Figure 1.

Inhibition of tumor angiogenesis by simvastatin through a paracrine‐related mechanism. A, 4T1 tumors from simvastatin‐treated and control mice were double‐immunostained for CD31 (green) and α‐smooth muscle actin (α‐SMA) (red), and B, quantified for microvessel density and vessels with pericyte coverage (n = 8). White arrows indicate vascular sprouts; yellow arrows indicate vascular pericyte. Scale bar = 100 μm. C, Micrographs of TRITC‐Lectin‐perfused and CD31‐stained vessels in control and simvastatin‐treated 4T1 tumors. TRITC‐Lectin was injected into the tail vein of mice 15 min before they were killed. Scale bar = 100 μm. D, Quantification of Lectin‐perfused CD31⁺ vessels (% total CD31⁺ vessels) in 4T1 tumors (n = 6). E, Representative images showing in vivo growth curve of 4T1 tumors from mice untreated or treated with simvastatin (SMV) (n = 8). F, G, SMV pretreatment (0.5 μmol/L) reduced the tube formation ability of HUVECs, which was promoted by the tumor cell‐conditioned medium of 4T1 tumor cells (n = 6). HUVECs were cultured in serum free medium (SFM) or conditioned medium (CM) of 4T1 cells, untreated (Con) or pretreated with SMV. H, I, SMV pretreatment greatly inhibited the proliferative ability of HUVECs (EC) cultured in (H) 4T1 or (I) MDA‐MB‐231 conditioned medium (CM) (n = 6). Quantitative data are indicated as mean ± SD. *P < .05; ***P < .001. ns, no statistically significant difference (P > .05)