Primo Vascular System of Murine Melanoma and Heterogeneity of Tissue Oxygenation of the Melanoma

Murine melanoma requires the complex development of lymphatic, vascular, and non-vascular structures. A possible relationship between the primo vascular system (PVS) and the melanoma metastasis has been proposed. In particular, the PVS may be involved in oxygen transport. Vasculogenic-like networks, similar to the PVS, have been found within melanoma tumors, but their functional relationship with the PVS and meridian structures are unclear. Herein, we report on the use of an electrochemical O2 sensor to study oxygenation levels of melanoma tumors in mice. We consistently found higher tissue oxygenation in specific sites of tumors (n = 5). These sites were strongly associated with vascular structures or the PVS. Furthermore, the PVS on the tumor surface was associated with adipose tissue. Our findings suggest that the PVS is involved in the regulation of metastasis.