In our previous studies, sulfatase 2 (Sulf2) was found to upregulate
vascular endothelial growth factor-D (
VEGF-D) expression in
breast cancer. As
VEGF-D plays an important role in lymphangiogenesis, we hypothesized that Sulf2 facilitates lymphangiogenesis in
breast cancer by regulating
VEGF-D. To evaluate the functions of Sulf2 on lymphangiogenesis in
breast cancer, proliferation, apoptosis, cell cycle, cell mobility and tube-formation of lymphatic endothelial cells (LECs) were measured in vitro. Lymphangiogenesis in nude mouse ears and
breast cancer xenografts were examined in vivo. Furthermore, the expression levels of related signaling pathway genes were screened and verified in LECs. We found that Sulf2 significantly increased the mobility and tube formation of the LECs, inhibited
cisplatin-induced LEC apoptosis, but had no effect on cell proliferation and the cell cycle. Moreover, recombinant Sulf2 (rSulf2) combined with
VEGF-D further promoted the proliferation, cell cycle, mobility and tube-like structure formation in the LECs, and at the same time inhibited
cisplatin-induced apoptosis especially in the late stage. Sulf2 also significantly increased the density of lymphatic vessels in mouse ears and
breast cancer xenografts in vivo. AKT1 was also shown to be upregulated and activated by Sulf2. Our results confirmed that Sulf2 facilitated lymphangiogenesis in
breast cancer cells by regulating
VEGF-D and that the AKT1‑related signaling pathway was involved.