The transcript ENST00000444125 of lncRNA LINC01503 promotes cancer stem cell properties of glioblastoma cells via reducing FBXW1 mediated GLI2 degradation.

LINC010503 is a novel oncogenic lncRNA in multiple cancers. In this study, we further explored the expression of LINC010503 transcripts and their regulations on the glioblastoma (GBM) stem cell (GSC) properties. LINC01503 transcription patterns in GBM and normal brain tissues were compared using RNA-seq data from Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA)-GBM. GBM cell lines (U251 and U87) were used as in vitro cell models for cellular and molecular studies. The results showed that ENST00000444125 was the dominant transcript of LINC01503 in both normal and tumor tissues. Its expression was significantly elevated in the tumor group and associated with poor survival outcomes. LINC01503 had both cytoplasmic and nuclear distribution. It positively modulated the expression of multiple GSC markers, including CD133, SOX2, NESTIN, ALDH1A1, and MSI1, and tumorsphere formation in U251 and U87 cells. RNA pull-down and RIP-qPCR assay confirmed an interaction between ENST00000444125 and GLI2. ENST00000444125 positively regulated the half-life of the GLI2 protein in GBM cells. ENST00000444125 overexpression reduced GLI2 ubiquitination and partially attenuated FBXW1 overexpression induced GLI2 ubiquitination. ENST00000444125 overexpression could activate Wnt/ß-catenin signaling in GBM cells. However, these activating effects were remarkedly hampered when GLI2 was knocked down. In conclusion, this study revealed that LINC01503 might have isoform-specific dysregulation in GBM. Among the two major transcripts expressed in GBM cells, ENST00000444125 might be the major functional transcript. Its upregulation might enhance the GSC properties of GBM cells via reducing FBXW1-mediated proteasomal degradation of GLI2.

Protective effects of perfluorooctyl-bromide nanoparticles on early brain injuries following subarachnoid hemorrhage in rats.

To investigate the protective effects of perfluorooctyl-bromide (PFOB) nanoparticles on early brain injury (EBI) following subarachnoid hemorrhage (SAH), a total of 120 rats were randomly assigned to the following groups: Sham operation group (n = 40), SAH group (n = 40), and SAH + PFOB group (n = 40). Endovascular perforation was performed to induce subarachnoid hemorrhage. Brain water content was measured 24 h after surgery. Meanwhile, morphological changes in the rat hippocampal CA1 region were examined using light and transmission electron microscopy. The rate of neuronal apoptosis in rat hippocampal CA1 region was determined using TUNEL assay. Protein and mRNA expression levels of Caspase-3, Bax, and Bcl-2 were measured using western blot and RT-PCR assays 12, 24, 48, and 72 h after surgery. Compared to the SAH group, the SAH + PFOB group had significantly lower brain water content (P<0.01), with alleviated morphological abnormalities in HE-stained neurons and significantly decreased neurons with karyopyknosis and hyperchromatism in the hippocampal CA1 region. Electron microscopy revealed reduction of neuronal apoptosis, alleviation of glial cell swelling, and mitigation of perivascular edema in the hippocampal region. Immunohistochemical analysis showed that the expression of apoptosis-related factors Caspase-3 and Bax was significantly reduced, while that of the anti-apoptotic factor Bcl-2 was significantly increased. TUNEL staining showed that neuronal apoptosis was significantly reduced in the hippocampal CA1 region (P<0.01). RT-PCR and Western-blot data indicated that expressions of Caspase-3 and Bax were both significantly reduced, while bcl-2 expression was increased significantly at 12, 24, 48, and 72 h after SAH (P<0.01). Together, our data support that PFOB nanoparticles with high oxygen content could counteract ischemia and hypoxia, block neuronal apoptotic pathways, reduce neuronal apoptosis, and therefore, achieve neuroprotective effects in EBI following SAH.