Endostatin inhibits the proliferation and migration of B16 cells by inducing macrophage polarity to M1‑type

Abstract

Malignant melanoma is a common skin tumor that easily metastasizes and has a poor prognosis. endostatin is an endogenous vascular endothelial inhibitor that mainly suppresses tumor growth by inhibiting the proliferation of vascular endothelial cells and by reducing the formation of tumor microvessels, however the immunological function of endostatin remains unclear. Previously, we have found that an over-expression endostatin (pendostatin) plasmid induced raW264.7 cells' polarity to M1-type macrophage. To elucidate the effect of M1-type macrophages induced by endostatin on melanoma B16 cells, the present study transfected raW264.7 cells with pendostatin plasmid and co-cultured them with B16 cells. compared with the control group, the expression of matrix metalloproteinase (MMP)-2, MMP-9 and proliferating cell nuclear antigen in B16 cells was inhibited by M1-type macrophages, but cleaved caspase-3 and cleaved caspase-8 were significantly upregulated and the ratio of Bax/Bcl-2 was increased. These results indicated that M1 macrophages induced by pendostatin plasmid inhibited the proliferation and migration of B16 cells and promoted their apoptosis. These findings suggest that the inhibitory effect of endostatin on melanoma is not limited to directly inhibiting tumor microvessel formation, but it may also be related to regulating changes in macrophage polarity.

Macrophages in melanoma: A double‑edged sword and targeted therapy strategies (Review)

“…M1 polarization of macrophages inhibits the proliferation of melanoma (41). By contrast, an increased number of M2 macrophages promotes melanoma growth (42).…”