The EIF2AK3 Knockout 143B Polyclonal Cells product consists of a heterogeneous population of CRISPR/Cas9-edited human 143B osteosarcoma cells carrying targeted disruptions in the EIF2AK3 gene, which encodes the endoplasmic reticulum (ER) stress sensor kinase PERK. Generated without single-cell cloning, this polyclonal knockout pool provides a robust loss-of-function model to interrogate PERK-dependent signaling pathways in a neoplastic osteoblast-like context.
The 143B cell line is derived from a primary osteosarcoma of a 13-year-old female and is characterized by high tumorigenicity and metastatic potential. These adherent cells exhibit osteoblast-like features, making them a widely used model for investigating osteosarcoma biology, bone metastasis, and cancer cell signaling. Their robust growth and genetic tractability render them well-suited for CRISPR-based gene disruption studies.
EIF2AK3 (PERK) is a type I transmembrane kinase that acts as a primary sensor of ER stress. Upon accumulation of unfolded proteins, PERK dissociates from the chaperone BiP/HSPA5, autophosphorylates, and subsequently phosphorylates the ?? subunit of eIF2?? on Ser51. This phosphorylation attenuates global protein synthesis while selectively promoting translation of ATF4, a transcription factor that induces expression of CHOP (DDIT3), GADD34 (PPP1R15A), and genes involved in amino acid metabolism and redox control. PERK also directly phosphorylates NRF2 (NFE2L2) to drive antioxidant programs. Within the broader unfolded protein response, PERK signaling intersects with IRE1 and ATF6 arms, and the GADD34/PP1 complex mediates dephosphorylation of eIF2?? as negative feedback. Under sustained stress, CHOP upregulates pro-apoptotic Bcl-2 family members such as Bim and Puma, tilting the balance toward cell death; PERK also influences autophagy regulation.
In the 143B osteosarcoma model, PERK-mediated UPR signaling is anticipated to influence tumor cell survival, proliferation, and metastatic behavior. Osteosarcoma cells, as professional secretory cells producing extracellular matrix components, may exhibit elevated basal ER stress, making them sensitive to UPR perturbations. Dysregulation of PERK has been implicated in cancer progression, with roles in adapting to nutrient deprivation and hypoxic tumor microenvironments. Additionally, loss-of-function mutations in EIF2AK3 cause Wolcott-Rallison syndrome, a disorder characterized by epiphyseal dysplasia and insulin-dependent diabetes, underscoring PERK??s importance in bone development and metabolism. Thus, these knockout cells enable dissection of PERK??s unique contributions to osteosarcoma pathobiology, including its impact on resistance to ER stress-inducing chemotherapeutics and its crosstalk with cell death pathways.
The EIF2AK3 Knockout 143B Polyclonal Cells are suitable for a range of functional assays, including Western blotting for phosphorylated eIF2??, ATF4, and CHOP under ER stress induction, RT-qPCR for UPR target genes, and viability/apoptosis assays with PERK inhibitors such as GSK2606414. Migration, invasion, phospho-signaling, and RNA-seq analyses further support investigations of metastatic potential and signaling rewiring. This versatile tool aids basic and translational research in ER stress and cancer biology. For further information or custom solutions, please contact Ascent Research.
