Overexpression of miR-206 suppressed the mutual promotion of malignant behaviors and gemcitabine resistance in the CCA-CAF environment. (A-B) The proliferation and migration abilities of HUCCT1 cells cocultured with miR-206-mimic/CAFs were explored by colony formation and Transwell assays. (C) The effects of miR-206-mimic/CAFs on HUCCT1 cell resistance to gemcitabine were evaluated by CCK-8 and colony formation assays. (D) The cycle distribution of HUCCT1 cells cocultured with miR-206-mimic/CAFs was analyzed by FCM. (E) Sphere formation by HUCCT1 cells cocultured with miR-206-mimic/CAFs were detected and assessed. Scale bar=100 µm. (F) Expression of Nang, Sox2 and Oct4 in HUCCT1 cells was detected by qPCR. (G) MiR-206-mimic/CAFs combined with HUCCT1 cells were subcutaneously coinjected into mice. After gemcitabine treatment for 3-4 weeks, the mice were sacrificed, subcutaneous tumors were imaged, and tumor volume was calculated. (H) The mRNA level of TGF-beta1 in HUCCT1 cells cocultured with miR-206-mimic/CAFs was detected by qPCR. (I) Alpha-SMA and FAP expression in NFs cocultured with miR-206-mimic/HUCCT1 cells was evaluated by IF assay. NFs culture alone as negative control. Scale bar=100 µm. (J) The mRNA levels of IL-1beta, IL-6, IL-8, VEGF-alpha and CXCL12 in NFs cocultured with miR-206-mimic/HUCCT1 cells were detected by qPCR. NFs culture alone as negative control. The data are shown as the mean ± SD, * P <0.05, ** P <0.01, *** P <0.001.