Authors: Minsik Park, Joohwan Kim, Taesam Kim, Suji Kim, Wonjin Park, Kwon-Soo Ha, Sung Hwan Cho, Moo-Ho Won, Jeong-Hyung Lee, Young-Guen Kwon, Young-Myeong Kim
Published: 2021-10-25
DOI: 10.1038/s12276-021-00690-z
Source: Full article
AbstractLow-dose metronomic chemotherapy (LDMC) inhibits tumor angiogenesis and growth by targeting tumor-associated endothelial cells, but the molecular mechanism has not been fully elucidated. Here, we examined the functional role of regulated in development and DNA damage responses 1 (REDD1), an inhibitor of mammalian target of rapamycin complex 1 (mTORC1), in LDMC-mediated endothelial cell dysfunction. Low-dose doxorubicin (DOX) treatment induced REDD1 expression in cultured vascular and lymphatic endothelial cells and subsequently repressed the mRNA expression of mTORC1-dependent translation of vascular endothelial growth factor receptor (Vegfr)-2/3, resulting in the inhibition of VEGF-mediated angiogenesis and lymphangiogenesis. These regulatory effects of DOX-induced REDD1 expression were additionally confirmed by loss- and gain-of-function studies. Furthermore, LDMC with DOX significantly suppressed tumor angiogenesis, lymphangiogenesis, vascular permeability, growth, and metastasis in B16 melanoma-bearing wild-type but notRedd1-deficient mice. Altogether, our findings indicate that REDD1 is a crucial determinant of LDMC-mediated functional dysregulation of tumor vascular and lymphatic endothelial cells by translational repression ofVegfr-2/3transcripts, supporting the potential therapeutic properties of REDD1 in highly progressive or metastatic tumors.