This product comprises a polyclonal population of CAL-27 cells engineered with CRISPR/Cas9-mediated disruption of the BBC3 gene (Homo sapiens). The knockout model enables a loss-of-function approach to dissect the biological roles of the encoded PUMA protein, a critical pro-apoptotic factor. This polyclonal knockout cell population is suited for experiments requiring a heterogeneous genetic background, reflecting the complexity of tumor cell populations.
The host cell line, CAL-27, is an established human tongue squamous cell carcinoma model derived from a head and neck tumor. These adherent epithelial cells exhibit aggressive growth characteristics and retain key molecular features of oral cancer, including sensitivity to p53-mediated stress responses. As a clinically relevant cellular context, CAL-27 provides a robust platform for studying apoptosis regulation and therapeutic vulnerabilities in oral squamous cell carcinoma.
BBC3 encodes PUMA, a BH3-only member of the BCL-2 family that functions as a pivotal link between upstream stress signals and mitochondrial apoptosis. Under DNA damage, the transcription factor p53/TP53 directly activates BBC3 expression; additional regulators such as E2F1 and FOXO3a also contribute to its transcriptional control. PUMA protein then engages anti-apoptotic binding partners??notably BCL-2, BCL-XL, and MCL-1??neutralizing their inhibitory effects on the pore-forming effectors BAX and BAK. This liberation triggers BAX/BAK oligomerization, mitochondrial outer membrane permeabilization, cytochrome c release, and subsequent activation of caspase-9, which in turn cleaves and activates executioner caspases including caspase-3. This cascade represents a core executioner mechanism of intrinsic apoptosis, integrating signals from DNA damage, oncogene activation, and cytokine withdrawal.
In the CAL-27 background, disruption of BBC3 provides an invaluable tool for examining apoptosis evasion, a hallmark of many solid tumors. Oral squamous cell carcinomas frequently display aberrant apoptotic signaling, and the loss of PUMA function can mimic the anti-apoptotic adaptations that promote tumor survival and chemoresistance. This model thus allows researchers to study how cancer cells withstand genotoxic stress, as well as to explore the interplay between p53 status (wild-type or mutant) and downstream death pathways. The polyclonal nature further permits assessment of heterogeneous responses to apoptotic stimuli within a mixed population, mirroring the clonal diversity of real tumors.
Researchers can employ this knockout model in a range of assays including Annexin V/propidium iodide flow cytometry to quantify apoptosis, western blotting for detection of cleaved caspase-3 and caspase-9, and cell viability assays such as MTT or CellTiter-Glo. RT-qPCR analysis can confirm reduced PUMA transcript levels, while immunofluorescence enables visualization of cytochrome c release from mitochondria. Colony formation assays provide insight into long-term proliferative capacity following genotoxic treatment. This product is particularly useful for investigations into p53-dependent apoptosis, DNA damage response pathways, and mechanisms of drug resistance in oral cancer. For further information, please contact Ascent Research.
