IGFBP5 Knockout MCF-7 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population in which the IGFBP5 gene has been disrupted, generating a heterogeneous loss-of-function model for studying insulin-like growth factor binding protein 5. This product is supplied as a polyclonal pool, meaning it contains multiple distinct genetic edits across the population, offering a robust and versatile tool for functional genomics and cancer research. The polyclonal format eliminates the need for single-cell cloning and is ideally suited for pooled screening, bulk functional assays, and pathway dissection where clonal homogeneity is not required. By ablating IGFBP5 expression, researchers can directly interrogate the protein’s dual roles in IGF-dependent signaling modulation and IGF-independent cellular processes without the confounding influence of compensatory clonal adaptation often observed in monoclonal cell lines.
MCF-7 is a widely characterized human breast adenocarcinoma cell line of epithelial origin, originally derived from a pleural effusion of a patient with metastatic mammary carcinoma. These cells express estrogen receptor alpha (ER??) and are extensively used as a model system for luminal A breast cancer. They retain many characteristics of the original tumor, including hormone responsiveness and a relatively non-aggressive, epithelial phenotype. MCF-7 cells are particularly valuable for studying growth factor signaling, apoptosis, and cell migration, as they harbor wild-type p53 and exhibit moderate levels of IGF1R. Their well-documented signaling networks and amenability to genetic manipulation make MCF-7 an optimal host for creating IGFBP5 knockout models aimed at decoding the complex interplay between IGF bioavailability, apoptotic regulation, and metastatic potential.
IGFBP5 functions as a high-affinity secreted binding protein for insulin-like growth factors IGF1 and IGF2, sequestering these ligands from the type 1 IGF receptor (IGF1R) and thereby attenuating downstream signaling cascades. In its canonical role, IGFBP5 limits activation of the IRS1/AKT and MAPK pathways, which are normally stimulated by IGF1R ligation and are critical for cell survival, proliferation, and metabolism. Beyond IGF sequestration, IGFBP5 exerts IGF-independent effects by interacting with extracellular matrix components, integrins, and other binding partners such as the acid-labile subunit (ALS). These interactions can promote apoptosis by regulating BAX expression and modulate cell migration, potentially through p53-dependent mechanisms. The mechanistic summary of IGFBP5 action thus involves both ligand blocking and direct signaling modulation, positioning it at a nexus of growth factor signaling and tumor suppressor pathways.
In the MCF-7 cellular context, IGFBP5 knockout disrupts a critical regulatory node that integrates hormonal and growth factor cues. MCF-7 cells exhibit endogenous IGFBP5 expression, which is regulated by upstream factors including retinoic acid, TGF-beta, IGF1, and p53. Loss of IGFBP5 in these cells is predicted to enhance IGF1R-mediated signaling, leading to increased phosphorylation of IRS1, AKT, and MAPK, while concurrently diminishing the pro-apoptotic influence mediated by BAX and p53. This knockout model therefore provides a platform to dissect how estrogen receptor-positive breast cancer cells might subvert IGFBP5-dependent growth inhibition and apoptosis during tumor progression. The polyclonal nature of the knockout pool ensures that a spectrum of mutations is represented, reflecting the genetic heterogeneity often observed in tumor populations and allowing for the assessment of dominant phenotypes across a broad range of knockout efficiencies.
This IGFBP5 knockout cell pool is a powerful reagent for a multitude of research applications. It is ideal for probing the IGF signaling axis using western blotting and RT-qPCR to quantify changes in phospho-AKT, total MAPK, BAX, and cell cycle regulators. Functional assays such as proliferation assays, apoptosis assays, and migration/invasion assays can be employed to evaluate the impact of IGFBP5 loss on cell behavior and to screen therapeutic compounds targeting the IGF pathway. Additionally, these cells can serve as a control for overexpression studies and as a background for further genetic modifications. For detailed technical specifications, custom media formulations, or bulk ordering, please contact Ascent Research.
