A microfluidic Braille valve platform for on-demand production, combinatorial screening and sorting of chemically distinct droplets.

Droplet microfluidics is a powerful tool for a variety of biological applications including single-cell genetics, antibody discovery and directed evolution. All these applications make use of genetic libraries, illustrating the difficulty of generating chemically distinct droplets for screening applications. This protocol describes our Braille Display valving platform for on-demand generation of droplets with different chemical contents (16 different reagents and combinations thereof), as well as sorting droplets with different chemical properties, on the basis of fluorescence signals.

The interactions of Bcl9/Bcl9L with β-catenin and Pygopus promote breast cancer growth, invasion, and metastasis.

Canonical Wnt/β-catenin signaling is an established regulator of cellular state and its critical contributions to tumor initiation, malignant tumor progression and metastasis formation have been demonstrated in various cancer types. Here, we investigated how the binding of β-catenin to the transcriptional coactivators B-cell CLL/lymphoma 9 (Bcl9) and Bcl9-Like (Bcl9L) affected mammary gland carcinogenesis in the MMTV-PyMT transgenic mouse model of metastatic breast cancer. Conditional knockout of both Bcl9 and Bcl9L resulted into tumor cell death.

Parsing β-catenin's cell adhesion and Wnt signaling functions in malignant mammary tumor progression.

During malignant progression, epithelial cancer cells dissolve their cell-cell adhesion and gain invasive features. By virtue of its dual function, β-catenin contributes to cadherin-mediated cell-cell adhesion, and it determines the transcriptional output of Wnt signaling: via its N terminus, it recruits the signaling coactivators Bcl9 and Pygopus, and via the C terminus, it interacts with the general transcriptional machinery. This duality confounds the simple loss-of-function analysis of Wnt signaling in cancer progression.

Immuno-Oncology Biomarkers for Personalized Immunotherapy in Breast Cancer.

The immune checkpoint blockade therapy has drastically advanced treatment of different types of cancer over the past few years. Female breast cancer is the second leading cause of death in the overall burden of cancers worldwide that is encouraging healthcare professionals to improve cancer care management. The checkpoint blockade therapies combined with novel agents become the recent focus of various clinical trials in breast cancer.

The Eleventh ENBDC Workshop: Advances in Technology Help to Unveil Mechanisms of Mammary Gland Development and Cancerogenesis.

The eleventh annual workshop of the European Network for Breast Development and Cancer, Methods in mammary gland biology and breast cancer, took place on the 16th to 18th of May 2019 in Weggis, Switzerland. The main topics of the meeting were high resolution genomics and proteomics for the study of mammary gland development and cancer, breast cancer signaling, tumor microenvironment, preclinical models of breast cancer, and tissue morphogenesis. Exciting novel findings in, or highly relevant to, mammary gland biology and breast cancer field were presented, with insights into the methods used to obtain them.

Improving Drug Penetrability with iRGD Leverages the Therapeutic Response to Sorafenib and Doxorubicin in Hepatocellular Carcinoma.

iRGD is a derivative of the integrin-binding peptide RGD, which selectively increases the penetrability of tumor tissue to various coadministered substances in several preclinical models. In this study, we investigated the ability of iRGD to improve the delivery of sorafenib and doxorubicin therapy in hepatocellular carcinoma (HCC) using established mouse models of the disease. A contrast-enhanced MRI method was developed in parallel to assess the in vivo effects of iRGD in this setting.

Expression of the miR-302/367 cluster in glioblastoma cells suppresses tumorigenic gene expression patterns and abolishes transformation related phenotypes.

Cellular transformation is initiated by the activation of oncogenes and a closely associated developmental reprogramming of the epigenetic landscape. Transcription factors, regulators of chromatin states and microRNAs influence cell fates in development and stabilize the phenotypes of normal, differentiated cells and of cancer cells. The miR-302/367 cluster, predominantly expressed in human embryonic stem cells (hESs), can promote the cellular reprogramming of human and mouse cells and contribute to the generation of iPSC.

Stat5 Exerts Distinct, Vital Functions in the Cytoplasm and Nucleus of Bcr-Abl+ K562 and Jak2(V617F)+ HEL Leukemia Cells.

Signal transducers and activators of transcription (Stats) play central roles in the conversion of extracellular signals, e.g., cytokines, hormones and growth factors, into tissue and cell type specific gene expression patterns.

Inhibiting STAT5 by the BET bromodomain inhibitor JQ1 disrupts human dendritic cell maturation.

Maturation of dendritic cells (DCs) is required to induce T cell immunity, whereas immature DCs can induce immune tolerance. Although the transcription factor STAT5 is suggested to participate in DC maturation, its role in this process remains unclear. In this study, we investigated the effect of STAT5 inhibition on LPS-induced maturation of human monocyte-derived DCs (Mo-DCs).

Resistance of Cancer Cells to Targeted Therapies Through the Activation of Compensating Signaling Loops.

The emergence of low molecular weight kinase inhibitors as "targeted" drugs has led to remarkable advances in the treatment of cancer patients. The clinical benefits of these tumor therapies, however, vary widely in patient populations and with duration of treatment. Intrinsic and acquired resistance against such drugs limits their efficacy.

STAT3 induction of miR-146b forms a feedback loop to inhibit the NF-κB to IL-6 signaling axis and STAT3-driven cancer phenotypes.

Interleukin-6 (IL-6)-mediated activation of signal transducer and activator of transcription 3 (STAT3) is a mechanism by which chronic inflammation can contribute to cancer and is a common oncogenic event. We discovered a pathway, the loss of which is associated with persistent STAT3 activation in human cancer. We found that the gene encoding the tumor suppressor microRNA miR-146b is a direct STAT3 target gene, and its expression was increased in normal breast epithelial cells but decreased in tumor cells.

The inhibition of stat5 by a Peptide aptamer ligand specific for the DNA binding domain prevents target gene transactivation and the growth of breast and prostate tumor cells.

The signal transducer and activator of transcription Stat5 is transiently activated by growth factor and cytokine signals in normal cells, but its persistent activation has been observed in a wide range of human tumors. Aberrant Stat5 activity was initially observed in leukemias, but subsequently also found in carcinomas. We investigated the importance of Stat5 in human tumor cell lines.

Dual roles of the transcription factor grainyhead-like 2 (GRHL2) in breast cancer.

Using a retrovirus-mediated cDNA expression cloning approach, we identified the grainyhead-like 2 (GRHL2) transcription factor as novel protooncogene. Overexpression of GRHL2 in NIH3T3 cells induced striking morphological changes, an increase in cell proliferation, anchorage-independent growth, and tumor growth in vivo. By combining a microarray analysis and a phylogenetic footprinting analysis with various biochemical assays, we identified the epidermal growth factor receptor family member Erbb3 as a novel GRHL2 target gene.

STAT3 silencing inhibits glioma single cell infiltration and tumor growth.

Background: Diffuse infiltration remains the fulcrum of glioblastoma's incurability, leading inevitably to recurrence. Therefore, uncovering the pathological mechanism is imperative. Because signal transducer and activator of transcription 3 (STAT3) correlates with glioma malignancy and predicts poor clinical outcome, we determined its role in glioma single cell infiltration and tumor growth.

Transforming growth factor β signaling regulates the invasiveness of normal mammary epithelial cells and the metastasis formation of tumor cells.

Abstract Breast cancer patients with disseminated metastatic disease still have a very unfavorable prognosis. Investigations into the molecular mechanisms that underlie metastasis formation have a high priority and can possibly result in improved therapeutic interventions. The process of oncogenic epithelial to mesenchymal transition (EMT) has recently become a focus in cancer research because it encompasses many of the phenotypic traits characteristic of metastatic cells, e.

Stat5 assumes distinct functions in mammary gland development and mammary tumor formation.

The mammary epithelium comprises luminal and basal cells which originate from multipotent mammary stem cells (MaSCs). They form ductal structures embedded in the mammary fat pad in virgin mice and differentiate during pregnancy into alveoli under the control of hormones and growth factors and the activation of specific transcription factors. Genetic manipulations of embryonic stem cells and the derivation of transgenic mice allowed the study of regulatory genes in mammary epithelial cells of particular differentiation states.

The potential of amniotic fluid stem cells for cellular therapy and tissue engineering.

Introduction: Foetal cells present in amniotic fluid (AF) have been used for many years to perform prenatal genetic screening. Recent reports suggested that these cells might have additional benefits. AF contains, in addition to committed and differentiated cells, a subpopulation with stem cell characteristics.

miR-212 and miR-132 are required for epithelial stromal interactions necessary for mouse mammary gland development.

MicroRNAs are small noncoding RNAs that carry out post-transcriptional regulation of the expression of their target genes. However, their roles in mammalian organogenesis are only beginning to be understood. Here we show that the microRNA-212/132 family (which comprises miR-212 and miR-132) is indispensable during the development of the mammary glands in mice, particularly for the regulation of the outgrowth of the epithelial ducts.

Murine amniotic fluid stem cells contribute mesenchymal but not epithelial components to reconstituted mammary ducts.

Introduction: Amniotic fluid harbors cells indicative of all three germ layers, and pluripotent fetal amniotic fluid stem cells (AFSs) are considered potentially valuable for applications in cellular therapy and tissue engineering. We investigated whether it is possible to direct the cell fate of AFSs in vivo by transplantation experiments into a particular microenvironment, the mammary fat pad. This microenvironment provides the prerequisites to study stem cell function and the communication between mesenchymal and epithelial cells.

Mammary epithelial reconstitution with gene-modified stem cells assigns roles to Stat5 in luminal alveolar cell fate decisions, differentiation, involution, and mammary tumor formation.

The mammary gland represents a unique model system to study gene functions in adult stem cells. Mammary stem cells (MaSCs) can regenerate a functional epithelium on transplantation into cleared fat pads. We studied the consequences of distinct genetic modifications of MaSCs on their repopulation and differentiation ability.

Stem cells of the breast and cancer therapy.

Breast cancer remains a significant public health problem despite advances in the understanding of the molecular and cellular events that underlie the disease. Crucial pathways regulating the cell cycle, proliferation and survival of breast cancer cells have been investigated and aberrant components of these pathways have been exploited as new drug targets. However, the mortality from breast cancer is only slowly declining.