Dataset Information

A Novel Tissue and Stem Cell Specific TERF1 Splice Variant Is Downregulated in Tumour Cells.

ABSTRACT: In this study, we describe the identification of a novel splice variant of TERF1/PIN2, one of the main components of the telomeric shelterin complex. This new splice variant is identical to TERF1, apart from a 30 amino acid internal insertion near to the C-terminus of TERF1. Based on genome comparison analyses and RNA expression data, we show that this splice variant is conserved among hominidae but absent from all other species. RNA expression and histological analyses show specific expression in human spermatogonial and hematopoietic stem cells (HSCs), while all other analyzed tissues lack the expression of this TERF1-isoform, hence the name TERF1-tsi (TERF1-tissue-specific-isoform). In addition, we could not detect any expression in primary human cells and established cancer cell lines. Immunohistochemistry results involving two new rabbit polyclonal antibodies, generated against TERF1-tsi specific peptides, indicate nuclear localization of TERF1-tsi in a subset of spermatogonial stem cells. In line with this observation, immunofluorescence analyzes in various cell lines consistently revealed that ectopic TERF1-tsi localizes to the cell nucleus, mainly but not exclusively at telomeres. In a first attempt to evaluate the impact of TERF1-tsi in the testis, we have tested its expression in normal testis samples versus matched tumor samples from the same patients. Both RT-PCR and IHC show a specific downregulation of TERF1-tsi in tumor samples while the expression of TERF1 and PIN2 remains unchanged.

SUBMITTER: Morcos YAT

PROVIDER: S-EPMC6981981 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

A Novel Tissue and Stem Cell Specific TERF1 Splice Variant Is Downregulated in Tumour Cells.

Morcos Yousef Ashraf Tawfik YAT Najjar Gregoire G Meessen Sabine S Witt Britta B Azoitei Anca A Kumar Mukesh M Wakileh Gamal G Schwarz Klaus K Schrezenmeier Hubert H Zengerling Friedemann F Bolenz Christian C Günes Cagatay C

International journal of molecular sciences 20191220 1

In this study, we describe the identification of a novel splice variant of TERF1/PIN2, one of the main components of the telomeric shelterin complex. This new splice variant is identical to TERF1, apart from a 30 amino acid internal insertion near to the C-terminus of TERF1. Based on genome comparison analyses and RNA expression data, we show that this splice variant is conserved among hominidae but absent from all other species. RNA expression and histological analyses show specific expression ...[more]

PMID: 31877678

Similar Datasets

Project description:BackgroundMyostatin, encoded by the MSTN gene comprising 3 exons, is a potent negative regulator of skeletal muscle growth. Although a variety of myostatin inhibitors have been invented for increasing muscle mass in muscle wasting diseases, no effective inhibitor is currently available for clinical use. Myostatin isoforms in several animals have been reported to inhibit myostatin, but an isoform has never been identified for the human MSTN gene, a conserved gene among animals. Here, a splice variant of the human MSTN gene was explored.MethodsTranscripts and proteins were analysed by reverse transcription-PCR amplification and western blotting, respectively. Proteins were expressed from expression plasmid. Myostatin signalling was assayed by the SMAD-responsive luciferase activity. Cell proliferation was assayed by the Cell Counting Kit-8 (CCK-8) assay and cell counting. Cell cycle was analysed by the FastFUCCI system.ResultsReverse transcription-PCR amplification of the full-length MSTN transcript in CRL-2061 rhabdomyosarcoma cells revealed two bands consisting of a thick expected-size product and a thin additional small-size product. Sequencing of the small-size product showed a 963-bp deletion in the 5' end of exon 3, creating exon 3s, which contained unusual splice acceptor TG dinucleotides. The novel variant was identified in other human cell lines, although it was not identified in skeletal muscle. The 251-amino acid isoform encoded by the novel variant (myostatin-b) was identified in CRL-2061 rhabdomyosarcoma cells. Transfection of a myostatin-b expression plasmid into CRL-2061 and myoblast cells inhibited endogenous myostatin signalling (44%, P < 0.001 and 63%, P < 0.001, respectively). Furthermore, myostatin-b inhibited myostatin signalling induced by recombinant myostatin (68.8%, P < 0.001). In remarkable contrast, myostatin-b did not inhibit the myostatin signalling induced by recombinant growth differentiation factor 11 (9.2%, P = 0.70), transforming growth factor β (+3.1%, P = 0.83) or activin A (+1.1%, P = 0.96). These results indicate the myostatin-specific inhibitory effect of myostatin-b. Notably, the expression of myostatin-b in myoblasts significantly enhanced cell proliferation higher than the mock-transfected cells by the CCK-8 and direct cell counting assays (60%, P < 0.05 and 39%, P < 0.05, respectively). Myostatin-b increased the percentage of S-phase cells significantly higher than that of the mock-transfected cells (53% vs. 80%, P < 0.05).ConclusionsWe cloned a novel human MSTN variant produced by unorthodox splicing. The variant encoded a novel myostatin isoform, myostatin-b, that inhibited myostatin signalling by myostatin-specific manner and enhanced myoblast proliferation by shifting cell cycle. Myostatin-b, which has myostatin-specific inhibitory activity, could be developed as a natural myostatin inhibitor.

Dataset Information

A Novel Tissue and Stem Cell Specific TERF1 Splice Variant Is Downregulated in Tumour Cells.

Publications

A Novel Tissue and Stem Cell Specific TERF1 Splice Variant Is Downregulated in Tumour Cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets