This product comprises a polyclonal population of HGC-27 human gastric carcinoma cells featuring CRISPR/Cas9-mediated targeted disruption of the CCNT2 gene, which encodes the cyclin T2 regulatory subunit of the positive transcription elongation factor b (P-TEFb) complex. The polyclonal nature of the knockout cell population ensures representation of a range of editing events, providing a robust model for studying loss-of-function effects without the biases of a single clonal isolate.
HGC-27 is an epithelial-like cell line derived from the lymph node metastasis of a human gastric carcinoma. These malignant cells retain characteristic features of advanced gastric cancer, including deregulated proliferation, invasive potential, and dysregulated transcriptional programs. As an established and widely used model for gastric cancer biology, HGC-27 offers a physiologically relevant context in which to dissect the contributions of specific transcriptional regulators to tumorigenic phenotypes and to screen therapeutic interventions.
CCNT2 (cyclin T2) is the regulatory cyclin partner of CDK9 in the P-TEFb complex, which phosphorylates serine-2 residues of the RNA polymerase II C-terminal domain (CTD) to stimulate transcriptional elongation. P-TEFb is regulated by reversible association with the 7SK snRNP inhibitory complex (comprising HEXIM1 and 7SK RNA) and by BRD4, which recruits the kinase to active gene loci. NF-??B signaling can drive CCNT2 expression, connecting inflammatory pathways to transcriptional activation. Downstream, P-TEFb activity facilitates the expression of oncogenic transcription factors such as MYC and is essential for HIV-1 Tat-mediated transactivation, as Tat directly binds cyclin T1/T2 to recruit P-TEFb to the viral LTR promoter.
In gastric cancer, CCNT2-driven transcription elongation sustains proliferation and survival gene expression. Disrupting CCNT2 in HGC-27 cells creates a loss-of-function model to probe P-TEFb contributions to malignant transcription, cell cycle progression, and invasion. Since HGC-27 cells support HIV-1 infection and Tat-mediated transactivation, this knockout population is also suitable for studying host factors in viral latency and reactivation and for testing CDK9-cyclin T interface inhibitors.
This knockout model is suited for functional genomics and pharmacological studies. Typical assays include RNA-seq for elongation-dependent transcriptome changes, ChIP-qPCR for RNA polymerase II occupancy, and western blotting for phospho-RNAPII Ser2 to gauge P-TEFb activity. Co-immunoprecipitation verifies loss of CCNT2?CCDK9 complexes, and HIV-1 LTR luciferase reporter assays quantify Tat-dependent activation. Cell proliferation and migration assays reveal functional consequences of CCNT2 loss in gastric cancer cells. Overall, this polyclonal knockout population is a versatile tool for transcription elongation research, HIV latency studies, cancer gene expression profiling, and CDK9 inhibitor validation. For further technical details or custom applications, please contact Ascent Research.
