title: Organotypic culture in three dimensions prevents radiation-induced transformation in human lung epithelial cells.
abstract: The effects of radiation in two-dimensional (2D) cell culture conditions may not recapitulate tissue responses as modeled in three-dimensional (3D) organotypic culture. In this study, we determined if the frequency of radiation-induced transformation and cancer progression differed in 3D compared to 2D culture. Telomerase immortalized human bronchial epithelial cells (HBECs) with shTP53 and mutant KRas expression were exposed to various types of radiation (gamma, (+)H, (56)Fe) in either 2D or 3D culture. After irradiation, 3D structures were dissociated and passaged as a monolayer followed by measurement of transformation, cell growth and expression analysis. Cells irradiated in 3D produced significantly fewer and smaller colonies in soft agar than their 2D-irradiated counterparts (gamma P = 0.0004; (+)H P = 0.049; (56)Fe P < 0.0001). The cell culture conditions did not affect cell killing, the ability of cells to survive in a colony formation assay, and proliferation rates after radiation-implying there was no selection against cells in or dissociated from 3D conditions. However, DNA damage repair and apoptosis markers were increased in 2D cells compared to 3D cells after radiation. Ideally, expanding the utility of 3D culture will allow for a better understanding of the biological consequences of radiation exposure.
authors.affiliation: Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, 75235, United States of America.
authors.forename: Mariam
authors.initials: M
authors.lastname: El-Ashmawy
authors.affiliation: Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, 75235, United States of America.
authors.forename: Melissa
authors.initials: M
authors.lastname: Coquelin
authors.affiliation: Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, 75235, United States of America.
authors.forename: Krishna
authors.initials: K
authors.lastname: Luitel
authors.affiliation: Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, 75235, United States of America.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Batten
authors.affiliation: Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, 75235, United States of America.
authors.forename: Jerry W
authors.initials: JW
authors.lastname: Shay
mesh_terms: D017209:Apoptosis / Q000528:radiation effects; D001980:Bronchi / Q000378:metabolism* / Q000473:pathology; D018929:Cell Culture Techniques / Q000379:methods*; D002461:Cell Line, Transformed; D002471:Cell Transformation, Neoplastic / Q000473:pathology / Q000528:radiation effects*; D004249:DNA Damage; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D005720:Gamma Rays / Q000009:adverse effects*; D005786:Gene Expression Regulation / Q000528:radiation effects; D006801:Humans