Ptgs2 Knockout CT26 Cell Line

The Ptgs2 Knockout CT26 Cell Line is a CRISPR/Cas9-edited murine colorectal carcinoma model with targeted disruption of the Ptgs2 gene, which encodes cyclooxygenase-2 (COX-2). This knockout cell line abolishes COX-2 enzymatic activity, abrogating prostaglandin E2 (PGE2) synthesis and its downstream tumor-promoting signals. It serves as a definitive loss-of-function tool for studying COX-2-mediated oncogenic processes in a genetically defined, tumorigenic epithelial context.

The parental CT26 cell line originates from BALB/c mouse colorectal carcinoma and exhibits an adherent epithelial phenotype. CT26 is widely used as a syngeneic tumor model for colorectal cancer research, owing to its aggressive tumorigenicity and capacity to form tumors in immunocompetent hosts. It recapitulates key aspects of colorectal carcinoma progression, including angiogenesis, invasion, and immune cell infiltration, providing a clinically relevant platform for studying inflammation-driven carcinogenesis.

Ptgs2 codes for the inducible isoform of prostaglandin-endoperoxide synthase, which catalyzes the committed step in prostanoid biosynthesis from arachidonic acid. COX-2 expression is rapidly induced by proinflammatory cytokines like IL-1?? and TNF-??, as well as LPS, through NF-??B, AP-1, and MAPK/ERK pathways. The enzyme works with mPGES-1 to convert arachidonic acid to PGE2, the predominant prostanoid in many cancers. Secreted PGE2 acts via EP2 and EP4 receptors to stimulate adenylate cyclase, raising intracellular cAMP and activating PKA, which in turn phosphorylates and stabilizes ??-catenin. Concurrently, EP2/EP4 transactivate PI3K/AKT signaling, further enhancing ??-catenin nuclear translocation and the expression of proliferative, survival, and angiogenic genes such as VEGF, Bcl-2, and MMP-2/9.

In CT26 cells, endogenous COX-2 drives an autocrine loop that promotes proliferation, survival, and motility via PGE2. Knockout of Ptgs2 disrupts this circuit, leading to marked reductions in PGE2 secretion and downstream effectors. Phospho-AKT, ??-catenin, and ERK phosphorylation levels are diminished, and Vegf transcription is downregulated. Functional consequences include impaired cell growth as measured by MTT assay, reduced transwell migration and invasion, and increased susceptibility to apoptosis. These phenotypes underscore the critical role of COX-2 in CT26 tumor biology and position the knockout line as a powerful negative control for pharmacological and genetic experiments.

This cell line is tailored for investigations into the molecular underpinnings of inflammation-associated colorectal cancer, COX-2 inhibitor profiling, and study of EP receptor signaling. It enables in vitro assays such as PGE2 ELISA, western blot for pathway markers, and cell-based functional tests, as well as in vivo xenograft evaluation of tumor growth and metastasis. Researchers can apply the model to explore COX-2’s contribution to drug resistance, immune evasion, and angiogenic switching. For additional details or consultation, please contact Ascent Research.