Integrins regulate hERG1 dynamics by girdin-dependent Gαi3: signaling and modeling in cancer cells.

The hERG1 potassium channel is aberrantly over expressed in tumors and regulates the cancer cell response to integrin-dependent adhesion. We unravel a novel signaling pathway by which integrin engagement by the ECM protein fibronectin promotes hERG1 translocation to the plasma membrane and its association with β1 integrins, by activating girdin-dependent Gαi3 proteins and protein kinase B (Akt). By sequestering hERG1, β1 integrins make it avoid Rab5-mediated endocytosis, where unbound channels are degraded.

DNA supercoiling restricts the transcriptional bursting of neighboring eukaryotic genes.

DNA supercoiling has emerged as a major contributor to gene regulation in bacteria, but how DNA supercoiling impacts transcription dynamics in eukaryotes is unclear. Here, using single-molecule dual-color nascent transcription imaging in budding yeast, we show that transcriptional bursting of divergent and tandem GAL genes is coupled. Temporal coupling of neighboring genes requires rapid release of DNA supercoils by topoisomerases.

Combination Therapy with a Bispecific Antibody Targeting the hERG1/β1 Integrin Complex and Gemcitabine in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) represents an unmet medical need. Difficult/late diagnosis as well as the poor efficacy and high toxicity of chemotherapeutic drugs result in dismal prognosis. With the aim of improving the treatment outcome of PDAC, we tested the effect of combining Gemcitabine with a novel single chain bispecific antibody (scDb) targeting the cancer-specific hERG1/β1 integrin complex.

Quantifying how post-transcriptional noise and gene copy number variation bias transcriptional parameter inference from mRNA distributions.

Transcriptional rates are often estimated by fitting the distribution of mature mRNA numbers measured using smFISH (single molecule fluorescence hybridization) with the distribution predicted by the telegraph model of gene expression, which defines two promoter states of activity and inactivity. However, fluctuations in mature mRNA numbers are strongly affected by processes downstream of transcription. In addition, the telegraph model assumes one gene copy but in experiments, cells may have two gene copies as cells replicate their genome during the cell cycle.

Post-transplant de-novo renal phospholipidosis in a kidney transplant recipient: Fabry disease or something else?

Renal phospholipidosis is a rare cause of proteinuria and kidney dysfunction. We describe a kidney transplant recipient who presented with slowly rising serum creatinine, nephrotic range proteinuria, and lower extremity edema 10 years post transplant. He was diagnosed with renal phospholipidosis on the transplant kidney biopsy.

Hemidesmosomes modulate force generation via focal adhesions.

Hemidesmosomes are specialized cell-matrix adhesion structures that are associated with the keratin cytoskeleton. Although the adhesion function of hemidesmosomes has been extensively studied, their role in mechanosignaling and transduction remains largely unexplored. Here, we show that keratinocytes lacking hemidesmosomal integrin α6β4 exhibit increased focal adhesion formation, cell spreading, and traction-force generation.

Quantifying cellular forces and biomechanical properties by correlative micropillar traction force and Brillouin microscopy.

Cells sense and respond to external physical forces and substrate rigidity by regulating their cell shape, internal cytoskeletal tension, and stiffness. Here we show that the combination of micropillar traction force and noncontact Brillouin microscopy provides access to cell-generated forces and intracellular mechanical properties at optical resolution. Actin-rich cytoplasmic domains of 3T3 fibroblasts showed significantly higher Brillouin shifts, indicating a potential increase in stiffness when adhering on fibronectin-coated glass compared to soft PDMS micropillars.

Role of c-MET Inhibitors in Overcoming Drug Resistance in Spheroid Models of Primary Human Pancreatic Cancer and Stellate Cells.

Pancreatic stellate cells (PSCs) are a key component of tumor microenvironment in pancreatic ductal adenocarcinoma (PDAC) and contribute to drug resistance. c-MET receptor tyrosine kinase activation plays an important role in tumorigenesis in different cancers including PDAC. In this study, effects of PSC conditioned medium (PCM) on c-MET phosphorylation (by immunocytochemistry enzyme-linked immunosorbent assay (ELISA)) and drug response (by sulforhodamine B assay) were investigated in five primary PDAC cells.

Repetitive switching between DNA-binding modes enables target finding by the glucocorticoid receptor.

Transcription factor mobility is a determining factor in the regulation of gene expression. Here, we have studied the intranuclear dynamics of the glucocorticoid receptor (GR) by using fluorescence recovery after photobleaching and single-molecule microscopy. First, we have described the dynamic states in which the GR occurs.

The Activity of Kv 11.1 Potassium Channel Modulates F-Actin Organization During Cell Migration of Pancreatic Ductal Adenocarcinoma Cells.

Cell migration exerts a pivotal role in tumor progression, underlying cell invasion and metastatic spread. The cell migratory program requires f-actin re-organization, generally coordinated with the assembly of focal adhesions. Ion channels are emerging actors in regulating cell migration, through different mechanisms.

The microbiome of pancreatic cancer: from molecular diagnostics to new therapeutic approaches to overcome chemoresistance caused by metabolic inactivation of gemcitabine.

: Pancreatic cancer is a complex disease, with an extremely poor response to chemotherapy. Emerging evidence indicates that the tumor microenvironment (TME) might play an important role in mediating chemoresistance. : The evaluated study by Geller and collaborators describes several bacterial species within pancreatic tumor tissues and TME and investigated their roles in gemcitabine chemoresistance.

A mechanopharmacology approach to overcome chemoresistance in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a highly chemoresistant malignancy. This chemoresistant phenotype has been historically associated with genetic factors. Major biomedical research efforts were concentrated that resulted in the identification of subtypes characterized by specific genetic lesions and gene expression signatures that suggest important biological differences.

The conformational state of hERG1 channels determines integrin association, downstream signaling, and cancer progression.

Ion channels regulate cell proliferation, differentiation, and migration in normal and neoplastic cells through cell-cell and cell-extracellular matrix (ECM) transmembrane receptors called integrins. K flux through the human ether-à-go-go-related gene 1 (hERG1) channel shapes action potential firing in excitable cells such as cardiomyocytes. Its abundance is often aberrantly high in tumors, where it modulates integrin-mediated signaling.

SIRT1-SIRT3 Axis Regulates Cellular Response to Oxidative Stress and Etoposide.

Sirtuins are conserved NAD -dependent deacylases. SIRT1 is a nuclear and cytoplasmic sirtuin involved in the control of histones a transcription factors function. SIRT3 is a mitochondrial protein, which regulates mitochondrial function.

New views and insights into intracellular trafficking of drug-delivery systems by fluorescence fluctuation spectroscopy.

Biomaterials in the nanometer size range can be engineered for site-specific delivery of drugs after injection into the blood circulation. However, translation of such nanomedicines from the bench to the bedside is still hindered by many extracellular and intracellular barriers. To realize the concept of targeted drug delivery with nanomedicines, research groups are studying intensively the extra- and intra-cellular mechanisms involved as a response to the physicochemical properties of the nanomedicines.

The role of cytoskeleton networks on lipid-mediated delivery of DNA.

Background: Lipid-mediated delivery of DNA is hindered by extracellular and intracellular barriers that significantly reduce the transfection efficiency of synthetic nonviral vectors.

Results: In this study we investigated the role of the actin and microtubule networks on the uptake and cytoplasmic transport of multicomponent cationic liposome-DNA complexes in CHO-K1 live cells by means of confocal laser scanning microscopy and 3D single particle tracking. Treatment with actin (latrunculin B)- and microtubule-disrupting (nocodazole) reagents indicated that intracellular trafficking of complexes predominantly involves microtubule-dependent active transport.

Intracellular trafficking of cationic liposome-DNA complexes in living cells.

Three-dimensional single-particle tracking (SPT) was used to calculate the mean square displacement (MSD) and the diffusion coefficients of multicomponent cationic liposome-DNA complexes (lipoplexes) in CHO-K1 living cells. In untreated (NT) control cells, we found that the intracellular lipoplex motion was either directed or Brownian with active transportation being definitely more frequent (more than 70%) than Brownian diffusion. The MSD analysis was supported by the calculation of the three-dimensional asphericity, , which was close to unity, denoting the preponderant occurrence of movement along a direction.