Background:　The　presence　of　cancer　stem　cells　(CSCs)　is　currently　regarded　as　one　of　the　main　culprits　of　tumor　formation　and　therapy　failure.　It　is　known　that　chronic　inflammation　is　associated　with　CSCs,　but　it　is　not　clear　yet　how　inflammation　affects　the　development　of　CSCs.　In　the　present　study　we　aimed　to　examine　the　relationship　between　cancer　cell　stimulation　mediated　by　immune　cells　and　the　acquisition　of　a　CSC-like　phenotype.　Methods:　Cancer　cells　derived　from　single　hepatocarcinoma　HepG2　cells　were　treated　with　mouse　splenic　B　cells　(MSBCs)　and　mouse　peritoneal　macrophage　cells　(MPMCs),　respectively.　The　stem　cell-like　characteristics　of　the　resulting　HepG2　cells　(MSBC-HepG2　and　MPMC-HepG2)　were　evaluated　using　different　assays,　including　biomarker　assays,　in　vitro　tumoroid　and　colony　forming　assays,　in　vivo　tumor　forming　assays　and　signal　transduction　pathway　activation　assays.　Results:　Various　stemness　characteristics　of　HepG2　cells,　including　self-renewal,　proliferation,　chemoresistance　and　tumorigenicity　were　evaluated.　The　expression　levels　of　stemness-related　genes　and　its　encoded　proteins　in　the　MSBC-HepG2　and　MPMC-HepG2　cells　were　assessed　using　RT-PCR　and　FACS　analyses.　We　found　that　MSBC-HepG2　and　MPMC-HepG2　cells　possess　hepatic　CSC　properties,　including　persistent　self-renewal,　extensive　proliferation,　drug　resistance,　high　tumorigenic　capacity　and　over-expression　of　CSC-related　genes　and　proteins　(i.e.,　EpCAM,　ALDH,　CD133　and　CD44),　compared　to　the　parental　cells.　We　also　found　that　1x103　MSBC-HepG2　and　MPMC-HepG2　cells　were　able　to　form　tumors　in　NOD/SCID　mice　and　that　the　Notch　and　SHH　signaling　pathways　were　highly　activated　in　MSBC-HepG2　cells.　Conclusions:　We　conclude　that　the　immune　system　may　have　a　double-edge　effect　on　cancer　development.　On　one　hand,　immune　cells　such　as　B　lymphocytes　and　macrophages　may　recognize,　attack　and　eliminate　cancer　cells,　whereas　on　the　other　hand,　they　may　promote　a　subset　of　cancer　cells　to　acquire　stem　cell-like　characteristics.　©　2015,　International　Society　for　Cellular　Oncology.