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Induction of genotoxic damage and ROS production in HCT116 TP53+/+ and HCT116TP53-/- colorectal cancer cell lines by
Chiara Naldoni1, Irene Guidotti1, Matilde Matteoli1
1Dipartimento di Biologia, Unità di Genetica, University of Pisa, Via Derna 1, 56126 Pisa, Italy.
Abstract:
Reactive oxygen species (ROS) play a dual role in cancer biology, contributing to both tumor progression and therapeutic responses. Many chemotherapeutic agents exert their cytotoxic effects through ROS generation, although the extent and biological relevance of this process remain influenced by cellular context, including the functional status of tumor suppressor genes such as TP53. In this study, we investigated the induction of genomic damage and oxidative stress in two isogenic human colorectal cancer cell lines-HCT116TP53+/+ and HCT116TP53-/--after exposure to four commonly used anticancer agents: oxaliplatin (OXA), irinotecan (IRI), paclitaxel (PAC), and 5-fluorouracil (5-FU). Drug concentrations were selected to ensure cell viability while inducing genotoxicity. Genome damage was assessed by micronucleus (MN) assay. ROS production was measured using the BODIPY581/591 C11 lipid peroxidation fluorescent probe. Our results showed that OXA and IRI induced both significant MN formation and robust ROS production in a dose-dependent manner, while PAC predominantly triggered genomic damage with limited ROS generation. Conversely, 5-FU exhibited marginal (or no) effect on both endpoints. Notably, with regard to the extent of ROS accumulation and MN induction, no significant differences were detected under the tested conditions between the two HCT116 cell lines. This suggests that under non-cytotoxic conditions, p53 is not a critical modulator of oxidative responses to these agents. Overall, our data reveal a drug-specific pattern of genome and oxidative damage in HCT116 colorectal cancer cells, emphasizing the importance of considering drug mechanism of action in evaluating redox responses. These insights may contribute to the development of targeted combinatorial therapies aimed at modulating oxidative stress, especially in TP53-mutated tumors.
Insights
Common chemotherapy drugs cause DNA damage and oxidative stress in colorectal cancer cells, but p53 status doesn't alter these responses. Drug choice impacts the type and extent of damage, guiding future targeted therapies.
Area of Science:
- Cancer Biology
- Genotoxicology
- Oxidative Stress Research
Background:
- Reactive oxygen species (ROS) have a complex role in cancer, influencing tumor growth and treatment outcomes.
- Chemotherapeutic agents often induce cancer cell death via ROS generation, but this is modulated by cellular factors like the TP53 tumor suppressor gene.
- Understanding drug-induced oxidative stress and genomic damage is crucial for optimizing cancer therapy.
Purpose of the Study:
- To investigate the induction of genomic damage and oxidative stress by common anticancer agents in colorectal cancer cells with differing TP53 statuses.
- To determine if TP53 functional status influences the cellular response to genotoxicity and ROS production induced by oxaliplatin, irinotecan, paclitaxel, and 5-fluorouracil.
Main Methods:
- Utilized isogenic HCT116 colorectal cancer cell lines (TP53+/+ and TP53-/-).
- Exposed cells to oxaliplatin, irinotecan, paclitaxel, and 5-fluorouracil at non-cytotoxic, genotoxic concentrations.
- Assessed genomic damage using the micronucleus (MN) assay and measured ROS production via BODIPY581/591 C11 fluorescence.
Main Results:
- Oxaliplatin and irinotecan induced significant dose-dependent micronucleus formation and ROS production.
- Paclitaxel primarily caused genomic damage with minimal ROS induction, while 5-fluorouracil had negligible effects on both endpoints.
- No significant differences in ROS accumulation or MN induction were observed between TP53+/+ and TP53-/- cells, suggesting p53 is not critical for these responses under tested conditions.
Conclusions:
- Colorectal cancer cells exhibit drug-specific patterns of genomic and oxidative damage in response to chemotherapy.
- TP53 status does not appear to be a critical modulator of oxidative stress or genotoxicity under non-cytotoxic conditions.
- These findings highlight the importance of drug mechanisms in redox response and may inform the development of targeted therapies for TP53-mutated tumors.
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