ABSTRACT
A key step for metastatic outgrowth involves the generation of a deeply altered microenvironment (niche) that supports the malignant behavior of cancer cells. The complexity of the metastatic niche has posed a significant challenge in elucidating the underlying programs driving its origin. Here, by focusing on early stages of breast cancer metastasis to the lung in mice, we describe a cancer-dependent chromatin remodeling and activation of developmental programs in alveolar type 2 (AT2) cells within the niche. We show that metastatic cells can prime AT2 cells into a reprogrammed multilineage state. In turn, this cancer-induced reprogramming of AT2 cells promoted stem-like features in cancer cells and enhanced their initiation capacity. In conclusion, we propose the concept of "reflected stemness" as an early phenomenon during metastatic niche initiation, wherein metastatic cells reprogram the local tissue into a stem-like state that enhances intrinsic cancer-initiating potential, creating a positive feedback loop where tumorigenic programs are amplified.
ABSTRACT
Physical activity in children is associated with several cognitive benefits. Since children and adolescents spend an increasing amount of time engaged in sedentary behavior both at school and in their free time, movement breaks during class hours, in which students are physically active, may be beneficial for effective learning. The aim of this systematic research is to provide an overview of prospective studies investigating the influence of classroom-based physical activity (CB-PA) interventions on attention and on-task behavior in school-aged children and adolescents aged between 4 and 18 years. A systematic search of electronic databases (PubMed, Science Direct, PsycINFO, Ovid), according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, was performed from July 2020 to March 2021. Study characteristics data were analyzed and a methodological quality assessment, using a modified Downs and Black checklist, of both randomized and non-randomized studies was conducted. Overall, the available evidence points to a beneficial effect of exercise on attention and on-task behavior in a classroom setting. However, methodological differences concerning participants and duration and type of physical activity should be considered when comparing the results. Further studies with more comparable methodology are needed to provide a better understanding of the effect of CB-PA on attention and on-task behavior.
