title: A novel coculture technique demonstrates that normal human prostatic fibroblasts contribute to tumor formation of LNCaP cells by retarding cell death.
abstract: The microenvironment influences the progression of an epithelial malignancy. To examine the effect of fibroblasts on epithelial cells by direct cell-cell contact in vitro, a coculture system was designed to assess cell death and proliferation of two cell populations when grown together. We used a green fluorescent dye to stain fibroblasts and distinguish them from unstained epithelial cells by a flow cytometer. We show that tumor cell death is 5-fold less when cocultured with normal human prostatic fibroblasts than when cultured alone. In contrast, proliferation of tumor cells was similar when cocultured with normal human prostatic fibroblasts or when grown alone. The reduction in tumor cell death during coculture appears to play a significant role in promoting tumor formation. Combination of prostatic fibroblasts with LNCaP xenografts formed large tumors at a high frequency with a low apoptotic index in vivo, whereas, LNCaP xenografts alone formed small infrequent tumors with a high apoptotic index. Therefore, prostatic fibroblasts promote tumor formation by retarding the apoptotic pathways in tumor cells.
authors.affiliation: Cancer Research Center, University of California at San Francisco, 94143-0506, USA.
authors.forename: A F
authors.initials: AF
authors.lastname: Olumi
authors.forename: P
authors.initials: P
authors.lastname: Dazin
authors.forename: T D
authors.initials: TD
authors.lastname: Tlsty
mesh_terms: D000818:Animals; D002450:Cell Communication; D016923:Cell Death; D002455:Cell Division; D018920:Coculture Techniques; D004847:Epithelial Cells / Q000502:physiology; D005347:Fibroblasts / Q000502:physiology*; D005434:Flow Cytometry; D005452:Fluoresceins; D006801:Humans; D008297:Male; D051379:Mice; D011467:Prostate / Q000166:cytology*; D011471:Prostatic Neoplasms / Q000209:etiology*; D013194:Staining and Labeling
chemical_list: D005452:Fluoresceins; C069306:5-chloromethylfluorescein