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Enhancement of viability of radiosensitive (PBMC) and resistant (MDA-MB-231) clones in low-dose-rate cobalt-60 radiation therapy.

Falcão PL, Motta BM, de Lima FC, Lima CV, Campos TP - Radiol Bras (2015 May-Jun)

Bottom Line: Radiosensitive PBMC showed decrease in viability at 2 Gy, and a more significant decrease at 10 Gy for both dose rates.MDAMB- 231 cells presented viability decrease only at higher dose and dose rate.The results showed MDA-MB-231 clone expansion at low dose rate after 48-72 hours post-radiation.

View Article: PubMed Central - PubMed

Affiliation: Postdoc, Associate Professor at Universidade Federal do Amazonas (UFAM), Manaus, AM, Brazil.

ABSTRACT

Objective: In the present study, the authors investigated the in vitro behavior of radio-resistant breast adenocarcinoma (MDA-MB-231) cells line and radiosensitive peripheral blood mononuclear cells (PBMC), as a function of different radiation doses, dose rates and postirradiation time kinetics, with a view to the interest of clinical radiotherapy.

Materials and methods: The cells were irradiated with Co-60, at 2 and 10 Gy and two different exposure rates, 339.56 cGy.min(-1) and the other corresponding to one fourth of the standard dose rates, present over a 10-year period of cobalt therapy. Post-irradiation sampling was performed at pre-established kinetics of 24, 48 and 72 hours. The optical density response in viability assay was evaluated and a morphological analysis was performed.

Results: Radiosensitive PBMC showed decrease in viability at 2 Gy, and a more significant decrease at 10 Gy for both dose rates. MDAMB- 231 cells presented viability decrease only at higher dose and dose rate. The results showed MDA-MB-231 clone expansion at low dose rate after 48-72 hours post-radiation.

Conclusion: Low dose rate shows a possible potential clinical impact involving decrease in management of radio-resistant and radiosensitive tumor cell lines in cobalt therapy for breast cancer.

No MeSH data available.


Related in: MedlinePlus

Survival curve determined by the MTT test, before and after invitro MDA-MB-231 cells culture exposure at the dose of 10 Gy. Theblack bar represents the control with non-irradiated cells and the light graybar represents the culture irradiated with 10 Gy, with the dose rate X = 339.56cGy/min and X/4. The bars express the mean of triplicates and the standarddeviation for MDA-MB-231 cell cultures irradiated at the dose of 10 Gy and alsofor the respective control (non-irradiated). The signal * representsstatistically significant difference in relation to the bars without *(p < 0.05).
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f05: Survival curve determined by the MTT test, before and after invitro MDA-MB-231 cells culture exposure at the dose of 10 Gy. Theblack bar represents the control with non-irradiated cells and the light graybar represents the culture irradiated with 10 Gy, with the dose rate X = 339.56cGy/min and X/4. The bars express the mean of triplicates and the standarddeviation for MDA-MB-231 cell cultures irradiated at the dose of 10 Gy and alsofor the respective control (non-irradiated). The signal * representsstatistically significant difference in relation to the bars without *(p < 0.05).

Mentions: Dose of 10 Gy at standard rates and at one fourth of the standard -Figure 5 shows a significant decrease(p < 0.05) in cell viability when the cells suspensionreceived a dose of 10 Gy, measured 24 hours after the exposure at the rate of 339.56cGy.min-1 in relation to the non irradiated control. The decrease incell viability at such a dose increasingly followed the time kinetics in contrast tothe effect observed when the cells suspension received the dose of 2 Gy at the samerate. Equally to the radiosensitive cells, the behavior of the MDA-MB-231radioresistant clones shows viability recovery at the reduced rate, while at thestandard rate such a recovery is not perceptible.


Enhancement of viability of radiosensitive (PBMC) and resistant (MDA-MB-231) clones in low-dose-rate cobalt-60 radiation therapy.

Falcão PL, Motta BM, de Lima FC, Lima CV, Campos TP - Radiol Bras (2015 May-Jun)

Survival curve determined by the MTT test, before and after invitro MDA-MB-231 cells culture exposure at the dose of 10 Gy. Theblack bar represents the control with non-irradiated cells and the light graybar represents the culture irradiated with 10 Gy, with the dose rate X = 339.56cGy/min and X/4. The bars express the mean of triplicates and the standarddeviation for MDA-MB-231 cell cultures irradiated at the dose of 10 Gy and alsofor the respective control (non-irradiated). The signal * representsstatistically significant difference in relation to the bars without *(p < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492568&req=5

f05: Survival curve determined by the MTT test, before and after invitro MDA-MB-231 cells culture exposure at the dose of 10 Gy. Theblack bar represents the control with non-irradiated cells and the light graybar represents the culture irradiated with 10 Gy, with the dose rate X = 339.56cGy/min and X/4. The bars express the mean of triplicates and the standarddeviation for MDA-MB-231 cell cultures irradiated at the dose of 10 Gy and alsofor the respective control (non-irradiated). The signal * representsstatistically significant difference in relation to the bars without *(p < 0.05).
Mentions: Dose of 10 Gy at standard rates and at one fourth of the standard -Figure 5 shows a significant decrease(p < 0.05) in cell viability when the cells suspensionreceived a dose of 10 Gy, measured 24 hours after the exposure at the rate of 339.56cGy.min-1 in relation to the non irradiated control. The decrease incell viability at such a dose increasingly followed the time kinetics in contrast tothe effect observed when the cells suspension received the dose of 2 Gy at the samerate. Equally to the radiosensitive cells, the behavior of the MDA-MB-231radioresistant clones shows viability recovery at the reduced rate, while at thestandard rate such a recovery is not perceptible.

Bottom Line: Radiosensitive PBMC showed decrease in viability at 2 Gy, and a more significant decrease at 10 Gy for both dose rates.MDAMB- 231 cells presented viability decrease only at higher dose and dose rate.The results showed MDA-MB-231 clone expansion at low dose rate after 48-72 hours post-radiation.

View Article: PubMed Central - PubMed

Affiliation: Postdoc, Associate Professor at Universidade Federal do Amazonas (UFAM), Manaus, AM, Brazil.

ABSTRACT

Objective: In the present study, the authors investigated the in vitro behavior of radio-resistant breast adenocarcinoma (MDA-MB-231) cells line and radiosensitive peripheral blood mononuclear cells (PBMC), as a function of different radiation doses, dose rates and postirradiation time kinetics, with a view to the interest of clinical radiotherapy.

Materials and methods: The cells were irradiated with Co-60, at 2 and 10 Gy and two different exposure rates, 339.56 cGy.min(-1) and the other corresponding to one fourth of the standard dose rates, present over a 10-year period of cobalt therapy. Post-irradiation sampling was performed at pre-established kinetics of 24, 48 and 72 hours. The optical density response in viability assay was evaluated and a morphological analysis was performed.

Results: Radiosensitive PBMC showed decrease in viability at 2 Gy, and a more significant decrease at 10 Gy for both dose rates. MDAMB- 231 cells presented viability decrease only at higher dose and dose rate. The results showed MDA-MB-231 clone expansion at low dose rate after 48-72 hours post-radiation.

Conclusion: Low dose rate shows a possible potential clinical impact involving decrease in management of radio-resistant and radiosensitive tumor cell lines in cobalt therapy for breast cancer.

No MeSH data available.


Related in: MedlinePlus