Studying chemosensory processing desires precise chemical cue presentation, behavioral response monitoring, and large-scale neuronal activity recording. Here we present Fish-on-Chips, a set of ...optofluidic tools for highly-controlled chemical delivery while simultaneously imaging behavioral outputs and whole-brain neuronal activities at cellular resolution in larval zebrafish. These include a fluidics-based swimming arena and an integrated microfluidics-light sheet fluorescence microscopy (µfluidics-LSFM) system, both of which utilize laminar fluid flows to achieve spatiotemporally precise chemical cue presentation. To demonstrate the strengths of the platform, we used the navigation arena to reveal binasal input-dependent behavioral strategies that larval zebrafish adopt to evade cadaverine, a death-associated odor. The µfluidics-LSFM system enables sequential presentation of odor stimuli to individual or both nasal cavities separated by only ~100 µm. This allowed us to uncover brainwide neural representations of cadaverine sensing and binasal input summation in the vertebrate model. Fish-on-Chips is readily generalizable and will empower the investigation of neural coding in the chemical senses.
The molecular signatures of cells in the brain have been revealed in unprecedented detail, yet the ageing-associated genome-wide expression changes that may contribute to neurovascular dysfunction in ...neurodegenerative diseases remain elusive. Here, we report zonation-dependent transcriptomic changes in aged mouse brain endothelial cells (ECs), which prominently implicate altered immune/cytokine signaling in ECs of all vascular segments, and functional changes impacting the blood-brain barrier (BBB) and glucose/energy metabolism especially in capillary ECs (capECs). An overrepresentation of Alzheimer disease (AD) GWAS genes is evident among the human orthologs of the differentially expressed genes of aged capECs, while comparative analysis revealed a subset of concordantly downregulated, functionally important genes in human AD brains. Treatment with exenatide, a glucagon-like peptide-1 receptor agonist, strongly reverses aged mouse brain EC transcriptomic changes and BBB leakage, with associated attenuation of microglial priming. We thus revealed transcriptomic alterations underlying brain EC ageing that are complex yet pharmacologically reversible.
One of greatest challenges to the successful treatment of cancer is drug resistance. An exciting approach is the eradication of cancer stem cells (CSCs). However, little is known about key signals ...regulating the formation and expansion of CSCs. Moreover, lack of a reliable predictive preclinical model has been a major obstacle to discover new cancer drugs and predict their clinical activity. Here, in ovarian cancer, a highly chemoresistant tumor that is rapidly fatal, we provide the first evidence demonstrating the causal involvement of mechanical stimulus in the CSC phenotype using a customizable microfluidic platform and three-dimensional spheroids, which most closely mimic tumor behavior. We found that ovarian cancer cells significantly acquired the expression of epithelial-to-mesenchymal transition and CSC markers and a remarkable chemoresistance to clinically relevant doses of frontline chemotherapeutic drugs cisplatin and paclitaxel when grown under fluid shear stress, which corroborates with the physiological attainable levels in the malignant ascites, but not under static condition. Furthermore, we uncovered a new link of microRNA-199a-3p, phosphatidylinositol 3-kinase/Akt, and multidrug transporter activation in shear stress-induced CSC enrichment. Our findings shed new light on the significance of hydrodynamics in cancer progression, emphasizing the need of a flow-informed framework in the development of therapeutics.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Ovarian cancer is characterized by extensive peritoneal metastasis, with tumor spheres commonly found in the malignant ascites. This is associated with poor clinical outcomes and currently lacks ...effective treatment. Both the three-dimensional (3D) environment and the dynamic mechanical forces are very important factors in this metastatic cascade. However, traditional cell cultures fail to recapitulate this natural tumor microenvironment. Thus, in vivo-like models that can emulate the intraperitoneal environment are of obvious importance. In this study, a new microfluidic platform of the peritoneum was set up to mimic the situation of ovarian cancer spheroids in the peritoneal cavity during metastasis. Ovarian cancer spheroids generated under a non-adherent condition were cultured in microfluidic channels coated with peritoneal mesothelial cells subjected to physiologically relevant shear stress. In summary, this dynamic 3D ovarian cancer-mesothelium microfluidic platform can provide new knowledge on basic cancer biology and serve as a platform for potential drug screening and development.
Paraneoplastic neurological syndromes are independent of metastasis, direct tumour infiltration, or known indirect mechanisms such as toxicity, ectopic hormone secretion, or induced coagulopathies.1 ...Paraneoplastic neurological syndromes may affect any part of the nervous system, and are believed to result when an immunologic response is directed against shared antigens that are ectopically expressed by the tumour, but otherwise predominantly expressed by the nervous system (onconeural antigens).1 Antibodies can be detected in the serum or cerebrospinal fluid of many, but not all, patients with PNS.2 Diagnosing PNS requires identification of the type of neurological syndrome based on neurological signs and symptoms, the detection of well-characterised onconeural antibodies, and the presence of a cancer.3 Paraneoplastic neurological syndromes are rare in patients with solid tumours, and probably even rarer among patients with lymphomas.4 The predominant types of PNS in lymphomas are paraneoplastic cerebellar degeneration in Hodgkin's lymphoma, and dermatomyositis/polymyositis in both Hodgkin's lymphoma and non-Hodgkin's lymphoma. Traditionally considered a variant of multiple sclerosis, presence of the disease-specific aquaporin-4 antibody, which plays a direct role in the pathogenesis of NMOSD, distinguishes the two entities.5 Recently, NMOSD is increasingly recognised as a paraneoplastic disorder especially in men or in patients who present in older age.6 Paraneoplastic NMOSD has been reported in a wide variety of tumour histological types but mostly in solid tumours.6 We recently encountered a definite case of PNS in a patient who was diagnosed with mantle cell lymphoma (MCL) and shortly afterwards developed neurological symptoms due to NMOSD. Early recognition of a neurological syndrome as paraneoplastic often leads to the discovery and treatment of the underlying tumour, which is a crucial step in the management of the PNS.1 2 Author contributions All authors have made substantial contributions to the concept or design; acquisition of data; analysis or interpretation of data; drafting of the article; and critical revision for important intellectual content.
Background
Hepatocellular carcinoma is a disease of great concern. Surgery is the treatment of choice, but there is still a high recurrence rate after resection.
Objectives
To determine the benefits ...and harms of neoadjuvant and adjuvant therapies compared to surgery alone or surgery and placebo/supportive therapy after curative resection for operable hepatocellular carcinoma.
Search methods
We searched The Cochrane Hepato‐Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, Chinese Biomedical Database, and US National Cancer Institute's Physician's Data Query Trials Database until 2005. References of the identified trials were also searched for identifying further trials.
Selection criteria
Randomised and quasi‐randomised trials that compared hepatocellular carcinoma patients who were given and not given neoadjuvant/adjuvant therapy as a supplement to curative liver resection.
Data collection and analysis
Data were extracted independently by two authors and discrepancies resolved by consensus. The survival and disease‐free survival curves were compared using their one, two, three, four, and five‐year survival rates, median survival times, and the result of the significance tests (P‐values).
Main results
A total of 12 randomised trials were identified, totaling 843 patients. The size of the randomised clinical trials ranged from 30 to 155 patients. Both preoperative (neoadjuvant) and postoperative (adjuvant), systemic and locoregional (+/‐ embolisation), chemo‐ and immunotherapy interventions were tested. Treatment regimens and patients selected were not comparable, so no pooling was done. Only one regimen using preoperative transcatheter arterial chemoembolisation with doxorubicin was similar in two trials. Four of the twelve trials reported survival benefit at five years when given adjuvant or neoadjuvant therapy. Disease‐free survival was reported in nine trials, and the estimated hazard ratios show that disease‐free survival was significant in two trials at five years. These two trials had not shown a survival advantage, but the recurrence was significantly lower in patients given adjuvant or neoadjuvant therapy. The highest toxicity rate was in a trial using oral 1‐hexylcarbamoyl 5‐fluorouracil which resulted in 12 out of 38 patients being withdrawn from the trial because of adverse events.
Authors' conclusions
There is no clear evidence for efficacy of any of the adjuvant and neo‐adjuvant protocols reviewed, but there is some evidence to suggest that adjuvant therapy may be beneficial offering prolonged disease‐free survival. In order to detect a realistic treatment advantage, larger trials with lower risk of systematic error will have to be conducted.
CRISPR-Cas adaptive immune systems protect bacteria and archaea against foreign genetic elements. In Escherichia coli, Cascade (CRISPR-associated complex for antiviral defense) is an RNA-guided ...surveillance complex that binds foreign DNA and recruits Cas3, a trans-acting nuclease helicase for target degradation. Here, we use single-molecule imaging to visualize Cascade and Cas3 binding to foreign DNA targets. Our analysis reveals two distinct pathways dictated by the presence or absence of a protospacer-adjacent motif (PAM). Binding to a protospacer flanked by a PAM recruits a nuclease-active Cas3 for degradation of short single-stranded regions of target DNA, whereas PAM mutations elicit an alternative pathway that recruits a nuclease-inactive Cas3 through a mechanism that is dependent on the Cas1 and Cas2 proteins. These findings explain how target recognition by Cascade can elicit distinct outcomes and support a model for acquisition of new spacer sequences through a mechanism involving processive, ATP-dependent Cas3 translocation along foreign DNA.
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•Cascade can locate targets through PAM-dependent and PAM-independent pathways•PAM-dependent recognition enables direct recruitment of the Cas3 translocase/nuclease•PAM-independent recognition requires Cas1-Cas2 for Cas3 recruitment•Cas1-Cas2 serve as trans-acting factors that regulate Cas3 activities
Single-molecule analysis of the bacterial Cascade complex reveals two distinct pathways leading to differential regulation of Cas3 DNA translocase and nuclease activities.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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