Medical Radiology and Radiation Safety. 2026. Vol. 71. № 4

DOI:10.33266/1024-6177-2026-71-4-12-20

V.G. Shuvatova, D.A. Shaposhnikova, K.V. Kondratyev, E.Yu. Moskaleva

RADIOSENSITIVITY OF MCF-7 HUMAN BREAST CANCER STEM CELLS CULTURED AS 2D- AND 3D-CULTURES

National Research Center “Kurchatov Institute”, Moscow, Russia

Contact person: E.Yu. Moskaleva, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it. ; This email address is being protected from spambots. You need JavaScript enabled to view it.

ABSTRACT

Purpose: Tumor cells cultured under special conditions in 3D cultures (3DK) are characterized by higher radioresistance than cells in 2D cultures (2DK), but it is not known how the conditions of these two cultivation methods affect the radiosensitivity of cancer stem cells (СSCs). In this regard, the aim of the work was to compare human breast adenocarcinoma cells of the MCF-7 line, cultured in the form of 2DK and 3DK, according to the parameters characterizing the rate of cell proliferation, the content of CSCs and the radiosensitivity of the cells of these cultures and CSCs in their composition when exposed to γ-radiation.

Material and methods: To characterize the rate of cell proliferation in 2DK and 3DK, cell doubling time was analyzed by dynamic cell counting using light microscopy; cell cycle parameters and the proportion of proliferating cells based on the number of Ki67+ cells were assessed using flow cytometry. The content of CSCs was assessed by the proportion and number of cells with the CD44+/CD24-/low phenotype, by the size of the SP fraction and by the proportion of cells with high aldehyde dehydrogenase activity using flow cytometry. Cells were γ-irradiated using the GUT-200M system at doses of 1–8 Gy at a dose rate of 0.75 Gy/min. Cell radiosensitivity was assessed using the D0 and Dq indices. 

Results: MCF-7 cells cultured as 3DK were shown to have a longer cell doubling time and slower proliferation, than 2DK cells as was assessed by cell cycle parameters and the proportion of Ki67+ cells. Culturing cells as 3DK resulted in a 10-fold increase in the СSC content, as assessed by all СSC determination methods used, compared to 2DK cells. The radioresistance of MCF-7 CSCs when cultured as 2DK cells (D0=3.0±0.5 Gy) is twice as high as that of the total 2DK cell population (D0=1.5±0.2 Gy). The radioresistance of MCF-7 CSCs when cultured as 3DK cells does not differ from that of the total 3DK cell population (D0=2.5±0.3 and 2.2±0.3 Gy, respectively). The radiosensitivity of MCF-7 CSCs when cultured as 2DK and 3DK cells under the influence of γ-radiation is the same, despite the higher radioresistance of the overall 3DK cell population. 3DK cells, as well as CSCs in 3DK, are characterized by a higher capacity for sublethal damage repair, assessed by the Dq value, than in 2DK, although these differences were statistically insignificant.

Conclusion: The radioresistance of MCF-7 CSCs when cultured as 2DK cells is twice as high as that of the entire 2D cell population, while when cultured as 3DK cells, the radioresistance of CSCs and the entire cell population is equal. The radiosensitivity of MCF-7 CSCs when cultured as 2DK and 3DK to γ-irradiation is equal, despite the higher radioresistance of the entire 3DK cell population than that of 2DK cells.

Keywords: cancer stem cells, radiosensitivity, breast cancer, cell culture, MCF-7 line, 2D culture, 3D culture, mammospheres

For citation:  Shuvatova VG, Shaposhnikova DA, Kondratyev KV, Moskaleva EYu. Radiosensitivity of MCF-7 Human Breast Cancer Stem Cells cultured as 2D- and 3D-Cultures. Medical Radiology and Radiation Safety. 2026;71(4):12–20. DOI:10.33266/1024-6177-2026-71-4-12-20

References

1. Хмелевский Е.В., Трофимова О.П. Рак молочной железы // Стандарты лучевой терапии / Под ред. А.Д. Каприна, А.А. Костина, Е.В. Хмелевского. М.: ГЭОТАР-Медиа, 2020. С. 253-269 [Khmelevskiy Ye.V., Trofimova O.P. Breast Cancer. Standarty Luchevoy Terapii = Standards of Radiation Therapy. Ed. A.D. Kaprin, A.A. Kostin, Ye.V. Khmelevskiy. Moscow, GEOTAR-Media Publ.,2020. P. 253-259 (In Russ.)]. URL: https://www.rosmedlib.ru/book/ISBN9785970455814.html.

2. Шахзадова А.О., Старинский В.В., Лисичникова И.В. Состояние онкологической помощи населению России в 2022 году // Сибирский онкологический журнал. 2023. Т.22. №5. С. 5-13 [Shakhzadova A.O., Starinskiy V.V., Lisichnikova I.V. State of Oncological Care for the Population of Russia in 2022. Sibirskiy Onkologicheskiy Zhurnal = Siberian Journal of Oncology. 2023;22;5:5-13 (In Russ.)]. Doi: 10.21294/1814-4861-2023-22-5-5-13.

3. Korzets Y., Levitas D., Grubstein A., Corn B.W., Amir E., Goldvaser H. Efficacy and Safety of the Addition of Internal Mammary Irradiation to Standard Adjuvant Radiation in Early-Stage Breast Cancer: A Systematic Review and Meta-Analysis. Curr Oncol. 2022;29;9:6657-6673. Doi: 10.3390/curroncol29090523. 

4. Bonnet D., Dick J.E. Human Acute Myeloid Leukemia is Organized as a Hierarchy that Originates from a Primitive Hematopoietic Cell. Nat Med. 1997;3;7:730-7. Doi: 10.1038/nm0797-730. PMID: 9212098. 

5. Reya T., Morrison S.J., Clarke M.F., Weissman I.L. Stem Cells, Cancer, and Cancer Stem Cells. Nature. 2001;414;6859:105-11. Doi: 10.1038/35102167. PMID: 11689955.

6. Al-Hajj M., Wicha M.S., Benito-Hernandez A., Morrison S.J., Clarke M.F. Prospective Identification of Tumorigenic Breast Cancer Cells. Proc Natl Acad Sci USA. 2003;100;7:3983-8. Doi: 10.1073/pnas.0530291100. PMID: 12629218.

7. Dontu G., Abdallah W.M., Foley J.M., Jackson K.W., Clarke M.F., Kawamura M.J., Wicha M.S. In Vitro Propagation and Transcriptional Profiling of Human Mammary Stem/Progenitor Cells. Genes Dev. 2003;17;10:1253-70. Doi: 10.1101/gad.1061803. PMID: 12756227.

8. Ponti D., Costa A., Zaffaroni N., Pratesi G., Petrangolini G., Coradini D., Pilotti S., Pierotti M.A., Daidone M.G. Isolation and in Vitro Propagation of Tumorigenic Breast Cancer Cells with Stem/Progenitor Cell Properties. Cancer Res. 2005;65;13:5506-11. Doi: 10.1158/0008-5472.CAN-05-0626. PMID: 15994920. 

9. Wang J.L., Yu J.P., Sun Z.Q., Sun S.P. Radiobiological Characteristics of Cancer Stem Cells from Esophageal Cancer Cell Lines. World J Gastroenterol. 2014;20;48:18296-305. Doi: 10.3748/wjg.v20.i48.18296. PMID: 25561796.

10. Phillips T.M., McBride W.H., Pajonk F. The Response of CD24(-/low)/CD44+ Breast Cancer-Initiating Cells to Radiation. J Natl Cancer Inst. 2006;98;24:1777-85. Doi: 10.1093/jnci/djj495. PMID: 17179479.

11. Krause M., Dubrovska A., Linge A., Baumann M. Cancer Stem Cells: Radioresistance, Prediction of Radiotherapy Outcome and Specific Targets for Combined Treatments. Adv Drug Deliv Rev. 2017;109:63-73. Doi: 10.1016/j.addr.2016.02.002. PMID: 26877102. 

12. Zamulaeva I.A., Selivanova E.I., Kiseleva V.I., Matchuk O.N., Krikunova L.I., Mkrtchyan L.S., Kaprin A.D. Correlation of Radiation Response of Cervical Cancer Stem Cells with their Initial Number before Treatment and Molecular Genetic Features of Papillomavirus Infection. Bull Exp Biol Med. 2020;170;2:241-245. Doi: 10.1007/s10517-020-05043-w.

13. Zamulaeva I., Selivanova E., Matchuk O., Kiseleva V., Mkrtchyan L., Krikunova L. Radiation Response of Cervical Cancer Stem Cells is Associated with Pretreatment Proportion of These Cells and Physical Status of HPV DNA. Int J Mol Sci. 2021;22;3:1445. Doi: 10.3390/ijms22031445. PMID: 33535561.

14. He L., Wick N., Germans S.K., Peng Y. The Role of Breast Cancer Stem Cells in Chemoresistance and Metastasis in Triple-Negative Breast Cancer. Cancers. 2021;13;24:6209. Doi: 10.3390/cancers13246209. PMID: 34944829.

 PDF (RUS) Full-text article (in Russian)

Conflict of interest.The authors declare no conflict of interest.

Financing. The work was carried out as part of the state assignment for the Kurchatov Institute.

Contribution. V.G. Shuvatova – development of the research design, conducting experiments, analysis of the obtained results, and writing the article; D.A. Shaposhnikova – conducting and analyzing the data of experiments using flow cytometry; K.V. Kondratyev – dosimetric analysis and conducting γ-irradiation sessions of cells; E.Yu. Moskaleva – development of the research concept, data analysis, writing, and scientific editing of the article.

Article received: 20.03.2026. Accepted for publication: 25.04.2026.