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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 PBMC culture exposure with the dose of 2 Gy. The black barrepresents the control of non-irradiated cells and the light gray barrepresents the culture irradiated with 2 Gy. The cells were irradiated with thedose rate X = 339.56 cGy/min and X/4. The bars express the mean of triplicatesand the standard deviation for PBMC cultures irradiated with the dose of 2 Gyand also for the respective control (non-irradiated cell lines). The signal *represents statistically significant difference in relation to the bars without*. (p < 0.05).
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f02: Survival curve determined by the MTT test, before and after invitro PBMC culture exposure with the dose of 2 Gy. The black barrepresents the control of non-irradiated cells and the light gray barrepresents the culture irradiated with 2 Gy. The cells were irradiated with thedose rate X = 339.56 cGy/min and X/4. The bars express the mean of triplicatesand the standard deviation for PBMC cultures irradiated with the dose of 2 Gyand also for the respective control (non-irradiated cell lines). The signal *represents statistically significant difference in relation to the bars without*. (p < 0.05).

Mentions: 2 Gy dose at standard rates and at one fourth of the standard -Figure 2 shows the cell viability curveevaluated at the MTT test for the in vitro PBMCs culture, withhomogenized suspension of cells from PBMCs culture vials (T-25) which were irradiatedwith 2 Gy at the standard dose rate of 339.56 cGy.min-1 and of 84.89cGy.min-1. The data show a statistically significant decrease(p < 0.05) in the OD at the dose of 2 Gy in relation to thecontrol at all studied times. Similar behavior in the cell line survival decrease atthe 24-hours time for both dose rates can also be observed. It is interesting tonotice that at the pre-established times, the increased cell proliferation wasobserved in the control (non-irradiated cells), which might be a consequence of thephysiological process of cell replication (mitosis). However, at the 48-hours time,as the cell viability at the standard dose rate and at one fourth of that iscompared, it is suggested that, with the radiosensitive cell line, the radiation doserate effects can already be observed due to the change in viability, showing that thedecrease in dose rate induces a greater viability. The same effect can be observed atthe 72-hour time, not as clearly though.


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 PBMC culture exposure with the dose of 2 Gy. The black barrepresents the control of non-irradiated cells and the light gray barrepresents the culture irradiated with 2 Gy. The cells were irradiated with thedose rate X = 339.56 cGy/min and X/4. The bars express the mean of triplicatesand the standard deviation for PBMC cultures irradiated with the dose of 2 Gyand also for the respective control (non-irradiated cell lines). The signal *represents statistically 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

f02: Survival curve determined by the MTT test, before and after invitro PBMC culture exposure with the dose of 2 Gy. The black barrepresents the control of non-irradiated cells and the light gray barrepresents the culture irradiated with 2 Gy. The cells were irradiated with thedose rate X = 339.56 cGy/min and X/4. The bars express the mean of triplicatesand the standard deviation for PBMC cultures irradiated with the dose of 2 Gyand also for the respective control (non-irradiated cell lines). The signal *represents statistically significant difference in relation to the bars without*. (p < 0.05).
Mentions: 2 Gy dose at standard rates and at one fourth of the standard -Figure 2 shows the cell viability curveevaluated at the MTT test for the in vitro PBMCs culture, withhomogenized suspension of cells from PBMCs culture vials (T-25) which were irradiatedwith 2 Gy at the standard dose rate of 339.56 cGy.min-1 and of 84.89cGy.min-1. The data show a statistically significant decrease(p < 0.05) in the OD at the dose of 2 Gy in relation to thecontrol at all studied times. Similar behavior in the cell line survival decrease atthe 24-hours time for both dose rates can also be observed. It is interesting tonotice that at the pre-established times, the increased cell proliferation wasobserved in the control (non-irradiated cells), which might be a consequence of thephysiological process of cell replication (mitosis). However, at the 48-hours time,as the cell viability at the standard dose rate and at one fourth of that iscompared, it is suggested that, with the radiosensitive cell line, the radiation doserate effects can already be observed due to the change in viability, showing that thedecrease in dose rate induces a greater viability. The same effect can be observed atthe 72-hour time, not as clearly though.

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