S100A9 Knockout Cell Line (A549)

The choice depends on whether you are studying S100A9 (MRP14, calgranulin B)'s role as a calcium-binding damage-associated molecular pattern (DAMP) or its functions as part of the S100A8/A9 calprotectin heterodimer in inflammation and cancer biology. The Knockout line is the standard tool for asking whether S100A9 is required for these processes — S100A9 is normally expressed by myeloid cells but is upregulated in many epithelial cancers including lung cancer (relevant to A-549), where it contributes to tumor progression and inflammation. Overexpression is useful for studying S100A9 in inflammation models or for testing its role in chemoattraction and innate immunity. For inflammation and cancer research, the EDITGENE S100A9 Knockout in A-549 is highly relevant — A-549 is a lung adenocarcinoma cell line, and S100A9 has been implicated in lung cancer progression, neutrophil extracellular trap formation, and chronic inflammation contexts. S100A8 (heterodimer partner) expression analysis is essential given that calprotectin functions primarily as the S100A8/A9 heterodimer. Rescue with wild-type or calcium-binding-deficient S100A9 enables structure-function studies. S100A9 inhibitors (paquinimod, tasquinimod) specificity testing benefits from this knockout.

Primary applications: • Calprotectin biology: S100A8/A9 heterodimer formation and stability analysis given functional dependence on the heterodimer. • Lung cancer phenotype: proliferation, migration, invasion, and EMT marker analysis in A-549 to assess S100A9's contribution to lung cancer biology. • Inflammatory signaling: NF-κB activation, cytokine production, and TLR4/RAGE signaling in response to inflammatory stimuli given S100A9's DAMP activity. • S100A9 inhibitor specificity: critical genetic control for paquinimod, tasquinimod, and other S100A8/A9-targeting compounds in cancer and autoimmune disease development. EDITGENE recommends this model for researchers investigating S100A9/calprotectin biology, lung cancer inflammation, and S100A8/A9-targeted therapeutic development.

Yes. S100A9 rescue experiments require attention to heterodimer biology: • Construct design: use a codon-modified S100A9 sequence with a small C-terminal tag (FLAG, HA). S100A9 is small (~114 amino acids) with two EF-hand calcium-binding domains — preserve N-terminal sequence that mediates S100A8 partnership. • Calcium-binding-deficient rescue: EF-hand mutations (canonical E to Q substitutions in the calcium-coordinating residues) abolish calcium binding and downstream conformational changes, serving as the standard specificity control. • S100A8 partnership: S100A9 functions primarily as the S100A8/A9 heterodimer — rescue interpretation should account for S100A8 expression in A-549. • Functional readout: rescue should restore calprotectin-dependent activities including TLR4/RAGE binding, MMP9 secretion modulation, and inflammatory signaling. A-549 transduces efficiently with lentivirus and supports stable rescue line generation.