Identifying and characterizing functionally relevant microRNAs and 5’isomiRs in triple-negative breast cancer

Triple-negative breast cancer is a highly aggressive breast cancer subtype and the treatment options are mainly limited to chemotherapy, however, the patients frequently develop resistance. As endogenous regulators of gene expression, microRNAs are involved in tumor development, progression and treatment resistance. microRNA sequence variants with a shifted seed sequence are termed 5’isomiRs and extend the complexity and impact of the miRNome in cancer. A shift in the seed sequence by only one nucleotide can drastically alter the target spectrum of a 5’isomiR compared to its canonical microRNA. Hence, this study aims at identifying microRNAs and 5’isomiRs with a potential role in tumorigenesis and chemoresistance and focuses on characterizing their functional differences in triple-negative breast cancer. I selected microRNAs and 5’isomiRs that were differentially expressed between tumor and normal tissue of patients from the TCGA cohort and, thus, potentially involved in tumorigenesis and chemoresistance. Growing mammospheres from MDA-MB-231, HCC1806 and SUM-159 cells that overexpressed the selected microRNAs as pooled library enriched for cells with increased stemness and chemoresistance. Read-out of the library composition by NanoString after several sphere generations revealed strong enrichment of pre-miR-103a-1. In validation experiments, pre-miR-103a-1 overexpression did not influence stemness or chemoresistance. In the second part of the project, I focused on the functional characterization of miR-1307-3p I0 and its 5’isomiR miR-1307-3p I1. Both were selected from the list of differentially expressed microRNAs based on their similar expression levels. Phenotypic assays in triple-negative breast cancer cell lines showed that both microRNAs reduce migration, miR-1307-3p I0 in a cell line-specific manner and less pronounced than miR-1307-3p I1. miR-1307-3p I1 repressed proliferation in a cell line-dependent context. Target predictions identified genes that might contribute to these phenotypes and explain differences between cell lines. The putative targets suggested that miR-1307-3p I0 plays a role in autophagy. In summary, I showed that miR-1307-3p I0 and I1 influence different and similar phenotypes in a partially cell line-dependent manner by targeting specific as well as shared putative target subsets. This study underlines how complex and context-dependent microRNAs and their 5’isomiRs modulate gene expression and that they are of biological relevance. Consequently, diagnostic, prognostic and therapeutic approaches should discriminate between 5’isomiRs

Is Strain Elastography (IO-SE) sufficient for characterization of liver lesions before surgical resection, or is contrast enhanced ultrasound (CEUS) necessary?

Aim To evaluate the diagnostic accuracy of IO-SE in comparison to IO-CEUS for the differentiation between malignant and benign liver lesions. Material and Methods In a retrospective diagnostic study IO-CEUS and SE examinations of 49 liver lesions were evaluated and compared to histopathological examinations. Ultrasound was performed using a multifrequency linear probe (6–9 MHz). The loops of CEUS were evaluated up to 5 min. The qualitative characterization of IO-SE was based on a color coding system (blue = hard, red = soft). Stiffness of all lesions was quantified by a specific scaling of 0–6 (0 = low, 6 = high) using 7 ROIs (2 central, 5 peripheral). Results All malignant lesions displayed a characteristic portal venous washout and could be diagnosed correctly by IO-CEUS. 3/5 benign lesions could not be characterized properly either by IO-CEUS or IO-SE prior to resection. Thus for IO-CEUS sensitivity, specificity, positive and negative predictive value and accuracy were 100%, 40%, 94%, 100% and 94%. Lesion sizes were between 8 and 59 mm in diameter. Regarding the IO-SE, malignant lesions showed a marked variability. In qualitative analysis, 31 of the malignant lesions were blue colored denoting overall induration. Thirteen malignant lesions showed an inhomogenous color pattern with partial indurations. Two of the benign lesions also displayed overall induration. The other benign lesions showed an inhomogenous color mapping. Calculated sensitivity of the SE was 70.5%, specificity 60%, PPV 94%, NPV 18.75%, and accuracy 69%. Conclusion IO-CEUS is useful for localization and characterization of liver lesions prior to surgical resection whereas IO-SE provided correct characterization only for a limited number of lesions

Combining Biocompatible and Biodegradable Scaffolds and Cold Atmospheric Plasma for Chronic Wound Regeneration

Skin regeneration is a quite complex process. Epidermal differentiation alone takes about 30 days and is highly regulated. Wounds, especially chronic wounds, affect 2% to 3% of the elderly population and comprise a heterogeneous group of diseases. The prevailing reasons to develop skin wounds include venous and/or arterial circulatory disorders, diabetes, or constant pressure to the skin (decubitus). The hallmarks of modern wound treatment include debridement of dead tissue, disinfection, wound dressings that keep the wound moist but still allow air exchange, and compression bandages. Despite all these efforts there is still a huge treatment resistance and wounds will not heal. This calls for new and more efficient treatment options in combination with novel biocompatible skin scaffolds. Cold atmospheric pressure plasma (CAP) is such an innovative addition to the treatment armamentarium. In one CAP application, antimicrobial effects, wound acidification, enhanced microcirculations and cell stimulation can be achieved. It is evident that CAP treatment, in combination with novel bioengineered, biocompatible and biodegradable electrospun scaffolds, has the potential of fostering wound healing by promoting remodeling and epithelialization along such temporarily applied skin replacement scaffolds

Biotin tagging of MeCP2 in mice reveals contextual insights into the Rett syndrome transcriptome

Mutations in MECP2 cause Rett syndrome (RTT), an X-linked neurological disorder characterized by regressive loss of neurodevelopmental milestones and acquired psychomotor deficits. However, the cellular heterogeneity of the brain impedes an understanding of how MECP2 mutations contribute to RTT. Here we developed a Cre-inducible method for cell-type-specific biotin tagging of MeCP2 in mice. Combining this approach with an allelic series of knock-in mice carrying frequent RTT-associated mutations (encoding T158M and R106W) enabled the selective profiling of RTT-associated nuclear transcriptomes in excitatory and inhibitory cortical neurons. We found that most gene-expression changes were largely specific to each RTT-associated mutation and cell type. Lowly expressed cell-type-enriched genes were preferentially disrupted by MeCP2 mutations, with upregulated and downregulated genes reflecting distinct functional categories. Subcellular RNA analysis in MeCP2-mutant neurons further revealed reductions in the nascent transcription of long genes and uncovered widespread post-transcriptional compensation at the cellular level. Finally, we overcame X-linked cellular mosaicism in female RTT models and identified distinct gene-expression changes between neighboring wild-type and mutant neurons, providing contextual insights into RTT etiology that support personalized therapeutic interventions

Color coded perfusion imaging with contrast enhanced ultrasound (CEUS) for post-interventional success control following trans-arterial chemoembolization (TACE) of hepatocellular carcinoma

Aim Evaluation of an external color coded perfusion quantification software with CEUS for the post-interventional success control following TACE in patients with HCC. Material and methods 31 patients (5 females, 26 males, age range 34-82 years, mean 66.8 years) with 59 HCC lesions underwent superselective TACE using DSM Beads between 01/2015 and 06/2018. All patients underwent CEUS by an experienced examiner using a convex multifrequency probe (1-6 MHz) within 24 hours following TACE to detect residual tumor tissue. Retrospective evaluation using a perfusion quantification software regarding pE, TTP, mTT, Ri and WiAUC in the center of the lesion, the margin and surrounding liver. Results In all lesions, a post-interventional visual reduction of the tumor microvascularization was observed. Significant differences between center of the lesion vs. margin and surrounding liver were found regarding peak enhancement (867.8 +/- 2416 center vs 2028 +/- 3954 margin p< 0.005) and center 867.8 +/- 2416 vs 2824 +/- 4290 surrounding liver, p<0.0001)). However, no significant differences were found concerning Ri, WiAuC, mTT and TTP. Conclusion CEUS with color-coded perfusion imaging is a valuable supporting tool for post-interventional success control following TACE of liver lesions. Peak enhancement seems to be the most valuable parameter

Self-Affirmation Improves Problem-Solving under Stress

High levels of acute and chronic stress are known to impair problem-solving and creativity on a broad range of tasks. Despite this evidence, we know little about protective factors for mitigating the deleterious effects of stress on problem-solving. Building on previous research showing that self-affirmation can buffer stress, we tested whether an experimental manipulation of self-affirmation improves problem-solving performance in chronically stressed participants. Eighty undergraduates indicated their perceived chronic stress over the previous month and were randomly assigned to either a self-affirmation or control condition. They then completed 30 difficult remote associate problem-solving items under time pressure in front of an evaluator. Results showed that self-affirmation improved problem-solving performance in underperforming chronically stressed individuals. This research suggests a novel means for boosting problem-solving under stress and may have important implications for understanding how self-affirmation boosts academic achievement in school settings. © 2013 Creswell et al

Diagnosis of pericardial effusion with a new generation hand-carried ultrasound device in cardiothoracic intensive care unit patients

Background: Technological advances introduced hand-carried ultrasound (HCU) imagers in daily clinical workflow providing several benefits such as fast bedside availability and prompt diagnosis. Purpose: To evaluate the diagnostic yield of a latest generation HCU imager compared to contrast-enhanced multidetector computed tomography (MDCT) for the detection of pericardial effusion (PE) in cardiothoracic intensive care unit (ICU) patients. Material and Methods: Thirty-six patients from a cardiothoracic ICU were enrolled to this study irrespective of their underlying disease. All patients were examined with a new generation HCU for the presence of PE. Definite diagnosis of PE was based on findings of MDCT as standard of reference. Statistical analysis was performed using PASW 18. Results: PE was identified in 20 patients by MDCT (prevalence 56%). The HCU examination was carried out technically successfully in all patients. Sensitivity, specificity, positive and negative predictive value of HCU for the diagnosis of PE were 75%, 88%, 88%, and 74%, respectively. Conclusion: HCU provides rapid, practical, reliable, and cost-effective diagnosis of PE in patients on cardiothoracic ICU

Considering sex as a biological variable in preclinical research

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154390/1/fsb2fj201600781r.pd