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Background: While radiotherapy is the important modality in the treatment of breast cancer cells, radioresistance of some tumor cell lines such as MDA-MB-231 is still a limitation that must be considered. Objectives: The present study was done to examine the effect of the conditioned medium of the human umbilical cord Wharton's jelly stem cells (hWJSCs + CM) on the radiosensitivity of MDA-MB-231 cells in combination with megavoltage-radiations. Methods: Groups are Control, CM, GY, and GY + CM. In irradiation groups, breast cancer cells were exposured with 4, 6, and 8 Gy radiation. Each group includes different doses of the conditioned medium of hWJSCs (25%, 50%, and 75%). Results: The MTT assay showed that the proliferative activity of Gy + CM groups at all doses of condition medium decreased significantly compared with the control, rather than Gy groups. Trypan blue viability test showed that the survival rate of MDA-MB-231 cells significantly reduced in the CM and 8 Gy + CM groups compared with the control group, rather than Gy groups. MDA-MB-231 cells lost their normal spindle shape and became thinner and longer after 48h of treatment and the number of cells sharply reduced in Gy + CM groups compared with the control group, rather than Gy groups. These changes were accompanied by inducing significant up-regulation of Interleukin-6 (IL-6) in the 4 Gy + CM and 8 Gy + CM groups compared with the control group, rather than Gy groups and as a consequence, a decrease in the amount of transmembrane tumor necrosis factor-α (tmTNF-α) as a pro-inflammatory cytokine in the Gy + CM groups compared with the control group, rather than Gy groups. Also, we indicated that the radiosensitivity of breast cancer cells was probably enhanced by an increase in different doses of the conditioned medium of stem cells. Conclusions: Treatment of the MDA-MB-231 cells with hWJSCs + CM plus radiotherapy inhibited the growth and proliferation of cancer cells and this method is a novel strategy for breast cancer therapy by overcoming radioresistance.

Background and Objectives: The increasing demand of people and students for computer technology and the Internet has caused mental health problems and social communication in them. In this study, the relationship between Internet addiction and general health in students of Qom University of Medical Sciences has been investigated. Methods: This descriptive-correlation study was performed on 321 students living in Qom dormitory of medical sciences through demographic, general health (GHQ) and Internet addiction questionnaires. Data analysis was performed using SPSS software in two parts: descriptive statistics, mean, frequency, frequency percentage and inferential statistics of Pearson correlation coefficient and univariate linear regression. Results: 79.8% of students were regular users and 20.2% of students were addicted to the Internet and no severe Internet addiction was observed. According to the general health questionnaire, 13.1% of students had mild disorder, 66% had moderate disorder and 20.9% had severe disorder. Pearson correlation coefficient between scales and general health in general with Internet addiction showed a significant and positive relationship at a significant level of 0.05. In linear regression analysis, the only variable is the duration of internet connection under the same conditions in terms of other variables that predict the general health score. Conclusion: There is a significant and positive relationship between public health and Internet addiction. Preventing the complications and dangers of Internet addiction is essential and requires educational, counseling, and behavioral planning among vulnerable students.