1
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Machitani M, Nomura A, Yamashita T, Yasukawa M, Ueki S, Fujita KI, Ueno T, Yamashita A, Tanzawa Y, Watanabe M, Taniguchi T, Saitoh N, Kaneko S, Kato Y, Mano H, Masutomi K. Maintenance of R-loop structures by phosphorylated hTERT preserves genome integrity. Nat Cell Biol 2024; 26:932-945. [PMID: 38806647 DOI: 10.1038/s41556-024-01427-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 04/23/2024] [Indexed: 05/30/2024]
Abstract
As aberrant accumulation of RNA-DNA hybrids (R-loops) causes DNA damage and genome instability, cells express regulators of R-loop structures. Here we report that RNA-dependent RNA polymerase (RdRP) activity of human telomerase reverse transcriptase (hTERT) regulates R-loop formation. We found that the phosphorylated form of hTERT (p-hTERT) exhibits RdRP activity in nuclear speckles both in telomerase-positive cells and telomerase-negative cells with alternative lengthening of telomeres (ALT) activity. The p-hTERT did not associate with telomerase RNA component in nuclear speckles but, instead, with TERRA RNAs to resolve R-loops. Targeting of the TERT gene in ALT cells ablated RdRP activity and impaired tumour growth. Using a genome-scale CRISPR loss-of-function screen, we identified Fanconi anaemia/BRCA genes as synthetic lethal partners of hTERT RdRP. Inactivation of RdRP and Fanconi anaemia/BRCA genes caused accumulation of R-loop structures and DNA damage. These findings indicate that RdRP activity of p-hTERT guards against genome instability by removing R-loop structures.
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Affiliation(s)
- Mitsuhiro Machitani
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Akira Nomura
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
- Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Isehara, Japan
| | - Taro Yamashita
- Department of Gastroenterology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Mami Yasukawa
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Saori Ueki
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Ken-Ichi Fujita
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Toshihide Ueno
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, Japan
| | - Akio Yamashita
- Department of Investigative Medicine, University of the Ryukyus Graduate School of Medicine, Nakagami, Japan
| | - Yoshikazu Tanzawa
- Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Isehara, Japan
| | - Masahiko Watanabe
- Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine, Isehara, Japan
| | - Toshiyasu Taniguchi
- Department of Molecular Life Science, Tokai University School of Medicine, Isehara, Japan
| | - Noriko Saitoh
- Division of Cancer Biology, The Cancer Institute of JFCR, Tokyo, Japan
| | - Shuichi Kaneko
- Department of Gastroenterology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Yukinari Kato
- Department of Antibody Drug Development, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Molecular Pharmacology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroyuki Mano
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, Japan
| | - Kenkichi Masutomi
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan.
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2
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Kurimoto M, Rockenbach Y, Kato A, Natsume A. Prediction of Tumor Development and Urine-Based Liquid Biopsy for Molecule-Targeted Therapy of Gliomas. Genes (Basel) 2023; 14:1201. [PMID: 37372381 DOI: 10.3390/genes14061201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 05/21/2023] [Accepted: 05/25/2023] [Indexed: 06/29/2023] Open
Abstract
The timing of the acquisition of tumor-specific gene mutations and the systems by which these gene mutations are acquired during tumorigenesis were clarified. Advances in our understanding of tumorigenesis are being made every day, and therapies targeting fundamental genetic alterations have great potential for cancer treatment. Moreover, our research team successfully estimated tumor progression using mathematical modeling and attempted early diagnosis of brain tumors. We developed a nanodevice that enables urinary genetic diagnosis in a simple and noninvasive manner. Mainly on the basis of our research and experience, this review article presents novel therapies being developed for central nervous system cancers and six molecules, which upon mutation cause tumorigenesis and tumor progression. Further understanding of the genetic characteristics of brain tumors will lead to the development of precise drugs and improve individual treatment outcomes.
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Affiliation(s)
- Michihiro Kurimoto
- Department of Neurosurgery, Aichi Children's Health and Medical Center, Obu 464-8710, Japan
| | - Yumi Rockenbach
- Institute of Innovation for Future Society, Nagoya University, Nagoya 464-8601, Japan
| | - Akira Kato
- Institute of Innovation for Future Society, Nagoya University, Nagoya 464-8601, Japan
| | - Atsushi Natsume
- Institute of Innovation for Future Society, Nagoya University, Nagoya 464-8601, Japan
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3
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Arita H, Ichimura K. Prognostic significance of TERT promoter mutations in adult-type diffuse gliomas. Brain Tumor Pathol 2022; 39:121-129. [DOI: 10.1007/s10014-021-00424-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/19/2021] [Indexed: 12/12/2022]
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4
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Matsuda Y, Yamashita T, Ye J, Yasukawa M, Yamakawa K, Mukai Y, Machitani M, Daigo Y, Miyagi Y, Yokose T, Oshima T, Ito H, Morinaga S, Kishida T, Minamoto T, Yamada S, Takei J, Kaneko MK, Kojima M, Kaneko S, Masaki T, Hirata M, Haba R, Kontani K, Kanaji N, Miyatake N, Okano K, Kato Y, Masutomi K. Phosphorylation of
hTERT
at threonine 249 is a novel tumor biomarker of aggressive cancer with poor prognosis in multiple organs. J Pathol 2022; 257:172-185. [PMID: 35094384 PMCID: PMC9315154 DOI: 10.1002/path.5876] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 11/07/2022]
Abstract
Recent evidence indicates that RNA‐dependent RNA polymerase (RdRP) activity of human telomerase reverse transcriptase (hTERT) regulates expression of target genes and is directly involved in tumor formation in a telomere‐independent manner. Non‐canonical function of hTERT has been considered as a therapeutic target for cancer therapy. We have previously shown that hTERT phosphorylation at threonine 249 (p‐hTERT), which promotes RdRP activity, is an indicator of an aggressive phenotype and poor prognosis in liver and pancreatic cancers, using two cohorts with small sample sizes with polyclonal p‐hTERT antibody. To clarify the clinical relevance of p‐hTERT, we developed a specific monoclonal antibody and determined the diagnostic and prognostic value of p‐hTERT in cancer specimens using a large cohort. A monoclonal antibody for phosphorylated hTERT (p‐hTERT) at threonine 249 was developed and validated. The antibody was used for the immunohistochemical staining of formalin‐fixed, paraffin‐embedded specimens from 1523 cases of lung, colon, stomach, pancreatic, liver, breast, and kidney cancers. We detected elevated p‐hTERT expression levels in cases with a high mitotic activity, high pathological grade, and high nuclear pleomorphism. Elevated p‐hTERT expression was an independent prognostic factor for lung, pancreatic, and liver cancers. Furthermore, p‐hTERT expression was associated with immature and aggressive features, such as adenosquamous carcinoma (lung and pancreas), invasive type of cancer (lung), high serum alpha‐fetoprotein level (liver), and triple‐negative status (breast). In conclusion, RdRP activity indicated by p‐hTERT expression predicts aggressive cancer phenotypes in various types of cancer. Thus, p‐hTERT is a novel biomarker for the diagnosis of aggressive cancers with a poor prognosis. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Yoko Matsuda
- Oncology Pathology, Department of Pathology and Host‐Defense, Faculty of Medicine Kagawa University, 1750‐1 Ikenobe, Miki‐cho Kita‐gun Kagawa 761‐0793 Japan
| | - Taro Yamashita
- Department of Gastroenterology Kanazawa University Graduate School of Medical Sciences 13‐1 Takara‐machi Kanazawa Ishikawa 920‐8641 Japan
| | - Juanjuan Ye
- Oncology Pathology, Department of Pathology and Host‐Defense, Faculty of Medicine Kagawa University, 1750‐1 Ikenobe, Miki‐cho Kita‐gun Kagawa 761‐0793 Japan
| | - Mami Yasukawa
- Division of Cancer Stem Cell National Cancer Center Research Institute 5‐1‐1 Tsukiji, Chuo‐ku Tokyo 104‐0045 Japan
| | - Keiko Yamakawa
- Oncology Pathology, Department of Pathology and Host‐Defense, Faculty of Medicine Kagawa University, 1750‐1 Ikenobe, Miki‐cho Kita‐gun Kagawa 761‐0793 Japan
| | - Yuri Mukai
- Oncology Pathology, Department of Pathology and Host‐Defense, Faculty of Medicine Kagawa University, 1750‐1 Ikenobe, Miki‐cho Kita‐gun Kagawa 761‐0793 Japan
| | - Mitsuhiro Machitani
- Division of Cancer Stem Cell National Cancer Center Research Institute 5‐1‐1 Tsukiji, Chuo‐ku Tokyo 104‐0045 Japan
| | - Yataro Daigo
- Department of Medical Oncology and Cancer Center
- Center for Advanced Medicine against Cancer, Shiga University of Medical Science Otsu Shiga 520‐2192 Japan
- Center for Antibody and Vaccine Therapy, Research Hospital, Institute of Medical Science Hospital, The University of Tokyo Tokyo 108‐8639 Japan
| | - Yohei Miyagi
- Kanagawa Cancer Center Research Institute, 2‐3‐2 Nakao, Asahi‐ku Yokohama 241‐8515 Japan
| | | | | | | | | | - Takeshi Kishida
- Department of Urology, Kanagawa Cancer Center, 2‐3‐2 Nakao, Asahi‐ku Yokohama 241‐8515 Japan
| | - Toshinari Minamoto
- Divison of Translational and Clinical Oncology, Cancer Research Institute, Kanazawa University, 13‐1 Takara‐machi Kanazawa 920‐0934 Japan
| | - Shinji Yamada
- Department of Antibody Drug Development Tohoku University Graduate School of Medicine, 2‐1 Seiryo‐machi, Aoba‐ku Sendai Miyagi 980‐8575 Japan
| | - Junko Takei
- Department of Antibody Drug Development Tohoku University Graduate School of Medicine, 2‐1 Seiryo‐machi, Aoba‐ku Sendai Miyagi 980‐8575 Japan
| | - Mika K. Kaneko
- Department of Antibody Drug Development Tohoku University Graduate School of Medicine, 2‐1 Seiryo‐machi, Aoba‐ku Sendai Miyagi 980‐8575 Japan
| | - Motohiro Kojima
- Division of Pathology, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, 6‐5‐1 Kashiwanoha, Kashiwa‐shi Chiba 277‐0882 Japan
| | - Shuichi Kaneko
- Department of Gastroenterology Kanazawa University Graduate School of Medical Sciences 13‐1 Takara‐machi Kanazawa Ishikawa 920‐8641 Japan
| | | | | | | | | | - Nobuhiro Kanaji
- Department of Internal Medicine, Division of Hematology Rheumatology and Respiratory Medicine
| | | | - Keiichi Okano
- Department of Gastroenterological Surgery, Faculty of Medicine Kagawa University, 1750‐1 Ikenobe, Miki‐cho Kita‐gun Kagawa 761‐0793 Japan
| | - Yukinari Kato
- Department of Antibody Drug Development Tohoku University Graduate School of Medicine, 2‐1 Seiryo‐machi, Aoba‐ku Sendai Miyagi 980‐8575 Japan
- Department of Molecular Pharmacology Tohoku University Graduate School of Medicine, 2‐1 Seiryo‐machi, Aoba‐ku Sendai Miyagi 980‐8575 Japan
| | - Kenkichi Masutomi
- Division of Cancer Stem Cell National Cancer Center Research Institute 5‐1‐1 Tsukiji, Chuo‐ku Tokyo 104‐0045 Japan
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5
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Pradhan RK, Ramakrishna W. Transposons: Unexpected players in cancer. Gene 2022; 808:145975. [PMID: 34592349 DOI: 10.1016/j.gene.2021.145975] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/19/2021] [Accepted: 09/24/2021] [Indexed: 12/21/2022]
Abstract
Transposons are repetitive DNA sequences encompassing about half of the human genome. They play a vital role in genome stability maintenance and contribute to genomic diversity and evolution. Their activity is regulated by various mechanisms considering the deleterious effects of these mobile elements. Various genetic risk factors and environmental stress conditions affect the regulatory pathways causing alteration of transposon expression. Our knowledge of the biological role of transposons is limited especially in various types of cancers. Retrotransposons of different types (LTR-retrotransposons, LINEs and SINEs) regulate a plethora of genes that have a role in cell reprogramming, tumor suppression, cell cycle, apoptosis, cell adhesion and migration, and DNA repair. The regulatory mechanisms of transposons, their deregulation and different mechanisms underlying transposon-mediated carcinogenesis in humans focusing on the three most prevalent types, lung, breast and colorectal cancers, were reviewed. The modes of regulation employed include alternative splicing, deletion, insertion, duplication in genes and promoters resulting in upregulation, downregulation or silencing of genes.
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6
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Nakano T, Fujimoto K, Tomiyama A, Takahashi M, Achiha T, Arita H, Kawauchi D, Yasukawa M, Masutomi K, Kondo A, Narita Y, Maehara T, Ichimura K. Eribulin prolongs survival in an orthotopic xenograft mouse model of malignant meningioma. Cancer Sci 2021; 113:697-708. [PMID: 34839570 PMCID: PMC8819309 DOI: 10.1111/cas.15221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 11/04/2021] [Accepted: 11/22/2021] [Indexed: 11/27/2022] Open
Abstract
Meningioma is the most common intracranial tumor, with generally favorable patient prognosis. However, patients with malignant meningioma typically experience recurrence, undergo multiple surgical resections, and ultimately have a poor prognosis. Thus far, effective chemotherapy for malignant meningiomas has not been established. We recently reported the efficacy of eribulin (Halaven) for glioblastoma with a telomerase reverse transcriptase (TERT) promoter mutation. This study investigated the anti–tumor effect of eribulin against TERT promoter mutation‐harboring human malignant meningioma cell lines in vitro and in vivo. Two meningioma cell lines, IOMM‐Lee and HKBMM, were used in this study. The strong inhibition of cell proliferation by eribulin via cell cycle arrest was demonstrated through viability assay and flow cytometry. Apoptotic cell death in malignant meningioma cell lines was determined through vital dye assay and immunoblotting. Moreover, a wound healing assay revealed the suppression of tumor cell migration after eribulin exposure. Intraperitoneal administration of eribulin significantly prolonged the survival of orthotopic xenograft mouse models of both malignant meningioma cell lines implanted in the subdural space (P < .0001). Immunohistochemistry confirmed apoptosis in brain tumor tissue treated with eribulin. Overall, these results suggest that eribulin is a potential therapeutic agent for malignant meningiomas.
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Affiliation(s)
- Tomoyuki Nakano
- Division of Brain Tumor Translational Research, National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan.,Department of Neurosurgery, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan.,Department of Brain Disease Translational Research, Juntendo University School of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Kenji Fujimoto
- Division of Brain Tumor Translational Research, National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan.,Department of Neurosurgery, Graduate School of Life Sciences, Kumamoto University, Honjo, Kumamoto, Japan
| | - Arata Tomiyama
- Division of Brain Tumor Translational Research, National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan.,Department of Brain Disease Translational Research, Juntendo University School of Medicine, Bunkyo-ku, Tokyo, Japan.,Department of Neurosurgery, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Masamichi Takahashi
- Division of Brain Tumor Translational Research, National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan.,Department of Neurosurgery and Neuro-Oncology, National Cancer Center Hospital, Chuo-ku, Tokyo, Japan
| | - Takamune Achiha
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Hideyuki Arita
- Department of Neurosurgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Daisuke Kawauchi
- Division of Brain Tumor Translational Research, National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan.,Department of Neurological Surgery, Chiba University Graduate School of Medicine, Chuo-ku, Chiba-shi, Chiba, Japan
| | - Mami Yasukawa
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan
| | - Kenkichi Masutomi
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan
| | - Akihide Kondo
- Department of Neurosurgery, Juntendo University School of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Yoshitaka Narita
- Department of Neurosurgery and Neuro-Oncology, National Cancer Center Hospital, Chuo-ku, Tokyo, Japan
| | - Taketoshi Maehara
- Department of Neurosurgery, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Koichi Ichimura
- Division of Brain Tumor Translational Research, National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan.,Department of Brain Disease Translational Research, Juntendo University School of Medicine, Bunkyo-ku, Tokyo, Japan
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7
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Machitani M, Yasukawa M, Nakashima J, Furuichi Y, Masutomi K. RNA-dependent RNA polymerase, RdRP, a promising therapeutic target for cancer and potentially COVID-19. Cancer Sci 2020; 111:3976-3984. [PMID: 32805774 PMCID: PMC7461281 DOI: 10.1111/cas.14618] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/11/2020] [Accepted: 08/13/2020] [Indexed: 12/12/2022] Open
Abstract
A recent outbreak of coronavirus disease (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 has driven a global pandemic with catastrophic consequences. The rapid development of promising therapeutic strategies against COVID-19 is keenly anticipated. Family Coronaviridae comprises positive, single-stranded RNA viruses that use RNA-dependent RNA polymerase (RdRP) for viral replication and transcription. As the RdRP of viruses in this family and others plays a pivotal role in infection, it is a promising therapeutic target for developing antiviral agents against them. A critical genetic driver for many cancers is the catalytic subunit of telomerase: human telomerase reverse transcriptase (hTERT), identified initially as an RNA-dependent DNA polymerase. However, even though hTERT is a DNA polymerase, it has phylogenetic and structural similarities to viral RdRPs. Researchers worldwide, including the authors of this review, are engaged in developing therapeutic strategies targeting hTERT. We have published a series of papers reporting that hTERT has RdRP activity and that this RdRP activity in hTERT is essential for tumor formation. Here, we review the enzymatic function of RdRP in virus proliferation and tumor development, reminding us of how the study of the novel coronavirus has brought us to the unexpected intersection of cancer research and RNA virus research.
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Affiliation(s)
- Mitsuhiro Machitani
- Division of Cancer Stem CellNational Cancer Center Research InstituteTokyoJapan
| | - Mami Yasukawa
- Division of Cancer Stem CellNational Cancer Center Research InstituteTokyoJapan
| | - Jotaro Nakashima
- Division of Cancer Stem CellNational Cancer Center Research InstituteTokyoJapan
| | | | - Kenkichi Masutomi
- Division of Cancer Stem CellNational Cancer Center Research InstituteTokyoJapan
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8
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Alibardi L. Immunostaining of telomerase in embryonic and juvenile feather follicle of the chick labels proliferating cells for feather formation. ZOOLOGY 2020; 146:125846. [PMID: 33813250 DOI: 10.1016/j.zool.2020.125846] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 09/05/2020] [Accepted: 09/16/2020] [Indexed: 11/26/2022]
Abstract
Feathers regenerate through proliferation of cells derived from follicle stem cells. Immunoloblotting for telomerase in chick embryonic and juvenile feathers shows immunopositive bands around 100 kDa, 75 and 60 kDa only in embryonic feathers, indicating fragmentation of the protein due to physiological processing or artifacts derived from protein extraction. Immunolabeling for telomerase is present in the cytoplasm and nuclei of cells of the collar epithelium and bulge located in the follicle, and in sparse cells of the dermal papilla. PCNA-immunolabeling indicates that the collar and dermal papilla contain numerous proliferating cells, including the ramogenic zone where barb ridges are formed. Ultrastructural labeling indicates that a telomerase-like protein or its fragment is localized in nucleoli and in sparse nuclear clumps, likely representing Cajal bodies. The cytoplasm shows sparse immune-gold particles, also associated to mitochondria and sparse keratin filaments. An intense labeling is present in some areas of condensing chromosomes in dividing cells. Since telomerase positive cells are also seen in suprabasal layers of the collar epithelium and in the ramogenic zone, it is suggested that they represent dividing cells, most likely transit amplifying cells that give rise to the corneocytes of feathers. The significance of telomerase localization in chromatin is unknown.
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Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and Department of Biology, University of Bologna, Bologna, Italy.
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9
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Telomerase Biogenesis and Activities from the Perspective of Its Direct Interacting Partners. Cancers (Basel) 2020; 12:cancers12061679. [PMID: 32599885 PMCID: PMC7352425 DOI: 10.3390/cancers12061679] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/20/2020] [Accepted: 06/22/2020] [Indexed: 12/15/2022] Open
Abstract
Telomerase reverse transcriptase (TERT)—the catalytic subunit of telomerase—is reactivated in up to 90% of all human cancers. TERT is observed in heterogenous populations of protein complexes, which are dynamically regulated in a cell type- and cell cycle-specific manner. Over the past two decades, in vitro protein–protein interaction detection methods have discovered a number of endogenous TERT binding partners in human cells that are responsible for the biogenesis and functionalization of the telomerase holoenzyme, including the processes of TERT trafficking between subcellular compartments, assembly into telomerase, and catalytic action at telomeres. Additionally, TERT have been found to interact with protein species with no known telomeric functions, suggesting that these complexes may contribute to non-canonical activities of TERT. Here, we survey TERT direct binding partners and discuss their contributions to TERT biogenesis and functions. The goal is to review the comprehensive spectrum of TERT pro-malignant activities, both telomeric and non-telomeric, which may explain the prevalence of its upregulation in cancer.
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10
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Yasukawa M, Ando Y, Yamashita T, Matsuda Y, Shoji S, Morioka MS, Kawaji H, Shiozawa K, Machitani M, Abe T, Yamada S, Kaneko MK, Kato Y, Furuta Y, Kondo T, Shirouzu M, Hayashizaki Y, Kaneko S, Masutomi K. CDK1 dependent phosphorylation of hTERT contributes to cancer progression. Nat Commun 2020; 11:1557. [PMID: 32214089 PMCID: PMC7096428 DOI: 10.1038/s41467-020-15289-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 03/03/2020] [Indexed: 12/24/2022] Open
Abstract
The telomerase reverse transcriptase is upregulated in the majority of human cancers and contributes directly to cell transformation. Here we report that hTERT is phosphorylated at threonine 249 during mitosis by the serine/threonine kinase CDK1. Clinicopathological analyses reveal that phosphorylation of hTERT at threonine 249 occurs more frequently in aggressive cancers. Using CRISPR/Cas9 genome editing, we introduce substitution mutations at threonine 249 in the endogenous hTERT locus and find that phosphorylation of threonine 249 is necessary for hTERT-mediated RNA dependent RNA polymerase (RdRP) activity but dispensable for reverse transcriptase and terminal transferase activities. Cap Analysis of Gene Expression (CAGE) demonstrates that hTERT phosphorylation at 249 regulates the expression of specific genes that are necessary for cancer cell proliferation and tumor formation. These observations indicate that phosphorylation at threonine 249 regulates hTERT RdRP and contributes to cancer progression in a telomere independent manner. Regulated telomerase reverse transcriptase (hTERT) activity is common in human tumors. Here, the authors show that hTERT is phosphorylated by CDK1 and that this event is necessary for hTERT-mediated RNA dependent RNA polymerase activity but not for reverse transcriptase and terminal transferase activities.
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Affiliation(s)
- Mami Yasukawa
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
| | - Yoshinari Ando
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
| | - Taro Yamashita
- Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, 920-8641, Japan
| | - Yoko Matsuda
- Department of Pathology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, 173-0015, Japan.,Oncology Pathology, Department of Pathology and Host-Defense, Kagawa University, Kagawa, 761-0793, Japan
| | - Shisako Shoji
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, 230-0045, Japan
| | - Masaki Suimye Morioka
- Preventive Medicine and Applied Genomics Unit, RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045, Japan
| | - Hideya Kawaji
- Preventive Medicine and Applied Genomics Unit, RIKEN Center for Integrative Medical Sciences, Yokohama, 230-0045, Japan.,RIKEN Preventive Medicine and Diagnosis Innovation Program, Wako, 351-0198, Japan
| | - Kumiko Shiozawa
- Division of Rare Cancer Research, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
| | - Mitsuhiro Machitani
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
| | - Takaya Abe
- Animal Resource Development Unit, RIKEN Center for Life Science Technologies, Kobe, 650-0047, Japan.,Genetic Engineering Team, RIKEN Center for Life Science Technologies, Kobe, 650-0047, Japan
| | - Shinji Yamada
- Department of Antibody Drug Development, Tohoku University Graduate School of Medicine, Sendai, 980-8575, Japan
| | - Mika K Kaneko
- Department of Antibody Drug Development, Tohoku University Graduate School of Medicine, Sendai, 980-8575, Japan
| | - Yukinari Kato
- Department of Antibody Drug Development, Tohoku University Graduate School of Medicine, Sendai, 980-8575, Japan.,New Industry Creation Hatchery Center, Tohoku University, Sendai, 980-8579, Japan
| | - Yasuhide Furuta
- Animal Resource Development Unit, RIKEN Center for Life Science Technologies, Kobe, 650-0047, Japan.,Genetic Engineering Team, RIKEN Center for Life Science Technologies, Kobe, 650-0047, Japan
| | - Tadashi Kondo
- Division of Rare Cancer Research, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
| | - Mikako Shirouzu
- Laboratory for Protein Functional and Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, 230-0045, Japan
| | | | - Shuichi Kaneko
- Department of Gastroenterology, Kanazawa University Graduate School of Medical Science, Kanazawa, 920-8641, Japan
| | - Kenkichi Masutomi
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, 104-0045, Japan.
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11
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Abstract
As cells replicate their DNA during mitosis, telomeres are shortened due to the inherent limitations of the DNA replication process. Maintenance of telomere length is critical for cancer cells to overcome cellular senescence induced by telomere shortening. Telomerase reverse transcriptase (TERT) is the rate-limiting catalytic subunit of telomerase, an RNA-dependent DNA polymerase that lengthens telomeric DNA to maintain telomere homeostasis. TERT promoter mutations, which result in the upregulation of TERT transcription, have been identified in several central nervous system (CNS) tumors, including meningiomas, medulloblastomas, and primary glial neoplasms. Furthermore, TERT promoter hypermethylation, which also results in increased TERT transcription, has been observed in ependymomas and pediatric brain tumors. The high frequency of TERT dysregulation observed in a variety of high-grade cancers makes telomerase activity an attractive target for developing novel therapeutics. In this review, we briefly discuss normal telomere biology, as well as the structure, function, and regulation of TERT in normal human cells. We also highlight the role of TERT in cancer biology, focusing on primary CNS tumors. Finally, we summarize the clinical significance of TERT promoter mutations in cancer, the molecular mechanisms through which these mutations promote oncogenesis, and recent advances in cancer therapies targeting TERT.
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Affiliation(s)
- Bhuvic Patel
- Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Rukayat Taiwo
- Department of Neurological Surgery, Stanford University, Stanford, California, USA
| | - Albert H Kim
- Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Gavin P Dunn
- Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.,Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, Missouri, USA
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12
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Gutbrod MJ, Martienssen RA. Conserved chromosomal functions of RNA interference. Nat Rev Genet 2020; 21:311-331. [PMID: 32051563 DOI: 10.1038/s41576-019-0203-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2019] [Indexed: 12/21/2022]
Abstract
RNA interference (RNAi), a cellular process through which small RNAs target and regulate complementary RNA transcripts, has well-characterized roles in post-transcriptional gene regulation and transposon repression. Recent studies have revealed additional conserved roles for RNAi proteins, such as Argonaute and Dicer, in chromosome function. By guiding chromatin modification, RNAi components promote chromosome segregation during both mitosis and meiosis and regulate chromosomal and genomic dosage response. Small RNAs and the RNAi machinery also participate in the resolution of DNA damage. Interestingly, many of these lesser-studied functions seem to be more strongly conserved across eukaryotes than are well-characterized functions such as the processing of microRNAs. These findings have implications for the evolution of RNAi since the last eukaryotic common ancestor, and they provide a more complete view of the functions of RNAi.
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Affiliation(s)
- Michael J Gutbrod
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Robert A Martienssen
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA. .,Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
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13
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Smith-Sonneborn J. Telomerase Biology Associations Offer Keys to Cancer and Aging Therapeutics. Curr Aging Sci 2020; 13:11-21. [PMID: 31544708 PMCID: PMC7403649 DOI: 10.2174/1874609812666190620124324] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/07/2019] [Accepted: 05/24/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Although telomerase has potential for age-related disease intervention, the overexpression of telomerase in about 90% of cancers, and in HIV virus reservoirs, cautions against se in anti-aging telomerase therapeutics. While multiple reviews document the canonical function of telomerase for maintenance of telomeres, as well as an increasing numbers of reviews that reveal new non-canonical functions of telomerase, there was no systematic review that focuses on the array of associates of the subunit of Telomerase Reverse transcriptase protein (TERT) as pieces of the puzzle to assemble a picture of the how specific TERT complexes uniquely impact aging and age-related diseases and more can be expected. METHODS A structured search of bibliographic data on TERT complexes was undertaken using databases from the National Center for Biotechnology Information Pubmed with extensive access to biomedical and genomic information in order to obtain a unique documented and cited overview of TERT complexes that may uniquely impact aging and age-related diseases. RESULTS The TERT associations include proper folding, intracellular TERT transport, metabolism, mitochondrial ROS (Reactive Oxygen Species) regulation, inflammation, cell division, cell death, and gene expression, in addition to the well-known telomere maintenance. While increase of cell cycle inhibitors promote aging, in cancer, the cell cycle check-point regulators are ambushed in favor of cell proliferation, while cytoplasmic TERT protects a cell cycle inhibitor in oxidative stress. The oncogene cMyc regulates gene expression for overexpression of TERT, and reduction of cell cycle inhibitors-the perfect storm for cancer promotion. TERT binds with the oncogene RMRP RNA, and TERT-RMRP function can regulate levels of that oncogene RNA, and TERT in a TBN complex can regulate heterochromatin. Telomerase benefit and novel function in neurology and cardiology studies open new anti- aging hope. GV1001, a 16 amino acid peptide of TERT that associates with Heat Shock Proteins (HSP's), bypasses the cell membrane with remarkable anti disease potential. CONCLUSIONS TERT "associates" are anti-cancer targets for downregulation, but upregulation in antiaging therapy. The overview revealed that unique TERT associations that impact all seven pillars of aging identified by the Trans-NIH Geroscience Initiative that influence aging and urge research for appropriate targeted telomerase supplements/ stimulation, and inclusion in National Institute on Aging Intervention Testing Program. The preference for use of available "smart drugs", targeted to only cancer, not off-target anti- aging telomerase is implied by the multiplicity of TERT associates functions.
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Affiliation(s)
- Joan Smith-Sonneborn
- Department Zoology and Physiology, University of Wyoming, Laramie, Wyoming, WY, USA
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14
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Ségal-Bendirdjian E, Geli V. Non-canonical Roles of Telomerase: Unraveling the Imbroglio. Front Cell Dev Biol 2019; 7:332. [PMID: 31911897 PMCID: PMC6914764 DOI: 10.3389/fcell.2019.00332] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 11/27/2019] [Indexed: 12/11/2022] Open
Abstract
Telomerase plays a critical role in stem cell function and tissue regeneration that depends on its ability to elongate telomeres. For nearly two decades, it turned out that TERT regulates a broad spectrum of functions including signal transduction, gene expression regulation, and protection against oxidative damage that are independent of its telomere elongation activity. These conclusions that were mainly obtained in cell lines overexpressing telomerase were further strengthened by in vivo models of ectopic expression of telomerase or models of G1 TERT knockout mice without detectable telomere dysfunction. However, the later models were questioned due to the presence of aberrantly shortened telomere in the germline of the parents TERT+/- that were used to create the G1 TERT -/- mice. The physiological relevance of the functions associated with overexpressed telomerase raised also some concerns due to artifactual situations and localizations and complications to quantify the level of TERT. Another concern with non-canonical functions of TERT was the difficulty to separate a direct TERT-related function from secondary effects. Despite these concerns, more and more evidence accumulates for non-canonical roles of telomerase that are non-obligatory extra-telomeric. Here, we review these non-canonical roles of the TERT subunit of telomerase. Also, we emphasize recent results that link TERT to mitochondria and protection to reactive oxygen species suggesting a protective role of TERT in neurons. Throughout this review, we dissect some controversies regarding the non-canonical functions of telomerase and provide some insights to explain these discrepancies. Finally, we discuss the importance of understanding these alternative functions of telomerase for the development of anticancer strategies.
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Affiliation(s)
- Evelyne Ségal-Bendirdjian
- INSERM UMR-S 1124, Team: Cellular Homeostasis, Cancer and Therapies, INSERM US36, CNRS UMS 2009, BioMedTech Facilities, Université de Paris, Paris, France
| | - Vincent Geli
- Marseille Cancer Research Center, U1068 INSERM, UMR 7258 CNRS, Aix Marseille University, Institut Paoli-Calmettes, Equipe labellisée Ligue, Marseille, France
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15
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Maekawa T, Liu B, Nakai D, Yoshida K, Nakamura KI, Yasukawa M, Koike M, Takubo K, Chatton B, Ishikawa F, Masutomi K, Ishii S. ATF7 mediates TNF-α-induced telomere shortening. Nucleic Acids Res 2019; 46:4487-4504. [PMID: 29490055 PMCID: PMC5961373 DOI: 10.1093/nar/gky155] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 02/20/2018] [Indexed: 12/23/2022] Open
Abstract
Telomeres maintain the integrity of chromosome ends and telomere length is an important marker of aging. The epidemiological studies suggested that many types of stress including psychosocial stress decrease telomere length. However, it remains unknown how various stresses induce telomere shortening. Here, we report that the stress-responsive transcription factor ATF7 mediates TNF-α–induced telomere shortening. ATF7 and telomerase, an enzyme that elongates telomeres, are localized on telomeres via interactions with the Ku complex. In response to TNF-α, which is induced by various stresses including psychological stress, ATF7 was phosphorylated by p38, leading to the release of ATF7 and telomerase from telomeres. Thus, a decrease of ATF7 and telomerase on telomeres in response to stress causes telomere shortening, as observed in ATF7-deficient mice. These findings give credence to the idea that various types of stress might shorten telomere.
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Affiliation(s)
- Toshio Maekawa
- Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
| | - Binbin Liu
- Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan.,Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8577, Japan
| | - Daisuke Nakai
- Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan.,Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8577, Japan
| | - Keisuke Yoshida
- Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
| | - Ken-Ichi Nakamura
- Research Team for Geriatric Diseases, Tokyo Metropolitan Institute of Gerontology, Sakaecho 35-2, Itabashi-ku, Tokyo 173-0015, Japan
| | - Mami Yasukawa
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Manabu Koike
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Kaiyo Takubo
- Research Team for Geriatric Diseases, Tokyo Metropolitan Institute of Gerontology, Sakaecho 35-2, Itabashi-ku, Tokyo 173-0015, Japan
| | - Bruno Chatton
- Université de Strasbourg, UMR7242 Biotechnologie et Signalisation Cellulaire, Ecole Supérieure de Biotechnologie de Strasbourg, BP10413, Illkirch, France
| | - Fuyuki Ishikawa
- Department of Gene Mechanisms, Graduate School of Biostudies, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kenkichi Masutomi
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Shunsuke Ishii
- Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan.,Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8577, Japan
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16
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Takahashi M, Miki S, Fujimoto K, Fukuoka K, Matsushita Y, Maida Y, Yasukawa M, Hayashi M, Shinkyo R, Kikuchi K, Mukasa A, Nishikawa R, Tamura K, Narita Y, Hamada A, Masutomi K, Ichimura K. Eribulin penetrates brain tumor tissue and prolongs survival of mice harboring intracerebral glioblastoma xenografts. Cancer Sci 2019; 110:2247-2257. [PMID: 31099446 PMCID: PMC6609810 DOI: 10.1111/cas.14067] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 04/24/2019] [Accepted: 05/13/2019] [Indexed: 12/16/2022] Open
Abstract
Glioblastoma is one of the most devastating human malignancies for which a novel efficient treatment is urgently required. This pre-clinical study shows that eribulin, a specific inhibitor of telomerase reverse transcriptase (TERT)-RNA-dependent RNA polymerase, is an effective anticancer agent against glioblastoma. Eribulin inhibited the growth of 4 TERT promoter mutation-harboring glioblastoma cell lines in vitro at subnanomolar concentrations. In addition, it suppressed the growth of glioblastoma cells transplanted subcutaneously or intracerebrally into mice, and significantly prolonged the survival of mice harboring brain tumors at a clinically equivalent dose. A pharmacokinetics study showed that eribulin quickly penetrated brain tumors and remained at a high concentration even when it was washed away from plasma, kidney or liver 24 hours after intravenous injection. Moreover, a matrix-assisted laser desorption/ionization mass spectrometry imaging analysis revealed that intraperitoneally injected eribulin penetrated the brain tumor and was distributed evenly within the tumor mass at 1 hour after the injection whereas only very low levels of eribulin were detected in surrounding normal brain. Eribulin is an FDA-approved drug for refractory breast cancer and can be safely repositioned for treatment of glioblastoma patients. Thus, our results suggest that eribulin may serve as a novel therapeutic option for glioblastoma. Based on these data, an investigator-initiated registration-directed clinical trial to evaluate the safety and efficacy of eribulin in patients with recurrent GBM (UMIN000030359) has been initiated.
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Affiliation(s)
- Masamichi Takahashi
- Department of Neurosurgery and Neuro-Oncology, National Cancer Center Hospital, Tokyo, Japan.,Division of Brain Tumor Translational Research, National Cancer Center Research Institute, Tokyo, Japan
| | - Shunichiro Miki
- Department of Neurosurgery and Neuro-Oncology, National Cancer Center Hospital, Tokyo, Japan.,Division of Brain Tumor Translational Research, National Cancer Center Research Institute, Tokyo, Japan
| | - Kenji Fujimoto
- Division of Brain Tumor Translational Research, National Cancer Center Research Institute, Tokyo, Japan
| | - Kohei Fukuoka
- Division of Brain Tumor Translational Research, National Cancer Center Research Institute, Tokyo, Japan
| | - Yuko Matsushita
- Department of Neurosurgery and Neuro-Oncology, National Cancer Center Hospital, Tokyo, Japan.,Division of Brain Tumor Translational Research, National Cancer Center Research Institute, Tokyo, Japan
| | - Yoshiko Maida
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Mami Yasukawa
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Mitsuhiro Hayashi
- Division of Molecular Pharmacology, National Cancer Center Research Institute, Tokyo, Japan
| | - Raku Shinkyo
- Tsukuba Research Laboratory, Eisai, Tsukuba, Japan
| | | | - Akitake Mukasa
- Department of Neurosurgery, The University of Tokyo, Tokyo, Japan
| | - Ryo Nishikawa
- Department of Neuro-Oncology/Neurosurgery, Saitama Medical University International Medical Center, Hidaka, Japan
| | - Kenji Tamura
- Department of Breast and Medical Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Yoshitaka Narita
- Department of Neurosurgery and Neuro-Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Akinobu Hamada
- Division of Molecular Pharmacology, National Cancer Center Research Institute, Tokyo, Japan
| | - Kenkichi Masutomi
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Koichi Ichimura
- Division of Brain Tumor Translational Research, National Cancer Center Research Institute, Tokyo, Japan
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17
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Esposito MR, Binatti A, Pantile M, Coppe A, Mazzocco K, Longo L, Capasso M, Lasorsa VA, Luksch R, Bortoluzzi S, Tonini GP. Somatic mutations in specific and connected subpathways are associated with short neuroblastoma patients' survival and indicate proteins targetable at onset of disease. Int J Cancer 2018; 143:2525-2536. [PMID: 29992558 DOI: 10.1002/ijc.31748] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 05/24/2018] [Accepted: 06/21/2018] [Indexed: 12/29/2022]
Abstract
Neuroblastoma (NB) is an embryonic malignancy of the sympathetic nervous system with heterogeneous biological, morphological, genetic and clinical characteristics. Although genomic studies revealed the specific biological features of NB pathogenesis useful for new therapeutic approaches, the improvement of high-risk (HR)-NB patients overall survival remains unsatisfactory. To further clarify the biological basis of disease aggressiveness, we used whole-exome sequencing to examine the genomic landscape of HR-NB patients at stage M with short survival (SS) and long survival (LS). Only a few genes, including SMARCA4, SMO, ZNF44 and CHD2, were recurrently and specifically mutated in the SS group, confirming the low recurrence of common mutations in this tumor. A systems biology approach revealed that in the two patient groups, mutations occurred in different pathways. Mutated genes (ARHGEF11, CACNA1G, FGF4, PTPRA, PTK2, ANK3, SMO, NTNG2, VCL and NID2) regulate the MAPK pathway associated with the organization of the extracellular matrix, cell motility through PTK2 signaling and matrix metalloproteinase activity. Moreover, we detected mutations in LAMA2, PTK2, LAMA4, and MMP14 genes, impairing MET signaling, in SFI1 and CHD2 involved in centrosome maturation and chromosome remodeling, in AK7 and SPTLC2, which regulate the metabolism of nucleotides and lipoproteins, and in NALCN, SLC12A1, SLC9A9, which are involved in the transport of small molecules. Notably, connected networks of somatically mutated genes specific for SS patients were identified. The detection of mutated genes present at the onset of disease may help to address an early treatment of HR-NB patients using FDA-approved compounds targeting the deregulated pathways.
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Affiliation(s)
- Maria Rosaria Esposito
- Neuroblastoma Laboratory, Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padua, Italy
| | - Andrea Binatti
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Marcella Pantile
- Neuroblastoma Laboratory, Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padua, Italy
| | - Alessandro Coppe
- Department of Women's and Children's Health, University of Padova, Padua, Italy
| | - Katia Mazzocco
- Translational Research Department, Laboratory Medicine, Diagnostics and Services U.O.C. Pathological Anatomy, IRCCS Giannina Gaslini Institute, Genoa, Italy
| | - Luca Longo
- U.O.C. Bioterapie, Ospedale Policlinico San Martino, Genoa, Italy
| | - Mario Capasso
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy.,CEINGE Biotecnologie Avanzate, Naples, Italy.,IRCCS SDN, Istituto di Ricerca Diagnostica e Nucleare, Naples, Italy
| | | | - Roberto Luksch
- Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | | | - Gian Paolo Tonini
- Neuroblastoma Laboratory, Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padua, Italy
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18
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Maida Y, Yasukawa M, Ghilotti M, Ando Y, Masutomi K. Semi-quantitative Detection of RNA-dependent RNA Polymerase Activity of Human Telomerase Reverse Transcriptase Protein. J Vis Exp 2018. [PMID: 29985366 PMCID: PMC6101702 DOI: 10.3791/57021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Human telomerase reverse transcriptase (TERT) is the catalytic subunit of telomerase, and it elongates telomere through RNA-dependent DNA polymerase activity. Although TERT is named as a reverse transcriptase, structural and phylogenetic analyses of TERT demonstrate that TERT is a member of right-handed polymerases, and relates to viral RNA-dependent RNA polymerases (RdRPs) as well as viral reverse transcriptase. We firstly identified RdRP activity of human TERT that generates complementary RNA stand to a template non-coding RNA and contributes to RNA silencing in cancer cells. To analyze this non-canonical enzymatic activity, we developed RdRP assay with recombinant TERT in 2009, thereafter established in vitro RdRP assay for endogenous TERT. In this manuscript, we describe the latter method. Briefly, TERT immune complexes are isolated from cells, and incubated with template RNA and rNTPs including radioactive rNTP for RdRP reaction. To eliminate single-stranded RNA, reaction products are treated with RNase I, and the final products are analyzed with polyacrylamide gel electrophoresis. Radiolabeled RdRP products can be detected by autoradiography after overnight exposure.
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Affiliation(s)
- Yoshiko Maida
- Division of Cancer Stem Cell, National Cancer Center Research Institute
| | - Mami Yasukawa
- Division of Cancer Stem Cell, National Cancer Center Research Institute
| | - Marco Ghilotti
- Division of Cancer Stem Cell, National Cancer Center Research Institute
| | - Yoshinari Ando
- Division of Cancer Stem Cell, National Cancer Center Research Institute
| | - Kenkichi Masutomi
- Division of Cancer Stem Cell, National Cancer Center Research Institute;
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19
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Elevated TERT Expression in TERT-Wildtype Adult Diffuse Gliomas: Histological Evaluation with a Novel TERT-Specific Antibody. BIOMED RESEARCH INTERNATIONAL 2018; 2018:7945845. [PMID: 29693015 PMCID: PMC5859900 DOI: 10.1155/2018/7945845] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 12/10/2017] [Accepted: 01/17/2018] [Indexed: 11/27/2022]
Abstract
Telomerase reverse transcriptase (TERT) is important for the biology of diffuse gliomas. TERT promoter mutations are selectively observed among 1p/19q-codeleted oligodendrogliomas and isocitrate dehydrogenase gene- (IDH-) wildtype glioblastoma (GBM). However, TERT transcripts range widely in various cancers including gliomas, and TERT protein expression has been rarely investigated thus far. It would be thus critical to examine the expression level of TERT in tumors in addition to its mutational status, and sensitive and specific methods are urgently needed to examine TERT protein expression for the assessment of TERT biology in gliomas. Using our newly developed TERT-specific monoclonal antibody (TMab-6) applicable to human tissue, we found an unexpected increase in TERT expression in TERT-wildtype as well as TERT-mutated gliomas and in tumor vasculature. This is the first extensive analysis on the expression of TERT immunoreactivity in human glioma tissue, suggesting that TERT protein expression may be regulated by several mechanisms in addition to its promoter mutation.
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20
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Garrido-Ramos MA. Satellite DNA: An Evolving Topic. Genes (Basel) 2017; 8:genes8090230. [PMID: 28926993 PMCID: PMC5615363 DOI: 10.3390/genes8090230] [Citation(s) in RCA: 222] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/12/2017] [Accepted: 09/13/2017] [Indexed: 12/22/2022] Open
Abstract
Satellite DNA represents one of the most fascinating parts of the repetitive fraction of the eukaryotic genome. Since the discovery of highly repetitive tandem DNA in the 1960s, a lot of literature has extensively covered various topics related to the structure, organization, function, and evolution of such sequences. Today, with the advent of genomic tools, the study of satellite DNA has regained a great interest. Thus, Next-Generation Sequencing (NGS), together with high-throughput in silico analysis of the information contained in NGS reads, has revolutionized the analysis of the repetitive fraction of the eukaryotic genomes. The whole of the historical and current approaches to the topic gives us a broad view of the function and evolution of satellite DNA and its role in chromosomal evolution. Currently, we have extensive information on the molecular, chromosomal, biological, and population factors that affect the evolutionary fate of satellite DNA, knowledge that gives rise to a series of hypotheses that get on well with each other about the origin, spreading, and evolution of satellite DNA. In this paper, I review these hypotheses from a methodological, conceptual, and historical perspective and frame them in the context of chromosomal organization and evolution.
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Affiliation(s)
- Manuel A Garrido-Ramos
- Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
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21
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Kang HJ, Cui Y, Yin H, Scheid A, Hendricks WPD, Schmidt J, Sekulic A, Kong D, Trent JM, Gokhale V, Mao H, Hurley LH. A Pharmacological Chaperone Molecule Induces Cancer Cell Death by Restoring Tertiary DNA Structures in Mutant hTERT Promoters. J Am Chem Soc 2016; 138:13673-13692. [PMID: 27643954 DOI: 10.1021/jacs.6b07598] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Activation of human telomerase reverse transcriptase (hTERT) is necessary for limitless replication in tumorigenesis. Whereas hTERT is transcriptionally silenced in normal cells, most tumor cells reactivate hTERT expression by alleviating transcriptional repression through diverse genetic and epigenetic mechanisms. Transcription-activating hTERT promoter mutations have been found to occur at high frequencies in multiple cancer types. These mutations have been shown to form new transcription factor binding sites that drive hTERT expression, but this model cannot fully account for differences in wild-type (WT) and mutant promoter activation and has not yet enabled a selective therapeutic strategy. Here, we demonstrate a novel mechanism by which promoter mutations activate hTERT transcription, which also sheds light on a unique therapeutic opportunity. Promoter mutations occur in a core promoter region that forms tertiary structures consisting of a pair of G-quadruplexes involved in transcriptional silencing. We show that promoter mutations exert a detrimental effect on the folding of one of these G-quadruplexes, resulting in a nonfunctional silencer element that alleviates transcriptional repression. We have also identified a small drug-like pharmacological chaperone (pharmacoperone) molecule, GTC365, that acts at an early step in the G-quadruplex folding pathway to redirect mutant promoter G-quadruplex misfolding, partially reinstate the correct folding pathway, and reduce hTERT activity through transcriptional repression. This transcription-mediated repression produces cancer cell death through multiple routes including both induction of apoptosis through inhibition of hTERT's role in regulating apoptosis-related proteins and induction of senescence by decreasing telomerase activity and telomere length. We demonstrate the selective therapeutic potential of this strategy in melanoma cells that overexpress hTERT.
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Affiliation(s)
- Hyun-Jin Kang
- University of Arizona , College of Pharmacy, 1703 East Mabel Street, Tucson, Arizona 85721, United States
| | - Yunxi Cui
- Department of Chemistry and Biochemistry and School of Biomedical Sciences, Kent State University , Kent, Ohio 44242, United States
| | - Holly Yin
- Translational Genomics Research Institute , 445 North Fifth Street, Phoenix, Arizona 85004, United States
| | - Amy Scheid
- College of Science, University of Arizona , 1040 East Fourth Street, Tucson, Arizona 85721, United States
| | - William P D Hendricks
- Translational Genomics Research Institute , 445 North Fifth Street, Phoenix, Arizona 85004, United States
| | - Jessica Schmidt
- Department of Dermatology, Mayo Clinic , 13400 East Shea Boulevard, Scottsdale, Arizona 85259, United States
| | - Aleksandar Sekulic
- Department of Dermatology, Mayo Clinic , 13400 East Shea Boulevard, Scottsdale, Arizona 85259, United States
| | - Deming Kong
- State Key Laboratory of Medicinal Chemical Biology, College of Chemistry, Nankai University , Tianjin 300071, People's Republic of China
| | - Jeffrey M Trent
- Translational Genomics Research Institute , 445 North Fifth Street, Phoenix, Arizona 85004, United States
| | - Vijay Gokhale
- BIO5 Institute , 1657 East Helen Street, Tucson, Arizona 85721, United States
| | - Hanbin Mao
- Department of Chemistry and Biochemistry and School of Biomedical Sciences, Kent State University , Kent, Ohio 44242, United States
| | - Laurence H Hurley
- University of Arizona , College of Pharmacy, 1703 East Mabel Street, Tucson, Arizona 85721, United States.,BIO5 Institute , 1657 East Helen Street, Tucson, Arizona 85721, United States.,Arizona Cancer Center , 1515 North Campbell Avenue, Tucson, Arizona 85724, United States
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22
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Abstract
A considerable fraction of the eukaryotic genome is made up of satellite DNA constituted of tandemly repeated sequences. These elements are mainly located at centromeres, pericentromeres, and telomeres and are major components of constitutive heterochromatin. Although originally satellite DNA was thought silent and inert, an increasing number of studies are providing evidence on its transcriptional activity supporting, on the contrary, an unexpected dynamicity. This review summarizes the multiple structural roles of satellite noncoding RNAs at chromosome level. Indeed, satellite noncoding RNAs play a role in the establishment of a heterochromatic state at centromere and telomere. These highly condensed structures are indispensable to preserve chromosome integrity and genome stability, preventing recombination events, and ensuring the correct chromosome pairing and segregation. Moreover, these RNA molecules seem to be involved also in maintaining centromere identity and in elongation, capping, and replication of telomere. Finally, the abnormal variation of centromeric and pericentromeric DNA transcription across major eukaryotic lineages in stress condition and disease has evidenced the critical role that these transcripts may play and the potentially dire consequences for the organism.
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23
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Molecular targets of gambogic acid in cancer: recent trends and advancements. Tumour Biol 2016; 37:12915-12925. [DOI: 10.1007/s13277-016-5194-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 07/13/2016] [Indexed: 12/11/2022] Open
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24
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De Novo RNA Synthesis by RNA-Dependent RNA Polymerase Activity of Telomerase Reverse Transcriptase. Mol Cell Biol 2016; 36:1248-59. [PMID: 26830230 DOI: 10.1128/mcb.01021-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 01/27/2016] [Indexed: 12/12/2022] Open
Abstract
RNA-dependent RNA polymerase (RdRP) plays key roles in RNA silencing to generate double-stranded RNAs. In model organisms, such as Caenorhabditis elegans and Neurospora crassa, two types of small interfering RNAs (siRNAs), primary siRNAs and secondary siRNAs, are expressed; RdRP produces secondary siRNAs de novo, without using either Dicer or primers, while primary siRNAs are processed by Dicer. We reported that human telomerase reverse transcriptase (TERT) has RdRP activity and produces endogenous siRNAs in a Dicer-dependent manner. However, de novo synthesis of siRNAs by human TERT has not been elucidated. Here we show that the TERT RdRP generates short RNAs that are complementary to template RNAs and have 5'-triphosphorylated ends, which indicates de novo synthesis of the RNAs. In addition, we confirmed short RNA synthesis by TERT in several human carcinoma cell lines and found that TERT protein levels are positively correlated with RdRP activity.
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25
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Teichroeb JH, Kim J, Betts DH. The role of telomeres and telomerase reverse transcriptase isoforms in pluripotency induction and maintenance. RNA Biol 2016; 13:707-19. [PMID: 26786236 DOI: 10.1080/15476286.2015.1134413] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Telomeres are linear guanine-rich DNA structures at the ends of chromosomes. The length of telomeric DNA is actively regulated by a number of mechanisms in highly proliferative cells such as germ cells, cancer cells, and pluripotent stem cells. Telomeric DNA is synthesized by way of the ribonucleoprotein called telomerase containing a reverse transcriptase (TERT) subunit and RNA component (TERC). TERT is highly conserved across species and ubiquitously present in their respective pluripotent cells. Recent studies have uncovered intricate associations between telomeres and the self-renewal and differentiation properties of pluripotent stem cells. Interestingly, the past decade's work indicates that the TERT subunit also has the capacity to modulate mitochondrial function, to remodel chromatin structure, and to participate in key signaling pathways such as the Wnt/β-catenin pathway. Many of these non-canonical functions do not require TERT's catalytic activity, which hints at possible functions for the extensive number of alternatively spliced TERT isoforms that are highly expressed in pluripotent stem cells. In this review, some of the established and potential routes of pluripotency induction and maintenance are highlighted from the perspectives of telomere maintenance, known TERT isoform functions and their complex regulation.
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Affiliation(s)
- Jonathan H Teichroeb
- a Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry , The University of Western Ontario , London , Ontario , Canada
| | - Joohwan Kim
- a Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry , The University of Western Ontario , London , Ontario , Canada
| | - Dean H Betts
- a Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry , The University of Western Ontario , London , Ontario , Canada.,b Children's Health Research Institute, Lawson Health Research Institute , London , Ontario , Canada
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26
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Maida Y, Masutomi K. Telomerase reverse transcriptase moonlights: Therapeutic targets beyond telomerase. Cancer Sci 2015; 106:1486-92. [PMID: 26331588 PMCID: PMC4714691 DOI: 10.1111/cas.12806] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 08/25/2015] [Accepted: 08/26/2015] [Indexed: 12/26/2022] Open
Abstract
Telomeres, the repetitive sequences at chromosomal ends, protect intact chromosomes. Telomeres progressively shorten through successive rounds of cell divisions, and critically shortened telomeres trigger senescence and apoptosis. The enzyme that elongates telomeres and maintains their structure is known as telomerase. The catalytic subunit of this enzyme (telomerase reverse transcriptase [TERT]) is expressed at a high level in malignant cells, but at a very low level in normal cells. Although telomerase activity was long believed to be the only function of TERT, emerging evidence indicates that TERT plays roles beyond telomeres. For example, TERT contributes to stem cell maintenance and cell reprogramming processes in a manner independent of its canonical function. Even some types of splice variants that lack the telomerase catalytic domains exhibit the functions in a manner that does not depend on telomerase activity. We recently demonstrated that the RNA-dependent RNA polymerase (RdRP) activity of TERT is involved in regulation of gene silencing and heterochromatic transcription. Moreover, TERT RdRP activity is mediated by a newly identified complex, distinct from the authentic telomerase complex, that plays a role in cancer stem cells in a telomere maintenance independent manner. TERT has attracted interest as a molecular target for anticancer treatment, but previous efforts aimed at developing novel therapeutic strategies focused only on the canonical function of TERT. However, accumulating evidence about the non-canonical functions of TERT led us to speculate that the functions other than telomerase might be therapeutic targets as well. In this review, we discuss the non-canonical functions of TERT and their potential applications for anticancer treatment.
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Affiliation(s)
- Yoshiko Maida
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Kenkichi Masutomi
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
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27
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Butler AA, Webb WM, Lubin FD. Regulatory RNAs and control of epigenetic mechanisms: expectations for cognition and cognitive dysfunction. Epigenomics 2015; 8:135-51. [PMID: 26366811 DOI: 10.2217/epi.15.79] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The diverse functions of noncoding RNAs (ncRNAs) can influence virtually every aspect of the transcriptional process including epigenetic regulation of genes. In the CNS, regulatory RNA networks and epigenetic mechanisms have broad relevance to gene transcription changes involved in long-term memory formation and cognition. Thus, it is becoming increasingly clear that multiple classes of ncRNAs impact neuronal development, neuroplasticity, and cognition. Currently, a large gap exists in our knowledge of how ncRNAs facilitate epigenetic processes, and how this phenomenon affects cognitive function. In this review, we discuss recent findings highlighting a provocative role for ncRNAs including lncRNAs and piRNAs in the control of epigenetic mechanisms involved in cognitive function. Furthermore, we discuss the putative roles for these ncRNAs in cognitive disorders such as schizophrenia and Alzheimer's disease.
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Affiliation(s)
- Anderson A Butler
- Department of Neurobiology, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
| | - William M Webb
- Department of Neurobiology, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
| | - Farah D Lubin
- Department of Neurobiology, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
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28
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Simonicova L, Dudekova H, Ferenc J, Prochazkova K, Nebohacova M, Dusinsky R, Nosek J, Tomaska L. Saccharomyces cerevisiae as a model for the study of extranuclear functions of mammalian telomerase. Curr Genet 2015; 61:517-27. [PMID: 25567623 DOI: 10.1007/s00294-014-0472-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 12/25/2014] [Accepted: 12/28/2014] [Indexed: 10/24/2022]
Abstract
The experimental evidence from the last decade made telomerase a prominent member of a family of moonlighting proteins performing different functions at various cellular loci. However, the study of extratelomeric functions of the catalytic subunit of mammalian telomerase (TERT) is often complicated by the fact that it is sometimes difficult to distinguish them from its role(s) at the chromosomal ends. Here, we present an experimental model for studying the extranuclear function(s) of mammalian telomerase in the yeast Saccharomyces cerevisiae. We demonstrate that the catalytic subunit of mammalian telomerase protects the yeast cells against oxidative stress and affects the stability of the mitochondrial genome. The advantage of using S. cerevisiae to study of mammalian telomerase is that (1) mammalian TERT does not interfere with its yeast counterpart in the maintenance of telomeres, (2) yeast telomerase is not localized in mitochondria and (3) it does not seem to be involved in the protection of cells against oxidative stress and stabilization of mtDNA. Thus, yeast cells can be used as a 'test tube' for reconstitution of mammalian TERT extranuclear function(s).
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Affiliation(s)
- Lucia Simonicova
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska dolina, B-1, 84215, Bratislava, Slovak Republic
| | - Henrieta Dudekova
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska dolina, B-1, 84215, Bratislava, Slovak Republic
| | - Jaroslav Ferenc
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska dolina, B-1, 84215, Bratislava, Slovak Republic
| | - Katarina Prochazkova
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska dolina, B-1, 84215, Bratislava, Slovak Republic
| | - Martina Nebohacova
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Mlynska dolina, CH-1, 84215, Bratislava, Slovak Republic
| | - Roman Dusinsky
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska dolina, B-1, 84215, Bratislava, Slovak Republic
| | - Jozef Nosek
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Mlynska dolina, CH-1, 84215, Bratislava, Slovak Republic
| | - Lubomir Tomaska
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynska dolina, B-1, 84215, Bratislava, Slovak Republic.
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29
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Telomerase reverse transcriptase regulates microRNAs. Int J Mol Sci 2015; 16:1192-208. [PMID: 25569094 PMCID: PMC4307298 DOI: 10.3390/ijms16011192] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 12/26/2014] [Indexed: 12/30/2022] Open
Abstract
MicroRNAs are small non-coding RNAs that inhibit the translation of target mRNAs. In humans, most microRNAs are transcribed by RNA polymerase II as long primary transcripts and processed by sequential cleavage of the two RNase III enzymes, DROSHA and DICER, into precursor and mature microRNAs, respectively. Although the fundamental functions of microRNAs in RNA silencing have been gradually uncovered, less is known about the regulatory mechanisms of microRNA expression. Here, we report that telomerase reverse transcriptase (TERT) extensively affects the expression levels of mature microRNAs. Deep sequencing-based screens of short RNA populations revealed that the suppression of TERT resulted in the downregulation of microRNAs expressed in THP-1 cells and HeLa cells. Primary and precursor microRNA levels were also reduced under the suppression of TERT. Similar results were obtained with the suppression of either BRG1 (also called SMARCA4) or nucleostemin, which are proteins interacting with TERT and functioning beyond telomeres. These results suggest that TERT regulates microRNAs at the very early phases in their biogenesis, presumably through non-telomerase mechanism(s).
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30
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Yamaguchi S, Maida Y, Yasukawa M, Kato T, Yoshida M, Masutomi K. Eribulin mesylate targets human telomerase reverse transcriptase in ovarian cancer cells. PLoS One 2014; 9:e112438. [PMID: 25375122 PMCID: PMC4223061 DOI: 10.1371/journal.pone.0112438] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 10/06/2014] [Indexed: 11/19/2022] Open
Abstract
Treatment of advanced ovarian cancer involves platinum-based chemotherapy. However, chemoresistance is a major obstacle. Cancer stem cells (CSCs) are thought to be one of the causes of chemoresistance, but the underlying mechanism remains elusive. Recently, human telomerase reverse transcriptase (hTERT) has been reported to promote CSC-like traits. In this study, we found that a mitotic inhibitor, eribulin mesylate (eribulin), effectively inhibited growth of platinum-resistant ovarian cancer cell lines. Eribulin-sensitive cells showed a higher efficiency for sphere formation, suggesting that these cells possess an enhanced CSC-like phenotype. Moreover, these cells expressed a higher level of hTERT, and suppression of hTERT expression by siRNA resulted in decreased sensitivity to eribulin, suggesting that hTERT may be a target for eribulin. Indeed, we found that eribulin directly inhibited RNA-dependent RNA polymerase (RdRP) activity, but not telomerase activity of hTERT in vitro. We propose that eribulin targets the RdRP activity of hTERT and may be an effective therapeutic option for CSCs. Furthermore, hTERT may be a useful biomarker to predict clinical responses to eribulin.
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Affiliation(s)
- Satoko Yamaguchi
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Yoshiko Maida
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Mami Yasukawa
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
| | - Tomoyasu Kato
- Department of Gynecology, National Cancer Center Hospital, Tokyo, Japan
| | - Masayuki Yoshida
- Department of Pathology and Clinical Laboratories, National Cancer Center Hospital, Tokyo, Japan
| | - Kenkichi Masutomi
- Division of Cancer Stem Cell, National Cancer Center Research Institute, Tokyo, Japan
- * E-mail:
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31
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Abstract
A quintessential trait of stem cells is embedded in their ability to self-renew without incurring DNA damage as a result of genome replication. One key self-renewal factor is the nucleolar GTP-binding protein nucleostemin (also known as guanine-nucleotide-binding protein-like 3, GNL3, in invertebrate species). Several studies have recently pointed to an unexpected role of nucleostemin in safeguarding the genome integrity of stem and cancer cells. Since its discovery, the predominant presence of nucleostemin in the nucleolus has led to the notion that it might function in the card-carrying event of the nucleolus--the biogenesis of ribosomes. As tantalizing as this might be, a ribosomal role of nucleostemin is refuted by evidence from recent studies, which argues that nucleostemin depletion triggers a primary event of DNA damage in S phase cells that then leads to ribosomal perturbation. Furthermore, there have been conflicting reports regarding the p53 dependency of nucleostemin activity and the cell cycle arrest profile of nucleostemin-depleted cells. In this Commentary, I propose a model that explains how the many contradictory observations surrounding nucleostemin can be reconciled and suggest that this protein might not be as multi-tasking as has been previously perceived. The story of nucleostemin highlights the complexity of the underlying molecular events associated with the appearance of any cell biological phenotype and also signifies a new understanding of the genome maintenance program in stem cells.
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Affiliation(s)
- Robert Y L Tsai
- Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
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32
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Zhang Y, Calado R, Rao M, Hong JA, Meeker AK, Dumitriu B, Atay S, McCormick PJ, Garfield SH, Wangsa D, Padilla-Nash HM, Burkett S, Zhang M, Kunst TF, Peterson NR, Xi S, Inchauste S, Altorki NK, Casson AG, Beer DG, Harris CC, Ried T, Young NS, Schrump DS. Telomerase variant A279T induces telomere dysfunction and inhibits non-canonical telomerase activity in esophageal carcinomas. PLoS One 2014; 9:e101010. [PMID: 24983628 PMCID: PMC4077737 DOI: 10.1371/journal.pone.0101010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 06/02/2014] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Although implicated in the pathogenesis of several chronic inflammatory disorders and hematologic malignancies, telomerase mutations have not been thoroughly characterized in human cancers. The present study was performed to examine the frequency and potential clinical relevance of telomerase mutations in esophageal carcinomas. METHODS Sequencing techniques were used to evaluate mutational status of telomerase reverse transcriptase (TERT) and telomerase RNA component (TERC) in neoplastic and adjacent normal mucosa from 143 esophageal cancer (EsC) patients. MTS, flow cytometry, time lapse microscopy, and murine xenograft techniques were used to assess proliferation, apoptosis, chemotaxis, and tumorigenicity of EsC cells expressing either wtTERT or TERT variants. Immunoprecipitation, immunoblot, immunofluorescence, promoter-reporter and qRT-PCR techniques were used to evaluate interactions of TERT and several TERT variants with BRG-1 and β-catenin, and to assess expression of cytoskeletal proteins, and cell signaling. Fluorescence in-situ hybridization and spectral karyotyping techniques were used to examine telomere length and chromosomal stability. RESULTS Sequencing analysis revealed one deletion involving TERC (TERC del 341-360), and two non-synonymous TERT variants [A279T (2 homozygous, 9 heterozygous); A1062T (4 heterozygous)]. The minor allele frequency of the A279T variant was five-fold higher in EsC patients compared to healthy blood donors (p<0.01). Relative to wtTERT, A279T decreased telomere length, destabilized TERT-BRG-1-β-catenin complex, markedly depleted β-catenin, and down-regulated canonical Wnt signaling in cancer cells; these phenomena coincided with decreased proliferation, depletion of additional cytoskeletal proteins, impaired chemotaxis, increased chemosensitivity, and significantly decreased tumorigenicity of EsC cells. A279T expression significantly increased chromosomal aberrations in mouse embryonic fibroblasts (MEFs) following Zeocin™ exposure, as well as Li Fraumeni fibroblasts in the absence of pharmacologically-induced DNA damage. CONCLUSIONS A279T induces telomere dysfunction and inhibits non-canonical telomerase activity in esophageal cancer cells. These findings warrant further analysis of A279T expression in esophageal cancers and premalignant esophageal lesions.
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Affiliation(s)
- Yuwei Zhang
- Thoracic Surgery Section, Thoracic and GI Oncology Branch; National Cancer Institute, Bethesda, Maryland, United States of America
| | - Rodrigo Calado
- National Heart, Lung, and Blood Institute, Bethesda, Maryland, United States of America
| | - Mahadev Rao
- Thoracic Surgery Section, Thoracic and GI Oncology Branch; National Cancer Institute, Bethesda, Maryland, United States of America
| | - Julie A. Hong
- Thoracic Surgery Section, Thoracic and GI Oncology Branch; National Cancer Institute, Bethesda, Maryland, United States of America
| | - Alan K. Meeker
- Departments of Pathology and Oncology, Johns Hopkins University of Medicine, Baltimore, Maryland, United States of America
| | - Bogdan Dumitriu
- National Heart, Lung, and Blood Institute, Bethesda, Maryland, United States of America
| | - Scott Atay
- Thoracic Surgery Section, Thoracic and GI Oncology Branch; National Cancer Institute, Bethesda, Maryland, United States of America
| | - Peter J. McCormick
- Laboratory of Cellular Oncology, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Susan H. Garfield
- Laboratory of Experimental Carcinogenesis, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Danny Wangsa
- Section of Cancer Genomics, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Hesed M. Padilla-Nash
- Section of Cancer Genomics, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Sandra Burkett
- Comparative Molecular Cytogenetics Core Facility, National Cancer Institute, Frederick, Maryland, United States of America
| | - Mary Zhang
- Thoracic Surgery Section, Thoracic and GI Oncology Branch; National Cancer Institute, Bethesda, Maryland, United States of America
| | - Tricia F. Kunst
- Thoracic Surgery Section, Thoracic and GI Oncology Branch; National Cancer Institute, Bethesda, Maryland, United States of America
| | - Nathan R. Peterson
- National Heart, Lung, and Blood Institute, Bethesda, Maryland, United States of America
| | - Sichuan Xi
- Thoracic Surgery Section, Thoracic and GI Oncology Branch; National Cancer Institute, Bethesda, Maryland, United States of America
| | - Suzanne Inchauste
- Thoracic Surgery Section, Thoracic and GI Oncology Branch; National Cancer Institute, Bethesda, Maryland, United States of America
| | - Nasser K. Altorki
- Department of Thoracic Surgery, Weill Cornell Medical Center, New York, New York, United States of America
| | - Alan G. Casson
- Department of Surgery, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - David G. Beer
- Section of Thoracic Surgery, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Curtis C. Harris
- Laboratory of Human Carcinogenesis, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Thomas Ried
- Section of Cancer Genomics, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Neal S. Young
- National Heart, Lung, and Blood Institute, Bethesda, Maryland, United States of America
| | - David S. Schrump
- Thoracic Surgery Section, Thoracic and GI Oncology Branch; National Cancer Institute, Bethesda, Maryland, United States of America
- * E-mail:
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