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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.

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At least 55 records · Page 3

Maternal undernutrition modulates hepatic MicroRNAs expression in the early life of offspring

Emerging studies revealed that a poor intrauterine environment elicited by maternal nutrient restriction (MNR) is associated with an increased risk of metabolic diseases in adulthood. Previous research has shown that microRNAs (miRNAs) exert pivotal roles in modulating molecular pathways involved in disease pathogenesis and progression. In this respect, we herein examined miRNA profiles in samples of liver from offspring whose mothers were fed either with a 50% food-restricted diet or standard laboratory chow during pregnancy. Our findings enumerated that miR-181a, involved in lipid metabolism, was found to be downregulated in the liver of MNR offspring at 1 day of age when compared to that of control offspring. We also noted that overexpression of miR-181a reduced the lipid droplets after treatment with oleic acid for 48 h, which suppressed the expressions levels of SIRT1, FOXO1, KLF6 and PPARγ in BRL-3A cells, while the opposite results were observed with decreased expression of miR-181a. Furthermore, the luciferase reporter assay confirmed the direct interactions between miR-181a with KLF6 and SIRT1. In adults, the MNR offspring elucidated increased TG content, decreased expression of miR-181a, and increased expressions levels of SIRT1, FOXO1, KLF6, and PPARγ in liver tissues. Collectively, these findings provided novel evidence that MNR could regulate miRNAs expression, which might be related to lipid metabolism in MNR offspring.

60 APPLIED LIFE SCIENCES↗

Organotypic platform for studying cancer cell metastasis

Highlights: • Liver and brain slices can be stable, realistic in vitro 3D models. • Cell stiffness and adhesion to the tissue play determinant roles in cellular invasion in 3D. • MEK inhibitors can lead to increased cell stiffness and adhesion forces, and consequently reduced cancer cell invasion. • MDA-MB-231 breast cancer cells migrate faster and deeper into brain tissue compared to liver tissue. Metastasis is the leading cause of mortality in cancer patients. To migrate to distant sites, cancer cells would need to adapt their behaviour in response to different tissue environments. Thus, it is essential to study this process in models that can closely replicate the tumour microenvironment. Here, we evaluate the use of organotypic liver and brain slices to study cancer metastasis. Morphological and viability parameters of the slices were monitored daily over 3 days in culture to assess their stability as a realistic 3D tissue platform for in vitro metastatic assays. Using these slices, we evaluated the invasion of MDA-MB-231 breast cancer cells and of a subpopulation that was selected for increased motility. We show that the more aggressive invasion of the selected cells likely resulted not only from their lower stiffness, but also from their lower adhesion to the surrounding tissue. Different invasion patterns in the brain and liver slices were observed for both subpopulations. Cells migrated faster in the brain slices (with an amoeboid-like mode) compared to in the liver slices (where they migrated with mesenchymal or collective migration-like modes). Inhibition of the Ras/MAPK/ERK pathway increased cell stiffness and adhesion forces, which resulted in reduced invasiveness. These results illustrate the potential for organotypic tissue slices to more closely mimic in vivo conditions during cancer cell metastasis than most in vitro models.

60 APPLIED LIFE SCIENCES↗

High-resolution deep view microscopy of cells and tissues

Methods, experimental setups and perspectives of three-dimensional deep view imaging microscopy of cell or tissue samples are reported. Preliminary biophysical and clinically relevant examples are presented. (paper)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Estimates of Alpha/Beta (α/β) Ratios for Individual Late Rectal Toxicity Endpoints: An Analysis of the CHHiP Trial

Changes in fraction size of external beam radiation therapy exert nonlinear effects on subsequent toxicity. Commonly described by the linear-quadratic model, fraction size sensitivity of normal tissues is expressed by the α/β ratio. We sought to study individual α/β ratios for different late rectal effects after prostate external beam radiation therapy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Normal Tissue Injury Induced by Photon and Proton Therapies: Gaps and Opportunities

Despite technological advances in radiation therapy (RT) and cancer treatment, patients still experience adverse effects. Proton therapy (PT) has emerged as a valuable RT modality that can improve treatment outcomes. Normal tissue injury is an important determinant of the outcome; therefore, for this review, we analyzed 2 databases: (1) clinical trials registered with ClinicalTrials.gov and (2) the literature on PT in PubMed, which shows a steady increase in the number of publications. Most studies in PT registered with ClinicalTrials.gov with results available are nonrandomized early phase studies with a relatively small number of patients enrolled. From the larger database of nonrandomized trials, we listed adverse events in specific organs/sites among patients with cancer who are treated with photons and protons to identify critical issues. The present data demonstrate dosimetric advantages of PT with favorable toxicity profiles and form the basis for comparative randomized prospective trials. A comparative analysis of 3 recently completed randomized trials for normal tissue toxicities suggests that for early stage non-small cell lung cancer, no meaningful comparison could be made between stereotactic body RT and stereotactic body PT due to low accrual (NCT01511081). In addition, for locally advanced non-small cell lung cancer, a comparison of intensity modulated RT with passive scattering PT (now largely replaced by spot-scanned intensity modulated PT), PT did not provide any benefit in normal tissue toxicity or locoregional failure over photon therapy. Finally, for locally advanced esophageal cancer, proton beam therapy provided a lower total toxicity burden but did not improve progression-free survival and quality of life (NCT01512589). The purpose of this review is to inform the limitations of current trials looking at protons and photons, considering that advances in technology, physics, and biology are a continuum, and to advocate for future trials geared toward accurate precision RT that need to be viewed as an iterative process in a defined path toward delivering optimal radiation treatment. A foundational understanding of the radiobiologic differences between protons and photons in tumor and normal tissue responses is fundamental to, and necessary for, determining the suitability of a given type of biologically optimized RT to a patient or cohort.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Dual role of Fam208a during zygotic cleavage and early embryonic development

Maintenance of genome stability is essential for every living cell as genetic information is repeatedly challenged during DNA replication in each cell division event. Errors, defects, delays, and mistakes that arise during mitosis or meiosis lead to an activation of DNA repair processes and in case of their failure, programmed cell death, i.e. apoptosis, could be initiated. Fam208a is a protein whose importance in heterochromatin maintenance has been described recently. In this work, we describe the crucial role of Fam208a in sustaining genome stability during cellular division. }The targeted depletion of Fam208a in mice using CRISPR/Cas9 led to embryonic lethality before E12.5. We also used the siRNA approach to downregulate Fam208a in zygotes to avoid the influence of maternal RNA in the early stages of development. This early downregulation increased arresting of the embryonal development at the two-cell stage and the occurrence of multipolar spindles formation. To investigate this further, we used the yeast two-hybrid (Y2H) system and identified new putative interaction partners Gpsm2, Svil, and Itgb3bp. Their co-expression with Fam208a was assessed by RT-qPCR profiling and in situ hybridization [1] in multiple murine tissues. Based on these results we proposed that Fam208a functions within the HUSH complex by interaction with Mphosph8 as these proteins are not only able to physically interact but also co-localise. We are bringing new evidence that Fam208a is a multi-interacting protein affecting genome stability on the cell division level at the earliest stages of development and by interaction with methylation complex in adult tissues. }In addition to its epigenetic functions, Fam208a appears to have an important role in the zygotic division, possibly via interaction with newly identified putative partners Gpsm2, Svil, and Itgb3bp.

60 APPLIED LIFE SCIENCES↗

KIF18b-dependent hypomethylation of PARPBP gene promoter enhances oxaliplatin resistance in colorectal cancer

Highlights: • High expression of PARPBP promotes oxaliplatin resistance of CRC. • KIF18b induces PARPBP expression by suppressing promoter methylation. • SP1 recruits DNMT3b to methylate PARPBP promoter. • KIF18b disturbs the recruitment of DNMT3b to PARPBP promoter. As the new platinum drug oxaliplatin has been widely used in clinical treatment of colorectal cancer (CRC), oxaliplatin resistance has become a burning problem. In this study, higher expression of PARP-1 binding protein (PARPBP) was detected in oxaliplatin-resistant CRC (OR-CRC) cells than in non-resistant cells. Further research showed that kinesin family member 18 b (KIF18b) induced the overexpression of PARPBP, sustaining oxaliplatin resistance in OR-CRC cells. Through exploring the PARPBP gene promoter, we found that SP1-recruited DNMT3b methylated PARPBP promoter to suppress transcription in CRC cells, and increased KIF18b attenuated the recruitment of DNMT3b to PARPBP promoter by directly interacting with SP1 in OR-CRC cells. Clinical analysis suggested a positive relationship between KIF18b and PARPBP in CRC tissues and indicated poor prognosis in CRC patients with high level of KIF18b or PARPBP. In summary, KIF18b-induced PARPBP contributes to the resistant phenotype of OR-CRC.

60 APPLIED LIFE SCIENCES↗

Salivary and Dental Complications in Childhood Cancer Survivors Treated With Radiation Therapy to the Head and Neck: A Pediatric Normal Tissue Effects in the Clinic (PENTEC) Comprehensive Review

Radiation therapy (RT) to the head and neck (H&N) region is critical in the management of various pediatric malignancies; however, it may result in late toxicity. This comprehensive review from the Pediatric Normal Tissue Effects in the Clinic (PENTEC) initiative focused on salivary dysfunction and dental abnormalities in survivors who received RT to the H&N region as children.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Substrate stiffness modulates endothelial cell function via the YAP-Dll4-Notch1 pathway

Highlights: • Soft stiffness increases Dll4 expression in endothelial cells via YAP suppression. • Soft substrate-induced Dll4-Notch1 signaling is facilitated by VEGF stimulation. • Elevated Dll4-Notch1 signaling contributes to the regulation of VEGFRs expression. • Substrate stiffness modulates gene expression linked to endothelial cell function. Endothelial cells adapt their functions as a consequence of sensing extracellular substrate stiffness; these alterations allow them to maintain their vascular structure and function. Substrate stiffness-mediated yes-associated protein 1 (YAP) activation plays an important role in mechano-transduction and pro-angiogenic phenotype of endothelial cells, and Delta-like ligand 4 (Dll4)-Notch1 signaling is closely related to angiogenesis; however, the impact of substrate stiffness-mediated interrelation of these pathways on endothelial cell functions remains elusive. We confirmed that endothelial cells on softer substrates not only elongate cellular aspects but also attenuate YAP activation compared to cells on stiffer substrates. Endothelial cells on softer substrates also upregulate the vascular endothelial growth factor receptor 1 (VEGFR1) and VEGFR2 mRNA expression that is enhanced by VEGF stimulation. We determined that endothelial cells on softer substrates increased Dll4 expression, but not Notch1 expression, via YAP signaling. Moreover, endothelial cells on soft substrates induced not only VEGFRs upregulation but also suppression of pro-inflammatory interleukin-6 and plasminogen activator inhibitor-1 mRNA expression and the facilitation of anti-coagulant thrombomodulin and pro-coagulant tissue factor mRNA expression. Our results suggest that endothelial cells activate the YAP-Dll4-Notch signaling pathway in response to substrate stiffness and dictate cellular function.

60 APPLIED LIFE SCIENCES↗

Normal Tissue Response of Combined Temporal and Spatial Fractionation in Proton Minibeam Radiation Therapy

Proton minibeam radiation therapy, a spatial fractionation concept, widens the therapeutic window. By reducing normal tissue toxicities, it allows a temporally fractionated regime with high daily doses. However, an array shift between daily fractions can affect the tissue-sparing effect by decreasing the total peak-to-valley dose ratio. Therefore, combining temporal fractions with spatial fractionation raises questions about the impact of daily applied dose modulations, reirradiation accuracies, and total dose modulations.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Involvement of TFAP2A in the activation of GSDMD gene promoter in hyperoxia-induced ALI

Highlights: • Hyperoxia exposure increases GSDMD expression in rat lung tissue and A549 cells. • The core promoter region of GSDMD located in −98/-12 bp relative to TSS. • E2F4 and TFAP2A positively regulate the basal transcriptional activity of GSDMD by directly binding to its promoter. • TFAP2A directly drives the expression of GSDMD in hyperoxia-inducedA549 cells. • TFAP2A expression is increased in lung tissues of rats with hyperoxia-induced ALI and linearly correlated with GSDMD. Oxygen therapy is a common treatment in neonatal intensive care units, but long-term continuous hyperoxia ventilation may induce acute lung injury (ALI). Gasdermin D (GSDMD)-mediated pyroptosis participates in various diseases including ALI, but the role of GSDMD in hyperoxia-induced ALI is yet understood. Here, we showed a significant increase in GSDMD after exposure to high oxygen. To elucidate the molecular mechanisms involved in GSDMD regulation, we identified the core promoter of GSDMD, −98 ~ −12 bp relative to the transcriptional start site (TSS). The results of mutational analysis, overexpression or siRNA interference, EMSA and ChIP demonstrated that E2F4 and TFAP2A positively regulate the transcriptional activity of the GSDMD by binding to its promoter. However, only TFAP2A showed a regulatory effect on the expression of GSDMD. Moreover, TFAP2A was increased in the lung tissues of rats exposed to hyperoxia and showed a strong linear correlation with GSDMD. Our results indicated that TFAP2A positively regulates the GSDMD expression via binding to the promoter region of GSDMD.

60 APPLIED LIFE SCIENCES↗

Multicellular Spheroids as In Vitro Models of Oxygen Depletion During FLASH Irradiation

The differential response of normal and tumor tissues to ultrahigh-dose-rate radiation (FLASH) has raised new hope for treating solid tumors but, to date, the mechanism remains elusive. One leading hypothesis is that FLASH radiochemically depletes oxygen from irradiated tissues faster than it is replenished through diffusion. The purpose of this study was to investigate these effects within hypoxic multicellular tumor spheroids through simulations and experiments.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Integrating Multiomics Information in Deep Learning Architectures for Joint Actuarial Outcome Prediction in Non-Small Cell Lung Cancer Patients After Radiation Therapy

Novel actuarial deep learning neural network (ADNN) architectures are proposed for joint prediction of radiation therapy outcomes—radiation pneumonitis (RP) and local control (LC)—in stage III non-small cell lung cancer (NSCLC) patients. Unlike normal tissue complication probability/tumor control probability models that use dosimetric information solely, our proposed models consider complex interactions among multiomics information including positron emission tomography (PET) radiomics, cytokines, and miRNAs. Additional time-to-event information is also used in the actuarial prediction.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

The Impact of Radiation Therapy in Children and Adolescents With Metastatic Rhabdomyosarcoma

There is limited evidence to define the role of radiation therapy in children with metastatic rhabdomyosarcoma (mRMS). In the international BERNIE study, children with mRMS or non-RMS soft tissue sarcoma were randomized to receive standard chemotherapy with or without bevacizumab, with radiation therapy to all disease sites recommended after chemotherapy cycle 6. We retrospectively evaluated the impact of radiation therapy on survival in the mRMS cohort.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Perimatrix of middle ear cholesteatoma: A granulation tissue with a specific transcriptomic signature

Objectives/Hypothesis: To establish comprehensive transcriptomic profiles of cholesteatoma perimatrix tissue and granulation tissue from chronic otitis media (COM) that did not develop cholesteatoma, which can indicate molecular pathways involved in the cholesteatoma perimatrix pathology and invasiveness. Study Design: Retrospective Case Series. Methods: Transcriptome data were obtained from cholesteatoma perimatrix tissue and COM granulation tissue by an Illumina iScan microarray. Differentially expressed genes (DEGs) were subsequently analyzed using both bioinformatical functional annotation and network analysis. Expression of candidate genes (MMP9 and LCN2) was validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) on a larger group of samples. Results: Analysis of the transcriptome led to the identification of 169 differentially expressed genes between investigated tissues. Bioinformatic analysis suggested that most significant biological processes involving DEGs were previously described in cholesteatoma pathology. Network analysis identified ERBB2, TFAP2A, and TP63 as major hubs of the DEGs molecular network. Furthermore, it was observed that the cellular component most significantly enriched in DEGs was extracellular space containing 47 DEGs. Using qRT-PCR, it was confirmed that mRNA levels of the major extracellular hub (MMP9) are increased, whereas its interacting molecule (LCN2) mRNA levels were decreased in cholesteatoma perimatrix tissue compared to COM granulation tissue. Conclusions: The current study approach offers an overall look at molecular mechanisms that describe the cholesteatoma entity by focusing exclusively on the perimatrix processes in comparison to COM granulation tissue. The observed differences in gene expression between cholesteatoma perimatrix and COM granulation tissue could suggest novel markers potentially influenced by the perimatrix–matrix molecular interplay, which is not present in COM without cholesteatoma. Level of Evidence: NA. Laryngoscope, 130:E220–E227, 2020. © 2019 The American Laryngological, Rhinological and Otological Society, Inc.

60 APPLIED LIFE SCIENCES↗

Irradiation at Ultra-High (FLASH) Dose Rates Reduces Acute Normal Tissue Toxicity in the Mouse Gastrointestinal System

Preclinical studies using ultra-high dose rate (FLASH) irradiation have demonstrated reduced normal tissue toxicity compared with conventional dose rate (CONV) irradiation, although this finding is not universal. We investigated the effect of temporal pulse structure and average dose rate of FLASH compared with CONV irradiation on acute intestinal toxicity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Single- and Multifraction Stereotactic Radiosurgery Dose/Volume Tolerances of the Brain

As part of the American Association of Physicists in Medicine Working Group on Stereotactic Body Radiotherapy investigating normal tissue complication probability (NTCP) after hypofractionated radiation therapy, data from published reports (PubMed indexed 1995-2018) were pooled to identify dosimetric and clinical predictors of radiation-induced brain toxicity after single-fraction stereotactic radiosurgery (SRS) or fractionated stereotactic radiosurgery (fSRS).

62 RADIOLOGY AND NUCLEAR MEDICINE↗