Caffeic Acid Phenethyl Ester Increases Radiosensitivity of Estrogen Receptor-Positive and -Negative Breast Cancer Cells by Prolonging Radiation-Induced DNA Damage.
- Author:
Nastaran Masoudi KHORAM
1
;
Bahareh BIGDELI
;
Alireza NIKOOFAR
;
Bahram GOLIAEI
Author Information
- Publication Type:Original Article
- Keywords: Breast neoplasms; Caffeic acid phenethyl ester; DNA damage; Radiation-sensitizing agents
- MeSH: Breast Neoplasms*; Breast*; Cause of Death; Cell Line; Comet Assay; DNA Damage*; DNA*; Estrogens*; Female; Humans; Propolis; Radiation Tolerance*; Radiation-Sensitizing Agents; Radiotherapy; Recurrence
- From:Journal of Breast Cancer 2016;19(1):18-25
- CountryRepublic of Korea
- Language:English
- Abstract: PURPOSE: Breast cancer is an important cause of death among women. The development of radioresistance in breast cancer leads to recurrence after radiotherapy. Caffeic acid phenethyl ester (CAPE), a polyphenolic compound of honeybee propolis, is known to have anticancer properties. In this study, we examined whether CAPE enhanced the radiation sensitivity of MDA-MB-231 (estrogen receptor-negative) and T47D (estrogen receptor-positive) cell lines. METHODS: The cytotoxic effect of CAPE on MDA-MB-231 and T47D breast cancer cells was evaluated by performing an 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. To assess clonogenic ability, MDA-MB-231 and T47D cells were treated with CAPE (1 µM) for 72 hours before irradiation, and then, a colony assay was performed. A comet assay was used to determine the number of DNA strand breaks at four different times. RESULTS: CAPE decreased the viability of both cell lines in a dose- and time-dependent manner. In the clonogenic assay, pretreatment of cells with CAPE before irradiation significantly reduced the surviving fraction of MDA-MB-231 cells at doses of 6 and 8 Gy. A reduction in the surviving fraction of T47D cells was observed relative to MDA-MB-231 at lower doses of radiation. Additionally, CAPE maintained radiation-induced DNA damage in T47D cells for a longer period than in MDA-MB-231 cells. CONCLUSION: Our results indicate that CAPE impairs DNA damage repair immediately after irradiation. The induction of radiosensitivity by CAPE in radioresistant breast cancer cells may be caused by prolonged DNA damage.
