Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “MAMMARY GLANDS”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records

Dose Fractionation During Puberty Is More Detrimental to Mammary Gland Development Than an Equivalent Acute Dose of Radiation Exposure

Computed tomographic (CT) scans in adolescents have increased dramatically in recent years. However, the effects of cumulative low-dose exposures on the development of radiation sensitive organs, such as the mammary gland, is unknown. The purpose of this work was to define the effects of dose rate on mammary organ formation during puberty, an especially sensitive window in mammary development. We used a fractionated low-dose x-ray exposure to mimic multiple higher dose CT scans, and we hypothesized that fractionated exposure would have less of an effect on the number of mammary gland defects compared with an acute exposure.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

IL-1β is a key inflammatory cytokine that weakens lactation-specific tight junctions of mammary epithelial cells

Highlights: • TNF-α, IL-1β, and IL-6 directly affect tight junctions of MECs in different ways. • IL-1β rapidly disrupts tight junctions at tricellular contacts between MECs. • IL-1β decreases the amount of tight junction proteins and weaken the TJ barrier. • Activation of p38 by IL-1β triggers disruption of tight junctions. In lactating mammary glands, alveolar mammary epithelial cells (MECs) produce milk and form less-permeable tight junctions (TJs). However, alveolar TJs are weakened with a reduction in milk production in mammary glands due to mastitis or weaning in the presence of high levels of IL-1β, IL-6, or TNF-α. In this study, using in vitro cultured model of MECs with milk-producing ability and lactation-specific TJs, we investigated whether the aforementioned cytokines affect MEC TJs. The results showed that TNF-α, IL-1β, and IL-6 affected lactation-specific TJs in different ways. In particular, upon activation of p38 and JNK signalling, IL-1β caused rapid disruption of TJs at tricellular contact points. IL-1β treatment led to decreased CLDN3, CLDN4, and OCLN levels and a weakened TJ barrier. The adverse effects of IL-1β on TJs were mimicked by anisomycin, which is an activator of p38 and JNK signalling, and were blocked by MEC pretreatment with a p38 inhibitor but not a JNK inhibitor. The mislocalization of tricellulin at tricellular contact areas was confirmed in MECs treated with IL-1β or anisomycin. These results indicate that IL-1β is a key cytokine that adversely affects the TJs between MECs by activating p38.

60 APPLIED LIFE SCIENCES↗

Alterations in Progesterone Receptor Isoform Balance in Normal and Neoplastic Breast Cells Modulates the Stem Cell Population

To investigate the role of PR isoforms on the homeostasis of stem cells in the normal and neoplastic mammary gland, we used PRA and PRB transgenic mice and the T47D human breast cancer cell line and its derivatives, T47D YA and YB (manipulated to express only PRA or PRB, respectively). Flow cytometry and mammosphere assays revealed that in murine breast, overexpression of PRB leads to an increase in luminal and basal progenitor/stem cells. Ovariectomy had a negative impact on the luminal compartment and induced an increase in mammosphere-forming capacity in cells derived from WT and PRA mice only. Treatment with ICI 182,780 augmented the mammosphere-forming capacity of cells isolated from WT and PRA mice, whilst those from PRB remained unaltered. T47D YB cells showed an increase in the CD44+/CD24Low/- subpopulation; however, the number of tumorspheres did not vary relative to T47D and YA, even though they were larger, more irregular, and had increased clonogenic capacity. T47D and YA tumorspheres were modulated by estrogen/antiestrogens, whereas YB spheres remained unchanged in size and number. Our results show that alterations in PR isoform balance have an impact on normal and tumorigenic breast progenitor/stem cells and suggest a key role for the B isoform, with implications in response to antiestrogens.

stem cells↗

Evidence for accelerated aging in mammary epithelia of women carrying germline BRCA1 or BRCA2 mutations

During aging in the human mammary gland, luminal epithelial cells lose lineage fidelity by expressing markers normally expressed in myoepithelial cells. We hypothesize that loss of lineage fidelity is a general manifestation of epithelia that are susceptible to cancer initiation. In the present study, we show that histologically normal breast tissue from younger women who are susceptible to breast cancer, as a result of harboring a germline mutation in BRCA1, BRCA2 or PALB2 genes, exhibits hallmarks of accelerated aging. These include proportionately increased luminal epithelial cells that acquired myoepithelial markers, decreased proportions of myoepithelial cells and a basal differentiation bias or failure of differentiation of cKit + progenitors. High-risk luminal and myoepithelial cells are transcriptionally enriched for genes of the opposite lineage, inflammatory- and cancer-related pathways. We have identified breast-aging hallmarks that reflect a convergent biology of cancer susceptibility, regardless of the specific underlying genetic or age-dependent risk or the associated breast cancer subtype.

60 APPLIED LIFE SCIENCES↗

Examining metastatic behavior within 3D bioprinted vasculature for the validation of a 3D computational flow model

Understanding the dynamics of circulating tumor cell (CTC) behavior within the vasculature has remained an elusive goal in cancer biology. To elucidate the contribution of hydrodynamics in determining sites of CTC vascular colonization, the physical forces affecting these cells must be evaluated in a highly controlled manner. To this end, we have bioprinted endothelialized vascular beds and perfused these constructs with metastatic mammary gland cells under physiological flow rates. By pairing these in vitro devices with an advanced computational flow model, we found that the bioprinted analog was readily capable of evaluating the accuracy and integrated complexity of a computational flow model, while also highlighting the discrete contribution of hydrodynamics in vascular colonization. This intersection of these two technologies, bioprinting and computational simulation, is a key demonstration in the establishment of an experimentation pipeline for the understanding of complex biophysical events.

42 ENGINEERING↗

Interrogating the role of the milk microbiome in mastitis in the multi-omics era

There is growing interest in a functional understanding of milk-associated microbiota as there is ample evidence that host-associated microbial communities play an active role in host health and phenotype. Mastitis, characterized by painful inflammation of the mammary gland, is prevalent among lactating humans and agricultural animals and is associated with significant clinical and economic consequences. The etiology of mastitis is complex and polymicrobial and correlative studies have indicated alterations in milk microbial community composition. Recent evidence is beginning to suggest that a causal relationship may exist between the milk microbiota and host phenotype in mastitis. Multi-omic approaches can be leveraged to gain a mechanistic, molecular level understanding of how the milk microbiome might modulate host physiology, thereby informing strategies to prevent and ameliorate mastitis. In this paper, we review existing studies that have utilized omics approaches to investigate the role of the milk microbiome in mastitis. We also summarize the strengths and challenges associated with the different omics techniques including metagenomics, metatranscriptomics, metaproteomics, metabolomics and lipidomics and provide perspective on the integration of multiple omics technologies for a better functional understanding of the milk microbiome.

metabolomics↗

Breast Cancer Molecular Subtype as a Predictor of Radiation Therapy Fractionation Sensitivity

The predictive benefit of breast cancer molecular subtypes for systemic therapy approaches has been well established; yet, there is a paucity of data regarding their use as a predictor of radiation therapy fractionation sensitivity. The purpose of this study was to determine whether rates of local recurrence (LR) for patients treated with hypofractionated (HF) radiation therapy, in comparison to conventional fractionation, differ across breast cancer molecular subtypes in a large, prospectively collected cohort treated with modern systemic therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

The Role of Circulating Tumor Cells in Breast Cancer and Implications for Radiation Treatment Decisions

Tumor biomarkers are used routinely in oncology to assign risk categorization, screen and assist in diagnosis of malignancy, allow for prognostication and prediction of outcomes and treatment response, and allow for monitoring of patients after treatment completion. Although tissue-based biomarkers have a long history of use, the emergence of liquid-based biomarkers, including circulating tumor cells (CTCs), may soon revolutionize the management of patients with cancer. Here, we review the discovery of CTCs and their role as prognostic and predictive biomarkers, with an emphasis on breast cancer. We discuss the platforms for CTC enumeration and focus on studies using the only US Food and Drug Administration–approved platform for CTC enumeration (CellSearch). In addition, we examine the role of CTCs in women with metastatic, inflammatory, and nonmetastatic breast cancer, as well as the clinical evidence for their use as a surrogate for radiation treatment response as well as surveillance after treatment. Finally, we conclude by investigating ongoing clinical studies assessing CTCs as radiation response predictors and discuss unanswered questions.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Safety Margins for the Delineation of the Left Anterior Descending Artery in Patients Treated for Breast Cancer

Cardiac toxicity after breast cancer (BC) radiation therapy is partly due to the large radiation doses to coronary arteries. The left anterior descending artery (LAD) is particularly exposed. A first step in achieving robust dose constraints to the LAD during treatment planning is homogeneous delineation based on guidelines. LAD delineation can be problematic due to heart movements. The aim of the study was to establish a safety margin for delineation of the LAD in patients with BC.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Trends in Use of Hypofractionated Whole Breast Radiation in Breast Cancer: An Analysis of the National Cancer Database

Use of hypofractionated radiation (HR) as a component of breast-conserving treatment (BCT) in breast cancer is relatively low in the United States despite studies demonstrating its efficacy and guidelines supporting its use from the American Society for Radiation Oncology (ASTRO) in 2011 and 2018. Little is known regarding national trends in uptake and factors associated with uptake of HR in the US since the 2011 ASTRO guidelines.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Simultaneous Targeting of RSK and AKT Efficiently Inhibits YB-1-Mediated Repair of Ionizing Radiation-Induced DNA Double-Strand Breaks in Breast Cancer Cells

Y-box binding protein 1 (YB-1) overexpression is associated with chemotherapy- and radiation therapy resistance. Ionizing radiation (IR), receptor tyrosine kinase ligands, and mutation in KRAS gene stimulate activation of YB-1. YB-1 accelerates the repair of IR-induced DNA double-strand breaks (DSBs). Ribosomal S6 kinase (RSK) is the main kinase inducing YB-1 phosphorylation. We investigated the impact of RSK targeting on DSB repair and radiosensitivity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Combination of Olaparib and Radiation Therapy for Triple Negative Breast Cancer: Preliminary Results of the RADIOPARP Phase 1 Trial

Preclinical studies have evidenced that triple-negative breast cancer (TNBC) cell lines are more sensitive to poly (ADP-ribose) polymerase inhibitors. This provides a strong rationale for developing a new therapeutic approach for TNBC management based on poly (ADP-ribose) polymerase inhibition. The primary goal of the RADIOPARP phase 1 trial was to evaluate the dose-limiting toxicities (DLT) and the maximum tolerated dose of olaparib combined with locoregional radiation therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗