Irradiated Extramedullary Acute Myeloid Leukemia Increases Survival in a Leukemic Mouse Model

PURPOSE/OBJECTIVE(S)

The systemic nature of AML likely limits their immunogenicity because antigen presentation is primarily mediated by splenic dendritic cells, which induces immune tolerance. Since antigen presentation in tissue draining lymph nodes can induce anti-tumor immune responses, we hypothesized that local irradiation of cutaneous, extramedullary leukemias will increase immunogenic cell death, dendritic cell maturation and improved survival.

MATERIALS/METHODS

A murine AML cell line C1498 was assessed for immunogenic markers calreticulin (CALR), HMGB1 and cGAS-STING pathway using fluorescence cytometry and qRT-PCR. Syngeneic mice were injected with C1498 subcutaneously to model extramedullary lesions and intravenously to model systemic leukemias. Cells and subcutaneous tumor were focally irradiated with 2 Gy or 8 Gy. Two-way ANOVA and Student's t-test were used for paired-wise comparisons. Survival was estimated by Kaplan-Meier plot and groups were compared using log-rank test.

RESULTS

C1498 cells or tumors irradiated with 2 Gy or 8 Gy showed increased CALR and HMGB1 as well as (cGAS/Md21b1; 5-fold; p<0.001) and interferon alpha (Ifna; 3-fold; p<0.001) after 48h (18- and 4-fold, respectively; p<0.05) compared to not treated controls (NTC). Irradiated C1498 subcutaneous tumors displayed increased CD11b-positive cells (9-fold; p<0.001), CD11c (6-fold; p<0.001), and MHCII-positive CD11c cells (4-fold; p<0.01) in irradiated tumors compared to NTC. Irradiation of subcutaneous C1498 tumors increased median survival in mice also injected with C1498 cells intravenously compared to non-irradiated mice bearing systemic leukemias (46 vs. 25 days; p<0.01). Irradiation of C1498 tumors combined with anti-PDL1 treatment further increased median survival in our leukemia model compared to untreated controls (>50 vs. <30 days; p<0.001).

CONCLUSION

Irradiated extramedullary AML increased immunogenic markers and activation of immune effector cells that correlated with increased survival in mice also bearing systemic leukemia. These results suggest focal irradiation of extramedullary AML may facilitate eradiation of systemic leukemias.

3D spheroid-microvasculature-on-a-chip for tumor-endothelium mechanobiology interplay

During the final stage of cancer metastasis, tumor cells embed themselves in distant capillary beds, from where they extravasate and establish secondary tumors. Recent findings underscore the pivotal roles of blood/lymphatic flow and shear stress in this intricate tumor extravasation process. Despite the increasing evidence, there is a dearth of systematic and biomechanical methodologies that accurately mimic intricate 3D microtissue interactions within a controlled hydrodynamic microenvironment. Addressing this gap, we introduce an easy-to-operate 3D Spheroid-Microvasculature-On-A-Chip (SMAC) model. Operating under both static and regulated flow conditions, the SMAC model facilitates the replication of the biomechanical interplay between heterogeneous tumor spheroids and endothelium in a quantitative manner. Serving as an in vitro model for metastasis mechanobiology, our model unveils the phenomena of 3D spheroid-induced endothelial compression and cell-cell junction degradation during tumor migration and expansion. Furthermore, we investigated the influence of shear stress on endothelial orientation, polarization, and tumor spheroid expansion. Collectively, our SMAC model provides a compact, cost-efficient, and adaptable platform for probing the mechanobiology of metastasis.

Autonomous Microlasers for Profiling Extracellular Vesicles from Cancer Spheroids

Self-propelled micro/nanomotors are emergent intelligent sensors for analyzing extracellular biomarkers in circulating biological fluids. Conventional luminescent motors are often masked by a highly dynamic and scattered environment, creating challenges to characterize biomarkers or subtle binding dynamics. Here we introduce a strategy to amplify subtle signals by coupling strong light-matter interactions on micromotors. A smart whispering-gallery-mode microlaser that can self-propel and analyze extracellular biomarkers is demonstrated through a liquid crystal microdroplet. Lasing spectral responses induced by cavity energy transfer were employed to reflect the abundance of protein biomarkers, generating exclusive molecular labels for cellular profiling of exosomes derived from 3D multicellular cancer spheroids. Finally, a microfluidic biosystem with different tumor-derived exosomes was employed to elaborate its sensing capability in complex environments. The proposed autonomous microlaser exhibits a promising method for both fundamental biological science and applications in drug screening, phenotyping, and organ-on-chip applications.

ALTEN: A High-Fidelity Primary Tissue-Engineering Platform to Assess Cellular Responses Ex Vivo

To fully investigate cellular responses to stimuli and perturbations within tissues, it is essential to replicate the complex molecular interactions within the local microenvironment of cellular niches. Here, the authors introduce Alginate-based tissue engineering (ALTEN), a biomimetic tissue platform that allows ex vivo analysis of explanted tissue biopsies. This method preserves the original characteristics of the source tissue's cellular milieu, allowing multiple and diverse cell types to be maintained over an extended period of time. As a result, ALTEN enables rapid and faithful characterization of perturbations across specific cell types within a tissue. Importantly, using single-cell genomics, this approach provides integrated cellular responses at the resolution of individual cells. ALTEN is a powerful tool for the analysis of cellular responses upon exposure to cytotoxic agents and immunomodulators. Additionally, ALTEN's scalability using automated microfluidic devices for tissue encapsulation and subsequent transport, to enable centralized high-throughput analysis of samples gathered by large-scale multicenter studies, is shown.

Differential regulation of STP, LTP and LTD by structurally diverse NMDA receptor subunit-specific positive allosteric modulators

Different types of memory are thought to rely on different types of synaptic plasticity, many of which depend on the activation of the N-Methyl-D Aspartate (NMDA) subtype of glutamate receptors. Accordingly, there is considerable interest in the possibility of using positive allosteric modulators (PAMs) of NMDA receptors (NMDARs) as cognitive enhancers. Here we firstly review the evidence that NMDA receptor-dependent forms of synaptic plasticity: short-term potentiation (STP), long-term potentiation (LTP) and long-term depression (LTD) can be pharmacologically differentiated by using NMDAR ligands. These observations suggest that PAMs of NMDAR function, depending on their subtype selectivity, might differentially regulate STP, LTP and LTD. To test this hypothesis, we secondly performed experiments in rodent hippocampal slices with UBP714 (a GluN2A/2B preferring PAM), CIQ (a GluN2C/D selective PAM) and UBP709 (a pan-PAM that potentiates all GluN2 subunits). We report here, for the first time, that: (i) UBP714 potentiates sub-maximal LTP and reduces LTD; (ii) CIQ potentiates STP without affecting LTP; (iii) UBP709 enhances LTD and decreases LTP. We conclude that PAMs can differentially regulate distinct forms of NMDAR-dependent synaptic plasticity due to their subtype selectivity.

This article is part of the Neuropharmacology Special Issue on ‘Glutamate Receptors – NMDA receptors’.

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NMDAR-dependent STP, LTP and LTD can be dissociated pharmacologically

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GluN2A/2B PAM UBP714 potentiates LTP and reduces LTD

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GluN2C/D PAM CIQ potentiates STP without affecting LTP

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NMDAR pan-PAM UBP709 potentiates LTD and reduces LTP

Stratified Disk Microrobots with Dynamic Maneuverability and Proton-Activatable Luminescence for in Vivo Imaging

Microrobots can expand our abilities to access remote, confined, and enclosed spaces. Their potential applications inside our body are obvious, e.g., to diagnose diseases, deliver medicine, and monitor treatment efficacy. However, critical requirements exist in relation to their operations in gastrointestinal environments, including resistance to strong gastric acid, responsivity to a narrow proton variation window, and locomotion in confined cavities with hierarchical terrains. Here, we report a proton-activatable microrobot to enable real-time, repeated, and site-selective pH sensing and monitoring in physiological relevant environments. This is achieved by stratifying a hydrogel disk to combine a range of functional nanomaterials, including proton-responsive molecular switches, upconversion nanoparticles, and near-infrared (NIR) emitters. By leveraging the 3D magnetic gradient fields and the anisotropic composition, the microrobot can be steered to locomote as a gyrating "Euler's disk", i.e., aslant relative to the surface and along its low-friction outer circumference, exhibiting a high motility of up to 60 body lengths/s. The enhanced magnetomotility can boost the pH-sensing kinetics by 2-fold. The fluorescence of the molecular switch can respond to pH variations with over 600-fold enhancement when the pH decreases from 8 to 1, and the integration of upconversion nanoparticles further allows both the efficient sensitization of NIR light through deep tissue and energy transfer to activate the pH probes. Moreover, the embedded down-shifting NIR emitters provide sufficient contrast for imaging of a single microrobot inside a live mouse. This work suggests great potential in developing multifunctional microrobots to perform generic site-selective tasks in vivo.

Advancements in 3D Cell Culture Systems for Personalizing Anti-Cancer Therapies

Over 90% of potential anti-cancer drug candidates results in translational failures in clinical trials. The main reason for this failure can be attributed to the non-accurate pre-clinical models that are being currently used for drug development and in personalised therapies. To ensure that the assessment of drug efficacy and their mechanism of action have clinical translatability, the complexity of the tumor microenvironment needs to be properly modelled. 3D culture models are emerging as a powerful research tool that recapitulates in vivo characteristics. Technological advancements in this field show promising application in improving drug discovery, pre-clinical validation, and precision medicine. In this review, we discuss the significance of the tumor microenvironment and its impact on therapy success, the current developments of 3D culture, and the opportunities that advancements that in vitro technologies can provide to improve cancer therapeutics.

Mammary Tumor Organoid Culture in Non-Adhesive Alginate for Luminal Mechanics and High-Throughput Drug Screening

Mammary tumor organoids have become a promising in vitro model for drug screening and personalized medicine. However, the dependency on the basement membrane extract (BME) as the growth matrices limits their comprehensive application. In this work, mouse mammary tumor organoids are established by encapsulating tumor pieces in non-adhesive alginate. High-throughput generation of organoids in alginate microbeads is achieved utilizing microfluidic droplet technology. Tumor pieces within the alginate microbeads developed both luminal- and solid-like structures and displayed a high similarity to the original fresh tumor in cellular phenotypes and lineages. The mechanical forces of the luminal organoids in the alginate capsules are analyzed with the theory of the thick-wall pressure vessel (TWPV) model. The luminal pressure of the organoids increase with the lumen growth and can reach 2 kPa after two weeks' culture. Finally, the mammary tumor organoids are treated with doxorubicin and latrunculin A to evaluate their application as a drug screening platform. It is found that the drug response is related to the luminal size and pressures of organoids. This high-throughput culture for mammary tumor organoids may present a promising tool for preclinical drug target validation and personalized medicine.

Enabling peristalsis of human colon tumor organoids on microfluidic chips

Peristalsis in the digestive tract is crucial to maintain physiological functions. It remains challenging to mimic the peristaltic microenvironment in gastrointestinal organoid culture. Here, we present a method to model the peristalsis for human colon tumor organoids on a microfluidic chip. The chip contains hundreds of lateral microwells and a surrounding pressure channel. Human colon tumor organoids growing in the microwell were cyclically contracted by pressure channel, mimicking thein vivomechano-stimulus by intestinal muscles. The chip allows the control of peristalsis amplitude and rhythm and the high throughput culture of organoids simultaneously. By applying 8% amplitude with 8 ∼ 10 times min^-1, we observed the enhanced expression of Lgr5 and Ki67. Moreover, ellipticine-loaded polymeric micelles showed reduced uptake in the organoids under peristalsis and resulted in compromised anti-tumor efficacy. The results indicate the importance of mechanical stimuli mimicking the physiological environment when usingin vitromodels to evaluate nanoparticles. This work provides a method for attaining more reliable and representative organoids models in nanomedicine.

Dual-wavelength demodulation technique for interrogating a shortest cavity in multi-cavity fiber-optic Fabry-Pérot sensors

This paper demonstrates, for the first time, a novel demodulation technique that can be applied for interrogating a shortest cavity in multi-cavity Fabry-Pérot (F-P) sensors. In this demodulation technique, using an amplified spontaneous emission (ASE) light source and two optical fiber broadband filters, the interference only occurs in a shortest F-P cavity that is shorter than the half of the coherence length. Using a signal calibration algorithm, two low-coherence interference optical signals with similar coherence lengths were calibrated to obtain two quadrature signals. Then, the change in the cavity length of the shortest F-P cavity was interrogated by the two quadrature signals and the arctangent algorithm. The experimental results show that the demodulation technique successfully extracted 1 kHz and 500 Hz vibration signals with 39.28 µm and 64.84 µm initial cavity lengths, respectively, in a multi-cavity F-P interferometer. The demodulation speed is up to 500 kHz, and the demodulation technique makes it possible for multi-cavity F-P sensors to measure dynamic and static parameters simultaneously. The results show that the demodulation technique has wide application potential in the dynamic measurement of multi-cavity F-P sensors.

Unidirectional intercellular communication on a microfluidic chip

Cell co-culture serves as a standard method to study intercellular communication. However, random diffusion of signal molecules during co-culture may arouse crosstalk among different types of cells and hide directive signal-target responses. Here, a microfluidic chip is proposed to study unidirectional intercellular communication by spatially controlling the flow of the signal molecules. The chip contains two separated chambers connected by two channels where the culture media flows oppositely. A zigzag signal-blocking channel is designed to study the function of a specific signal. The chip is applied to study the unidirectional communication between tumor cells and stromal cells. It shows that the expression of α-smooth muscle actin (a marker of cancer-associated fibroblast (CAF)) of both MRC-5 fibroblasts and mesenchymal stem cells can be up-regulated only by the secreta from invasive MDA-MB-231 cells, but not from non-invasive MCF-7 cells. The proliferation of the tumor cells can be improved by the stromal cells. Moreover, transforming growth factor beta 1 is found as one of the main factors for CAF transformation via the signal-blocking function. The chip achieves unidirectional cell communication along X-axis, signal concentration gradient along Y-axis and 3D cell culture along Z-axis, which provides a useful tool for cell communication studies.

Pathological changes from the originating to the peripheral sites of Sinonasal Inverted Papilloma are the underlying mechanisms of preoperative MRI-tumor origin prediction

BACKGROUND

Our previous study showed that convoluted cerebriform pattern (CCP)-based reverse tracing method in preoperative magnetic resonance imaging (MRI) is a reliable tool in predicting originating site of sinonasal inverted papilloma (SNIP). This study aimed to determine the underlying pathological mechanism of the preoperative MRI-CCP reverse tracing method by assessing the histopathological changes from the origin to the peripheral sites of SNIP.

METHODOLOGY

The originating site of SNIP was predicted by preoperative MRI in 30 consecutive patients suspected to have primary SNIP. Samples of SNIP originating and peripheral sites were processed by pathological staining for evaluation of stroma score, micro-vessel density (MVD), and tight junction proteins (claudin-5, zonula occludens (ZO)-1 and occludin) expression.

RESULTS

The originating site of SNIP was accurately predicted by preoperative MRI in all patients. Stroma scores, and MVD were significantly greater in the periphery of SNIP than in the originating site. In contrast, Claudin-5 expression in micro-vessels was greater at the originating site than the periphery.

CONCLUSIONS

More edematous stroma and intensive micro-vessels with defective tight junction in periphery of SNIP result in more contrast agent diffusing and CCP that can only be observed at the periphery of SNIP on T2 and contrast-enhanced T1 weighted MR images, which may be the mechanisms underlying the CCP reverse tracing method.

Prediction of malignant sinonasal inverted papilloma transformation by preoperative computed tomography and magnetic resonance imaging

BACKGROUND

Accurate preoperative prediction of the malignant transformation of sinonasal inverted papilloma (SNIP) is essential for radical resection of tumours and prevention of recurrence. We here explored the predictive value of preoperative computed tomography (CT) and magnetic resonance imaging (MRI).

METHODOLOGY

The study was performed on 268 patients with SNIP with (n = 78) or without (n = 190) coexistent malignant transformation. We used univariate and multivariate logistic regression analysis method to screen for independent risk factors, and established a nomogram model. Finally, using receiver operating characteristic curves, we assessed the diagnostic value of the independent risk factors for malignant transformation of SNIP.

RESULTS

We identified bone erosion on CT, change in convoluted cerebriform pattern (CCP) on MRI, and washout-type time intensity curve (TIC) of dynamic contrast-enhanced (DCE)-MRI were independent predictors of malignant transformation of SNIP. The scores of these three independent risk factors from the nomogram model were 10, 7 and 8, respectively. The area under the receiver operating characteristic curve for predicting SNIP malignancy was 0.954 for the nomogram model, 0.826 for bone erosion, 0.776 for washout-type TIC, and 0.810 for CCP mutation.

CONCLUSIONS

Of the independent risk factors and related combination identified, the nomogram model based on bone destruction on CT, CCP mutation on MRI, and washout-type TIC of DCE-MRI had the best predictive value for malignant transformation of SNIP.

Super-Resolution Mapping of Single Nanoparticles inside Tumor Spheroids

Cancer spheroids have structural, functional, and physiological similarities to the tumor, and have become a low-cost in vitro model to study the physiological responses of single cells and therapeutic efficacy of drugs. However, the tiny spheroid, made of a cluster of high-density cells, is highly scattering and absorptive, which prevents light microscopy techniques to reach the depth inside spheroids with high resolution. Here, a method is reported for super-resolution mapping of single nanoparticles inside a spheroid. It first takes advantage of the self-healing property of a "nondiffractive" doughnut-shaped Bessel beam from a 980 nm diode laser as the excitation, and further employs the nonlinear response of the 800 nm emission from upconversion nanoparticles, so that both excitation and emission at the near-infrared can experience minimal loss through the spheroid. These strategies lead to the development of a new nanoscopy modality with a resolution of 37 nm, 1/26th of the excitation wavelength. This method enables mapping of single nanoparticles located 55 µm inside a spheroid, with a resolution of 98 nm. It suggests a solution to track single nanoparticles and monitor their release of drugs in 3D multicellar environments.

Gradient-sized control of tumor spheroids on a single chip

Multicellular tumor spheroids are attracting more attention as a physiologically relevant in vitro tumor model for biomedical research. The size of spheroids is one of the critical parameters related to drug penetration and cellular responses. It remains challenging to generate a large number of gradient-sized spheroids in one culture vessel. Here, a liquid-dome method was used to simultaneously produce more than 200 gradient-sized spheroids on an agarose chip. Surface tension effect was used to modulate the liquid spatial distribution and achieve a range of spheroid sizes. MCF-7 cells formed multiple spheroids on the chips for concept validation. It showed that different configurations of the liquid domes exhibited different levels of size control. Relative to the smallest spheroids in the configuration, hemispheric and square domes produced spheroids up to 3.4 and 12.8-fold larger in area, respectively. In addition, the co-culture of MCF-7 and fibroblasts helped to elucidate the tendency of fibroblasts towards the spheroid center. Other size-dependent behaviors were profiled; larger spheroids behaved differently from smaller spheroids in terms of spheroid growth, drug penetration and cellular responses. This method breaks the boundary between the preparation of gradient-sized spheroids and significant time/labour demand. It can be useful for drug screening and in vitro tumor modelling.

Batch-producible MEMS fiber-optic Fabry-Perot pressure sensor for high-temperature application

A fiber-optic Fabry-Perot pressure sensor based on a micro-electro-mechanical system (MEMS) and CO₂ laser fusion technology is developed and experimentally demonstrated for high-temperature application. The sensing heads are batch-fabricated by anodically bonding the micromachined Pyrex glass wafer and local gold-plated silicon wafer. The separated sensing head and the single-mode fiber are fused together to form the Fabry-Perot cavity using the CO₂ laser. In order to improve the measurement accuracy in a high-temperature environment, a fiber Bragg grating is used as a temperature sensor for temperature decoupling. The experimental results show that the fiber-optic Fabry-Perot pressure sensor has a maximum nonlinearity of 0.4%. The maximal error of the pressure after temperature decoupling is less than 1.05% over a pressure range of 0-0.5 MPa and a temperature range of 20°C-350°C. The batch fabrication technology makes the sensors low cost and high uniformity.

Diaphragm-Free Fiber-Optic Fabry-Perot Interferometric Gas Pressure Sensor for High Temperature Application

A diaphragm-free fiber-optic Fabry-Perot (FP) interferometric gas pressure sensor is designed and experimentally verified in this paper. The FP cavity was fabricated by inserting a well-cut fiber Bragg grating (FBG) and hollow silica tube (HST) from both sides into a silica casing. The FP cavity length between the ends of the SMF and HST changes with the gas density. Using temperature decoupling method to improve the accuracy of the pressure sensor in high temperature environments. An experimental system for measuring the pressure under different temperatures was established to verify the performance of the sensor. The pressure sensitivity of the FP gas pressure sensor is 4.28 nm/MPa with a high linear pressure response over the range of 0.1–0.7 MPa, and the temperature sensitivity is 14.8 pm/°C under the range of 20–800 °C. The sensor has less than 1.5% non-linearity at different temperatures by using temperature decoupling method. The simple fabrication and low-cost will help sensor to maintain the excellent features required by pressure measurement in high temperature applications.

A novel electrolyte additive for improving the interfacial stability of LiMn2O4 cathode lithium-ion batteries at elevated temperature

Methanesulfonic acid 2,2,3,3-tetrafluoropropyl (TFPMS) is newly explored as a protection additive to improve the interfacial stability of LiMn₂O₄ cathode/electrolyte at an elevated temperature.

A Wide-Range Displacement Sensor Based on Plastic Fiber Macro-Bend Coupling

This paper proposes the strategy of fabricating an all fiber wide-range displacement sensor based on the macro-bend coupling effect which causes power transmission between two twisted bending plastic optical fibers (POF), where the coupling power changes with the bending radius of the fibers. For the sensor, a structure of two twisted plastic fibers is designed with the experimental platform that we constructed. The influence of external temperature and displacement speed shifts are reported. The displacement sensor performance is the sensor test at different temperatures and speeds. The sensor was found to be satisfactory at both room temperature and 70 °C when the displacement is up to 140 mm. The output power is approximately linear to a displacement of 110 mm–140 mm under room temperature and 2 mm/s speed at 19.805 nW/mm sensitivity and 0.12 mm resolution. The simple structure of the sensor makes it reliable for other applications and further utilizations, promising a bright future.

Cell therapy for bone nonunion: a retrospective study

AIM

The aim of this study was to report our experience in augmenting nonunion both with bone marrow mononuclear cells/mesenchymal stem cells (MSCs) and conventional surgical approaches; and for clinical applications, a simple, safe, and reproducible method to effectively treat bone mass loss disease.

METHODS

A retrospective analysis was performed on stem cell-treated bone nonunion patients from October 1, 2007 to October 1, 2009. Nine patients were categorized into two groups: group 1 consists of 3 patients who received autologous bone marrow mononuclear cells transplantation; group 2 consists of 6 patients who received umbilical cord MSCs (hUC-MSCs) transplantation. All patients accepted conventional surgical treatment and X-ray supervised at 3, 6, and 12 months or so after transplantation, while T cells' subtype was analyzed.

RESULTS

All patients were followed up for 36 months through recheck Out-patient Department and X-ray examination to observe the fracture healing. The mean time for clinical healing was comparable in both groups. The mean time of fracture lines blurred partly, continuous bone callus formation, marrow flow was 3.5M, 6.2M, and 9.1M, respectively, in the human umbilical cord mesenchymal stem cells (hUC-MSCs) treatment group. The compared healing times were 3.8 M, 7.1M and 10.6 months in autologous bone marrow mononuclear cells transplantation, respectively. The serum levels of CD4, CD56, and HLA-DR in hUC-MSCs graft group were negative, while the serum level of CD8 was 7.8% positive. Clearly, there was no significant difference in the percent of T subsets between the 2 groups of T cells' subtype.

CONCLUSION

Our study showed that patients treated by allograft-augmentation had no complications, reduced treatment- dissatisfaction. The use of hUC-MSCs should be offered to suitable patients in the preoperative consultation as a valuable alternative for autologous grafting and larger clinical trials should be considered in the future.

Increased nucleobindin-2 (NUCB2) transcriptional activity links the regulation of insulin sensitivity in Type 2 diabetes mellitus

The protein nucleobindin-2 (NUCB2) has been recently identified as a novel satiety regulator. However, its pathophysiological role in humans remains unknown. The aims of the present study are to explore whether plasma NUCB2-1 and NUCB2 transcription activity are increased in newly diagnosed Type 2 diabetes mellitus (nT2DM) and, if so, whether changing NUCB2-1 level is a physiologic response or a compensatory mechanism for impaired insulin action. The nT2DM, impaired glucose tolerance (IGT), and healthy people (NGT, normal glucose tolerance) groups were enrolled in this study. The peripheral and hepatic insulin actions in rats with intracerebroventricular (ICV) NUCB2-1 administration were examined by euglycemic-hyperinsulinemic clamps. Plasma NUCB2-1 levels were elevated in subjects with both nT2DM and IGT compared with normal controls. NUCB2 mRNA and protein contents of muscle and adipose tissues in T2DM patients were also significantly increased compared to controls. ICV NUCB2-1 infusion in rats inhibited hepatic phosphoenolpyruvate carboxykinase (PEPCK) activity, and this was sufficient to induce insulin sensitivity in the liver and peripheral tissues during euglycemic-hyperinsulinemic clamps. In T2DM patients, there were increases in plasma NUCB2-1 levels and increases in NUCB2 mRNA and protein contents in muscle and adipose tissues. These increases are presumably a compensatory response to defective insulin action.

Chronic intermittent hypoxia induces atherosclerosis by NF-κB-dependent mechanisms

Chronic intermittent hypoxia (CIH) causes atherosclerosis in mice fed a high cholesterol diet (HCD). The mechanisms by which CIH promotes atherosclerosis are incompletely understood. This study defined the mechanistic role of NF-κB pathway in CIH+HCD induced atherosclerosis. Wild type (WT) and mice deficient in the p50 subunit of NF-κB (p50-KO) were fed normal chow diet (ND) or HCD, and exposed to sham or CIH. Atherosclerotic lesions on the en face aortic preparation and cross-sections of aortic root were examined. In WT mice, neither CIH nor HCD exposure alone caused, but CIH+HCD caused evident atherosclerotic lesions on both preparations after 20weeks of exposure. WT mice on ND and exposed to CIH for 35.6weeks did not develop atherosclerotic lesions. P50 gene deletion diminished CIH+HCD induced NF-κB activation and abolished CIH+HCD induced atherosclerosis. P50 gene deletion inhibited vascular wall inflammation, reduced hepatic TNF-α level, attenuated the elevation in serum cholesterol level and diminished macrophage foam cell formation induced by CIH+HCD exposure. These results demonstrate that inhibition of NF-κB activation abrogates the activation of three major atherogenic mechanisms associated with an abolition of CIH+HCD induced atherosclerosis. NF-κB may be a central common pathway through which CIH+HCD exposure activates multiple atherogenic mechanisms, leading to atherosclerosis.

Abstract IA24: Drugging the undruggable: Small-molecule inhibition of Ras oncoprotein

Ras is a nucleotide-dependent switch that converts from an inactive GDP-bound state to an active GTP-bound state when activated by guanine nucleotide exchange factors, such as SOS. Active RasGTP then binds to and activates downstream signaling effectors. Ras is the most frequently mutated oncogene and hyperactive mutant Ras constitutively signals to effectors to promote cell survival, proliferation and metastasis. Thus, Ras oncoprotein has been considered by the cancer community to be one of the most important oncology drug targets. Despite the enormous interest and extensive exploratory efforts in industry and academia, small molecules that bind to Ras in a well-defined manner and exert inhibitory effects have not been uncovered to date. We report here the identification and characterization of small-molecule inhibitors of the Ras oncoprotein.

To explore a new means of directly targeting Ras, we used a fragment-based lead discovery approach via an NMR-based screen. Hits from the fragment screen were characterized for their interactions with Ras by NMR and X-ray crystallography and for their effects on Ras activation and signaling in reconstituted biochemical assays in vitro and in cellular assays in vivo. From the fragment-based screen, we identified a group of small molecules that each bind to a common site adjacent to the switch I/II regions in the Ras protein. X-ray crystallography studies of three compound-Ras complexes indicate that the binding site can be expanded upon ligand binding. Nucleotide exchange factors, notably SOS, are required to convert inactive RasGDP to active RasGTP. We determined that the compound-binding site is located at the interface of Ras and SOS. A subset of our Ras-binding molecules indeed inhibited SOS-mediated nucleotide exchange. Further mechanistic studies revealed that through steric hindrance the compounds block the formation of the Ras-SOS complex, a key intermediate of the exchange reaction. At the cellular level, our compounds inhibit the formation of active RasGTP and prevent Ras signaling to downstream effectors. To define the potential clinic utility of these compounds, we performed biological characterization of Ras-driven tumors and identified a subset of Ras mutant tumors that depend on nucleotide exchange factors for the activation of Ras, suggesting a specific profile for the use of exchange inhibitors.

We conclude that the compounds act as competitive inhibitors of nucleotide exchange to prevent the activation of Ras. The discovery of a binding pocket on Ras with functional significance represents a breakthrough finding that will offer a new direction for therapeutic intervention of Ras. Our findings provide new opportunities to target the “undruggable” Ras oncoprotein.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr IA24.

Motion Coordination for Construction Vehicles using Swarm Intelligence

In a variety of tasks performed in construction sites, coordinated operations of multi-vehicles are foreshadowed to outperform the deployment of a single vehicle in terms of increased capacity and flexibility. This paper presents the application of the particle swarm optimization (PSO) algorithm in deriving drive commands, speed and turning, for the vehicles such that they are steered into and maintained in desirable formations according to an assigned task. The PSO is adopted for its implementation simplicity and relaxing the need for analytical system models. To this end, the coordination of vehicles is posed as an optimization problem minimizing the translational and angular errors between the current vehicle positions and their corresponding targets. Inter-vehicle collisions are mitigated, in this work, by employing a behavioural-based reactive scheme together with a dynamical index rescheduling procedure. Simulation results for coordinated multi-vehicle motions, in benchmark formation patterns, are included to demonstrate the effectiveness of the proposed approach.

Acceptability of PRO2000 vaginal gel among HIV un-infected women in Pune, India

Acceptability of PRO2000 Gel, a candidate vaginal microbicide, among participants of its Phase I safety study in Pune, India is reported here. Forty-two eligible women were enrolled in a study requiring twice daily intra-vaginal product use for 14 consecutive days between menses. Acceptability was assessed at study exit through structured questionnaires among 41 participants who completed the product use, and five focus group discussions involving 31 study participants. The participants generally liked the product (40/41, 97.2%), especially its colour (40, 97.2%) and consistency (35, 85.3%). Thirty-four participants reported sexual intercourse within one hour of product use, at least once during the study period and sexual pleasure was reported to be better or unaffected among (30, 88.2%) participants. Nearly 70% did not like its smell and mentioned preference for a product that would be unnoticeable to the male partner. Participating women were concerned about privacy in usage and storage of the product. Acceptability of PRO2000 vaginal gel was good, but its smell will have to be improved. Counselling to address women's concerns about privacy and storage will be crucial. Women's preference for unnoticeable product indicates their empowerment and willingness to accept female-controlled options for HIV prevention.

NAD(+) and axon degeneration revisited: Nmnat1 cannot substitute for Wld(S) to delay Wallerian degeneration

The slow Wallerian degeneration protein (Wld(S)), a fusion protein incorporating full-length nicotinamide mononucleotide adenylyltransferase 1 (Nmnat1), delays axon degeneration caused by injury, toxins and genetic mutation. Nmnat1 overexpression is reported to protect axons in vitro, but its effect in vivo and its potency remain unclear. We generated Nmnat1-overexpressing transgenic mice whose Nmnat activities closely match that of Wld(S) mice. Nmnat1 overexpression in five lines of transgenic mice failed to delay Wallerian degeneration in transected sciatic nerves in contrast to Wld(S) mice where nearly all axons were protected. Transected neurites in Nmnat1 transgenic dorsal root ganglion explant cultures also degenerated rapidly. The delay in vincristine-induced neurite degeneration following lentiviral overexpression of Nmnat1 was significantly less potent than for Wld(S), and lentiviral overexpressed enzyme-dead Wld(S) still displayed residual neurite protection. Thus, Nmnat1 is significantly weaker than Wld(S) at protecting axons against traumatic or toxic injury in vitro, and has no detectable effect in vivo. The full protective effect of Wld(S) requires more N-terminal sequences of the protein.

Human VEGF165-myoblasts produce concomitant angiogenesis/myogenesis in the regenerative heart

Bioengineering the regenerative heart may provide a novel treatment for heart failure. On May 14, 2002, a 55-year-old man suffering from ischemic myocardial infarction received 25 injections carrying 465 million cGMP-produced pure myoblasts into his myocardium after coronary artery bypass grafting. As on August 28, 2002, his EKG was normal and showed no arrhythmia. His ejection fraction increased by 13%. He no longer experienced shortness of breath and angina as he did before the treatment. Three myogenesis mechanisms were elucidated with 17 human/porcine xenografts using cyclosporine as immunosuppressant. Some myoblasts developed to become cardiomyocytes. Others transferred their nuclei into host cardiomyocytes through natural cell fusion. As yet others formed skeletal myofibers with satellite cells. De novo production of contractile filaments augmented the heart contractility. Human myoblasts transduced with VEGF165 gene produced six times more capillaries in porcine myocardium than in placebo. Xenograft rejection was not observed for up to 20 weeks despite cyclosporine discontinuation at 6 weeks. Pros and cons of autografts vs. allografts are compared to guide future development of heart cell therapy.

[Field application of oral artesunate for preventing Schistosoma japonicum infection]

AIM

To assess the preventive effect of oral artesunate against S. japonicum infection.

METHODS

Residents in two pilots in the schistosomiasis endemic regions, 562 cases in Yanghe pilot, Wangjiang County and 218 cases in Shashan pilot, Guichi City, Anhui Province, were selected for this study. The residents were divided into two groups. Group I received artesunate 6 mg/kg once every 2 weeks for 4 times 2 wk after contacting with infested water from July to September in 1997. Group II received the same dosage of placebo at the corresponding times. Four weeks after the last administration, stool examination using hatching method and Kato's method was conducted to evaluate the effect.

RESULTS

In Yanghe pilot, 2 cases were hatching positive in the artesunate-treated group with an infection rate of 0.7% (2/273), while 11 cases were stool positive in placebo group with an infection rate of 3.8% (11/289) and a mean EPG of 26.40 +/- 1.49. In Shashan pilot, all cases in artesunate-treated group were stool negative, while 7 cases were stool positive in the placebo group with an infection rate of 6.3% (7/111), and a mean EPG of 14.23 +/- 2.14. The protection rate of artesunate was 80.9% and 100%, respectively, in the two pilots.

CONCLUSION

Artesunate can protect the residents from S. japonicum infection effectively.

The WldS protein protects against axonal degeneration: a model of gene therapy for peripheral neuropathy

The WldS mouse is a spontaneous mutant that is characterized by the phenotype of delayed degeneration of transected nerves (slow Wallerian degeneration). Molecular genetic analysis identified a mutation in this animal that codes for a unique protein expressed in brain tissue of WldS mice. We asked whether the WldS phenotype, in addition to delaying axonal degeneration after axotomy, might provide neuroprotection against toxic neuropathy. In dorsal root ganglia (DRG) cultures, neurites from WldS transiently exposed to vincristine not only resisted axonal degeneration but resumed growth after withdrawal of the toxin. Neurites from wild type mice died rapidly and did not recover. To prove that the identified mutation and its protein product are responsible for the WldS phenotype, we used an adenoviral gene transfer system to deliver the WldS to rat DRG neurons. Rat neurons expressing the WldS protein were resistant to vincristine-induced axonal degeneration, confirming the functional significance of the identified gene mutation. These data provide evidence that the WldS protein can be neuroprotective against vincristine neuropathy, and possibly other disorders characterized by axonal degeneration. In addition, delivery of this gene to wild type cells can transfer the WldS phenotype, providing the possibility of "gene therapy" for peripheral neuropathy.

Analysis of transition from long-term nonprogressive to progressive infection identifies sequences that may attenuate HIV type 1

Long-term nonprogressive human immunodeficiency virus type 1 (HIV-1) infection and its transition to progressive infection presents an opportunity to identify the molecular determinants of HIV-1 attenuation and pathogenesis. We studied an individual who underwent a transition from long-term nonprogressive to rapidly progressive infection. Because HIV-1 RNA genomes in plasma represent replicating virus, we developed a technique to clone full-length HIV-1 RNA genomes from plasma and used this technique to obtain clones from this individual before and during the transition. Most clones assayed were infectious, demonstrating that the RNA genomes encoded viable virus. Analysis of 20 complete HIV-1 RNA genomic sequences revealed one major difference between sequences found during the two phases of infection. During the nonprogressive phase, the predominant sequences had a large deletion in an Sp1-binding site and adjacent promoter in the U3 part of the long terminal repeat (LTR); when the infection became progressive, all viruses had intact Sp1 and promoter sequences and were derived from a minor species present earlier. Analysis of 184 clones of the LTR region obtained at five time points spanning a 7-year period confirmed this switch. In an in vitro assay, the deletion downregulated LTR-driven transcription of a reporter gene. In addition, analysis of cytotoxic T lymphocyte (CTL) epitopes predicted from the complete viral RNA genomes revealed multiple potential escape mutants that accumulated by the time of progression. These studies suggest that during the nonprogressive phase, the Sp1 enhancer-promoter deletion is likely to have played a role in decreasing replication, thereby attenuating HIV-1. The accumulation of CTL escape mutants suggests that a breakdown in immunologic surveillance may have allowed proliferation of intact virus, thus leading to rapid disease progression. These data reveal the viral and immune interactions characterizing a transition from long-term nonprogressive to rapidly progressive infection.

[Neo-adjuvant chemotherapy for breast cancer]

OBJECTIVE

To study the value and indications of a neo-adjuvant chemotherapy for breast cancers.

METHODS

Forty-three breast cancer patients were given the NF neo-adjuvant chemotherapy (Navelbine 25 mg/m2 and 5-Fu 500 mg/m2) for 3 cycles before the operation. Epirubicin (EPI 40 mg/m2) was added in patients with locally advanced lesions. G-CSF 75 micrograms subcutaneous injection was used to increase the white count as needed.

RESULTS

The overall response rate was 95.0%. Pre-operative neo-adjuvant chemotherapy showed CR in 3 patients (7.5%) and PR in 35 patients (87.5%) even though 2 patients (5.0%) were refractory. The follow-up ranged from 4 to 37 months (median 20 months). All patients are alive though 4 have developed recurrence or metastasis.

CONCLUSION

The pre-operative neo-adjuvant chemotherapy may preferably be given in 3 cycles from which those who benefit most are the breast cancer patients with inoperable lesions and who are planned to undergo breast-preserving surgery.

MAD2B is an inhibitor of the anaphase-promoting complex

Anaphase-promoting complex (APC), a ubiquitin ligase, controls both sister chromatid separation and mitotic exit. The APC is activated in mitosis and G1 by CDC20 and CDH1, and inhibited by the checkpoint protein MAD2, a specific inhibitor of CDC20. We show here that a MAD2 homolog MAD2B also inhibits APC. In contrast to MAD2, MAD2B inhibits both CDH1-APC and CDC20-APC. This inhibition is targeted to CDH1 and CDC20, but not directly to APC. Unlike MAD2, whose interaction with MAD1 is required for mitotic checkpoint control, MAD2B does not interact with MAD1, suggesting that MAD2B may relay a different cellular signal to APC.

[Genetic analysis of hereditary factor VII deficiency from a Chinese pedigree]

OBJECTIVE

To identify the mutation in coagulation factor VII gene from a Chinese patient with hereditary coagulation factor VII deficiency.

METHODS

The genomic DNA fragments of FVII gene from a propositus and normal subjects were amplified using polymerase chain reaction (PCR), and analyzed with direct sequencing of PCR products. The PCR amplified genomic DNA fragments of FVII gene from the propositus and her family members were analyzed using restriction enzyme Hgic I.

RESULTS

The FVII gene sequences of normal subjects were identical to the data published, while a missense mutation (TGT-->GGT) was found at codon 329 in FVII gene of the propositus. The heterozygous condition for the mutation was revealed in her three family members.

CONCLUSION

We have found a novel mutation (TGT-->GGT) at codon 329 in FVII gene of a patient with hereditary FVII deficiency, which leads to a cystein residue replaced by a glysine. PCR combined with restriction enzyme Hgic I digestion would be a rapid diagnostic method for this mutation.

Visualization of Mad2 dynamics at kinetochores, along spindle fibers, and at spindle poles in living cells

The spindle checkpoint prevents errors in chromosome segregation by inhibiting anaphase onset until all chromosomes have aligned at the spindle equator through attachment of their sister kinetochores to microtubules from opposite spindle poles. A key checkpoint component is the mitotic arrest-deficient protein 2 (Mad2), which localizes to unattached kinetochores and inhibits activation of the anaphase-promoting complex (APC) through an interaction with Cdc20. Recent studies have suggested a catalytic model for kinetochore function where unattached kinetochores provide sites for assembling and releasing Mad2-Cdc20 complexes, which sequester Cdc20 and prevent it from activating the APC. To test this model, we examined Mad2 dynamics in living PtK1 cells that were either injected with fluorescently labeled Alexa 488-XMad2 or transfected with GFP-hMAD2. Real-time, digital imaging revealed fluorescent Mad2 localized to unattached kinetochores, spindle poles, and spindle fibers depending on the stage of mitosis. FRAP measurements showed that Mad2 is a transient component of unattached kinetochores, as predicted by the catalytic model, with a t(1/2) of approximately 24-28 s. Cells entered anaphase approximately 10 min after Mad2 was no longer detectable on the kinetochores of the last chromosome to congress to the metaphase plate. Several observations indicate that Mad2 binding sites are translocated from kinetochores to spindle poles along microtubules. First, Mad2 that bound to sites on a kinetochore was dynamically stretched in both directions upon microtubule interactions, and Mad2 particles moved from kinetochores toward the poles. Second, spindle fiber and pole fluorescence disappeared upon Mad2 disappearance at the kinetochores. Third, ATP depletion resulted in microtubule-dependent depletion of Mad2 fluorescence at kinetochores and increased fluorescence at spindle poles. Finally, in normal cells, the half-life of Mad2 turnover at poles, 23 s, was similar to kinetochores. Thus, kinetochore-derived sites along spindle fibers and at spindle poles may also catalyze Mad2 inhibitory complex formation.

CGP57148B (STI-571) induces differentiation and apoptosis and sensitizes Bcr-Abl-positive human leukemia cells to apoptosis due to antileukemic drugs

The differentiation and apoptosis-sensitizing effects of the Bcr-Abl-specific tyrosine kinase inhibitor CGP57148B, also known as STI-571, were determined in human Bcr-Abl-positive HL-60/Bcr-Abl and K562 cells. First, the results demonstrate that the ectopic expression of the p185 Bcr-Abl fusion protein induced hemoglobin in the acute myeloid leukemia (AML) HL-60 cells. Exposure to low-dose cytosine arabinoside (Ara-C; 10 nmol/L) increased hemoglobin levels in HL-60/Bcr-Abl and in the chronic myeloid leukemia (CML) blast crisis K562 cells, which express the p210 Bcr-Abl protein. As compared with HL-60/neo, HL-60/Bcr-Abl and K562 cells were resistant to apoptosis induced by Ara-C, doxorubicin, or tumor necrosis factor-alpha (TNF-alpha), which was associated with reduced processing of caspase-8 and Bid protein and decreased cytosolic accumulation of cytochrome c (cyt c). Exposure to CGP57148B alone increased hemoglobin levels and CD11b expression and induced apoptosis of HL-60/Bcr-Abl and K562 cells. CGP57148B treatment down-regulated antiapoptotic XIAP, cIAP1, and Bcl-x(L), without affecting Bcl-2, Bax, Apaf-1, Fas (CD95), Fas ligand, Abl, and Bcr-Abl levels. CGP57148B also inhibited constitutively active Akt kinase and NFkappaB in Bcr-Abl-positive cells. Attenuation of NFkappaB activity by ectopic expression of transdominant repressor of IkappaB sensitized HL-60/Bcr-Abl and K562 cells to TNF-alpha but not to apoptosis induced by Ara-C or doxorubicin. Importantly, cotreatment with CGP57148B significantly increased Ara-C- or doxorubicin-induced apoptosis of HL-60/Bcr-Abl and K562 cells. This was associated with greater cytosolic accumulation of cyt c and PARP cleavage activity of caspase-3. These in vitro data indicate that combinations of CGP57148B and antileukemic drugs such as Ara-C may have improved in vivo efficacy against Bcr-Abl-positive acute leukemia.

Thrombocidins, microbicidal proteins from human blood platelets, are C-terminal deletion products of CXC chemokines

Antibacterial proteins are components of the innate immune system found in many organisms and produced by a variety of cell types. Human blood platelets contain a number of antibacterial proteins in their alpha-granules that are released upon thrombin activation. The present study was designed to purify these proteins obtained from human platelets and to characterize them chemically and biologically. Two antibacterial proteins were purified from platelet granules in a two-step protocol using cation exchange chromatography and continuous acid urea polyacrylamide gel electrophoresis and were designated thrombocidin (TC)-1 and TC-2. Characterization of these proteins using mass spectrometry and N-terminal sequencing revealed that TC-1 and TC-2 are variants of the CXC chemokines neutrophil-activating peptide-2 and connective tissue-activating peptide-III, respectively. TC-1 and TC-2 differ from these chemokines by a C-terminal truncation of 2 amino acids. Both TCs, but not neutrophil-activating peptide-2 and connective tissue-activating peptide-III, were bactericidal for Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Lactococcus lactis and fungicidal for Cryptococcus neoformans. Killing of B. subtilis by either TC appeared to be very rapid. Because TCs were unable to dissipate the membrane potential of L. lactis, the mechanism of TC-mediated killing most probably does not involve pore formation.