Enhanced DNA double-strand break repair of microbeam targeted A549 lung carcinoma cells by adjacent WI38 normal lung fibroblast cells via bi-directional signaling

Publication date: Available online 23 June 2017 Source:Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis Author(s): Alisa Kobayashi, Tengku Ahbrizal Farizal Tengku Ahmad, Narongchai Autsavapromporn, Masakazu Oikawa, Shino Homma-Takeda, Yoshiya Furusawa, Jun Wang, Teruaki Konishi Understanding the mechanisms underlying the radiation-induced bystander effect (RIBE) and bi-directional signaling between irradiated carcinoma cells and their surrounding non-irradiated normal cells is relevant to cancer radiotherapy. The present study investigated propagation of RIBE signals between human lung carcinoma A549 cells and normal lung fibroblast WI38 cells in bystander cells, either directly or indirectly contacting irradiated A549 cells. We prepared A549-GFP/WI38 co-cultures and A549-GFP/A549 co-cultures, in which A549-GFP cells stably expressing H2BGFP were co-cultured with either A549 cells or WI38 cells, respectively. Using the SPICE-NIRS microbeam, only the A549-GFP cells were irradiated with 500 protons per cell. The level of γ-H2AX, a marker for DNA double-strand breaks (DSB), was subsequently measured for up to 24h post-irradiation in three categories of cells: (1) “targeted”/irradiated A549-GFP cells; (2) “neighboring”/non-irradiated cells directly contacting the “targeted” cells; and (3) “distant”/non-irradiated cells, which were not in direct contact with the “targeted” cells. We found that DSB repair in targeted A549-GFP cell...
Source: Mutation Research Fundamental and Molecular Mechanisms of Mutagenesis - Category: Cytology Source Type: research