Cancer stem cells (CSCs) are a promising target for treating cancer, yet how CSC plasticity is maintained in vivo is unclear and is difficult to study in vitro. Here we establish a sustainable primary culture of Oct3/4(+)/Nanog(+) lung CSCs fed with CD90(+) cancer-associated fibroblasts (CAFs) to further advance our knowledge of preserving stem cells in the tumour microenvironment. Using transcriptomics we identify the paracrine network by which CAFs enrich CSCs through de-differentiation and reacquisition of stem cell-like properties. Specifically, we find that IGF1R signalling activation in cancer cells in the presence of CAFs expressing IGF-II can induce Nanog expression and promote stemness. Moreover, this paracrine signalling predicts overall and relapse-free survival in stage I non-small cell lung cancer (NSCLC) patients. IGF-II/ IGF1R signalling blockade inhibits Nanog expression and attenuates cancer stem cell features. Our data demonstrate that CAFs constitute a supporting niche for cancer stemness, and targeting this paracrine signalling may present a new therapeutic strategy for NSCLC. ; 藥理學科暨研究所 ; 醫學院 ; 醫學檢驗暨生物技術學系暨研究所 ; 醫學院 ; 附設醫院檢驗醫學部 ; 醫學院附設醫院 ; 病理學科暨研究所 ; 醫學院 ; 附設醫院病理部 ; 醫學院附設醫院 ; 醫學系內科 ; 醫學系 ; 醫學院 ; 附設醫院內科部 ; 醫學院附設醫院 ; 口腔生物科學研究所 ; 牙醫專業學院 ; 毒理學研究所 ; 醫學院 ; 期刊論文