The CCNT2 Knockout K-562 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population in which CCNT2 has been disrupted for loss-of-function studies. This knockout product provides a heterogeneous cell pool ideal for bulk assays that avoid clonal bias. Derived from the K-562 chronic myelogenous leukemia line, these cells serve as a BCR-ABL-positive model for studying Cyclin T2 biology.
K-562 cells originated from a pleural effusion of a 53-year-old female with CML in blast crisis. They harbor the BCR-ABL fusion oncogene, which constitutively activates PI3K/AKT, MAPK, and STAT3 pathways, driving uncontrolled proliferation. This cell line is a mainstay for leukemia research and is also capable of erythroid differentiation, offering a versatile platform for signaling and differentiation studies.
Cyclin T2 forms the P-TEFb complex with CDK9 to phosphorylate the RNA polymerase II C-terminal domain (CTD) at Ser2 and Ser5, triggering productive elongation of paused transcripts. Its activity is regulated by 7SK snRNP/HEXIM1 sequestration and by integration into the super elongation complex with AFF1/AFF4, ELL, and MLLT1. Upstream, CCNT2 is transcriptionally induced by MYC, NF-??B, and BCR-ABL signaling, while downstream it promotes expression of MYC target genes, FOS, JUN, and HSPA1A. Cyclin T2 also supports HIV-1 Tat-mediated transactivation of the LTR promoter.
In K-562 cells, BCR-ABL drives MYC expression, which upregulates Cyclin T2, sustaining CTD phosphorylation and leukemogenic transcription. Disrupting CCNT2 allows dissection of P-TEFb??s role in BCR-ABL-dependent proliferation, survival, and differentiation block. This model is especially valuable for validating CDK9 inhibitors like flavopiridol and dinaciclib in CML.
These polyclonal knockout cells support diverse assays, including Western blotting for phospho-CTD (Ser2/5), RT-qPCR of MYC and HSPA1A, RNA-seq, MTS proliferation, flow cytometry for cell cycle and apoptosis, co-IP of CDK9, ChIP-qPCR of RNA Pol II at promoters, CDK9 inhibitor sensitivity assays, colony formation, and HIV-1 LTR-luciferase reporter studies. For further details, please contact Ascent Research.
