The AFF4 Knockout HT29 Polyclonal Cells consist of a heterogeneous population of HT29 human colorectal adenocarcinoma cells engineered via CRISPR/Cas9-mediated disruption of the AFF4 gene. As a polyclonal knockout model, these cells harbor diverse loss-of-function variants across the AFF4 locus, enabling robust functional studies without single-cell clonal isolation. This product provides a genetically defined system for investigating AFF4-dependent transcriptional regulation within a colorectal cancer background.
The HT29 cell line was derived from a primary colorectal adenocarcinoma of a 44-year-old female patient. These cells exhibit an epithelial morphology and retain the capacity for enterocytic differentiation and mucin secretion, making them a well-characterized model of intestinal epithelial biology. Their differentiation potential is particularly valuable for examining how AFF4 ablation influences cell state transitions and secretory functions in colorectal cancer cells.
AFF4 encodes a scaffolding subunit of the super elongation complex (SEC), which orchestrates efficient transcriptional elongation by RNA polymerase II. AFF4 bridges interactions with multiple SEC components, including ELL1/2, AF9 (MLLT3), ENL (MLLT1), DOT1L, and the P-TEFb kinase module consisting of CDK9 and Cyclin T1. The SEC is recruited to chromatin by factors such as BRD4, MLL fusion proteins (e.g., MLL-AF4, MLL-AF9), and the PAF1 complex, driving expression of critical target genes. AFF4-dependent transcriptional outputs include oncogenes like MYC, BCL2, CDK6, and developmental regulators such as HOXA cluster genes and MEIS1. Additionally, AFF4 participates in Wnt/??-catenin?CTCF-mediated transcription, linking it to colorectal cancer signaling pathways. Disruption of AFF4 impairs SEC assembly and reduces processive elongation, thereby attenuating expression of these downstream effectors.
In HT29 cells, AFF4 is implicated in sustaining malignant phenotypes by enabling high-level transcription of proliferation-associated genes. Loss of AFF4 function in this colorectal adenocarcinoma model is expected to diminish MYC expression and compromise cell growth, survival, and differentiation programs. The polyclonal knockout population avoids clonal artefacts and reflects a range of editing outcomes, providing a more clinically relevant perspective on AFF4 dependency. This system is well-suited for dissecting the contribution of SEC-mediated elongation to colorectal cancer biology, particularly in the context of mucin-producing tumors.
Researchers can employ the AFF4 Knockout HT29 Polyclonal Cells to study transcriptional elongation mechanisms, evaluate the therapeutic potential of SEC inhibitors, and screen for synthetic lethal interactions with CDK9 inhibitors (such as flavopiridol) or BRD4 degraders. The cells support a wide array of experimental techniques, including western blotting and RT-qPCR for MYC and other targets, ChIP-qPCR for SEC occupancy, RNA-seq for global transcriptome profiling, cell proliferation and apoptosis assays, colony formation, and mucin-based differentiation readouts. Drug sensitivity studies and functional rescue experiments are also readily performed. For further technical details or custom inquiries, please contact Ascent Research.
