PCDH17 induces colorectal cancer metastasis by destroying the vascular endothelial barrier.

Compromised vascular integrity facilitates the cancer cells extravasation and metastasis. However, the mechanisms leading to a disruption in vascular integrity in colorectal cancer (CRC) remain unclear. In this study, PCDH17 expression was higher in the vascular endothelial cells of colon cancer with distant metastasis, and the rates of PCDH17⁺ endothelial cells (ECs) was associated with the M stage in clinical pathological characteristics analysis and correlated with a poor survival prognosis. The liver and lung metastatic dissemination of MC-38 was significantly decreased in PCDH17^-/-mice. The ubiquitination and degradation of VEGFR2 was prevented by the interaction between PCDH17 and the E3 ubiquitin ligase MARCH5, which causing the separation of internalized VE-cadherin, and increased the vascular permeability and metastasis of CRC. These results highlight the importance of PCDH17 in maintaining vascular integrity, which has emphasis for endothelial barrier function in metastatic cancer. PCDH17 has the potential to be a marker for predicting tumor metastasis as well as a viable treatment target for CRC.