Circulating extracellular vesicles release oncogenic miR-424 in experimental models and patients with aggressive prostate cancer

Extracellular vesicles (EVs) are relevant means for transferring signals across cells and facilitate propagation of oncogenic stimuli promoting disease evolution and metastatic spread in cancer patients. Here, we investigated the release of miR-424 in circulating small EVs or exosomes from prostate cancer patients and assessed the functional implications in multiple experimental models. We found higher frequency of circulating miR-424 positive EVs in patients with metastatic prostate cancer compared to patients with primary tumors and BPH. Release of miR-424 in small EVs was enhanced in cell lines (LNCaPabl), transgenic mice (Pb-Cre4;Ptenflox/flox;Rosa26ERG/ERG) and patient-derived xenograft (PDX) models of aggressive disease. EVs containing miR-424 promoted stem-like traits and tumor-initiating properties in normal prostate epithelial cells while enhanced tumorigenesis in transformed prostate epithelial cells. Intravenous administration of miR-424 positive EVs to mice, mimicking blood circulation, promoted miR-424 transfer and tumor growth in xenograft models. Circulating miR-424 positive EVs from patients with aggressive primary and metastatic tumors induced stem-like features when supplemented to prostate epithelial cells. This study establishes that EVs-mediated transfer of miR-424 across heterogeneous cell populations is an important mechanism of tumor self-sustenance, disease recurrence and progression. These findings might indicate novel approaches for the management and therapy of prostate cancer

Mechanistic Modeling of Genetic Circuits for ArsR Arsenic Regulation.

Bioreporters are living cells that generate an easily measurable signal in the presence of a chemical compound. They acquire their functionality from synthetic gene circuits, the configuration of which defines the response signal and signal-to-noise ratio. Bioreporters based on the Escherichia coli ArsR system have raised significant interest for quantifying arsenic pollution, but they need to be carefully optimized to accurately work in the required low concentration range (1-10 μg arsenite L-1). To better understand the general functioning of ArsR-based genetic circuits, we developed a comprehensive mechanistic model that was empirically tested and validated in E. coli carrying different circuit configurations. The model accounts for the different elements in the circuits (proteins, DNA, chemical species), and their detailed affinities and interactions, and predicts the (fluorescent) output from the bioreporter cell as a function of arsenite concentration. The model was parametrized using existing ArsR biochemical data, and then complemented by parameter estimations from the accompanying experimental data using a scatter search algorithm. Model predictions and experimental data were largely coherent for feedback and uncoupled circuit configurations, different ArsR alleles, promoter strengths, and presence or absence of arsenic efflux in the bioreporters. Interestingly, the model predicted a particular useful circuit variant having steeper response at low arsenite concentrations, which was experimentally confirmed and may be useful as arsenic bioreporter in the field. From the extensive validation we expect the mechanistic model to further be a useful framework for detailed modeling of other synthetic circuits

Development of a bacterial biosensor for arsenite detection

In order to provide an alternative measurement tool for arsenic contamination, we are developing a sensor that uses agarose beads containing a genetically engineered Escherichia coli strain producing a fluorescent signal in response to arsenite. Beads with cells are incorporated into a microfluidic system where they can be exposed to aqueous samples containing arsenic

Biochip with E. coli bacteria for detection of arsenic in drinking water

Arsenic and other pollutants are often present in trace amounts in drinking water in a number of countries. In aqueous solutions the sensitivity of arsenic- responsive bacterial bioreporters is far better than the performance of chemical field test kits. However, biological detection currently requires extensive handling and expensive fluorescence microscopy. We fabricated and tested microfluidic chips with fluorescent (GFP) E. coli bacteria that respond to arsenic. Measurement results of fluorescence intensity as function of arsenic concentration and exposure time are promising, showing a clear response to concentrations of 50 μg/l of arsenite

Weight reduction by topology optimization of an engine subframe mount, designed for additive manufacturing production

Additive Manufacturing (AM) technologies are getting more and more strategic for different purposes in many industrial fields. Among the most outstanding are part prototyping, single part to small batch production, relatively reduced manufacturing times and investments costs, reduced material consumption, and innovative and efficient shapes. The considerable advantages these technologies offer, compared to subtractive ones, make additive manufacturing a potentially industry-leading process in almost all domains - from aeronautics to the medical industry. Under these circumstances, the inspiration given by topology optimization tools can lead to feasible industrial parts, with fewer constraints in comparison to traditional manufacturing processes. The paper presents the development and the results obtained using topology optimization and design for AM technology on an automotive part: an engine mount sub-frame component for a rear middle engine sports car. The final design enables a significant weight reduction