The IGFBP5 Knockout T-47D Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the T-47D human breast cancer cell line. This product features targeted disruption of the IGFBP5 gene, providing a loss-of-function model to study insulin-like growth factor-binding protein 5 in breast cancer biology. The polyclonal format comprises a heterogeneous cell population with diverse gene-editing outcomes, enabling robust and reproducible phenotypic analysis without clonal bias.
The T-47D cell line was originally isolated from a pleural effusion of a ductal carcinoma and maintains an estrogen receptor-positive (ER+), progesterone receptor-positive (PR+) phenotype. As a widely used model of luminal breast cancer, T-47D cells exhibit hormone-responsive growth and are instrumental in studying endocrine therapy resistance and steroid receptor signaling mechanisms.
IGFBP5 functions as a secreted binding protein that modulates insulin-like growth factor (IGF) signaling by sequestering IGF1 and IGF2, thereby limiting their availability to activate the IGF1 receptor (IGF1R). This sequestration inhibits downstream cascades, including the PI3K/Akt and MAPK/ERK pathways, which are critical for cell proliferation and survival. Key components of these pathways include IRS1, PI3K, Akt, and mTOR. IGFBP5 is also regulated by p53 and transcriptionally promotes the expression of pro-apoptotic factors such as Bax and caspase-3, while downregulating cyclin D1 to impede cell cycle progression. Additional upstream regulators include estrogen receptor, TGF-beta/Smad signaling, and retinoids. Through interactions with fibronectin, LRP1, and integrins, IGFBP5 likely influences cell adhesion and migration.
In T-47D cells, IGFBP5 acts as a tumor suppressor, and its knockout allows dissection of the crosstalk between IGF and estrogen receptor signaling. This model is particularly valuable for investigating apoptosis resistance, proliferation control, and sensitivity to antiestrogens such as tamoxifen. The polyclonal knockout population captures diverse genetic modifications, enabling population-level analyses that reflect heterogeneous tumor behavior.
Researchers can employ these cells in a variety of assays, including proliferation and apoptosis assays to assess growth phenotypes, western blotting and RT-qPCR to confirm IGFBP5 loss and downstream target expression, and phospho-signaling analysis to examine pathway activation. Co-immunoprecipitation studies can probe altered protein interactions, while reporter assays and drug sensitivity tests facilitate investigation of transcriptional regulation and therapeutic responses. This knockout model is ideally suited for studying breast cancer progression, hormone therapy resistance, and apoptosis mechanisms. For additional information, please contact Ascent Research.
