title: [Establishment of a two-layer cell spheroid model and its applications in colorectal tumor cell-fibroblast interactions with effect on Cx43 expression].
abstract: OBJECTIVE
  To imitate tumor microenvironment in vivo through construction of two-layer cell spheroid as a three-dimensional tumor model, and to validate its application in the study of Cx43 expression in colorectal cancer cell-fibroblast interactions and colorectal cancer progression.
  
  
  METHODS
  The two-layer cell spheroid was constructed from SW620 colorectal cancer cells and HELF fibroblasts. The expression of Cx43 in the spheroid was detected by immunocytochemistry. The expression of Cx43 in cultured SW620 cells with or without co-cultured fibroblasts was detected by immunocytochemistry and immunofluorescence. The expression of Cx43 in colorectal cancer tissue was detected by immunohistochemistry.
  
  
  RESULTS
  The spheroid showed well-defined cellular morphology and clear boundary between two cell lines.Significant expression of Cx43 was found along the boundary.SW620 cells had no expression of Cx43 when cultured alone, while the expression of Cx43 was induced upon co-culturing with fibroblasts.In the colorectal cancer tissue, expression of Cx43 was minimal in the centre of tumor in contrast to an upregulated expression at invasive front.
  
  
  CONCLUSIONS
  The two-layer cell spheroid is an observable and sensitive model for cell-cell interaction for studies of tumor microenvironment.It can simulate colorectal cancer cell-fibroblast interactions through up-regulation of Cx43 expression.
authors.affiliation: Department of Pathology and Pathophysiology, Zhejiang University, Hangzhou 310058, China.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Pathology and Pathophysiology, Zhejiang University, Hangzhou 310058, China.
authors.forename: Shanli
authors.initials: S
authors.lastname: Lin
authors.affiliation: Department of Pathology and Pathophysiology, Zhejiang University, Hangzhou 310058, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Wen
authors.affiliation: Department of Pathology and Pathophysiology, Zhejiang University, Hangzhou 310058, China. E-mail: hongdeng@zju.edu.cn.
authors.forename: Hong
authors.initials: H
authors.lastname: Deng
mesh_terms: D002450:Cell Communication; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D018031:Connexin 43 / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology*; D006801:Humans; D018874:Spheroids, Cellular / Q000166:cytology / Q000378:metabolism*; D059016:Tumor Microenvironment; D015854:Up-Regulation
chemical_list: D018031:Connexin 43