Fig. 3

Overstimulation of sensory Nav1.8 + nerve fibers decreases melanoma growth. A Schematic diagram of the Nav1.8-Cre + /hM3Dq + experimental mouse model. Cre recombinase directs the expression of hM3Dq specifically to sensory neurons in those mice. After the administration of CNO to those mice, neuronal activity in sensory neurons is overactivated. B Representation of the protocol for subcutaneous allograft melanoma growth. 1 × 10⁵ B16F10 melanoma cells were subcutaneously injected into Nav1.8‐Cre⁻/hM3Dq + (n = 14) and Nav1.8‐Cre + /hM3Dq + (n = 13) mice, and tumors were removed for analysis after 16 days. CNO was injected daily intra-peritoneally at 1 mg/kg. C Development curve of tumor growth from Nav1.8‐Cre⁻/hM3Dq⁺ and Nav1.8‐Cre⁺/hM3Dq⁺. Tumor volumes were assessed over time with a caliper. D Representative macroscopic images of B16F10 melanoma tumors after dissection, left panel (Nav1.8‐Cre⁻/hM3Dq⁺) and right panel (Nav1.8‐Cre⁺/hM3Dq⁺). E Tumor weight. (Nav1.8‐Cre⁻/hM3Dq⁺: 0.38 ± 0.07; Nav1.8‐Cre⁺/hM3Dq⁺: 0.17 ± 0.03). F Tumor weight corrected by animal body weight. G Representative immunofluorescence images of tumors labelled for Ki67 (Ki67; green) to identify cell proliferation and nuclei (DAPI; blue). H Quantification of proliferation in melanomas from Nav1.8‐Cre⁻/hM3Dq⁺ and Nav1.8‐Cre⁺/hM3Dq⁺ animals. I Quantification of proliferation (Ki67 +) by flow cytometry in CD45- cells from tumors of Nav1.8‐Cre⁻/hM3Dq⁺ and Nav1.8‐Cre⁺/hM3Dq⁺ mice. J Representative immunofluorescence images of tumor sections labelled for endothelial cells (CD31; red) to identify blood vessels and nuclei (DAPI; blue). K Quantification of angiogenesis in melanomas by blood vessel area. Data are shown as mean ± SEM. Unpaired t test (ns P > 0.05; *P < 0.05; **P < 0.01)