2, KEAP1, BACH1, HIF1A, and AP-1, and interacts with NADPH-cytochrome P450 reductase (POR) for enzymatic activity.
In osteosarcoma, HO-1 expression is often elevated and associated with tumor growth, metastasis, and drug resistance. The HMOX1 knockout in 143B cells enables dissection of these roles by assessing how loss of HO-1-mediated heme degradation and antioxidant signaling affects cancer cell behavior. This model is particularly suited for investigating ferroptosis susceptibility and the NRF2/HO-1 axis in a disease-relevant context.
Typical applications include Western blotting and RT-qPCR to confirm HO-1 ablation and analyze NRF2 target genes, ROS detection with DCFDA, iron quantification (ferrozine), ferroptosis assays monitoring lipid peroxidation and GPX4, cell viability (CCK-8), apoptosis (Annexin V/PI), Transwell migration, colony formation, and in vivo xenograft tumor studies. These HMOX1 knockout 143B polyclonal cells serve as a critical tool for interrogating heme catabolism and oxidative stress signaling in bone malignancies. For further information, please contact Ascent Research.
