title: Invasion of carcinoma cells into reconstituted type I collagen gels: visual real-time analysis by time-lapse microscopy.
abstract: Stromal-epithelial interactions play a critical role in promoting tumorigenesis and invasion. To obtain detailed information on cancer cell behaviors on the stroma and kinetics of cell migration, which cannot be observed by conventionally-used Boyden chamber assays, this study was aimed at analyzing the cell invasion process in vitro using time-lapse microscopic observation. Serum-free conditions and reconstituted type I collagen gels which provided a basal membrane-stroma-like microenvironment were used to first establish a basal condition. Time-lapse microscopic observation for 30 h of cell invasion into the collagen gel revealed kinetic parameters and individualistic behavior of cancer cells. Of breast cancer MDA-MB-231 or MCF-7 cells and colon cancer LS180 or HT29 cells examined, MDA-MB-231 cells most rapidly disappeared from the collagen gel surface under basal conditions. Estrogen-dependent MCF-7 cells disappeared at a rate approximately two times slower than that of MDA-MB-231 cells under serum- and phenol red-free conditions. By the addition of 10 nM β-estradiol to the basal medium, MCF-7 cell invasion was facilitated to a rate similar to that of MDA-MB-231 cells. Microscopic analyses of collagen gel-sections demonstrated that most of the MDA-MB-231 and MCF-7 cells remained within 60 μm from the gel top under basal conditions, which is consistent with the observation obtained using Boyden chambers that no cells could cross the collagen I gel barrier unless 1% fetal calf serum was added to basal conditions. In summary, this study demonstrated future applicability of this method to understand the initial phase of cancer cell invasion processes.
authors.affiliation: Department of Applied Biochemistry, Tokai University, Hiratsuka, Kanagawa, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sakai
authors.forename: T
authors.initials: T
authors.lastname: Kurokawa
authors.forename: Y
authors.initials: Y
authors.lastname: Furui
authors.forename: Y
authors.initials: Y
authors.lastname: Kuronuma
authors.forename: M
authors.initials: M
authors.lastname: Sekiguchi
authors.forename: J
authors.initials: J
authors.lastname: Ando
authors.forename: Y
authors.initials: Y
authors.lastname: Inagaki
authors.forename: W
authors.initials: W
authors.lastname: Tang
authors.forename: M
authors.initials: M
authors.lastname: Nakata
authors.forename: Y
authors.initials: Y
authors.lastname: Fujita-Yamaguchi
mesh_terms: D002277:Carcinoma / Q000503:physiopathology*; D045744:Cell Line, Tumor; D024042:Collagen Type I; D005782:Gels; D006801:Humans; D066298:In Vitro Techniques; D009361:Neoplasm Invasiveness / Q000503:physiopathology*; D059008:Time-Lapse Imaging / Q000379:methods*
chemical_list: D024042:Collagen Type I; D005782:Gels