The HEXIM2 Knockout HT29 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population in which the human HEXIM2 gene has been disrupted. This knockout model provides a loss-of-function system to investigate the regulatory role of HEXIM2 in transcription elongation. The polyclonal nature of the population ensures diverse mutation spectra while preserving overall target gene disruption, making it suitable for functional studies in a heterogeneous cell background.
HT29 cells are a widely characterized human colorectal adenocarcinoma cell line originally derived from a primary tumor in a 44-year-old female. They serve as a model system for human intestinal epithelial biology, colorectal cancer research, and drug development, exhibiting features such as epithelial morphology and the ability to differentiate under specific conditions. Their well-documented genetic and phenotypic properties make them a robust host for studying gene function, particularly in the context of gastrointestinal malignancies.
HEXIM2 functions as a critical inhibitor of positive transcription elongation factor b (P-TEFb), which consists of CDK9 and cyclin T. By binding to 7SK small nuclear RNA, HEXIM2 sequesters P-TEFb in an inactive ribonucleoprotein complex, preventing CDK9-mediated phosphorylation of the C-terminal domain (CTD) of RNA polymerase II. This inhibition blocks transcription elongation at promoter-proximal regions. Key components of the 7SK snRNP pathway include LARP7, MEPCE, and the negative elongation factor (NELF). Knockout of HEXIM2 relieves this inhibition, leading to hyperphosphorylation of RNA Pol II CTD and increased expression of P-TEFb-dependent genes such as MYC, FOS, and BCL2.
In the HT29 colorectal cancer model, HEXIM2 loss-of-function allows enhanced P-TEFb activity, mimicking conditions of transcriptional dysregulation often observed in cancer. This disinhibition can drive aberrant expression of oncogenes and proliferation-associated genes, providing a platform to dissect the molecular consequences of unchecked transcription elongation. Researchers can use these cells to explore how HEXIM2-mediated regulation intersects with signaling pathways implicated in colorectal adenocarcinoma progression, including those responding to upstream cellular stress signals or hexamethylene bisacetamide (HMBA).
This polyclonal knockout product is ideal for a range of downstream applications including western blotting to assess phospho-RNA Pol II CTD levels, RT-qPCR to quantify changes in target gene expression (e.g., MYC, FOS), RNA-seq for transcriptome-wide profiling, and ChIP-qPCR to examine RNA Pol II occupancy. Additional uses include cell proliferation assays and drug sensitivity screening with P-TEFb inhibitors, facilitating the identification of novel therapeutic compounds. For further information or technical assistance, please contact Ascent Research.
