The level of antioxidants, 8OHDG, and mitochondrial membrane potential of tumor tissues depending on the location of colorectal cancer

Purpose of the study. To study the mitochondrial membrane potential, indicators of the enzymatic and non-enzymatic antioxidant systems, and the mtDNA damage index in the mitochondria of colorectal cancer (CRC) cells depending on its location, the presence of metastases in the lymph nodes, and the patient sex.

Patients and methods. The study included results obtained from 132 patients (52 women and 80 men) with T2-3N0M0 colon cancer. Mitochondria from intestinal and tumor tissue cells were isolated using differential centrifugation. The concentration of SOD-2, 8OHdG, vitamins A and E, GPO-1, and the membrane potential (ΔψM) were determined in mitochondria. Statistical analysis was performed using the program Statistica 10.0.

Results. In rectal tumor mitochondria with lymph node metastases, both men and women demonstrated increased 8-OHdG levels and decreased ΔψM compared with patients without lymph node metastases: in men, by 2.2-fold and 1.5-fold (p < 0.05), and in women, by 1.3-fold (p < 0.05) and 2.0-fold, respectively. In the left colon, tumor mitochondria in men with metastases showed a 2.4-fold increase in 8-OHdG, while ΔψM and vitamins A and E levels were reduced by 1.7-fold (p < 0.05), 2.4-fold, and 3.1-fold, respectively. In women, lymph node metastases were associated with decreased levels of vitamins A and E by 1.7-fold (p < 0.05) and 4.3-fold. In the right colon, tumor mitochondria in patients with metastases showed higher levels of vitamins A and E compared with those without metastases: vitamin A increased by 1.7-fold (p < 0.05) in men and 2.4-fold in women, and vitamin E by 4.2-fold and 3.9-fold, respectively. SOD-2 levels were 2.2-fold lower only in tumor mitochondria with metastases in men.

Conclusion. Mitochondrial oxidative stress is an important systemic phenomenon in progressive CRC, and its manifestations depend on patient sex and location.

1. Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2018 Nov;68(6):394–424. https://doi.org/10.3322/caac.21492 Erratum in: CA Cancer J Clin. 2020 Jul;70(4):313. https://doi.org/10.3322/caac.21609

2. La Vecchia S, Sebastián C. Metabolic pathways regulating colorectal cancer initiation and progression. Semin Cell Dev Biol. 2020 Feb;98:63–70. https://doi.org/10.1016/j.semcdb.2019.05.018

3. Wolf AMD, Fontham ETH, Church TR, Flowers CR, Guerra CE, LaMonte SJ, et al. Colorectal cancer screening for average-risk adults: 2018 guideline update from the American Cancer Society. CA Cancer J Clin. 2018 Jul;68(4):250–281. https://doi.org/10.3322/caac.21457

4. Cheung EC, Lee P, Ceteci F, Nixon C, Blyth K, Sansom OJ, Vousden KH. Opposing effects of TIGAR- and RAC1-derived ROS on Wnt-driven proliferation in the mouse intestine. Genes Dev. 2016 Jan 1;30(1):52–63. https://doi.org/10.1101/gad.271130.115

5. Zhang B, Pan C, Feng C, Yan C, Yu Y, Chen Z, Guo C, Wang X. Role of mitochondrial reactive oxygen species in homeostasis regulation. Redox Rep. 2022 Dec;27(1):45–52. https://doi.org/10.1080/13510002.2022.2046423

6. Hsu CC, Tseng LM, Lee HC. Role of mitochondrial dysfunction in cancer progression. Exp Biol Med (Maywood). 2016 Jun;241(12):1281–1295. https://doi.org/10.1177/1535370216641787

7. Luo Y, Ma J, Lu W. The Significance of Mitochondrial Dysfunction in Cancer. Int J Mol Sci. 2020 Aug 5;21(16):5598. https://doi.org/10.3390/ijms21165598

8. Wang S, Wu X, Bi W, Xu J, Hou L, Li G, et al. ROS-induced cytosolic release of mitochondrial PGAM5 promotes colorectal cancer progression by interacting with MST3. Nat Commun. 2025 Feb 6;16(1):1406. https://doi.org/10.1038/s41467-025-56444-2

9. Egorova MV, Afanasyev SA. Isolation of mitochondria from cells and tissues of animals and human: modern methodical approaches. Siberian Medical Journal. 2011;26(1-1):22–28. (In Russ.).

10. Gureev AP, Kokina AV, Syromyatnikov MYu, Popov VN. Optimization of methods for the mitochondria isolation from different mice tissues. Proceedings of Voronezh State University. Series: Chemistry. Biology. Pharmacy. 2015;4:61–65.(In Russ.).

11. Dekker E, Tanis PJ, Vleugels JLA, Kasi PM, Wallace MB. Colorectal cancer. Lancet. 2019 Oct 19;394(10207):1467–1480. https://doi.org/10.1016/s0140-6736(19)32319-0

12. Murphy MP. Mitochondrial dysfunction indirectly elevates ROS production by the endoplasmic reticulum. Cell Metab. 2013 Aug 6;18(2):145–146. https://doi.org/10.1016/j.cmet.2013.07.006

13. Forman HJ, Zhang H. Targeting oxidative stress in disease: promise and limitations of antioxidant therapy. Nat Rev Drug Discov. 2021 Sep;20(9):689–709. https://doi.org/10.1038/s41573-021-00233-1 Erratum in: Nat Rev Drug Discov. 2021 Aug;20(8):652. https://doi.org/10.1038/s41573-021-00267-5

14. Atkinson J, Harroun T, Wassall SR, Stillwell W, Katsaras J. The location and behavior of alpha-tocopherol in membranes. Mol Nutr Food Res. 2010 May;54(5):641–651. https://doi.org/10.1002/mnfr.200900439

15. Halliwell B. Reactive oxygen species (ROS), oxygen radicals and antioxidants: Where are we now, where is the field going and where should we go? Biochem Biophys Res Commun. 2022 Dec 10;633:17–19. https://doi.org/10.1016/j.bbrc.2022.08.098

16. Forman HJ, Zhang H. Targeting oxidative stress in disease: promise and limitations of antioxidant therapy. Nat Rev Drug Discov. 2021 Sep;20(9):689–709. https://doi.org/10.1038/s41573-021-00233-1 Epub 2021 Jun 30. Erratum in: Nat Rev Drug Discov. 2021 Aug;20(8):652. https://doi.org/10.1038/s41573-021-00267-5

17. Brigelius-Flohé R, Kipp A. Glutathione peroxidases in different stages of carcinogenesis. Biochim Biophys Acta.2009 Nov;1790(11):1555–1568. https://doi.org/10.1016/j.bbagen.2009.03.006

18. Baffy G. Mitochondrial uncoupling in cancer cells: Liabilities and opportunities. Biochim Biophys Acta Bioenerg.2017 Aug;1858(8):655–664. https://doi.org/10.1016/j.bbabio.2017.01.005

19. Kobayashi H, Imanaka S. Mitochondrial DNA Damage and Its Repair Mechanisms in Aging Oocytes. Int J Mol Sci. 2024 Dec 6;25(23):13144. https://doi.org/10.3390/ijms252313144

20. Xu X, Pang Y, Fan X. Mitochondria in oxidative stress, inflammation and aging: from mechanisms to therapeutic advances. Signal Transduct Target Ther. 2025 Jun 11;10(1):190. https://doi.org/10.1038/s41392-025-02253-4

21. Li C, Xue Y, Ba X, Wang R. The Role of 8-oxoG Repair Systems in Tumorigenesis and Cancer Therapy. Cells. 2022 Nov27;11(23):3798. https://doi.org/10.3390/cells11233798