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.
Breast Neoplasms* ; Breast* ; Cause of Death ; Cell Line ; Comet Assay ; DNA Damage* ; DNA* ; Estrogens* ; Female ; Humans ; Propolis ; Radiation Tolerance* ; Radiation-Sensitizing Agents ; Radiotherapy ; Recurrence

PURPOSEUnsafe behaviors are an important cause of accidents in adolescent age groups. This study was designed to examine the behaviors of adolescent pedestrians in southern Iran.

METHODSThis is a descriptive analytical cross-sectional study. The study population consisted of high school students in Shiraz, capital city of Fars Province, Iran. Five hundred and sixteen students were selected by multi-stage sampling. Data were collected by the use of three questionnaires, which included Persian copies of adolescent road user behavior questionnaire (ARBQ), Duke University Religious Index (DUREL), as well as the context and independent variables questionnaire.

RESULTSThe results showed that a decrease in dangerous behaviors on the road resulted in an increase in respondents' intrinsic religiosity. Also, engagement in unsafe crossing behavior in the road decreased with increasing respondents' intrinsic religiosity. Another finding showed that female students were less involved in dangerous play and planned protective behaviors on the road.

CONCLUSIONFindings clearly indicate that intrinsic religiosity has a significant role in reducing the risky road behaviors of students. Hence, religion may improve road safety in school students' road behavior in Iran.