219 research outputs found
COVID-19 School Re-openings: The Effect on Women’s Labor Force Participation
As schools and daycares closed in March of 2020, mothers left the labor market in droves, either completely giving up their jobs or significantly cutting back on hours in order to care for children and/or help facilitate online learning. Furthermore, fields historically dominated by women were particularly hard hit, such as education, hospitality, and retail causing many women who may not be mothers to leave the work force as well. This paper considers how women’s labor force participation has changed throughout the COVID-19 pandemic and how the re-opening of schools, in particular, has impacted women’s return to the workforce. Triple difference estimation shows a small but statistically significant positive effect for both women’s labor force participation and women’s employment status as schools re-open
Influence of CuO addition on dielectric and piezoelectric properties of (Bi 0. 5 Na 0. 5) TiO 3 - BaTiO 3 lead-free piezoceramics
Doping effects of CuO on the sintering behavior and electrical properties of 0.94(Bi0.5Na0.5)TiO3-0.06(BaTiO3)-xCuO (BNT-BT6-xCu) lead-free piezoceramic obtained by the conventional solid-state reaction method were investigated. Regarding the undoped system, it is already known that it presents the best densification values when it is sintered at 1150°C, however, the doped system was sintered at 1150°C, 1100°C, 1050°C, 1025°C, and 975°C to determine the effect of Cu on the densification process. Therefore, it was obtained that the CuO-doped samples sintered at 1050°C presented the highest density values and therefore were the ones chosen to perform the characterization tests together with the undoped system. The samples were characterized using X-ray diffraction (XRD), Raman microspectroscopy, and scanning electron microscopy (SEM) analysis, whereas the ferroelectric and dielectric properties were evaluated by means of ferroelectric hysteresis loops and impedance spectroscopy studies. As a result, the addition of CuO allowed an improvement in sinterability and densification, with the subsequent grain growth, and the improvement of the piezoelectric coefficient (d33).Fil: Difeo, Mauro CĂ©sar. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y TecnologĂa de Materiales. Universidad Nacional de Mar del Plata. Facultad de IngenierĂa. Instituto de Investigaciones en Ciencia y TecnologĂa de Materiales; ArgentinaFil: Ramajo, Leandro Alfredo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y TecnologĂa de Materiales. Universidad Nacional de Mar del Plata. Facultad de IngenierĂa. Instituto de Investigaciones en Ciencia y TecnologĂa de Materiales; ArgentinaFil: Castro, Miriam Susana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y TecnologĂa de Materiales. Universidad Nacional de Mar del Plata. Facultad de IngenierĂa. Instituto de Investigaciones en Ciencia y TecnologĂa de Materiales; Argentin
Kinetic and spectroscopic studies of haemoglobin and myoglobin from Urechis caupo. Distal residue effects
STING pathway expression in low-grade serous carcinoma of the ovary: an unexpected therapeutic opportunity?
Ovarian carcinoma histotypes are distinct diseases with variable clinical outcomes and response to treatment. There is a need for new subtype-specific treatment modalities, especially for women with widespread and chemo-resistant disease. Stimulator of interferon genes (STING) is a part of the cGAS-STING pathway that mediates innate immune defence against infectious DNA-containing pathogens and also detects tumour-derived DNA and generates intrinsic antitumour immunity. The STING signalling pathway is suppressed by several mechanisms in a variety of malignant diseases and, in some cancers that may be a requirement for cellular transformation. The aim of this study was to use immunohistochemistry to evaluate STING protein expression across normal tissue, paratubal and ovarian cysts, and ovarian tumour histotypes including ovarian carcinomas. Herein, we show that the fallopian tube ciliated cells express STING protein, whereas the secretory cells are negative. STING expression differs among ovarian cancer histotypes; low-grade serous ovarian carcinomas and serous borderline tumours have uniform high STING expression, while high-grade serous and endometrioid carcinomas have heterogeneous expression, and clear cell and mucinous carcinomas show low expression. As low-grade serous carcinomas are known to be genomically stable and typically lack a prominent host immune response, the consistently high STING expression is unexpected. High STING expression may reflect pathway activation or histogenesis and the mechanisms may be different in different ovarian carcinoma histotypes. Further studies are needed to determine whether the STING signalling pathway is active and whether these tumours would be candidates for therapeutic interventions that trigger innate immunity activation
Multiple Breast Cancer Cell-Lines Derived from a Single Tumor Differ in Their Molecular Characteristics and Tumorigenic Potential
Background Breast cancer cell lines are widely used tools to investigate breast cancer biology and to develop new therapies. Breast cancer tissue contains molecularly heterogeneous cell populations. Thus, it is important to understand which cell lines best represent the primary tumor and have similarly diverse phenotype. Here, we describe the development of five breast cancer cell lines from a single patient’s breast cancer tissue. We characterize the molecular profiles, tumorigenicity and metastatic ability in vivo of all five cell lines and compare their responsiveness to 4-hydroxytamoxifen (4-OHT) treatment. Methods Five breast cancer cell lines were derived from a single patient’s primary breast cancer tissue. Expression of different antigens including HER2, estrogen receptor (ER), CK8/18, CD44 and CD24 was determined by flow cytometry, western blotting and immunohistochemistry (IHC). In addition, a Fuorescent In Situ Hybridization (FISH) assay for HER2 gene amplification and p53 genotyping was performed on all cell lines. A xenograft model in nude mice was utilized to assess the tumorigenic and metastatic abilities of the breast cancer cells. Results We have isolated, cloned and established five new breast cancer cell lines with different tumorigenicity and metastatic abilities from a single primary breast cancer. Although all the cell lines expressed low levels of ER, their growth was estrogen-independent and all had high-levels of expression of mutated non-functional p53. The HER2 gene was rearranged in all cell lines. Low doses of 4-OHT induced proliferation of these breast cancer cell lines. Conclusions All five breast cancer cell lines have different antigenic expression profiles, tumorigenicity and organ specific metastatic abilities although they derive from a single tumor. None of the studied markers correlated with tumorigenic potential. These new cell lines could serve as a model for detailed genomic and proteomic analyses to identify mechanisms of organ-specific metastasis of breast cancer
The SRG Rat, a Sprague-Dawley Rag2/Il2rg Double-Knockout Validated for Human Tumor Oncology Studies
We have created the immunodeficient SRG rat, a Sprague-Dawley Rag2/Il2rg double knockout that lacks mature B cells, T cells, and circulating NK cells. This model has been tested and validated for use in oncology (SRG OncoRat®). The SRG rat demonstrates efficient tumor take rates and growth kinetics with different human cancer cell lines and PDXs. Although multiple immunodeficient rodent strains are available, some important human cancer cell lines exhibit poor tumor growth and high variability in those models. The VCaP prostate cancer model is one such cell line that engrafts unreliably and grows irregularly in existing models but displays over 90% engraftment rate in the SRG rat with uniform growth kinetics. Since rats can support much larger tumors than mice, the SRG rat is an attractive host for PDX establishment. Surgically resected NSCLC tissue from nine patients were implanted in SRG rats, seven of which engrafted and grew for an overall success rate of 78%. These developed into a large tumor volume, over 20,000 mm3 in the first passage, which would provide an ample source of tissue for characterization and/or subsequent passage into NSG mice for drug efficacy studies. Molecular characterization and histological analyses were performed for three PDX lines and showed high concordance between passages 1, 2 and 3 (P1, P2, P3), and the original patient sample. Our data suggest the SRG OncoRat is a valuable tool for establishing PDX banks and thus serves as an alternative to current PDX mouse models hindered by low engraftment rates, slow tumor growth kinetics, and multiple passages to develop adequate tissue banks
Activation of tumor suppressor protein PP2A inhibits KRAS-driven tumor growth
Targeted cancer therapies, which act on specific cancer-associated molecular targets, are predominantly inhibitors of oncogenic kinases. While these drugs have achieved some clinical success, the inactivation of kinase signaling via stimulation of endogenous phosphatases has received minimal attention as an alternative targeted approach. Here, we have demonstrated that activation of the tumor suppressor protein phosphatase 2A (PP2A), a negative regulator of multiple oncogenic signaling proteins, is a promising therapeutic approach for the treatment of cancers. Our group previously developed a series of orally bioavailable small molecule activators of PP2A, termed SMAPs. We now report that SMAP treatment inhibited the growth of KRAS-mutant lung cancers in mouse xenografts and transgenic models. Mechanistically, we found that SMAPs act by binding to the PP2A Aα scaffold subunit to drive conformational changes in PP2A. These results show that PP2A can be activated in cancer cells to inhibit proliferation. Our strategy of reactivating endogenous PP2A may be applicable to the treatment of other diseases and represents an advancement toward the development of small molecule activators of tumor suppressor proteins
KrĂĽppel-Like Factor 6 Expression Changes during Trophoblast Syncytialization and Transactivates ĂźhCG and PSG Placental Genes
BACKGROUND: Krüppel-like factor-6 (KLF6) is a widely expressed member of the Sp1/KLF family of transcriptional regulators involved in differentiation, cell cycle control and proliferation in several cell systems. Even though the highest expression level of KLF6 has been detected in human and mice placenta, its function in trophoblast physiology is still unknown. METHODOLOGY/PRINCIPAL FINDINGS: Herein, we explored KLF6 expression and sub-cellular distribution in human trophoblast cells differentiating into the syncytial pathway, and its role in the regulation of genes associated with placental development and pregnancy maintenance. Confocal immunofluorescence microscopy demonstrated that KLF6 is expressed throughout human cytotrophoblast differentiation showing no evident modifications in its nuclear and cytoplasmic localization pattern. KLF6 transcript and protein peaked early during the syncytialization process as determined by qRT-PCR and western blot assays. Overexpression of KLF6 in trophoblast-derived JEG-3 cells showed a preferential nuclear signal correlating with enhanced expression of human β-chorionic gonadotropin (βhCG) and pregnancy-specific glycoprotein (PSG) genes. Moreover, KLF6 transactivated βhCG5, PSG5 and PSG3 gene promoters. Deletion of KLF6 Zn-finger DNA binding domain or mutation of the consensus KLF6 binding site abolished transactivation of the PSG5 promoter. CONCLUSIONS/SIGNIFICANCE: Results are consistent with KLF6 playing a role as transcriptional regulator of relevant genes for placental differentiation and physiology such as βhCG and PSG, in agreement with an early and transient increase of KLF6 expression during trophoblast syncytialization
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