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Sun M, Moquet J, Barnard S, Mancey H, Burling D, Baldwin-Cleland R, Monahan K, Latchford A, Lloyd D, Bouffler S, Badie C, Anyamene NA, Ainsbury E. In vitro study of radiosensitivity in colorectal cancer cell lines associated with Lynch syndrome. Front Public Health 2024; 12:1369201. [PMID: 38638480 PMCID: PMC11024246 DOI: 10.3389/fpubh.2024.1369201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/18/2024] [Indexed: 04/20/2024] Open
Abstract
Introduction Lynch syndrome patients have an inherited predisposition to cancer due to a deficiency in DNA mismatch repair (MMR) genes which could lead to a higher risk of developing cancer if exposed to ionizing radiation. This pilot study aims to reveal the association between MMR deficiency and radiosensitivity at both a CT relevant low dose (20 mGy) and a therapeutic higher dose (2 Gy). Methods Human colorectal cancer cell lines with (dMMR) or without MMR deficiency (pMMR) were analyzed before and after exposure to radiation using cellular and cytogenetic analyses i.e., clonogenic assay to determine cell reproductive death; sister chromatid exchange (SCE) assay to detect the exchange of DNA between sister chromatids; γH2AX assay to analyze DNA damage repair; and apoptosis analysis to compare cell death response. The advantages and limitations of these assays were assessed in vitro, and their applicability and feasibility investigated for their potential to be used for further studies using clinical samples. Results Results from the clonogenic assay indicated that the pMMR cell line (HT29) was significantly more radio-resistant than the dMMR cell lines (HCT116, SW48, and LoVo) after 2 Gy X-irradiation. Both cell type and radiation dose had a significant effect on the yield of SCEs/chromosome. When the yield of SCEs/chromosome for the irradiated samples (2 Gy) was normalized against the controls, no significant difference was observed between the cell lines. For the γH2AX assay, 0, 20 mGy and 2 Gy were examined at post-exposure time points of 30 min (min), 4 and 24 h (h). Statistical analysis revealed that HT29 was only significantly more radio-resistant than the MLH1-deficient cells lines, but not the MSH2-deficient cell line. Apoptosis analysis (4 Gy) revealed that HT29 was significantly more radio-resistant than HCT116 albeit with very few apoptotic cells observed. Discussion Overall, this study showed radio-resistance of the MMR proficient cell line in some assays, but not in the others. All methods used within this study have been validated; however, due to the limitations associated with cancer cell lines, the next step will be to use these assays in clinical samples in an effort to understand the biological and mechanistic effects of radiation in Lynch patients as well as the health implications.
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Affiliation(s)
- Mingzhu Sun
- United Kingdom Health Security Agency, Department of Radiation Effects, Cytogenetics and Pathology Group, Radiation, Chemical and Environmental Hazards Directorate, Didcot, United Kingdom
| | - Jayne Moquet
- United Kingdom Health Security Agency, Department of Radiation Effects, Cytogenetics and Pathology Group, Radiation, Chemical and Environmental Hazards Directorate, Didcot, United Kingdom
| | - Stephen Barnard
- United Kingdom Health Security Agency, Department of Radiation Effects, Cytogenetics and Pathology Group, Radiation, Chemical and Environmental Hazards Directorate, Didcot, United Kingdom
| | - Hannah Mancey
- United Kingdom Health Security Agency, Department of Radiation Effects, Cytogenetics and Pathology Group, Radiation, Chemical and Environmental Hazards Directorate, Didcot, United Kingdom
| | - David Burling
- Intestinal Imaging Centre, St Mark's Hospital, London North West University Healthcare National Health Service Trust, Harrow, United Kingdom
| | - Rachel Baldwin-Cleland
- Intestinal Imaging Centre, St Mark's Hospital, London North West University Healthcare National Health Service Trust, Harrow, United Kingdom
| | - Kevin Monahan
- Lynch Syndrome Clinic, Centre for Familial Intestinal Cancer, St Mark's Hospital, London North West University Healthcare National Health Service Trust, Harrow, United Kingdom
| | - Andrew Latchford
- Lynch Syndrome Clinic, Centre for Familial Intestinal Cancer, St Mark's Hospital, London North West University Healthcare National Health Service Trust, Harrow, United Kingdom
| | - David Lloyd
- United Kingdom Health Security Agency, Department of Radiation Effects, Cytogenetics and Pathology Group, Radiation, Chemical and Environmental Hazards Directorate, Didcot, United Kingdom
| | - Simon Bouffler
- United Kingdom Health Security Agency, Department of Radiation Effects, Cytogenetics and Pathology Group, Radiation, Chemical and Environmental Hazards Directorate, Didcot, United Kingdom
| | - Christophe Badie
- United Kingdom Health Security Agency, Department of Radiation Effects, Cytogenetics and Pathology Group, Radiation, Chemical and Environmental Hazards Directorate, Didcot, United Kingdom
| | - Nicola A. Anyamene
- East and North Hertfordshire National Health Service Trust, Mount Vernon Cancer Centre, Northwood, United Kingdom
| | - Elizabeth Ainsbury
- United Kingdom Health Security Agency, Department of Radiation Effects, Cytogenetics and Pathology Group, Radiation, Chemical and Environmental Hazards Directorate, Didcot, United Kingdom
- Environmental Research Group Within the School of Public Health, Faculty of Medicine at Imperial College of Science, Technology and Medicine, London, United Kingdom
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