The lncSNHG5-ZNF281-CCL2/CCL5 signaling axis facilitates BC metastasis. (A) A mixture of MDA-MB-231 cells and NFs/Ctrl, CAFs/shNC, CAFs/shlncSNHG5, CAFs/shZNF281, CAFs/shlncSNHG5/ZNF281, CAFs/RS102895, CAFs/Maraviroc or CAFs/Cenicriviroc was orthotopically injected into nude mice for 6 weeks. Representative images of pulmonary metastases in the lung surface (upper panel) and lung section (scale bar, 200 µm) by H&E staining (lower panel) are shown. (B) The number of lung metastatic nodules in each group of mice was counted under a microscope. (C) The maximal area of lung metastasis in each group was quantified using SlideViewer software. (D-E) qRT-PCR was used to detect the mRNA expression of CCL2 and CCL5 in human breast tumors with (16 cases) or without (76 cases) metastasis and adjacent normal tissues (60 cases). (F-G) ELISA was used to determine CCL2 and CCL5 proteins in healthy donors (22 cases) and breast cancer patients with (14 cases) or without (30 cases) metastasis. (H) Kaplan-Meier survival analysis of relapse-free survival based on the combined low or high levels of CCL2 and CCL5 using the GSE25066 dataset. (I) The diagnostic value of CCL2 and CCL5 for poor BC prognosis was evaluated using ROC curves. Data are presented as the mean ± SD (*P < 0.05, **P < 0.01, ***P < 0.001. ****P < 0.0001).