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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 exposure of a healthy individual's PBMC culture at the doseof 10 Gy. The black bar represents the control of non-irradiated cells, and thelight gray bar represents the culture irradiated with 10 Gy. The cells wereirradiated with the dose rate of X = 339.56 cGy/min and X/4. The bars expressthe mean of triplicates and the standard deviation for PBMC cultures that wereirradiated with the dose of 10 Gy and also for the respective control(non-irradiated). The signal * represents statistically significant differenceonly in relation to the bar without * (p < 0.05); while **represents statistically significant difference in relation to neighboring barswithout *.
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f03: Survival curve determined by the MTT test, before and after invitro exposure of a healthy individual's PBMC culture at the doseof 10 Gy. The black bar represents the control of non-irradiated cells, and thelight gray bar represents the culture irradiated with 10 Gy. The cells wereirradiated with the dose rate of X = 339.56 cGy/min and X/4. The bars expressthe mean of triplicates and the standard deviation for PBMC cultures that wereirradiated with the dose of 10 Gy and also for the respective control(non-irradiated). The signal * represents statistically significant differenceonly in relation to the bar without * (p < 0.05); while **represents statistically significant difference in relation to neighboring barswithout *.

Mentions: 10 Gy dose at standard rates and at one fourth of the standard - Thedecrease in cell viability was extremely significant (p < 0.05)at the 24-, 48- and 72-hour time, not only in relation to the non-irradiated control,but also in an equivalent manner for the two dose rates, as shown on Figure 3. The mean OD percentage was reduced to 7%and 15%, particularly at the 72-hour time, suggesting that the high dosepotentializes cell death in the culture, tending to cell viability irreversibilitywhen the dose was applied at a rate of 339.56 cGy.min-1. However, at theone fourth dose rate, in spite of the OD reduction, a reversibility effect can beobserved in the cell viability decrease at the48-hour and even at the 72-hourtime.


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 exposure of a healthy individual's PBMC culture at the doseof 10 Gy. The black bar represents the control of non-irradiated cells, and thelight gray bar represents the culture irradiated with 10 Gy. The cells wereirradiated with the dose rate of X = 339.56 cGy/min and X/4. The bars expressthe mean of triplicates and the standard deviation for PBMC cultures that wereirradiated with the dose of 10 Gy and also for the respective control(non-irradiated). The signal * represents statistically significant differenceonly in relation to the bar without * (p < 0.05); while **represents statistically significant difference in relation to neighboring barswithout *.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f03: Survival curve determined by the MTT test, before and after invitro exposure of a healthy individual's PBMC culture at the doseof 10 Gy. The black bar represents the control of non-irradiated cells, and thelight gray bar represents the culture irradiated with 10 Gy. The cells wereirradiated with the dose rate of X = 339.56 cGy/min and X/4. The bars expressthe mean of triplicates and the standard deviation for PBMC cultures that wereirradiated with the dose of 10 Gy and also for the respective control(non-irradiated). The signal * represents statistically significant differenceonly in relation to the bar without * (p < 0.05); while **represents statistically significant difference in relation to neighboring barswithout *.
Mentions: 10 Gy dose at standard rates and at one fourth of the standard - Thedecrease in cell viability was extremely significant (p < 0.05)at the 24-, 48- and 72-hour time, not only in relation to the non-irradiated control,but also in an equivalent manner for the two dose rates, as shown on Figure 3. The mean OD percentage was reduced to 7%and 15%, particularly at the 72-hour time, suggesting that the high dosepotentializes cell death in the culture, tending to cell viability irreversibilitywhen the dose was applied at a rate of 339.56 cGy.min-1. However, at theone fourth dose rate, in spite of the OD reduction, a reversibility effect can beobserved in the cell viability decrease at the48-hour and even at the 72-hourtime.

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