RESUMEN
Breast cancer patients with estrogen receptor positive tumors face a constant risk of disease recurrence for the remainder of their lives. Dormant tumor cells residing in tissues such as the bone marrow may generate clinically significant metastases many years after initial diagnosis. Previous studies suggest that dormant cells display "stem like" properties (CSCs), which may be regulated by the immune system. Although many studies have examined tumor cell intrinsic characteristics of dormancy, the role of the immune system in controlling dormancy and its escape is not well understood. This scientific gap is due, in part, to a lack of immunocompetent mouse models of breast cancer dormancy with many studies involving human xenografts in immunodeficient mice. To overcome this limitation, we studied dormancy in immunocompetent, syngeneic mouse breast cancer models. We find that PyMT, Met-1 and D2.0R cell lines contain CSCs that display both short- and long-term metastatic dormancy in vivo, which is dependent on the host immune system. Natural killer cells were key for the metastatic dormancy phenotype observed for D2.0R and the role of NK cells in regulating CSCs was further investigated.Quiescent D2.0R CSC are resistant to NK cytotoxicity, while proliferative D2.0R CSC were sensitive to NK cytotoxicity both in vitro and in vivo. This resistance was mediated, in part, by the expression of Bach1 and Sox2 transcription factors. NK killing was enhanced by the STING agonist MSA-2. Collectively, our findings demonstrate the important role of immune regulation of breast tumor dormancy and highlight the importance of utilizing immunocompetent models to study this phenomenon.
RESUMEN
Antenatal screening and diagnostic testing for Down syndrome has greatly advanced over the past 30 years. The goal of this manuscript is to provide a review of the availability and accessibility of prenatal services and selective termination policies across Europe, Australia, New Zealand, and the United States for the period 1990-2021. We collected data from academic peer-reviewed journals, governmental documents, not-for-profit organizations, correspondence with experts, and other online sources without language restrictions. Prenatal screening services from 1990-2021 became increasingly available across countries, enabling expectant couples the opportunity to gain more accurate information earlier in the pregnancy before assuming the risk associated with more invasive techniques like CVS or amniocentesis. Many countries also began adopting prenatal screening as a qualification for prenatal diagnosis. As of 2021, at least 76.9% of countries offered full coverage for diagnostic testing for Down syndrome from government funding. Abortion coverage for a Down syndrome diagnosis was covered fully by government funding in 52.4% of countries in 1990, increasing to 73.8% in 2021. Understanding the changing landscape of prenatal services builds the foundation for future investigation into social policies that affect the prevalence of Down syndrome.
