The ID1-CULLIN3 Axis Regulates Intracellular SHH and WNT Signaling in Glioblastoma Stem Cells

SummaryInhibitor of differentiation 1 (ID1) is highly expressed in glioblastoma stem cells (GSCs). However, the regulatory mechanism responsible for its role in GSCs is poorly understood. Here, we report that ID1 activates GSC proliferation, self-renewal, and tumorigenicity by suppressing CULLIN3 ubiquitin ligase. ID1 induces cell proliferation through increase of CYCLIN E, a target molecule of CULLIN3. ID1 overexpression or CULLIN3 knockdown confers GSC features and tumorigenicity to murine Ink4a/Arf-deficient astrocytes. Proteomics analysis revealed that CULLIN3 interacts with GLI2 and DVL2 and induces their degradation via ubiquitination. Consistent with ID1 knockdown or CULLIN3 overexpression in human GSCs, pharmacologically combined control of GLI2 and β-CATENIN effectively diminishes GSC properties. A ID1-high/CULLIN3-low expression signature correlates with a poor patient prognosis, supporting the clinical relevance of this signaling axis. Taken together, a loss of CULLIN3 represents a common signaling node for controlling the activity of intracellular WNT and SHH signaling pathways mediated by ID1

Deep Learning-Based Virtual Optical Image Generation and Its Application to Early Crop Mapping

This paper investigates the potential of cloud-free virtual optical imagery generated using synthetic-aperture radar (SAR) images and conditional generative adversarial networks (CGANs) for early crop mapping, which requires cloud-free optical imagery at the optimal date for classification. A two-stage CGAN approach, including representation and generation stages, is presented to generate virtual Sentinel-2 spectral bands using all available information from Sentinel-1 SAR and Sentinel-2 optical images. The dual-polarization-based radar vegetation index and all available multi-spectral bands of Sentinel-2 imagery are particularly considered for feature extraction in the representation stage. A crop classification experiment using Sentinel-1 and -2 images in Illinois, USA, demonstrated that the use of all available scattering and spectral features achieved the best prediction performance for all spectral bands, including visible, near-infrared, red-edge, and shortwave infrared bands, compared with the cases that only used dual-polarization backscattering coefficients and partial input spectral bands. Early crop mapping with an image time series, including the virtual Sentinel-2 image, yielded satisfactory classification accuracy comparable to the case of using an actual time-series image set, regardless of the different combinations of spectral bands. Therefore, the generation of virtual optical images using the proposed model can be effectively applied to early crop mapping when the availability of cloud-free optical images is limited

Protective effect of triphlorethol-A from Ecklonia cava against ionizing radiation in vitro

We studied the cytoprotective effect of triphlorethol-A against gamma-ray radiation-induced oxidative stress. In this study, hydrogen peroxide, which is a reactive oxygen species (ROS), was detected using 2',7'-dichlorodihydrofluorescein diacetate (DCF-DA) assay. Triphlorethol-A reduced intracellular hydrogen peroxide generated by gamma-ray radiation. This compound provided protection against radiation-induced membrane lipid peroxidation and cellular DNA damage which are the main targets of radiation-induced damage. Triphlorethol-A protected the cell viability damaged by the radiation through inhibition of apoptosis. Triphlorethol-A reduced the expression of bax and activated caspase 3 induced by radiation, but recovered the expression of bcl-2 decreased by radiation. Taken together, the results suggest that triphlorethol-A protects cells against oxidative damage induced by radiation through reducing ROS