The CD109 Knockout K-562 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the K-562 human chronic myelogenous leukemia line, genetically disrupted at the CD109 locus to create a heterogeneous loss-of-function pool. This polyclonal format captures the diversity of editing events across the cell population, providing a robust model system that avoids clonal artifacts and better represents the biological variability of gene ablation. The gene disruption targets CD109, a cell surface glycoprotein that functions as a negative regulator of the transforming growth factor-beta (TGF??) signaling pathway, making these cells an essential tool for dissecting TGF??-dependent processes in leukemia biology.
The K-562 cell line, established from the pleural effusion of a 53-year-old female with chronic myelogenous leukemia in blast crisis, is a suspension lymphoblast line carrying the BCR-ABL1 fusion gene. It serves as a widely utilized model for hematopoietic differentiation and erythroleukemia research, as well as for studying signaling pathways involved in leukemogenesis. K-562 cells express key components of the TGF?? signaling cascade, including TGF?? receptors and downstream SMAD proteins, providing a relevant background in which to evaluate the functional impact of CD109 loss. The BCR-ABL-driven oncogenic context further positions these cells for investigations into kinase signaling crosstalk with TGF?? pathways.
CD109 encodes a GPI-anchored cell surface glycoprotein that negatively regulates TGF?? signaling by binding to TGFBR1/TGFBR2 and promoting receptor internalization and degradation. This reduces SMAD2/3 phosphorylation, attenuating transcription of TGF??-responsive genes such as PAI-1 and COL1A1. Its expression is regulated by STAT3 and miR-3182, and it interacts with inhibitory SMAD7 and SMURF2. Core components include TGFB1, SMAD4, and the receptors, forming an axis that controls proliferation, differentiation, and matrix production. Disruption of CD109 is expected to enhance TGF?? signaling.
In the K-562 leukemia background, loss of CD109 provides a model to investigate how unopposed TGF?? signaling impacts leukemic cell biology. TGF?? has dual roles in cancer, and its signaling is linked to leukemia stem cell maintenance and drug resistance in CML. By eliminating CD109-mediated feedback, these cells enable studies of sustained SMAD2/3 activation and its effects on proliferation, apoptosis, and differentiation in a BCR-ABL-driven context. They are particularly useful for examining crosstalk between CD109 and STAT3-driven oncogenic pathways.
These polyclonal knockout cells support functional assays such as phospho-SMAD2/3 western blotting, TGF?? luciferase reporter assays, and RT-qPCR of target genes including PAI-1 and COL1A1. Flow cytometry can confirm CD109 loss, and co-immunoprecipitation can explore interactions with TGF?? receptors or SMAD7. Applications include cancer stem cell studies, drug resistance research, and high-throughput screening of TGF?? pathway modulators. For further information, contact Ascent Research.
