The CCNT2 Knockout A-549 Polyclonal Cells represent a CRISPR/Cas9-mediated gene-disrupted polyclonal population derived from the A-549 human lung adenocarcinoma cell line, engineered to ablate Cyclin T2 (CCNT2) expression. This polyclonal knockout product provides a heterogeneous loss-of-function model suitable for studying transcriptional elongation and P-TEFb-dependent signaling without clonal isolation. Disruption of the CCNT2 locus impairs formation of the active positive transcription elongation factor b (P-TEFb) complex, enabling investigation of CDK9/cyclin-mediated phosphoregulation in a disease-relevant context.
The parental A-549 cell line was established from a 58-year-old male with lung adenocarcinoma and is widely recognized as a classic model for non-small cell lung cancer (NSCLC). A-549 cells exhibit epithelial morphology and retain key characteristics of alveolar epithelial type II cells, including expression of mutant KRAS. Their widespread use in cancer biology and drug discovery makes them an ideal host for dissecting transcription-targeted therapies.
CCNT2 serves as a regulatory cyclin for CDK9, and together they constitute the core of P-TEFb, which phosphorylates Ser2 of the RNA polymerase II C-terminal domain (CTD) to promote productive transcriptional elongation. CCNT2 is activated by MYC, NF-??B, and BRD4, while its activity is restrained by the HEXIM1?C7SK snRNP inhibitory complex. P-TEFb interacts with HIV-1 Tat, DSIF/SUPT5H, and the NELF complex, and phosphorylates downstream targets including MCL1 and BCL2. CCNT2 knockout disrupts P-TEFb activity, impairing RNA Pol II elongation and globally reducing short-lived transcripts such as oncogenes and anti-apoptotic factors, leading to cell cycle arrest and apoptosis, particularly in MYC- or NF-??B-driven cancers.
In the A-549 lung adenocarcinoma context, CCNT2 knockout creates a powerful tool for examining the reliance of NSCLC cells on transcriptional elongation addiction. Loss of CCNT2 is expected to sensitize cells to CDK9 inhibitors such as SNS-032 and flavopiridol, and to attenuate signaling through MYC and NF-??B pathways. This model facilitates the dissection of P-TEFb contributions to oncogene expression, apoptosis regulation, and cell cycle progression, while also providing a platform for HIV-1 Tat transactivation studies given CCNT2??s role in viral transcription.
Researchers can utilize this knockout population for mechanistic studies employing Western blotting to detect phospho-RNA Pol II (Ser2/Ser5), RT-qPCR for target genes including MYC and MCL1, and RNA-seq for global transcriptome analysis. Functional investigations are readily performed using Annexin V apoptosis assays, cell cycle flow cytometry, and dose?Cresponse analyses with CDK9 inhibitors. This model also supports HIV-1 transcription research and pharmacological evaluation of P-TEFb-directed compounds. For further information, please contact Ascent Research.
