DPY19L3 promotes vasculogenic mimicry by its -mannosyltransferase activity.

-mannosylation is a post-translational modification that occurs intracellularly in the endoplasmic reticulum. In humans, biosynthesis of -mannosylation in proteins containing thrombospondin type 1 repeat is catalyzed by the DPY19 family; nonetheless, biological functions of protein -mannosylation are not yet fully understood, especially in tumor progression. Vasculogenic mimicry (VM) is the formation of fluid-conducting channels by highly invasive and genetically deregulated tumor cells, enabling the tumors to form matrix-embedded vasculogenic structures, containing plasma and blood cells to meet the metabolic demands of rapidly growing tumors. In this study, we focused on DPY19L3, a -mannosyltransferase, and aimed to unravel its role in VM. Knockout of inhibited the formation of VM in HT1080 human fibrosarcoma cells. Re-expression of wild-type DPY19L3 recovered VM formation; however, DPY19L3 isoform2, an enzymatic activity-defect mutant, did not restore it, suggesting that the -mannosyltransferase activity of DPY19L3 is crucial to its function. Furthermore, the knockdown of in MDA-MB-231 breast cancer cells hindered its network formation ability. Altogether, our findings suggest that DPY19L3 is required for VM formation and stipulate the relevance of -mannosylation in oncogenesis.