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, 56Fe) 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; 56Fe 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.

Cytotoxic, chemosensitizing and radiosensitizing effects of curcumin based on thioredoxin system inhibition in breast cancer cells: 2D vs. 3D cell culture system

“…In addition, cell-cell interactions may promote the response to radiotherapy through a bystander effect. El-Ashmawy et al (35) reported that irradiation of human lung epithelial 3D cell cultures showed reduced frequency of progression toward malignant phenotypes compared with 2D monolayers regardless of the comparable number of colonies (35).…”

3D Breast Tumor Models for Radiobiology Applications

“…In 3D radiobiology studies, researchers have worked with scaffolds, hydrogels, and spheroids to incorporate the third dimension for a wide range of cancers including breast cancers [ 92 ], brain tumors [ 93 , 94 ], lung cancers [ 95 , 96 ], bladder cancer [ 97 ], chondrosarcoma [ 98 ] and oral squamous cell carcinoma [ 99 , 100 ]. The majority of these studies have demonstrated the differential effects of RT on 2D vs 3D cultures.…”