TITLE:
2,6-Dichloro-1,4-Benzoquinone Induces Oxidative Stress, Mitophagy-Related Gene Upregulation, and Insulin Signaling Pathway Suppression in T24 Bladder Cancer Cells
AUTHORS:
Daokui Fang
KEYWORDS:
Disinfection By-Products, Halobenzoquinone, 2, 6-DCBQ, RNA-Seq, Mitophagy
JOURNAL NAME:
Occupational Diseases and Environmental Medicine,
Vol.14 No.3,
July
8,
2026
ABSTRACT: 2,6-Dichloro-1,4-benzoquinone (2,6-DCBQ), a disinfection by-product frequently detected in drinking water, exhibits significant toxicity. However, it remains unregulated due to a lack of toxicological data. This study aims to generate toxicological data on 2,6-DCBQ and elucidate its mechanisms of toxicity in T24 bladder cancer cells. T24 cells were exposed to 10 - 250 μM 2,6-DCBQ. Cell viability was assessed using the CCK-8 assay to calculate the IC50. Cytotoxic effects at concentrations approximating 1/4 IC50, 1/2 IC50 and IC50 concentrations were evaluated using a lactate dehydrogenase (LDH) cytotoxicity detection kit. Oxidative stress levels were quantified via malondialdehyde (MDA) assay. RNA‑seq was employed to analyze changes in gene expression and signaling pathways in T24 cells following 2,6-DCBQ exposure. The results showed that 2,6-DCBQ exposure resulted in a dose‑dependent reduction in T24 cell viability and increased mortality. Higher doses induced oxidative damage. Transcriptomic analysis revealed abnormal upregulation of mitophagy‑related genes and downregulation of genes associated with the insulin signaling pathway in T24 cells. In conclusion, exposure to 2,6-DCBQ induces oxidative damage leading to cell death in T24 cells, with mitophagy-related pathways and the insulin signaling pathway identified as key contributors. These findings are limited to the bladder cancer cell model and further studies are needed to extrapolate to normal bladder tissue or human health.