Wenxia Changfu Formula inhibits NSCLC metastasis by halting TAMs-induced epithelial-mesenchymal transition via antagonistically modulating CCL18

Background: Our previous studies have shown that the Wenxia Changfu Formula (WCF) as a neoadjuvant therapy could inhibit the infiltration of M2 macrophages of the tumor microenvironment, and prevent the metastasis of lung cancer. Since tumor-associated macrophages (TAMs) affect epithelial-mesenchymal transition (EMT), here we investigated whether WCF halts lung cancer metastasis by attenuating TAM-induced EMT of NSCLC cells. Methods: The co-culture model was treated with or without WCF for 24 h. Consumption or addition of CCL18 in Co-CM and overexpression of Src in NSCLC cells was performed to explore the possible associated mechanisms. The combined effects of WCF and rCCL18 were examined with the nude mouse model by tail vein injection of A549. Results: Our data revealed that WCF down-regulated CD163 expression of macrophages, decreased the levels of CCL18 in the conditioned medium, and inhibited the growth and invasion capacities and the EMT of NSCLC cells induced by co-culture of macrophages. Moreover, consumption or addition of CCL18 enhanced or reduced the effect of WCF. Overexpression of Src in NSCLC cells reduced the inhibitory effects of WCF. Additionally, Src overexpression retrieved the effects of CCL18 depletion combined with WCF on EMT of NSCLC cells induced by co-culture. In vivo experiments, WCF inhibited rCCL18 induced metastasis of tumors in nude mice through blocking Src signaling. Conclusions: In summary, our findings suggested that WCF can inhibit NSCLC metastasis by halting TAMs-induced epithelial-mesenchymal transition via antagonistically modulating CCL18. This provides objective evidence for the future development and clinical application of WCF to NSCLC patients.