The CASP8 Knockout HGC-27 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population designed for loss-of-function studies of the initiator caspase, CASP8. This product comprises a heterogeneous pool of HGC-27 cells harboring disruptions in the CASP8 gene, generated via CRISPR/Cas9-mediated gene disruption, and serves as a versatile model for investigating the consequences of caspase-8 deficiency in a gastric carcinoma background. The polyclonal format allows researchers to study the population-level effects of CASP8 knockout, reflecting the diverse genetic alterations within the cell pool, and is suitable for a range of functional and mechanistic assays without the bias introduced by clonal selection. This knockout model is provided as a ready-to-use research tool for exploring apoptosis, necroptosis, and inflammatory signaling pathways.
The HGC-27 host cell line is a human epithelial cell line derived from the metastatic lymph node of a patient with poorly differentiated gastric adenocarcinoma. This cell line is widely utilized as an in vitro model for gastric cancer, retaining key characteristics of the primary tumor, such as invasive potential and dysregulated growth signaling. As an adherent cell line with a poorly differentiated phenotype, HGC-27 cells provide a relevant and aggressive cancer context for examining the role of cell death regulators. The gastric carcinoma origin of HGC-27 makes this knockout model particularly relevant for studying the molecular mechanisms underlying gastric cancer progression, drug resistance, and the interplay between cell death and inflammation in the tumor microenvironment.
Caspase-8, encoded by CASP8, functions as a critical initiator caspase in the extrinsic apoptosis pathway, activated downstream of death receptors such as FAS, TNFR1, and DR4/5 upon engagement by FAS ligand, TNF-alpha, or TRAIL. Upon receptor stimulation, caspase-8 is recruited to the death-inducing signaling complex (DISC) through the adaptor protein FADD, where it undergoes autoproteolytic activation. Active caspase-8 then directly cleaves and activates executioner caspases, including caspase-3 and caspase-7, leading to apoptosis. Additionally, caspase-8 cleaves the BH3-only protein BID to generate tBID, which engages the mitochondrial apoptotic pathway. Beyond apoptosis, caspase-8 negatively regulates necroptosis by cleaving RIPK1 and RIPK3, and participates in NF-kB activation and inflammatory signaling through interactions with TRADD, TRAF2, and c-FLIP. These multifaceted roles position caspase-8 as a central node controlling cell fate decisions.
In the context of HGC-27 gastric cancer cells, CASP8 knockout abrogates caspase-8 expression and function, thereby impairing death receptor-mediated extrinsic apoptosis and sensitizing cells to necroptotic cell death. The loss of caspase-8 disrupts the normal signaling balance between apoptosis and necroptosis, which can influence tumor cell survival in inflammatory microenvironments and alter responses to therapeutic agents that activate death receptors, such as TRAIL-based therapies. This knockout model enables the dissection of caspase-8-dependent versus -independent pathways in a highly aggressive and clinically relevant gastric adenocarcinoma cell line, providing insights into the molecular determinants of cancer cell fate and inflammation-driven tumor progression.
This CASP8 knockout polyclonal cell population is a powerful tool for a broad range of research applications, including apoptosis resistance studies, necroptosis pathway analysis, and drug sensitivity screening with death receptor ligands such as FASL or TRAIL. It facilitates the investigation of inflammatory signaling crosstalk in gastric cancer, particularly the interplay between caspase-8, NF-kB, and inflammasome activation. Typical assays include western blotting for caspase-8 and downstream targets like caspase-3 and BID, flow cytometric apoptosis analysis using annexin V/PI staining, cell viability measurements by MTT or CCK-8 assays, and necroptosis inhibition rescue experiments with necrostatin-1. Co-immunoprecipitation can be employed to examine DISC formation, while RT-qPCR and phospho-signaling analyses provide gene expression and pathway activation readouts. For further details or to discuss how this model can be integrated into your research projects, please contact Ascent Research.
