title: HepG2 cells acquire stem cell-like characteristics after immune cell stimulation.
abstract: 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 1x10(3) 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.
authors.affiliation: Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Wang
authors.affiliation: Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China.
authors.forename: Miqing
authors.initials: M
authors.lastname: Yang
authors.affiliation: Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Lin
authors.affiliation: Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China.
authors.forename: Hongzhen
authors.initials: H
authors.lastname: Ren
authors.affiliation: Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China.
authors.forename: Chaotong
authors.initials: C
authors.lastname: Lin
authors.affiliation: Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China.
authors.forename: Suling
authors.initials: S
authors.lastname: Lin
authors.affiliation: Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China.
authors.forename: Guoying
authors.initials: G
authors.lastname: Shen
authors.affiliation: Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China.
authors.forename: Binfeng
authors.initials: B
authors.lastname: Ji
authors.affiliation: Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China. mengchun@fzu.edu.cn.|, Qi Shan Campus, 2 Xue Yuan Road, University Town, Fuzhou, Fujian, 350108, People's Republic of China. mengchun@fzu.edu.cn.
authors.forename: Chun
authors.initials: C
authors.lastname: Meng
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001402:B-Lymphocytes / Q000166:cytology* / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D000066673:Cell Self Renewal / Q000187:drug effects; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D005260:Female; D053823:Hedgehog Proteins / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D017737:Macrophages, Peritoneal / Q000166:cytology* / Q000187:drug effects; D008807:Mice, Inbred BALB C; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D014411:Neoplastic Stem Cells / Q000187:drug effects / Q000276:immunology* / Q000473:pathology*; D051880:Receptors, Notch / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D018874:Spheroids, Cellular / Q000187:drug effects / Q000473:pathology; D013154:Spleen / Q000166:cytology
chemical_list: D016895:Culture Media, Serum-Free; D053823:Hedgehog Proteins; D051880:Receptors, Notch
keywords: Cancer stem cells; HepG2 cells; Peritoneal macrophage cells; Splenic B cells