BACKGROUND: Triple-negative breast cancer (TNBC) is a lethal mammary carcinoma subtype that affects females and is associated with a worse prognosis. Chemotherapy is the only conventional therapy available for patients with TNBC due to the lack of therapeutic targets. Yttrium oxide (YO) is a rare earth metal oxide, whose nanoparticle (NPs) formulations are used in various applications, including biological imaging, the material sciences, and the chemical synthesis of inorganic chemicals. However, the biological activity of YO-NPs against TNBC cells has not been fully explored. The current study was conducted to assess YO-NPs' anticancer activity against the human TNBC MDA-MB-231 cell line.

METHODS: Transmission electron microscopy (TEM), X-ray diffraction, Zeta potential, and dynamic light scattering (DLS) were used to characterize the YO-NPs. SRB cell viability, reactive oxygen species (ROS) measurement, single-cell gel electrophoresis (comet assay), qPCR, flow cytometry, and Western blot were employed to assess the anticancer activity of the YO-NPs.

RESULTS: Our results indicate favorable physiochemical properties of YO-NPs (with approximately average size 14 nm, Zeta Potential about - 53.2 mV, and polydispersity index = 0.630). YO-NPs showed a potent cytotoxic effect against MDA-MB-231 cells, with IC50 values of 74.4 µg/mL, without cytotoxic effect on the normal retina REP1 and human dermal fibroblast HDF cell lines. Further, treatment of MDA-MB-231 cells with IC50 YO-NPs resulted in increased oxidative stress, accumulation of intracellular ROS levels, and induced DNA damage assessed by Comet assay. Upon YO-NPs treatment, a significant increase in the early and late phases of apoptosis was revealed in MDA-MB-231 cells. qPCR results showed that YO-NPs significantly upregulated the pro-apoptotic genes CASP3 and CASP8 as well as ferroptosis-related gene heme oxygenase-1 (HO-1), whereas the anti-apoptotic gene BCL2 was significantly downregulated.

CONCLUSION: This study suggests that YO-NPs are safe on normal REP1 and HDF cells and exhibited a potent selective cytotoxic effect against the TNBC MDA-MB-231 cells through increasing levels of ROS generation with subsequent DNA damage, and induction of apoptosis and ferroptosis.

BACKGROUND: Triple-negative breast cancer (TNBC) is a lethal mammary carcinoma subtype that affects females and is associated with a worse prognosis. Chemotherapy is the only conventional therapy available for patients with TNBC due to the lack of therapeutic targets. Yttrium oxide (YO) is a rare earth metal oxide, whose nanoparticle (NPs) formulations are used in various applications, including biological imaging, the material sciences, and the chemical synthesis of inorganic chemicals. However, the biological activity of YO-NPs against TNBC cells has not been fully explored. The current study was conducted to assess YO-NPs' anticancer activity against the human TNBC MDA-MB-231 cell line.

METHODS: Transmission electron microscopy (TEM), X-ray diffraction, Zeta potential, and dynamic light scattering (DLS) were used to characterize the YO-NPs. SRB cell viability, reactive oxygen species (ROS) measurement, single-cell gel electrophoresis (comet assay), qPCR, flow cytometry, and Western blot were employed to assess the anticancer activity of the YO-NPs.

RESULTS: Our results indicate favorable physiochemical properties of YO-NPs (with approximately average size 14 nm, Zeta Potential about - 53.2 mV, and polydispersity index = 0.630). YO-NPs showed a potent cytotoxic effect against MDA-MB-231 cells, with IC50 values of 74.4 µg/mL, without cytotoxic effect on the normal retina REP1 and human dermal fibroblast HDF cell lines. Further, treatment of MDA-MB-231 cells with IC50 YO-NPs resulted in increased oxidative stress, accumulation of intracellular ROS levels, and induced DNA damage assessed by Comet assay. Upon YO-NPs treatment, a significant increase in the early and late phases of apoptosis was revealed in MDA-MB-231 cells. qPCR results showed that YO-NPs significantly upregulated the pro-apoptotic genes CASP3 and CASP8 as well as ferroptosis-related gene heme oxygenase-1 (HO-1), whereas the anti-apoptotic gene BCL2 was significantly downregulated.

CONCLUSION: This study suggests that YO-NPs are safe on normal REP1 and HDF cells and exhibited a potent selective cytotoxic effect against the TNBC MDA-MB-231 cells through increasing levels of ROS generation with subsequent DNA damage, and induction of apoptosis and ferroptosis.

The purpose of this paper is to examine the school-to-work transition of young people from subsequent school exit cohorts between 2001 and 2012 in Egypt, thus, presenting an early evidence on the adjustments of the labor market in terms of patterns of youth transition to a first job following the 2011 Egyptian uprising.

The analysis compares the early employment outcomes of those who left school after the January 25, 2011 uprising to that of those who left before 2011. The authors also separately control for the cohorts who left school in 2008 and 2009, in an attempt to disentangle any labor market adjustments that might have happened following the financial crisis, and before the revolution. Using novel and unexploited representative data from the 2014 Survey of Young People in Egypt (SYPE), the authors estimate the probability of transition to any first job within 18 months from leaving education and that of the transition to a good-quality job, controlling for the year of school exit. The authors also estimate the hazard of finding a first job and a good-quality job using survival analysis.

School exit cohorts of 2008–2009 (following the financial crisis) and those of 2011–2012 (in the aftermath of the 2011 uprisings) experienced a significantly higher likelihood of finding a first job within 18 months than that of the cohorts of 2001–2007. However, this came at the expense of the quality of job, conditional on having found a first job. The results of the hazard model show that school leavers after 2008 who were not able to transition to a job shortly after leaving school experienced longer unemployment spells than their peers who left school before 2007. The odds of finding a good-quality job appears to decline with time spent in non-employment or in a bad-quality first job.

This paper contributes to a limited, yet growing, literature on how school-to-work transition evolved during the global financial crisis and the Egyptian 2011 revolution. Using data from SYPE 2014, the most recent representative survey conducted in Egypt on youth and not previously exploited to study youth school-to-work transition, the paper investigates the short-term adjustments of the youth labor market opportunities during that critical period of Egypt and the region’s history.