Effects of low-dose, short-duration periods of asymmetric radiation on colony formation of C6 glioma cell cultures

Fractionation has its separate additional effect



C6 glioma cells, Fractionation, Radiation, Interval, Low dose


Background/Aim: Previous studies on fractionation in radiation therapy have been mainly based on applying equal doses over at least 6 h. The main purpose of fractionation is to increase normal tissue tolerance rather than tumor sensitivity. Thus, one can apply higher doses to the tumor. In contrast, new molecular studies indicate that high and low doses of radiation act by different mechanisms. This study was conducted to investigate the radiobiological effect of asymmetrical radiation doses.

Methods: This is an experimental study done in vitro with a G6 glioma cell line to investigate the responses when C6 glioma cells are irradiated with single doses of 30 and 230 cGy using an orthovoltage therapy device or doses split into 30 and 200 and 115 and 115 cGy within periods of 15 and 30 min. A total of 5 × 103 cells were transferred to polyethylene culture flasks for colony formation. A cluster containing more than 30 cells was considered a new colony.

Results: A single dose of 230 cGy caused a 56.8% reduction in colony formation. However, when 230 cGy was divided over 15- and 30-min periods in fractions of 30 and 200 cGy, colony formation was significantly reduced compared to the control group (68.13% and 52.64%, P = 0.030, respectively). This effect continued when the radiation dose was divided into equal fractions (115 and 115 cGy) with periods of 15 and 30 min (42.60%, P = 0.021 and 20.77%, P = 0.008, respectively).

Conclusion: According to these results, (i) short interval (15 and 30 min) fractionation significantly reduces colony formation compared to a single equal dose; and (ii) the protective mechanisms activated in cell response probably vary at different radiation doses and different fractions.


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Bernier J, Hall EJ, Giaccia A. Radiation oncology: a century of achievements. Nat Rev Cancer. 2004 Nov 17;(9):737-47. DOI: https://doi.org/10.1038/nrc1451

Holsti LR. Development of clinical radiotherapy since 1896. Acta Oncol. 1995 Jul 08;34(8):995-1003. DOI: https://doi.org/10.3109/02841869509127225

Moulder JE, Seymour C. Radiation fractionation: the search for isoeffect relationships and mechanisms. Int J Radiat Biol. 2018 Oct 02;94(8):743-51. DOI: https://doi.org/10.1080/09553002.2017.1376764

Yan W, Khan MK, Wu X, et al. Spatially fractionated radiation therapy: History, present and the future. Clin Transl Radiat Oncol. 2019 Oct 22;20:30-8. DOI: https://doi.org/10.1016/j.ctro.2019.10.004

Yin E, Nelson DO, Coleman MA, Peterson LE, Wyrobek AJ. Gene expression changes in mouse brain after exposure to low-dose ionizing radiation. Int J Radiat Biol. 2003 Jul 03;79(10):759-75. DOI: https://doi.org/10.1080/09553000310001610961

Coleman MA, Yin E, Peterson LE, et al. Low-dose irradiation alters the transcript profiles of human lymphoblastoid cells including genes associated with cytogenetic radioadaptive response. Radiat Res. 2005 Oct 01;164:369-82. DOI: https://doi.org/10.1667/RR3356.1

Park WY, Hwang CI, Im CN, et al. Identification of radiation-specific responses from gene expression profile. Oncogene. 2002 Dec 05;21(55):8521-8. DOI: https://doi.org/10.1038/sj.onc.1205977

Amundson SA, Lee RA, Koch-Paiz CA, et al. Differential responses of stress genes to low dose-rate gamma irradiation. Mol Cancer Res. 2003 Apr 01 ;1(6):445-52.

Sasaki MS, Ejima Y, Tachibana A, et al. DNA damage response pathway in radioadaptive response. Mutat Res. 2002 Jul 25;504(1-2):101-18. DOI: https://doi.org/10.1016/S0027-5107(02)00084-2

Tomascik-Cheeseman LM, Coleman MA, Marchetti F, et al. Differential basal expression of genes associated with stress response, damage control, and DNA repair among mouse tissues. Mutat Res. 2004 Jul 11;561(1-2):1-14. DOI: https://doi.org/10.1016/j.mrgentox.2004.02.011

Ikushima T. Chromosomal responses to ionizing radiation reminiscent of an adaptive response in cultured Chinese hamster cells. Mutat Res. 1987 Oct 01;180(2):215-21. DOI: https://doi.org/10.1016/0027-5107(87)90217-X

Ojima M, Ishii K, Hayashi T, Ito A. Induction of radio-adaptive response in colony formation by low dose X-ray irradiation. Physiol Chem Phys Med NMR. 2001 Mar 25;33(1):41-48.

Chendil D, Das A, Dey S, Mohiuddin M, Ahmed MM. Par-4, a pro-apoptotic gene, inhibits radiation-induced NF kappa B activity and Bcl-2 expression leading to induction of radiosensitivity in human prostate cancer cells PC-3. Cancer Biol Ther. 2002 Jan 07;1(2):152-60. DOI: https://doi.org/10.4161/cbt.61

Yang G, Li W, Jiang H, et al. Low-dose radiation may be a novel approach to enhance the effectiveness of cancer therapeutics. Int J Cancer. 2016 Nov 15;139(10):2157-68. DOI: https://doi.org/10.1002/ijc.30235

Ozmen T, Oktem G, Tuna S, et al. Different doses of radiation on agar colony forming development in C6 glioma cells: Assessment by thymidine labeling index, and bromodeoxyuridine labeling index. Turkey Clinic J Med Sci 2007 May 01; 27:321-7.

Bilge H. Beam characteristics of kilovoltage radiotherapy unit. J BUON. 2004 Jul 01;9(3):303-6.

Williams MV, Denekamp J, Fowler JF. A review of alpha/beta ratios for experimental tumors: implications for clinical studies of altered fractionation. Int J Radiat Oncol Biol Phys. 1985 Jan 01;11(1):87-96. DOI: https://doi.org/10.1016/0360-3016(85)90366-9

Withers HR. Cell cycle redistribution as a factor in multifraction irradiation. Radiology. 1975 Jan 01;114(1):199-202. DOI: https://doi.org/10.1148/114.1.199

Elkind MM, Sutton H. Radiation response of mammalian cells grown in culture. 1. Repair of X-ray damage in surviving Chinese hamster cells. Radiat Res. 1960 Oct 01;13:556-93. DOI: https://doi.org/10.2307/3570945

Hauptmann M, Haghdoost S, Gomolka M, et al. Differential Response and Priming Dose Effect on the Proteome of Human Fibroblast and Stem Cells Induced by Exposure to Low Doses of Ionizing Radiation. Radiat Res. 2016 Mar 01;185(3):299-312. DOI: https://doi.org/10.1667/RR14226.1

Nikjoo H, Emfietzoglou D, Liamsuwan T, Taleei R, Liljequist D, Uehara S. Radiation track, DNA damage and response-a review. Rep Prog Phys. 2016 Sep 21;79(11):116601. DOI: https://doi.org/10.1088/0034-4885/79/11/116601

Balcer-Kubiczek EK. Apoptosis in radiation therapy: a double-edged sword. Exp Oncol. 2012 Sep 01;34(3):277-85.

Falcke SE, Rühle PF, Deloch L, Fietkau R, Frey B, Gaipl US. Clinically Relevant Radiation Exposure Differentially Impacts Forms of Cell Death in Human Cells of the Innate and Adaptive Immune System. Int J Mol Sci. 2018 Nov 13;19(11):3574. DOI: https://doi.org/10.3390/ijms19113574

Enns L, Bogen KT, Wizniak J, Murtha AD, Weinfeld M. Low-dose radiation hypersensitivity is associated with p53-dependent apoptosis. Mol Cancer Res. 2004 Oct 01;2(10):557-66. DOI: https://doi.org/10.1158/1541-7786.557.2.10

Mirzaie-Joniani H, Eriksson D, Johansson A, et al. Apoptosis in HeLa Hep2 cells is induced by low-dose, low-dose-rate radiation. Radiat Res. 2002 Nov 01;158(5):634-40. DOI: https://doi.org/10.1667/0033-7587(2002)158[0634:AIHHCI]2.0.CO;2

Skwarchuk MW, Wouters BG, Skarsgard LD. Substructure in the radiation survival response at low dose: asynchronous and partially synchronized V79-WNRE cells. Int J Radiat Biol. 1993 Jul 03;64(5):601-12. DOI: https://doi.org/10.1080/09553009314551821

Krueger SA, Wilson GD, Piasentin E, Joiner MC, Marples B. The effects of G2-phase enrichment and checkpoint abrogation on low-dose hyper-radiosensitivity. Int J Radiat Oncol Biol Phys. 2010 Aug 01;77(5):1509-17. DOI: https://doi.org/10.1016/j.ijrobp.2010.01.028

Grobben B, De Deyn PP, Slegers H. Rat C6 glioma as experimental model system for the study of glioblastoma growth and invasion. Cell Tissue Res. 2002 Nov 06;310(3):257-70. DOI: https://doi.org/10.1007/s00441-002-0651-7






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Karaman Şule, Özben SG, Kesen ND, Karaçay Özge, Sakin ND, Dizdar Y. Effects of low-dose, short-duration periods of asymmetric radiation on colony formation of C6 glioma cell cultures: Fractionation has its separate additional effect. J Surg Med [Internet]. 2022 Sep. 20 [cited 2024 Jun. 23];6(9):809-12. Available from: https://jsurgmed.com/article/view/1028643