Abstract:
Objectives To induce and establish breast cancer cell sublines with radiation resistance in MCF-7.
Methods Breast cancer cell MCF-7 cells were repeatedly given individual doses of X-rays with liner accelerator to induce radiation resistance with adequate dosage. The intracellular ultrastructure of the strains was observed through scanning electron microscopy and transmission electron microscopy.The cell cycle distribution was examined by flow cytometry.Cell radiosensitivity as assayed by colony formation assay, and the survival fraction was calculated.The multi-target model that fit the cell survival curve was selected.
Results At the same irradiation condition and radiation dose, the radio-resistant sub-cell MCF-7R showed significant morphological changes, such as shape and organelles, compared with the parent strain MCF-7.Cell cycle analysis showed that MCF-7R had lower Percentage G2/M and slower proliferation tendency.Cell clone analysis demonstrated that MCF-7R had greater SF2(survival fraction after 2 Gy irradiation, increased by 34%.P < 0.001), Dq(2.261 to 3.695. P < 0.05) and Do(1.215 to 1.834, P < 0.05).
Conclusion The method of radiating cell step by step and repeatedly is viable to establish radio-resistant breast cancer sub-cell line, and the radioresistant sub-cell line MCF-7R has conspicuous changes in morphological and biological characteristics compared with the parental cell line.
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