The CCL7 Knockout AGS Polyclonal Cells represent a polyclonal population of AGS human gastric adenocarcinoma epithelial cells that have undergone CRISPR/Cas9-mediated disruption of the CCL7 gene, resulting in a loss-of-function model for the chemokine CCL7. This polyclonal knockout cell population allows for the study of CCL7-dependent signaling without the selection bias of a clonal line, retaining the heterogeneity inherent to the AGS cell line while effectively abolishing CCL7 expression and secretion.
The AGS cell line, derived from a human gastric adenocarcinoma, serves as a well-established epithelial model for investigating gastric cancer biology, H. pylori adhesion and pathogenesis, and mucosal responses to pro-inflammatory stimuli. As adherent epithelial cells, AGS cells exhibit characteristics of gastric mucosal epithelium and are permissive to studies of chemokine secretion, cell migration, and receptor-mediated signaling in a gastric tissue context.
CCL7 (monocyte chemotactic protein-3) is a CC chemokine that mediates chemotaxis of monocytes, eosinophils, basophils, and T cells through G protein-coupled receptors CCR1, CCR2, CCR3, and CCR5. In AGS cells, CCL7 expression is upregulated by pro-inflammatory cytokines such as TNF-??, IL-1??, and IFN-??, as well as LPS, primarily via NF-??B signaling. Upon receptor engagement, CCL7 activates downstream effectors including PI3K, AKT, ERK, and p38 MAPK pathways, leading to calcium mobilization and directed cell migration. Additionally, CCL7 interacts with glycosaminoglycans, which facilitate its immobilization and presentation on the cell surface or extracellular matrix. Knockout of CCL7 in this polyclonal population ablates the secretion of this chemokine, thereby interrupting paracrine and autocrine signaling loops that coordinate immune cell recruitment and tumor-microenvironment interactions.
Disruption of CCL7 expression in AGS cells provides a physiologically relevant model to dissect the contribution of tumor-derived chemokines to the gastric tumor microenvironment. Given the role of CCL7 in recruiting immune cells, its knockout in gastric adenocarcinoma cells is expected to impair chemotactic signaling to monocytes and other leukocytes, potentially reducing inflammation-associated tumor progression. This model enables investigation of how the absence of CCL7 alters the cytokine-cytokine receptor interaction network and modulates NF-??B and MAPK signaling pathways that are frequently dysregulated in gastric cancer. Consequently, the CCL7 knockout AGS polyclonal cells offer a valuable platform for exploring the interplay between epithelial-derived chemokines and the inflammatory milieu characteristic of gastric carcinogenesis.
Researchers can employ this polyclonal knockout cell population in chemotaxis assays to quantify the loss of immune cell migration towards AGS-conditioned medium, or in co-culture systems to assess changes in immune cell behavior. Quantitative RT-PCR and ELISA confirm the absence of CCL7 mRNA and secreted protein, while western blotting enables analysis of downstream signaling mediators such as phosphorylated ERK, AKT, and p38. Migration and invasion assays using these cells permit evaluation of autocrine effects on gastric cancer cell motility, and immunofluorescence can monitor surface expression of CCR1, CCR2, CCR3, and CCR5 receptors on interacting immune cells. This model is also suited for high-throughput screening of compounds that target chemokine-receptor axes and for studying mechanisms of chronic inflammation in gastric cancer progression. For further information or technical consultation, please contact Ascent Research.
