title: MALAT1 Long Non-coding RNA Expression in Thyroid Tissues: Analysis by In Situ Hybridization and Real-Time PCR.
abstract: Long non-coding RNAs (lncRNAs) are important for transcription and for epigenetic or posttranscriptional regulation of gene expression and may contribute to carcinogenesis. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), an lncRNA involved in the regulation of the cell cycle, cell proliferation, and cell migration, is known to be deregulated in multiple cancers. Here, we analyzed the expression of MALAT1 on 195 cases of benign and malignant thyroid neoplasms by using tissue microarrays for RNA in situ hybridization (ISH) and real-time PCR. MALAT1 is highly expressed in normal thyroid (NT) tissues and thyroid tumors, with increased expression during progression from NT to papillary thyroid carcinomas (PTCs) but is downregulated in poorly differentiated thyroid cancers (PDCs) and anaplastic thyroid carcinomas (ATCs) compared to NT. Induction of epithelial to mesenchymal transition (EMT) by transforming growth factor (TGF)-beta in a PTC cell line (TPC1) led to increased MALAT1 expression, supporting a role for MALAT1 in EMT in thyroid tumors. This is the first ISH study of MALAT1 expression in thyroid tissues. It also provides the first piece of evidence suggesting MALAT1 downregulation in certain thyroid malignancies. Our findings support the notion that ATCs may be molecularly distinct from low-grade thyroid malignancies and suggest that MALAT1 may function both as an oncogene and as a tumor suppressor in different types of thyroid tumors.
authors.affiliation: Department of Laboratory Medicine and Pathology K4/436, University of Wisconsin School of Medicine and Public Health, Box 8550, Madison, WI, 53792, USA.
authors.forename: Ranran
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Laboratory Medicine and Pathology K4/436, University of Wisconsin School of Medicine and Public Health, Box 8550, Madison, WI, 53792, USA.
authors.forename: Heather
authors.initials: H
authors.lastname: Hardin
authors.affiliation: Department of Laboratory Medicine and Pathology K4/436, University of Wisconsin School of Medicine and Public Health, Box 8550, Madison, WI, 53792, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.affiliation: Department of Laboratory Medicine and Pathology K4/436, University of Wisconsin School of Medicine and Public Health, Box 8550, Madison, WI, 53792, USA.
authors.forename: Jidong
authors.initials: J
authors.lastname: Chen
authors.affiliation: University of Bologna, Bologna, Italy.
authors.forename: Sofia
authors.initials: S
authors.lastname: Asioli
authors.affiliation: Rizzoli Institute, Bologna, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Righi
authors.affiliation: University of Turin, Turin, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Maletta
authors.affiliation: University of Turin, Turin, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Sapino
authors.affiliation: Department of Laboratory Medicine and Pathology K4/436, University of Wisconsin School of Medicine and Public Health, Box 8550, Madison, WI, 53792, USA. rvlloyd@wisc.edu.
authors.forename: Ricardo V
authors.initials: RV
authors.lastname: Lloyd
mesh_terms: D058750:Epithelial-Mesenchymal Transition / Q000235:genetics; D006801:Humans; D007091:Image Processing, Computer-Assisted; D017403:In Situ Hybridization; D062085:RNA, Long Noncoding / Q000096:biosynthesis*; D060888:Real-Time Polymerase Chain Reaction; D013961:Thyroid Gland / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology*; D046888:Tissue Array Analysis
chemical_list: C557041:MALAT1 long non-coding RNA, human; D062085:RNA, Long Noncoding
keywords: In situ hybridization; Long non-coding RNA; MALAT1; Papillary thyroid carcinoma; RT-PCR; Thyroid carcinoma