Recently, messenger RNAs in eukaryotes have shown to associate with antisense (AS) transcript partners that are often referred to as long noncoding RNAs (lncRNAs) whose function is largely unknown. Here, we have identified a natural AS transcript for tyrosine kinase containing immunoglobulin and epidermal growth factor homology domain-1 (tie-1), tie-1AS lncRNA in zebrafish, mouse, and humans. In embryonic zebrafish, tie-1AS lncRNA transcript is expressed temporally and spatially in vivo with its native target, the tie-1 coding transcript and in additional locations (ear and brain). The tie-1AS lncRNA selectively binds tie-1 mRNA in vivo and regulates tie-1 transcript levels, resulting in specific defects in endothelial cell con- IntroductionOver the past few years, intensive unbiased analysis of transcriptome species has revealed that eukaryotic genomes contain a variety of RNA species. RNA molecules are essentially classified into 2 types, protein coding and nonprotein coding. The protein-coding transcripts or messenger RNA (mRNA) account for only approximately 2.3% of the human genome. 1 The majority of transcription appears to be nonprotein coding or noncoding, and the function of these noncoding transcripts is largely unknown. 2 Of the noncoding RNAs, the regulatory short noncoding RNAs, such as microRNAs, are well studied. The long noncoding RNAs (lncRNAs), which compose the largest portion of the mammalian noncoding transcriptome, are the least understood, especially its function. 3,4 lncRNAs are oriented in sense or antisense (AS) direction with respect to a protein coding locus, and located in intronic or intergenic regions. 5 In humans and mice, 61% to 72% of all transcribed regions possess lncRNAs in AS orientation, 2,6 and AS lncRNA transcripts play important roles in pathogenesis. For instance, the BACE1-AS transcript was elevated in subjects with Alzheimer disease and in amyloid precursor protein transgenic mice. 7 A growing body of evidence suggests that lncRNAs for most critical physiologic processes will be identified. Angiogenesis, the development of new vasculature from existing vasculature, is one of the fundamental developmental physiologic processes regulated in a developing vertebrate embryo. 8 Here, we identify a natural AS transcript for tyrosine kinase containing immunoglobulin and epidermal growth factor homology domain-1 (tie-1), tie-1AS lncRNA in zebrafish, mouse, and humans. tie-1 is a cell-surface tyrosine kinase receptor for angiopoietin ligands that is known to play a role in vascular development in vertebrates. [9][10][11][12] In embryonic zebrafish, tie-1AS lncRNA transcript is expressed temporally and spatially in vivo with its native target, the tie-1 coding transcript, and in additional locations (ear and brain). Its expression is controlled by a 3-kb genomic fragment in the 3Ј region of tie-1, and the bioinformatic predicted hybrid structure between tie-1:tie-1AS was detected in vivo. Capped or uncapped tie-1AS lncRNA selectively binds tie-1 mRNA in vivo and regulates tie-1...

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NgBR is a type I receptor with a single transmembrane domain and was identified as a specific receptor for Nogo-B. Our recent findings demonstrated that NgBR binds farnesylated Ras and recruits Ras to the plasma membrane, which is a critical step required for the activation of Ras signaling in human breast cancer cells and tumorigenesis. Here, we first use immunohistochemistry and real-time PCR approaches to examine the expression patterns of Nogo-B and NgBR in both normal and breast tumor tissues. Then, we examine the relationship between NgBR expression and molecular subtypes of breast cancer, and the roles of NgBR in estrogen-dependent survivin signaling pathway. Results showed that NgBR and Nogo-B protein were detected in both normal and breast tumor tissues. However, the expression of Nogo-B and NgBR in breast tumor tissue was much stronger than in normal breast tissue. The statistical analysis demonstrated that NgBR is highly associated with ER-positive/HER2-negative breast cancer. We also found that the expression of NgBR has a strong correlation with the expression of survivin, which is a well-known apoptosis inhibitor. The correlation between NgBR and survivin gene expression was further confirmed by real-time PCR. In vitro results also demonstrated that estradiol induces the expression of survivin in ER-positive T47D breast tumor cells but not in ER-negative MDA-MB-468 breast tumor cells. NgBR knockdown with siRNA abolishes estradiol-induced survivin expression in ER-positive T47D cells but not in ER-negative MDA-MB-468 cells. In addition, estradiol increases the expression of survivin and cell growth in ER-positive MCF-7 and T47D cells whereas knockdown of NgBR with siRNA reduces estradiol-induced survivin expression and cell growth. In summary, these results indicate that NgBR is a new molecular marker for breast cancer. The data suggest that the expression of NgBR may be essential in promoting ER-positive tumor cell proliferation via survivin induction in breast cancer.

Nogo-B receptor (NgBR), a type I single transmembrane domain receptor is the specific receptor for Nogo-B. Our previous work demonstrated that NgBR is highly expressed in breast cancer cells, where it promotes epithelial mesenchymal transition (EMT), an important step in metastasis. Here, we show that both in vitro and in vivo increased expression of NgBR contributes to the increased chemoresistance of Bel7402/5FU cells, a stable 5-FU (5-Fluorouracil) resistant cell line related Bel7402 cells. NgBR knockdown abrogates S-phase arrest in Bel7402/5FU cells, which correlates with a reduction in G1/S phase checkpoint proteins p53 and p21. In addition, NgBR suppresses p53 protein levels through activation of the PI3K/Akt/MDM2 pathway, which promotes p53 degradation via the ubiquitin proteasome pathway and thus increases the resistance of human hepatocellular cancer cells to 5-FU. Furthermore, we found that NgBR expression is associated with a poor prognosis of human hepatocellular carcinoma (HCC) patients. These results suggest that targeting NgBR in combination with chemotherapeutic drugs, such as 5-FU, could improve the efficacy of current anticancer treatments.

The localization of prenylated Ras at the plasma membrane promotes activation of Ras by receptor tyrosine kinases and stimulates oncogenic signaling by mutant Ras. The Nogo-B receptor (NgBR) is a transmembrane receptor that contains a conserved hydrophobic pocket. Here, we demonstrate that the NgBR promotes the membrane accumulation of Ras by directly binding prenylated Ras at the plasma membrane. We show that NgBR knockdown diminishes the membrane localization of Ras in multiple cell types. NgBR overexpression in NIH-3T3 fibroblasts increases membrane-associated Ras, induces the transformed phenotype in vitro, and promotes the formation of fibrosarcoma in nude mice. NgBR knockdown in human breast cancer cells reduces Ras membrane localization, inhibits EGF-stimulated Ras signaling, and diminishes tumorigenesis of xenografts in nude mice. Our data demonstrate that NgBR is a unique receptor that promotes accumulation of prenylated Ras at the plasma membrane and promotes EGF pathways.

This study reports the effects of upconversion nanoparticles (UCNPs) LaF3:Yb,Er on zebrafish, with the aim of investigating UCNPs toxicity. LaF3:Yb,Er were prepared by an oleic acid/ionic liquid two-phase system, and characterized by transmission electron microscope and X-ray powder diffraction. 140 zebrafish embryos were divided into six test groups and one control group, and respectively were injected into 5, 25, 50, 100, 200, 400 μg/mL LaF3:Yb,Er@SiO2 solution, and respectively were raised for 5 days. Each experiment was repeated ten times. Results showed that water-soluble LaF3:Yb,Er were successfully prepared, and did not exhibit obvious toxicity to zebrafish embryos under 100 μg/mL, but exhibited chronic toxicities 200 μg/mL in vivo, resulting in malformations and delayed hatching rate and embryonic and larval development. The excretion channels of LaF3:Yb,Er in adult zebrafish were mainly found in the intestine after being injected evenly for 24 h. In conclusion, the exploration of LaF3:Yb,Er for in vivo applications in animals and humans must consider UCNPs biocompatibility.

Nogo-B receptor (NgBR) was identified as a specific receptor for binding Nogo-B, and is essential for the stability of Niemann-Pick type C2 protein (NPC2) and NPC2-dependent cholesterol trafficking. Here, we report that NgBR expression levels decrease in the fatty liver and that NgBR plays previously unrecognized roles in regulating hepatic lipogenesis via NPC2-independent pathways. To further elucidate the pathophysiological role of NgBR in mammals, we generated NgBR liver-specific knockout mice and investigated the roles of NgBR in hepatic lipid homeostasis. Our results showed that NgBR knockout in mouse liver did not decrease either NPC2 levels or increase NPC2-dependent intracellular cholesterol levels. However, NgBR deficiency still resulted in remarkable cellular lipid accumulation that was associated with increased free fatty acids (FFA) and triglycerides (TG) in hepatocytes in vitro and in mouse livers in vivo. Mechanistically, NgBR deficiency specifically promotes the nuclear translocation of the liver X receptor alpha (LXRα) and increases the expression of LXRα-targeted lipogenic genes. LXRα knockout attenuates the accumulation of FFA and TG caused by NgBR deficiency. In addition, we elucidated the mechanisms by which NgBR bridges the AMP-activated protein kinase α (AMPKα) signaling pathway with LXRα nuclear translocation and LXRα-mediated lipogenesis. Our study demonstrates that NgBR is a specific negative regulator for LXRα–dependent hepatic lipogenesis and suggests that loss of NgBR is a potential trigger for inducing hepatic steatosis.

An ideal brain-targeted nanocarrier must be sufficiently potent to penetrate the blood-brain barrier (BBB) and sufficiently competent to target the cells of interest with adequate optimized physiochemical features and biocompatibility. However, it is an enormous challenge to the researchers to organize the above-mentioned properties into a single nanocarrier particle. New frontiers in nanomedicine are advancing the research of new biomaterials. Herein, we demonstrate a straightforward strategy for brain targeting by encapsulating doxorubicin (DOX) into a naturally available and unmodified apoferritin nanocage (DOX-loaded APO). APO can specifically bind to cells expressing transferrin receptor 1 (TfR1). Because of the high expression of TfR1 in both brain endothelial and glioma cells, DOX-loaded APO can cross the BBB and deliver drugs to the glioma with TfR1. Subsequent research demonstrated that the DOX-loaded APO had good physicochemical properties (particle size of 12.03 ± 0.42 nm, drug encapsulation efficiency of 81.8 ± 1.1%) and significant penetrating and targeting effects in the coculture model of bEnd.3 and C6 cells in vitro. In vivo imaging revealed that DOX-loaded APO accumulated specifically in brain tumor tissues. Additionally, in vivo tumor therapy experiments (at a dosage of 1 mg/kg DOX) demonstrated that a longer survival period was observed in mice that had been treated with DOX-loaded APO (30 days) compared with mice receiving free DOX solution (19 days).