Tumor-associated macrophages (TAMs) are critical immune cells infiltrated into tumor. In present study, we evaluated the effects of Qi Ling (QL), a traditional Chinese medicine on paclitaxel resistance in prostate cancer cells and explored the underlying mechanisms. We administrated QL to rats and collected the serum from QL-treated rats (QL-serum). We established the co-culture system of TAMs/paclitaxel resistant prostate cancer cells. We treated the TAMs with QL-serum and measured the viability of paclitaxel resistant prostate cancer cells after exposing to paclitaxel. We monitored the expression of M1 and M2 markers, the expression and activation of IL-6/STAT3 signaling pathways in TAMs after QL treatment. We treated TAMs with QL-serum together with interleukin (IL)-6, measured the expression of M1 and M2 markers, and the viability of paclitaxel resistant prostate cancer cells. In co-culture system, QL-serum-treated TAMs decreased the paclitaxel resistance in the human prostate cancer cells. QL-serum treatment significantly up-regulated the expression of M1 markers inducible nitric oxide synthase and tumor necrosis factor α while decreased the expression of M2 markers IL-10 and chemokine (C-C motif) ligand 22. QL-serum suppressed the activation of IL-6/ signal transducer and activator of transcription 3 signaling pathway. All these effects of QL-serum were abolished in the presence of IL-6. Qi Ling re-programmed TAMs and decreases paclitaxel resistance in prostate cancer cells.
Keywords: Qi Ling; paclitaxel resistance; prostate cancer; tumor-associated macrophages.