title: Irradiated fibroblast-induced bystander effects on invasive growth of squamous cell carcinoma under cancer-stromal cell interaction.
abstract: The irradiated fibroblast-induced response of non-irradiated neighboring cells is called 'radiation-induced bystander effect', but it is unclear in non-irradiated human squamous cell carcinoma (SCC) cells. The present study shows that irradiated fibroblasts promoted the invasive growth of T3M-1 SCC cells, but not their apoptosis, more greatly than non-irradiated fibroblasts, using collagen gel invasion assay, immunohistochemistry and Western blot. The number of irradiated fibroblasts decreased to about 30% of that of non-irradiated fibroblasts, but irradiated fibroblasts increased the growth marker ki-67 display of SCC cells more greatly than non-irradiated fibroblasts. Irradiated fibroblasts did not affect the apoptosis marker ss-DNA expression of SCC cells. Irradiated fibroblasts enhanced the display of the following growth-, invasion- and motility-related molecules in SCC cells more greatly than non-irradiated fibroblasts: c-Met, Ras, mitogen-activated protein kinase (MAPK) cascade (Raf-1, MEK-1 and ERK-1/2), matrix metalloproteinase-1 and -9, laminin 5 and filamin A. Irradiated fibroblasts, but not non-irradiated ones, formed irradiation-induced foci (IRIF) of the genomic instability marker p53-binding protein 1 (53BP1) and expressed transforming growth factor-beta1 (TGF- beta1). Irradiated fibroblasts in turn enabled SCC cells to enhance 53BP1 IRIF formation more extensively than non-irradiated fibroblasts. Finally, effects of irradiated fibroblasts on growth and apoptosis of another HEp-2 SCC cell type were similar to those of T3M-1. These results suggest that irradiated fibroblasts promotes invasion and growth of SCC cells by enhancement of invasive growth-related molecules above through TGF- beta1-mediated bystander mechanism, in which irradiated fibroblast-induced genomic instability of SCC cells may be involved.
authors.affiliation: Department of Pathology & Biodefense, Faculty of Medicine, Saga University, Saga 849-8501, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Kamochi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakashima
authors.forename: Shigehisa
authors.initials: S
authors.lastname: Aoki
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Uchihashi
authors.forename: Hajime
authors.initials: H
authors.lastname: Sugihara
authors.forename: Shuji
authors.initials: S
authors.lastname: Toda
authors.forename: Sho
authors.initials: S
authors.lastname: Kudo
mesh_terms: D000818:Animals; D024201:Bystander Effect / Q000528:radiation effects*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004307:Dose-Response Relationship, Radiation; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology / Q000528:radiation effects; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D051379:Mice; D009062:Mouth Neoplasms / Q000378:metabolism / Q000473:pathology; D041681:NIH 3T3 Cells; D009361:Neoplasm Invasiveness; D009369:Neoplasms / Q000378:metabolism* / Q000473:pathology; D017154:Stromal Cells / Q000378:metabolism* / Q000473:pathology
chemical_list: D019394:Ki-67 Antigen