Notch ligand Delta-like 1 promotes the metastasis of melanoma by enhancing tumor adhesion

Notch signaling plays a vital role in tumorigenicity and tumor progression byregulating proliferation, invasion, and the tumor microenvironment. Previous researchby our group indicated that Notch ligand Delta-like 1 (Dll1) is involved inangiogenesis in melanoma, and we noticed that it took a longer time to trypsinizeDll1-expressing B16 melanoma cells than the control cells. In this article, weextended our study to investigate the effects of Dll1 on tumor cell adhesion andmetastasis. Dll1 overexpression activated Notch signaling in B16 tumor cells andsignificantly enhanced the adhering capacity of B16 tumor cells both invitro and in vivo. B16-Dll1 cells also had a highermetastatic potential than their counterpart in the mouse model of lung metastasis.Along with increased Dll1 expression, N-cadherin, but not E-cadherin, was upregulatedin B16-Dll1 cells. These data suggested that Notch ligand Dll1 may enhance theadhesion and metastasis of melanoma cells by upregulation of N-cadherin.