Efficient analyses of DNA double-strand breaks and the cell cycle in the secretory epithelial cells of fallopian tube fimbriae

ObjectiveReactive oxygen species (ROS)-induced DNA double-strand breaks (DSBs) are a feature of cancer initiation. Recently, the cells of origin of ovarian high-grade serous carcinoma (HGSC) have been identified as secretory cells in fallopian tube fimbriae, which might be heavily exposed to ROS after ovulation. Establishing a sensitive detection method for measuring DSBs and the cell cycle in fallopian tube secretory cells after ovulation is essential for facilitating research on ovarian cancer formation.Materials and methodsFimbrial epithelial cells from a prophylactically removed human fallopian tube were primarily cultured and immortalized by TP53/Rb-null and hTERT overexpression (FE25 cell line). Hydrogen peroxide (H2O2) was used to treat the FE25 cells to induce DNA DSBs. The DSBs and cell cycle were analyzed using flow cytometry. In addition, human specimens of fimbrial scrapings were subjected to the flow cytometry-based analysis.ResultsWe report an efficient flow cytometry-based method for analyzing the DSBs and cell cycle in immortalized fallopian tube secretory cells as well as in clinical specimens.ConclusionThis analysis method would facilitate the investigation of cancer initiation in fallopian tube fimbriae and other tissues with DSBs.