An optical-frequency synthesizer using integrated photonics.

Optical-frequency synthesizers, which generate frequency-stable light from a single microwave-frequency reference, are revolutionizing ultrafast science and metrology, but their size, power requirement and cost need to be reduced if they are to be more widely used. Integrated-photonics microchips can be used in high-coherence applications, such as data transmission 1 , highly optimized physical sensors 2 and harnessing quantum states 3 , to lower cost and increase efficiency and portability. Here we describe a method for synthesizing the absolute frequency of a lightwave signal, using integrated photonics to create a phase-coherent microwave-to-optical link. We use a heterogeneously integrated III-V/silicon tunable laser, which is guided by nonlinear frequency combs fabricated on separate silicon chips and pumped by off-chip lasers. The laser frequency output of our optical-frequency synthesizer can be programmed by a microwave clock across 4 terahertz near 1,550 nanometres (the telecommunications C-band) with 1 hertz resolution. Our measurements verify that the output of the synthesizer is exceptionally stable across this region (synthesis error of 7.7 × 10-15 or below). Any application of an optical-frequency source could benefit from the high-precision optical synthesis presented here. Leveraging high-volume semiconductor processing built around advanced materials could allow such low-cost, low-power and compact integrated-photonics devices to be widely used.

Systematic analysis reveals a functional role for STAMBPL1 in the epithelial-mesenchymal transition process across multiple carcinomas.

BACKGROUND: Deubiquitinating enzymes (DUBs) are linked to cancer progression and dissemination, yet less is known about their regulation and impact on epithelial-mesenchymal transition (EMT). METHODS: An integrative translational approach combining systematic computational analyses of The Cancer Genome Atlas cancer cohorts with CRISPR genetics, biochemistry and immunohistochemistry methodologies to identify and assess the role of human DUBs in EMT. RESULTS: We identify a previously undiscovered biological function of STAM-binding protein like 1 (STAMBPL1) deubiquitinase in the EMT process in lung and breast carcinomas. We show that STAMBPL1 expression can be regulated by mutant p53 and that its catalytic activity is required to affect the transcription factor SNAI1. Accordingly, genetic depletion and CRISPR-mediated gene knockout of STAMBPL1 leads to marked recovery of epithelial markers, SNAI1 destabilisation and impaired migratory capacity of cancer cells. Reversely, STAMBPL1 expression reprogrammes cells towards a mesenchymal phenotype. A significant STAMBPL1-SNAI1 co-signature was observed across multiple tumour types. Importantly, STAMBPL1 is highly expressed in metastatic tissues compared to matched primary tumour of the same lung cancer patient and its expression predicts poor prognosis. CONCLUSIONS: Our study provides a novel concept of oncogenic regulation of a DUB and presents a new role and predictive value of STAMBPL1 in the EMT process across multiple carcinomas.

miR-100-5p confers resistance to ALK tyrosine kinase inhibitors Crizotinib and Lorlatinib in EML4-ALK positive NSCLC.

Lung cancer causes the highest number of cancer-related deaths worldwide. Resistance to therapy is a major clinical issue contributing to the poor prognosis of lung cancer. In recent years, targeted therapy has become a concept where subgroups of non-small cell lung cancer (NSCLC) with genetically altered receptor tyrosine kinases are targeted by tyrosine kinase inhibitors (TKIs). One such subgroup harbors a gene fusion of echinoderm microtubule-associated protein-like 4 (EML4) with anaplastic lymphoma kinase (ALK). Although most NSCLC patients with EML4-ALK fusions initially respond to ALK TKI-therapy they eventually develop resistance. While ALK kinase domain mutations contribute to ALK TKI-refractoriness, they are only present in a fraction of all ALK TKI-resistant tumors. In this study we sought to explore a possible involvement of microRNAs (miRNAs) in conferring resistance to ALK TKIs in ALK TKI-refractory NSCLC cell lines. We subjected our ALK TKI-refractory cancer cells along with parental cancer cells to systematic miRNA expression arrays. Furthermore, ALK TKI-refractory cancer cells were exposed to a synthetic miRNA inhibitory Locked Nucleic Acid (LNA)-library in the presence of ALK TKIs Crizotinib or Lorlatinib. The outcome of the combined approaches uncovered miR-100-5p to confer resistance to Crizotinib and Lorlatinib in EML4-ALK NSCLC cells and to be a potential therapeutic target in drug resistance.

miR-126-5p targets Malate Dehydrogenase 1 in non-small cell lung carcinomas.

Malate Dehydrogenase (MDH) 1 has recently been shown to be highly expressed and display prognostic value in non-small cell lung carcinomas (NSCLCs). However, it is not known how MDH1 expression is regulated and there is no current molecular or chemical strategy that specifically targets MDH1. This may be due to structural and enzymatic similarities with its isoenzyme, malate dehydrogenase 2 (MDH2). However, MDH1 and MDH2 are encoded by distinct genes and this opens up the possibility for modulation at the expression level. Here, we screened in silico for microRNAs (miRs) that selectively targets the 3'UTR region of MDH1. These analyses revealed that mir-126-5p has three binding sites in the 3'UTR region of MDH1. Additionally, we show that expression of miR-126-5p suppresses the enzymatic activity of MDH1, mitochondrial respiration and caused cell death in NSCLC cell lines.

USP10 regulates the stability of the EMT-transcription factor Slug/SNAI2.

Epithelial-to-mesenchymal transition (EMT) is a fundamental mechanism governing the switch of cells from an epithelial to a motile mesenchymal-like state. This transdifferentiation is regulated by key transcription factors, including Slug. The stability and function of Slug can be regulated by multiple mechanisms, including ubiquitin-mediated post-translational modifications. Here, by using a genome wide siRNA screen for human deubiquitinating enzymes (DUBs), we identified USP10 as a deubiquitinase for Slug in cancer cells. USP10 interacts with Slug and mediates its degradation by the proteasome. Importantly, USP10 is concomitantly highly expressed with Slug in cancer biopsies. Genetic knockdown of USP10 leads to suppressed Slug levels with a decreased expression of the mesenchymal marker Vimentin. Further, it reduces the migratory capacity of cancer cells. Reversely, overexpression of USP10 elevates the level of both Slug and Vimentin. Our study identifies USP10 as a regulator of the EMT-transcription factor Slug and cell migration.

Characterization of a fully integrated heterogeneous silicon/III-V colliding pulse mode-locked laser with on-chip feedback.

A fully integrated heterogeneous silicon/III-V colliding pulse mode-locked laser with tunable on-chip optical feedback operating in the O-band is extensively investigated. The 19-GHz colliding pulsed laser operates in a wide mode-locking regime with good mode locking quality. By precisely controlling the strength and phase of the on-chip optical feedback signal, the laser exhibits clear periodic pulse shortening effects. The RF 3 dB linewidth was reduced by a factor of 4.7 down to 6 kHz, as compared to the free running state.

Impact of Acute Cardiac Complications After Subarachnoid Hemorrhage on Long-Term Mortality and Cardiovascular Events.

BACKGROUND: Cardiac complications frequently occur after subarachnoid hemorrhage (SAH) and are associated with an increased risk of neurological complications and poor outcomes. The aim of this study was to evaluate the impact of acute cardiac complications after SAH on long-term mortality and cardiovascular events. METHODS: All patients admitted to our Neuro intensive care unit with verified SAH from January 2010 to April 2015, and electrocardiogram, echocardiogram, and troponin T or NTproBNP data obtained within 72 h of admission were included in the study. Mortality data were obtained from the Swedish population register. Data regarding cause of death and hospitalization for cardiovascular events were obtained from the Swedish Board of Health and Welfare. RESULTS: A total of 455 patients were included in the study analysis. There were 102 deaths during the study period. Cardiac troponin release (HR 1.08, CI 1.02-1.15 per 100 ng/l, p = 0.019), NTproBNP (HR 1.05, CI 1.01-1.09 per 1000 ng/l, p = 0.018), and ST-T abnormalities (HR 1.53, CI 1.02-2.29, p = 0.040) were independently associated with an increased risk of death. However, these associations were significant only during the first 3 months after the hemorrhage. Cardiac events were observed in 25 patients, and cerebrovascular events were observed in 62 patients during the study period. ST-T abnormalities were independently associated with an increased risk of cardiac events (HR 5.52, CI 2.07-14.7, p < 0.001), and stress cardiomyopathy was independently associated with an increased risk of cerebrovascular events (HR 3.65, CI 1.55-8.58, p = 0.003). CONCLUSION: Cardiac complications after SAH are associated with an increased risk of short-term death. Patients with electrocardiogram abnormalities and stress cardiomyopathy need appropriate follow-up for the identification of cardiac disease or risk factors for cardiovascular disease.

The role of mitochondria in metabolism and cell death.

Mitochondria are complex organelles that play a central role in energy metabolism, control of stress responses and are a hub for biosynthetic processes. Beyond its well-established role in cellular energetics, mitochondria are critical mediators of signals to propagate various cellular outcomes. In addition mitochondria are the primary source of intracellular reactive oxygen species (ROS) generation and are involved in cellular Ca2+ homeostasis, they contain a self-destructive arsenal of apoptogenic factors that can be unleashed to promote cell death, thus displaying a shared platform for metabolism and apoptosis. In the present review, we will give a brief account on the integration of mitochondrial metabolism and apoptotic cell death.

Glucose metabolism provide distinct prosurvival benefits to non-small cell lung carcinomas.

Heterogeneity within the same tumor type has been described to be complex and occur at multiple levels. Less is known about the heterogeneity at the level of metabolism, within a tumor set, yet metabolic pathways are highly relevant to survival signaling in tumors. In this study, we profiled the glucose metabolism of several non-small cell lung carcinoma (NSCLC) cell lines and could show that, NSCLC display distinct glycolytic metabolism. Genetic and pharmacological perturbation of glycolysis was selectively toxic to NSCLCs with high rates of glycolysis. Furthermore, high expression of hexokinase-2, localized at the mitochondria, was a feature of the NSCLCs dependent on glucose catabolism. Our study provides evidence for quantitative metabolic diversity in NSCLCs and indicates that glucose metabolism provide differential prosurvival benefits to NSCLCs.

Critical role for hyperpolarization-activated cyclic nucleotide-gated channel 2 in the AIF-mediated apoptosis.

Cellular calcium uptake is a controlled physiological process mediated by multiple ion channels. The exposure of cells to either one of the protein kinase C (PKC) inhibitors, staurosporine (STS) or PKC412, can trigger Ca²(+) influx leading to cell death. The precise molecular mechanisms regulating these events remain elusive. In this study, we report that the PKC inhibitors induce a prolonged Ca²(+) import through hyperpolarization-activated cyclic nucleotide-gated channel 2 (HCN2) in lung carcinoma cells and in primary culture of cortical neurons, sufficient to trigger apoptosis-inducing factor (AIF)-mediated apoptosis. Downregulation of HCN2 prevented the drug-induced Ca²(+) increase and subsequent apoptosis. Importantly, the PKC inhibitors did not cause Ca²(+) entry into HEK293 cells, which do not express the HCN channels. However, introduction of HCN2 sensitized them to STS/PKC412-induced apoptosis. Mutagenesis of putative PKC phosphorylation sites within the C-terminal domain of HCN2 revealed that dephosphorylation of Thr549 was critical for the prolonged Ca²(+) entry required for AIF-mediated apoptosis. Our findings demonstrate a novel role for the HCN2 channel by providing evidence that it can act as an upstream regulator of cell death triggered by PKC inhibitors.

[Circulatory failure after bupropion overdose]. / Allt fler allvarliga förgiftningar med preparatet bupropion.

A case of massive overdose of sustained release bupropion tablets is described. The patient presented with GCS 3, tachycardic and in vasoplegic shock. ECHO and EKG were initially normal. The hemodynamic situation was stabilised with vasopressors, but 18 h after presentation the patient deteriorated with wide complex arrhythmias rapidly progressing to cardiac arrest. The patient was put on VA-ECMO after 35 minutes of CPR. Circulation could be stabilized and ECMO was discontinued after 36 h. The patient was extubated on day 6 and made a complete recovery on discharge two weeks after presentation. At 34h, with ongoing ECMO, 236 tablets (with visible print identifying them as bupropion) were evacuated from the patient's stomach by gastroscopy. The tablets were analysed by NMR (nuclear magnetic resonance) but no longer contained any active substance. Blood levels of bupropion and hydroxybupropion at 36h were 790 and 1300 µg/l. The case illustrates a worrying surge in serious bupropion poisonings as noted by the Swedish Poisons Information Centre during the last 5 years.

Modeling of Intracellular Taurine Levels Associated with Ovarian Cancer Reveals Activation of p53, ERK, mTOR and DNA-Damage-Sensing-Dependent Cell Protection.

Taurine, a non-proteogenic amino acid and commonly used nutritional supplement, can protect various tissues from degeneration associated with the action of the DNA-damaging chemotherapeutic agent cisplatin. Whether and how taurine protects human ovarian cancer (OC) cells from DNA damage caused by cisplatin is not well understood. We found that OC ascites-derived cells contained significantly more intracellular taurine than cell culture-modeled OC. In culture, elevation of intracellular taurine concentration to OC ascites-cell-associated levels suppressed proliferation of various OC cell lines and patient-derived organoids, reduced glycolysis, and induced cell protection from cisplatin. Taurine cell protection was associated with decreased DNA damage in response to cisplatin. A combination of RNA sequencing, reverse-phase protein arrays, live-cell microscopy, flow cytometry, and biochemical validation experiments provided evidence for taurine-mediated induction of mutant or wild-type p53 binding to DNA, activation of p53 effectors involved in negative regulation of the cell cycle (p21), and glycolysis (TIGAR). Paradoxically, taurine's suppression of cell proliferation was associated with activation of pro-mitogenic signal transduction including ERK, mTOR, and increased mRNA expression of major DNA damage-sensing molecules such as DNAPK, ATM and ATR. While inhibition of ERK or p53 did not interfere with taurine's ability to protect cells from cisplatin, suppression of mTOR with Torin2, a clinically relevant inhibitor that also targets DNAPK and ATM/ATR, broke taurine's cell protection. Our studies implicate that elevation of intracellular taurine could suppress cell growth and metabolism, and activate cell protective mechanisms involving mTOR and DNA damage-sensing signal transducti.

Knockout validation of LAMP2A antibodies for immunostaining in human cancer cells.

LAMP2A is the rate-limiting factor of chaperone-mediated autophagy (CMA), a unique selective protein degradative pathway. To date LAMP2A antibodies are not knockout (KO)-validated in human cells. We have recently generated human isoform-specific LAMP2A KO cells, and here we assessed the specificity of select commercial LAMP2A antibodies on wild-type and LAMP2A KO human cancer cells. While all tested antibodies were suitable for immunoblotting, the anti-LAMP2A antibody (ab18528) is likely to exhibit an off-target reactivity in immunostaining approaches using human cancer cells, and alternative antibodies, which seem more appropriate, are available.

The nutritional supplement taurine activates p53-dependent and independent tumor suppressor mechanisms in various cellular models of ovarian cancer.

Loss of treatment-induced ovarian carcinoma (OC) growth suppression poses a major clinical challenge because it leads to disease recurrence. Therefore, there is a compelling need for well- -tolerated approaches that can support tumor growth-suppression after therapy is stopped. We have profiled ascites as OC tumor microenvironments to search for potential non-toxic soluble components that would activate tumor suppressor pathways in OC cells. Our investigations revealed that low levels of taurine, a non-proteogenic sulfonic amino acid, were present within OC ascites. Taurine supplementation, beyond levels found in ascites, induced growth suppression without causing cytotoxicity in various OC cells, including chemotherapy-resistant cell clones and patient-derived organoids representing primary or chemotherapy recovered disease. Inhibition of proliferation by taurine was linked to increased mutant or wild-type p53 proteins binding to DNA, induction of p21, and independently of p53, TIGAR expression. Taurine-induced activation of p21 and TIGAR was associated with suppression of cell-cycle progression, glycolysis, and mitochondrial respiration. Expression of p21 or TIGAR in OC cells mimicked taurine-induced growth suppression. Our studies support the potential therapeutic value of taurine supplementation in OC.

Regrowth-free high-gain InGaAsP/InP active-passive platform via ion implantation.

We demonstrate a regrowth-free material platform to create monolithic InGaAsP/InP photonic integrated circuits (PICs) with high-gain active and low-loss passive sections via a PL detuning of >135 nm. We show 2.5 µm wide by 400 µm long semiconductor optical amplifiers with >40 dB/mm gain at 1570 nm, and passive waveguide losses <2.3 dB/mm. The bandgap in the passive section is detuned using low-energy 190 keV channelized phosphorous implantation and subsequent rapid thermal annealing to achieve impurity-induced quantum well intermixing (QWI). The PL wavelengths in the active and passive sections are 1553 and 1417 nm, respectively. Lasing wavelengths for 500 µm Fabry-Perot lasers are 1567 and 1453 nm, respectively.

A Method for Coexpression Analysis.

Gene coexpression network analysis is a commonly used approach in bioinformatics and biomedical research to construct coexpression networks and detect coexpressed genes. This type of analysis has proven valuable for gene function prediction and for disease biomarker discovery.Here, we introduce and guide researchers through a method of differential coexpression analysis focusing on key autophagy and metabolic genes. We utilized the open-source Cancer Cell Line Encyclopedia (CCLE ) project as this is one of the most comprehensive genomic and transcriptomic resources including more than 1000 cell lines of distinct origins. However, the coexpression analysis method described here can also be applied to any open-source dataset where the RNA expression are provided.We here provide detailed comprehensive practical instructions for investigators to successfully identify novel coexpression signatures.

A Method to Identify Potential Prognostic Markers Across Distinct Tumor Types.

The identification of novel biomarkers in cancer patients often requires both survival and gene expression analyses. The Kaplan-Meier survival analysis is one of the most common methods to assess the fraction of subjects living for a certain amount of time.Here, we describe a method for researchers to identify potential prognostic markers across distinct tumor types. We utilize The Cancer Genome Atlas (TCGA) as this is one of the most extensive and successful cancer genomics programs to date that includes expression data and clinical follow-up information for up to 33 distinct tumor types. Nevertheless, the method described here can also be applied to any open-source dataset where the RNA expression and clinical outcome are provided.We provide detailed practical instructions and advices for investigators to be able to successfully identify prognostic markers in cancer patients.

Extraction of Metabolites from Cancer Cells.

Cancer cells possess an elevated demand for nutrients and metabolites due to their uncontrolled proliferation and need to survive in unfavorable conditions. Autophagy is a conservative degradation pathway that counters lack of nutrients and provides organelle and protein quality control, beyond maintenance of cellular metabolism.Mass spectrometry-based metabolomics is a powerful tool to study the metabolome of a cell. Such analysis requires proper sample preparation including the extraction of metabolites. Here, we provide a protocol for the extraction of metabolites from adherent cancer cells suitable for global metabolome profiling by mass spectrometry.

Integrated InP-InGaAsP tunable coupled ring optical bandpass filters with zero insertion loss.

Second and third-order monolithically integrated coupled ring bandpass filters are demonstrated in the InP-InGaAsP material system with active semiconductor optical amplifiers (SOAs) and current injection phase modulators (PMs). Such integration achieves a high level of tunability and precise generation of optical filters in the RF domain at telecom wavelengths while simultaneously compensating for device insertion loss. Passband bandwidth tunability of 3.9 GHz to 7.1 GHz and stopband extinction up to 40 dB are shown for third-order filters. Center frequency tunability over a full free spectral range (FSR) is demonstrated, allowing for the placement of a filter anywhere in the telecom C-band. A Z-transform representation of coupled resonator filters is derived and compared with experimental results. A theoretical description of filter tunability is presented.

Etched beam splitters in InP/InGaAsP.

An etched beam splitter (EBS) photonic coupler based on frustrated total internal reflection (FTIR) is designed, fabricated and characterized in the InP/InGaAsP material system. The EBS offers an ultra compact footprint (8x11 µm) and a complete range of bar/cross coupling ratio designs. A novel pre-etching process is developed to achieve sufficient depth of the etched coupling gaps. Fabricated EBS couplers demonstrate insertion loss between 1 and 2.6 dB with transmission (cross-coupling) ≤ 10%. The results show excellent agreement with 3D finite-difference time-domain (FDTD) modeling. The coupling of EBS has weak wavelength dependence in the C-band, making it suitable for wavelength division multiplexing (WDM) or other wide bandwidth applications. Finally, the EBS is integrated with active semiconductor optical amplifier (SOA) and phase-modulator components; using a flattened ring resonator structure, a channelizing filter tunable in both amplitude and center frequency is demonstrated, as well as an EBS coupled ring laser.