Tissue inhibitor of metalloproteinase-1 promotes cell proliferation through YAP/TAZ activation in cancer

Tissue inhibitor of metalloproteinase-1 (TIMP-1), a member of the TIMP family (TIMP-1 to 4), is highly expressed in various types of cancer and forms a complex with its receptor CD63 and Integrin beta 1. However, the precise oncogenic mechanism of TIMP-1 remains unclear. Yes-associated protein (YAP) and transcriptional co-activator with PDZ binding motif (TAZ) are transcription co-activators enhancing the transcription of specific genes related to cell proliferation. But the mechanism of aberrant YAP/TAZ activation in cancer is not fully understood. Here, we showed that TIMP-1 activates YAP/TAZ as novel downstream targets to promote cell proliferation. The TIMP-1-CD63-Integrin beta 1 axis activates Src and promotes RhoA-mediated F-actin assembly, leading to LATS1/2 inactivation. This results in under-phosphorylation, protein stabilization and nuclear translocation of YAP/TAZ (YAP/TAZ activation); CTGF production; and cell proliferation. Furthermore, the TIMP-1-YAP/TAZ axis is aberrantly activated in various types of cancer cells or tissues. TIMP-1 knockdown inhibits cell proliferation through YAP/TAZ inactivation in cancer cells. This study found that TIMP-1 accelerates cell proliferation through YAP/TAZ activation in cancer, and suggests the TIMP-1-YAP/TAZ axis may be a novel potential drug target for cancer patients.