The DNPEP Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from the NCI-H1975 human lung adenocarcinoma cell line, with targeted disruption of the DNPEP gene.
This polyclonal loss-of-function model is generated by introduction of Cas9 ribonucleoprotein, yielding a heterogeneous pool of edited cells that avoids clonal selection bias.
This model enables investigation of DNPEP??s role in peptide maturation and antigen presentation.
NCI-H1975 is a female non-small cell lung adenocarcinoma epithelial line harboring the EGFR L858R mutation, derived from pleural effusion.
It is a clinically relevant model for EGFR-mutant lung cancer, widely used to study oncogenic signaling, drug resistance, and tumor-immune interactions, providing a context to examine DNPEP modulation of proteolytic pathways and to dissect the interplay between EGFR signaling and proteolytic regulation.
DNPEP encodes an aspartyl aminopeptidase that selectively removes N-terminal aspartate and glutamate residues from peptide substrates, functioning downstream of the proteasome in antigen processing.
It collaborates with ERAP1, ERAP2, TAP1/2, and HSP70/90, and is regulated by IFN-??, TNF-??, ER stress, and NRF2. Through trimming of peptides for MHC class I (HLA-A, B, C) bound to B2M, DNPEP shapes the antigen repertoire presented to CD8+ T cells.
In the NCI-H1975 EGFR L858R-mutant background, DNPEP knockout eliminates aspartyl aminopeptidase activity, leading to a potential accumulation of poorly trimmed peptides that may alter MHC class I loading and subsequent CD8+ T cell recognition. This model is valuable for studying how changes in the immunopeptidome affect tumor immune surveillance and for exploring the functional crosstalk between EGFR signaling and antigen processing pathways, with implications for responsiveness to EGFR inhibitors and immunotherapies.
These polyclonal knockout cells support a wide range of assays, including Western blotting and RT-qPCR for knockout confirmation, MTT and colony formation assays for proliferation, Transwell assays for migration and invasion, drug sensitivity testing with EGFR inhibitors (erlotinib, osimertinib), flow cytometry for MHC class I surface expression, T cell-mediated cytotoxicity assays, global transcriptome analysis by RNA-seq, and enzymatic assays for proteasome activity. For further information and technical support, please contact Ascent Research.
