TLR4 Activates the β-catenin Pathway to Cause Intestinal Neoplasia
Figure 7
Model for TLR4 driven tumorigenesis.
TLR4 promotes neoplasia through activation of the β-catenin pathway. Under normal conditions, TLR4 expression is low in the colon crypts, with few proliferating cells at their base expressing Lgr5 (green cells) and nuclear β-catenin. The majority of the cells along the crypt have β-catenin undergoing proteosomal degradation (membrane β-catenin). TLR4 activation results in activation of β-catenin, increased expression of Lgr5, and increased proliferation. In a third of CRCs, TLR4 is over-expressed, promoting tonic stimulation of cell proliferation and an expansion of cancer cells.