The LPA2 receptor PDZ domain affects canonical Wnt signaling in colon cancer cells.
Castañeda-Patlán, M. C., Morales, J. C. M.-, Morquecho-León, M. A., Briseño-Díaz, P., Solís, K. H., Romero-Ávila, M. T., García-Sáinz, J. A., & Robles-Flores, M. (2026). The LPA2 receptor PDZ domain affects canonical Wnt signaling in colon cancer cells. Cellular Signalling, 139, 112318. https://doi.org/10.1016/j.cellsig.2025.112318
Colorectal cancer is the third leading cause of cancer-related deaths worldwide. Aberrant canonical Wnt signaling is a hallmark of this cancer type. It has been reported that LPA is a bioactive lipid that plays different roles in colon cancer by activating its G-protein-coupled receptors, promoting cell proliferation, migration, survival, and angiogenesis. Although it has been reported that LPA activates canonical Wnt signaling, the mechanisms underlying their interaction remain unclear; this study aims to investigate them. As previously reported, LPA receptor expression changes under malignant conditions: while LPA1 is expressed at high levels and LPA2 is low in non-malignant 112CoN cells, the opposite occurs in malignant cells, with colon cancer cells showing low LPA1 levels and high LPA2 levels. We also observed that both LPA and Wnt-3a induce strong ERK activation in all colon cell lines; these effects are not additive. Additionally, LPA and Wnt-3a stimulate β-catenin transcriptional activity and its phosphorylation at residues S552 and S675, again in a non-additive manner. We further found that LPA2 and the Wnt effectors Dvl2 and Dvl3 co-precipitate in colon cancer cells, and that the PDZ-interacting motif in the carboxyl terminus of the LPA2 receptor is critical for their direct interaction. Moreover, expressing a mutated LPA2-PDZminus receptor inhibited cell migration while increasing proliferation. Remarkably, the LPA2-PDZminus receptor negatively affected its ability to activate canonical Wnt signaling and unexpectedly, it also impaired the Wnt-3a ligand-induced activation of canonical Wnt signaling in colon cancer cells.