Panoply™ Human TLR2 Over-expressing Stable Cell Line

Intrahepatic cholangiocarcinoma (ICC) is a rare and highly aggressive malignant tumor, often diagnosed at an advanced stage, which limits treatment options. Despite the rising incidence and mortality rates of ICC worldwide, its pathogenesis remains poorly understood. Here, researchers investigated the role of Toll-like receptor (TLR)2 in the pathogenesis and invasiveness of ICC, examining the impact of innate immune dysregulation on tumorigenesis and exploring its potential mechanisms. Immunohistochemical analysis, real-time quantitative PCR, and Western blotting experiments showed significantly elevated TLR2 expression levels in ICC tissues and cell lines. Silencing and overexpression experiments revealed that TLR2 promotes ICC cell migration and invasion, induces the expression of epithelial-mesenchymal transition (EMT) markers, and upregulates pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β, while simultaneously activating the NF-κB signaling pathway. Inhibition of NF-κB activity eliminated the effects of TLR2 on EMT, invasion, and migration, as well as the TLR2-induced upregulation of pro-inflammatory cytokines, and inhibited the restorative effects of exogenous TNF-α and IL-6 on EMT, migration, and invasion in the presence of TLR2. These results indicate that TLR2 plays a pro-tumor and pro-metastatic role in ICC by activating the NF-κB signaling pathway and inducing the upregulation of inflammatory cytokines, suggesting that TLR2 may be a potential new therapeutic target for ICC.

To determine whether TLR2 expression affects the invasion and migration abilities of ICC cell lines, researchers constructed TLR2 knockdown and TLR2 overexpression HuH-28 and RBE cell lines and assessed their proliferation, migration, and invasion abilities. Cell viability assays using the CCK-8 assay showed that TLR2 silencing inhibited the viability of HuH-28 and RBE cells, while TLR2 overexpression promoted cell viability, but the difference was not statistically significant (Figure 1B). Apoptosis assays showed enhanced apoptosis in the TLR2 knockdown cell line, while apoptosis was inhibited in the TLR2 overexpression cell line (Figure 1C). However, this difference also did not reach statistical significance. TLR2 silencing significantly inhibited the migration and invasion of HUH-28 and RBE cells, while TLR2 overexpression had the opposite effect, promoting migration and invasion to approximately three times the degree of the empty vector control group (Figures 1D and 1E).

Figure 1. High TLR2 levels facilitate ICC cell migration and invasion. (Liu B, et al., 2016)