Knockdown of CCL2 reduces tumor growth, fibrosis, and microvessel density in vivo. (A-B) HMC-1 cells transduced with an shRNA targeting CCL2 (RNAi, red [n = 6]) or an NTC (blue [n = 5]) were injected subcutaneously into NSG mice. (A) Calculated tumor volume over time and (B) measured tumor weight at day 34 after injection. (C-F) Sections prepared from paraffin-embedded tumors were stained with (C) hematoxylin and eosin, (D) Ki-67 indicating proliferation, (E) Chromotrope-aniline blue (CAB) indicating fibrosis, or (F) an antibody against von Willebrand factor staining microvessels. Representative pictures of tumors after CCL2 knockdown (RNAi, right subpanels) or controls (NTC, left subpanels) are shown. (G-I) Grading (scale of 0 to 4) of (G) inflammation and (H) fibrosis as well as (I) microvessel density of the tumors after CCL2 knockdown compared with controls (NTC). *P < .05, ***P < .001.