Probes for LONG

Long non-coding RNAs (lncRNAs) may contribute to carcinogenesis and tumor progression by regulating transcription and gene expression. The role of lncRNAs in the regulation of thyroid cancer progression is being extensively examined. Here, we analyzed three lncRNAs that were overexpressed in papillary thyroid carcinomas, long intergenic non-protein coding RNA, regulator of reprogramming (Linc-ROR, ROR) PVT1 oncogene (PVT1), and HOX transcript antisense intergenic RNA (HOTAIR) to determine their roles in thyroid tumor development and progression. ROR expression has not been previously examined in thyroid carcinomas. Tissue microarrays (TMAs) of formalin-fixed paraffin-embedded tissue sections from 129 thyroid cases of benign and malignant tissues were analyzed by in situ hybridization (ISH), automated image analysis, and real-time PCR. All three lncRNAs were most highly expressed in the nuclei of PTCs. SiRNA experiments with a PTC cell line, TPC1, showed inhibition of proliferation with siRNAs for all three lncRNAs while invasion was inhibited with siRNAs for ROR and HOTAIR. SiRNA experiments with ROR also led to increased expression of miR-145, supporting the role of ROR as an endogenous miR-145 sponge. After treatment with TGF-β, there was increased expression of ROR, PVT1, and HOTAIR in the PTC1 cell line compared to control groups, indicating an induction of their expression during epithelial to mesenchymal transition (EMT). These results indicate that ROR, PVT1, and HOTAIR have important regulatory roles during the development of PTCs.

Past studies have suggested that non-neuronal brain cells express the leptin receptor. However, the identity and distribution of these leptin receptor-expressing non-neuronal brain cells remain debated. This study assessed the distribution of the long form of the leptin receptor (LepRb) in non-neuronal brain cells using a reporter mouse model in which LepRb-expressing cells are permanently marked by tdTomato fluorescent protein (LepRb-CretdTomato). Double immunohistochemistry revealed that, in agreement with the literature, the vast majority of tdTomato-tagged cells across the mouse brain were neurons (i.e., based on immunoreactivity for NeuN). Non-neuronal structures also contained tdTomato-positive cells, including the choroid plexus and the perivascular space of the meninges and, to a lesser extent, the brain. Based on morphological criteria and immunohistochemistry, perivascular cells were deduced to be mainly pericytes. Notably, tdTomato-positive cells were immunoreactive for vitronectin and platelet derived growth factor receptor beta (PDGFBR). In situ hybridization studies confirmed that most tdTomato-tagged perivascular cells were enriched in leptin receptor mRNA (all isoforms). Using qPCR studies, we confirmed that the mouse meninges were enriched in Leprb and, to a greater extent, the short isoforms of the leptin receptor. Interestingly, qPCR studies further demonstrated significantly altered expression for Vtn and Pdgfrb in the meninges and hypothalamus of LepRb-deficient mice. Collectively, our data demonstrate that the only intracranial non-neuronal cells that express LepRb in the adult mouse are cells that form the blood-brain barrier, including, most notably, meningeal perivascular cells. Our data suggest that pericytic leptin signaling plays a role in the integrity of the intracranial perivascular space and, consequently, may provide a link between obesity and numerous brain diseases.