Transmembrane serine protease 2 cleaves nidogen 1 and inhibits extrahepatic liver cancer cell migration and invasion.

We aimed to confirm whether transmembrane serine protease 2 (TMPRSS2) regulates nidogen 1 (NID1) expression in extracellular vesicles (EVs) and metastatic hepatocellular carcinoma (HCC) cells. HCC cells, HUVEC cells, MRC-5 cells, HLE cells, MHCCLM3 cells, MHCC97L cells, H2P cells, H2M cells, as well as LO2 cells were cultured according to providers' instruction and EV models were established by using BALB/cAnN-nu mice to facilitate the verifications. We found that TMPRSS2 expression was inversely correlated with the metastatic potential of HCC cell lines. The expression of TMPRSS2 decreased in a time-dependent manner in tumor-bearing model mice implanted with MHCCLM3 cells compared with uninoculated mice. TMPRSS2 overexpression in MHCCLM3 and MHCC97L cells led to the significant downregulation of NID1 expression in total cell lysates and isolated EVs. In contrast, TMPRSS2 silencing resulted in the elevation of NID1 expression in cells and EVs. Administration of EVs from MHCCLM3 and MHCC97L cells with overexpressed or silenced TMPRSS2 inhibited or strengthened, respectively, the invasion, proliferation, and migration of LO2 tumor cells. EVs derived from MHCCLM3 and MHCC97L cells with overexpressed or depleted TMPRSS2 also deactivated or activated fibroblasts, respectively. These EVs secrete inflammatory cytokines and phosphorylated p65, facilitate the colonization of fibroblasts, and augment fibroblast growth and motility. These findings provide evidence for a new candidate drug targeting tumorigenic EV-NID1 to treat HCC.