The IGFBP5 Knockout A-549 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from the A-549 human lung adenocarcinoma epithelial cell line, featuring targeted disruption of the IGFBP5 gene. The polyclonal format preserves genetic heterogeneity, making it suitable for pooled functional studies. By eliminating IGFBP5 expression, these cells provide a robust loss-of-function model for dissecting the multifaceted roles of this secreted protein in cancer biology and extracellular matrix signaling.
The parental A-549 cell line originates from a lung adenocarcinoma of a 58-year-old Caucasian male and grows as an epithelial, adherent monolayer. An established model for lung adenocarcinoma, A-549 cells are widely employed in cancer biology, drug screening, and signal transduction research. They express wild-type TP53 and key components of the IGF signaling pathway, offering a physiologically relevant context for studying IGFBP5-dependent proliferation, apoptosis, and migration.
IGFBP5 is a secreted binding protein that sequesters insulin-like growth factors IGF1 and IGF2 with high affinity, reducing their interaction with the IGF1 receptor (IGF1R) and subsequently modulating the IRS1?CAKT1 and RAS?CMAPK signaling cascades. This canonical regulation impacts the phosphorylation of pro-apoptotic BAD and the expression of the cell cycle inhibitor CDKN1A (p21). In addition, IGFBP5 exerts IGF-independent effects via direct binding to extracellular matrix components, including collagen and thrombospondin-1, and to cell surface integrins such as integrin beta1, thereby controlling focal adhesion dynamics and cell migration. The transcription of IGFBP5 is activated by TP53 and TGFB1, and it is further modulated by retinoic acid, dexamethasone, and mechanical stretch, situating IGFBP5 at the intersection of growth factor, stress, and biomechanical signaling networks.
Disrupting IGFBP5 in A-549 cells unbalances the local regulation of IGF availability, leading to dysregulated IGF1R signaling and consequent alterations in proliferative, survival, and migratory phenotypes. The loss of IGFBP5’s ECM-integrin interactions further perturbs adhesion-dependent signaling and may facilitate epithelial-to-mesenchymal transition (EMT) driven by TGFB1. These cells therefore constitute a powerful tool for dissecting mechanisms of lung adenocarcinoma progression, chemoresistance, and stromal remodeling, with direct applicability to studies of metastasis and fibrosis.
Typical applications include lung cancer cell proliferation and apoptosis assays, chemoresistance profiling, EMT and fibrosis studies, and IGF pathway-targeted drug screening. Compatible analytical methods range from Western blotting, RT-qPCR, and ELISA for target validation to MTS viability assays, Annexin V/PI flow cytometry, Boyden chamber migration tests, phospho-RTK arrays, and RNA-seq. For additional technical details or custom inquiries, please contact Ascent Research.
