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Edwards CM, Kane JF, Smith JA, Grant DM, Johnson JA, Diaz MAH, Vecchi LA, Bracey KM, Omokehinde TN, Fontana JR, Karno BA, Scott HT, Vogel CJ, Lowery JW, Martin TJ, Johnson RW. PTHrP intracrine actions divergently influence breast cancer growth through p27 and LIFR. Breast Cancer Res 2024; 26:34. [PMID: 38409028 PMCID: PMC10897994 DOI: 10.1186/s13058-024-01791-z] [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: 07/14/2023] [Accepted: 02/19/2024] [Indexed: 02/28/2024] Open
Abstract
The role of parathyroid hormone (PTH)-related protein (PTHrP) in breast cancer remains controversial, with reports of PTHrP inhibiting or promoting primary tumor growth in preclinical studies. Here, we provide insight into these conflicting findings by assessing the role of specific biological domains of PTHrP in tumor progression through stable expression of PTHrP (-36-139aa) or truncated forms with deletion of the nuclear localization sequence (NLS) alone or in combination with the C-terminus. Although the full-length PTHrP molecule (-36-139aa) did not alter tumorigenesis, PTHrP lacking the NLS alone accelerated primary tumor growth by downregulating p27, while PTHrP lacking the NLS and C-terminus repressed tumor growth through p27 induction driven by the tumor suppressor leukemia inhibitory factor receptor (LIFR). Induction of p27 by PTHrP lacking the NLS and C-terminus persisted in bone disseminated cells, but did not prevent metastatic outgrowth, in contrast to the primary tumor site. These data suggest that the PTHrP NLS functions as a tumor suppressor, while the PTHrP C-terminus may act as an oncogenic switch to promote tumor progression through differential regulation of p27 signaling.
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Affiliation(s)
- Courtney M Edwards
- Graduate Program in Cancer Biology, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jeremy F Kane
- Graduate Program in Cancer Biology, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jailyn A Smith
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Déja M Grant
- Graduate Program in Cancer Biology, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
- Meharry Medical College, Nashville, TN, USA
| | - Jasmine A Johnson
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Maria A Hernandez Diaz
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Lawrence A Vecchi
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kai M Bracey
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Tolu N Omokehinde
- Graduate Program in Cancer Biology, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Joseph R Fontana
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University, Nashville, TN, 37232, USA
| | - Breelyn A Karno
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University, Nashville, TN, 37232, USA
| | - Halee T Scott
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University, Nashville, TN, 37232, USA
| | - Carolina J Vogel
- Marian University College of Osteopathic Medicine, Indianapolis, IN, USA
- Bone and Muscle Research Group, Marian University, Indianapolis, IN, USA
| | - Jonathan W Lowery
- Marian University College of Osteopathic Medicine, Indianapolis, IN, USA
- Bone and Muscle Research Group, Marian University, Indianapolis, IN, USA
- Academic Affairs, Marian University, Indianapolis, IN, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, USA
| | - T John Martin
- Bone Cell Biology and Disease Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia
- Department of Medicine, The University of Melbourne, St. Vincent's Hospital, Fitzroy, VIC, Australia
| | - Rachelle W Johnson
- Graduate Program in Cancer Biology, Vanderbilt University, Nashville, TN, USA.
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, USA.
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
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Edwards CM, Johnson RW. From Good to Bad: The Opposing Effects of PTHrP on Tumor Growth, Dormancy, and Metastasis Throughout Cancer Progression. Front Oncol 2021; 11:644303. [PMID: 33828987 PMCID: PMC8019909 DOI: 10.3389/fonc.2021.644303] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 02/22/2021] [Indexed: 11/13/2022] Open
Abstract
Parathyroid hormone related protein (PTHrP) is a multifaceted protein with several biologically active domains that regulate its many roles in normal physiology and human disease. PTHrP causes humoral hypercalcemia of malignancy (HHM) through its endocrine actions and tumor-induced bone destruction through its paracrine actions. PTHrP has more recently been investigated as a regulator of tumor dormancy owing to its roles in regulating tumor cell proliferation, apoptosis, and survival through autocrine/paracrine and intracrine signaling. Tumor expression of PTHrP in late stages of cancer progression has been shown to promote distant metastasis formation, especially in bone by promoting tumor-induced osteolysis and exit from dormancy. In contrast, PTHrP may protect against further tumor progression and improve patient survival in early disease stages. This review highlights current knowledge from preclinical and clinical studies examining the role of PTHrP in promoting tumor progression as well as skeletal and soft tissue metastasis, especially with regards to the protein as a regulator of tumor dormancy. The discussion will also provide perspectives on PTHrP as a prognostic factor and therapeutic target to inhibit tumor progression, prevent tumor recurrence, and improve patient survival.
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Affiliation(s)
- Courtney M Edwards
- Program in Cancer Biology, Vanderbilt University, Nashville, TN, United States.,Vanderbilt Center for Bone Biology, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Rachelle W Johnson
- Program in Cancer Biology, Vanderbilt University, Nashville, TN, United States.,Vanderbilt Center for Bone Biology, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States.,Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
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3
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He S, Tang J, Diao N, Liao Y, Shi J, Xu X, Xie F, Bai L. Parathyroid hormone-related protein activates HSCs via hedgehog signalling during liver fibrosis development. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2019; 47:1984-1994. [PMID: 31311343 DOI: 10.1080/21691401.2019.1615931] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Shuying He
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jing Tang
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Na Diao
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yan Liao
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jie Shi
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xiaoping Xu
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Fang Xie
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Lan Bai
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
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He S, Xue M, Liu C, Xie F, Bai L. Parathyroid Hormone-Like Hormone Induces Epithelial-to-Mesenchymal Transition of Intestinal Epithelial Cells by Activating the Runt-Related Transcription Factor 2. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 188:1374-1388. [PMID: 29577935 DOI: 10.1016/j.ajpath.2018.03.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 03/04/2018] [Accepted: 03/06/2018] [Indexed: 01/18/2023]
Abstract
Epithelial-to-mesenchymal transition (EMT) is a key contributor to fibroblast activation in fibrosis of multiple organs, including the intestine. Parathyroid hormone-like hormone (PTHLH) is an important factor in renal fibrosis and regulates several processes, including EMT. Herein, we investigated the role of PTHLH-induced EMT in intestinal fibrosis associated with Crohn disease. The expression levels of the EMT-related proteins, PTHLH, and parathyroid hormone receptor 1 (PTH1R) in intestinal tissues were determined by immunohistochemistry, and our results revealed that PTHLH and PTH1R were significantly elevated and associated with EMT marker expression. Moreover, neutralizing PTH1R and antagonizing PTHLH bioactivity prevented transforming growth factor-β1-induced EMT. PTH1R can propagate the protein kinase A (PKA) signal and activate downstream nuclear transcription factors, including runt-related transcription factor 2 (Runx2). In addition, lentiviral vector-PTHLH-treated mice were highly sensitive to 2,4,6-trinitrobenzene sulfonic acid, and analysis of the PTHLH-PTH1R axis revealed the involvement of PKA-Runx2 in PTHLH-induced EMT. Our results indicate that PTHLH triggered EMT in intestinal epithelial cells through the PKA-Runx2 pathway, which might serve as a therapeutic target for intestinal fibrosis in Crohn disease.
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Affiliation(s)
- Shuying He
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Minmin Xue
- Department of Gastroenterology, Chinese People's Liberation Army 254 Hospital, Tianjin, China
| | - Cuiping Liu
- Department of Critical Care Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Fang Xie
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Lan Bai
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
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Pountos I, Panteli M, Lampropoulos A, Jones E, Calori GM, Giannoudis PV. The role of peptides in bone healing and regeneration: a systematic review. BMC Med 2016; 14:103. [PMID: 27400961 PMCID: PMC4940902 DOI: 10.1186/s12916-016-0646-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Bone tissue engineering and the research surrounding peptides has expanded significantly over the last few decades. Several peptides have been shown to support and stimulate the bone healing response and have been proposed as therapeutic vehicles for clinical use. The aim of this comprehensive review is to present the clinical and experimental studies analysing the potential role of peptides for bone healing and bone regeneration. METHODS A systematic review according to PRISMA guidelines was conducted. Articles presenting peptides capable of exerting an upregulatory effect on osteoprogenitor cells and bone healing were included in the study. RESULTS Based on the available literature, a significant amount of experimental in vitro and in vivo evidence exists. Several peptides were found to upregulate the bone healing response in experimental models and could act as potential candidates for future clinical applications. However, from the available peptides that reached the level of clinical trials, the presented results are limited. CONCLUSION Further research is desirable to shed more light into the processes governing the osteoprogenitor cellular responses. With further advances in the field of biomimetic materials and scaffolds, new treatment modalities for bone repair will emerge.
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Affiliation(s)
- Ippokratis Pountos
- Department of Trauma & Orthopaedics, School of Medicine, University of Leeds, Leeds, UK
| | - Michalis Panteli
- Department of Trauma & Orthopaedics, School of Medicine, University of Leeds, Leeds, UK
| | | | - Elena Jones
- Unit of Musculoskeletal Disease, Leeds Institute of Rheumatic and Musculoskeletal Medicine, St. James University Hospital, University of Leeds, LS9 7TF, Leeds, UK
| | - Giorgio Maria Calori
- Department of Trauma & Orthopaedics, School of Medicine, ISTITUTO ORTOPEDICO GAETANO PINI, Milan, Italy
| | - Peter V Giannoudis
- Department of Trauma & Orthopaedics, School of Medicine, University of Leeds, Leeds, UK. .,NIHR Leeds Biomedical Research Unit, Chapel Allerton Hospital, LS7 4SA Leeds, West Yorkshire, Leeds, UK.
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Chukkapalli S, Levi E, Rishi AK, Datta NS. PTHrP attenuates osteoblast cell death and apoptosis induced by a novel class of anti-cancer agents. Endocrine 2016; 51:534-44. [PMID: 26260694 DOI: 10.1007/s12020-015-0699-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 07/18/2015] [Indexed: 11/30/2022]
Abstract
The effectiveness of chemotherapeutic agents often limits their use due to their negative effects on normal cells. Apoptosis regulatory protein (CARP)-1 functional mimetics (CFMs) belong to a novel class of compounds that possess anti-cancer properties with potential utility in breast and other cancers. In this study, we investigated the growth inhibitory action of CFM-4 and -5 in bone-forming osteoblasts and role of a skeletal regulator, parathyroid hormone (PTH)-related peptide (PTHrP), which is frequently associated with oncologic pathologies. MC3T3E1-clone4 (MC-4) or primary osteoblasts were treated with CFMs. Western blots were performed to determine specific protein expressions. MTT, TUNEL assay, ethidium bromide/acridine orange staining, and ApoAlert caspase profiling were used to investigate cell viability and apoptosis of osteoblasts. Immunofluorescence staining was performed to observe intracellular localization of CARP-1. Our studies revealed that CFM-4 and -5 suppressed growths of mature differentiated, but not proliferating, MC-4 cells and PTHrP attenuated this effect. Mechanistically, induction of CARP-1 protein by CFM-4 and -5 was partially decreased by PTHrP. While CARP-1 increased by CFM-4 or -5 correlated with activated caspase-3, PTHrP remarkably blocked caspase-3 activation. PTHrP also influenced translocation of CFM-induced CARP-1 from the nucleus to the cytoplasm. Our data identify a new function of PTHrP in maintaining osteoblast homeostasis in chemotherapy and define a role of CARP-1 in this process. The crosstalk of PTHrP and CFM-4 and -5 signaling highlights the importance of CFMs as potential anti-cancer therapeutics in breast and other cancers which adversely affect bone.
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Affiliation(s)
- Sahiti Chukkapalli
- Division of Endocrinology, Department of Internal Medicine, Wayne State University School of Medicine, 1107 Elliman Clinical Research Building, 421 East Canfield Avenue, Detroit, MI, 48201, USA
| | - Edi Levi
- Department of Pathology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
- VA Medical Center, Detroit, MI, 48201, USA
| | - Arun K Rishi
- Barbara Ann Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, 48201, USA
- VA Medical Center, Detroit, MI, 48201, USA
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Nabanita S Datta
- Division of Endocrinology, Department of Internal Medicine, Wayne State University School of Medicine, 1107 Elliman Clinical Research Building, 421 East Canfield Avenue, Detroit, MI, 48201, USA.
- Barbara Ann Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, 48201, USA.
- Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI, 48201, USA.
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7
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Ahn HS, Yun JM, Lee YB, Ko YM, Lee JE, Won HS, Kim SS, Kim YO. [Esophageal Cancer Initially Presenting as Severe Paraneoplastic Hypercalcemia Requiring Hemodialysis]. THE KOREAN JOURNAL OF GASTROENTEROLOGY 2015; 65:361-5. [PMID: 26087691 DOI: 10.4166/kjg.2015.65.6.361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Paraneoplastic hypercalcemia without bone metastasis occurs rarely in esophageal cancer. A 75-year-old man was admitted for general weakness and lethargy. Laboratory data showed high serum calcium level (corrected calcium 14.6 mg/dL), low parathyroid hormone level (3.3 pg/mL) and high parathyroid hormone-related peptide level (3.5 pmol/L). Esophagogastroscopy showed a malignant tumor in the esophagus. Histology showed moderately differentiated squamous cell carcinoma. Bone scan showed no evidence of bone metastasis. Since the patient's calcium levels remained high and mental state did not show improvement despite intravenous fluid therapy, diuretics and intravenous bisphosphonate, hemodialysis was started. After hemodialysis treatment, the serum calcium level subsequently normalized and his mental status improved. Herein, we report a rare case of paraneoplastic hypercalcemia in a patient with esophageal cancer.
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Affiliation(s)
- Hye Shin Ahn
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jong Min Yun
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Yeong Bok Lee
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Yu Mi Ko
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jung Eun Lee
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Hye Sung Won
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Sung Soo Kim
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Young Ok Kim
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
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Wright LE, Guise TA. The Role of PTHrP in Skeletal Metastases and Hypercalcemia of Malignancy. Clin Rev Bone Miner Metab 2014. [DOI: 10.1007/s12018-014-9160-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Soki FN, Park SI, McCauley LK. The multifaceted actions of PTHrP in skeletal metastasis. Future Oncol 2013; 8:803-17. [PMID: 22830401 DOI: 10.2217/fon.12.76] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
PTHrP, identified during the elucidation of mediators of malignancy-induced hypercalcemia, plays numerous roles in normal physiology as well as pathological conditions. Recent data support direct functions of PTHrP in metastasis, particularly from tumors with strong bone tropism. Bone provides a unique metastatic environment because of mineralization and the diverse cell populations in the bone marrow. PTHrP is a key regulator of tumor-bone interactions and regulates cells in the bone microenvironment through proliferative and prosurvival activities that prime the 'seed' and the 'soil' of the metastatic lesion. This review highlights recent findings regarding the role of PTHrP in skeletal metastasis, including direct actions in tumor cells, as well as alterations in the bone microenvironment and future perspectives involving the potential roles of PTHrP in the premetastatic niche, and tumor dormancy.
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Affiliation(s)
- Fabiana N Soki
- Department of Periodontics & Oral Medicine, University of Michigan School of Dentistry, 1011 North University Avenue, Ann Arbor, MI, USA
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Nakajima K, Tamai M, Okaniwa S, Nakamura Y, Kobayashi M, Niwa T, Horigome N, Ito N, Suzuki S, Nishio S, Komatsu M. Humoral hypercalcemia associated with gastric carcinoma secreting parathyroid hormone: a case report and review of the literature. Endocr J 2013; 60:557-62. [PMID: 23303131 DOI: 10.1507/endocrj.ej12-0406] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Hypercalcemia with concomitant elevation of serum parathyroid hormone (PTH) and PTH-related protein (PTHrP) levels was found in a patient with advanced gastric carcinoma and multiple liver metastases. The most common features are hypercalcemia associated with hypersecretion of PTHrP and physiological suppression of PTH secretion in the syndrome of humoral hypercalcemia of malignancy (HHM). Although we initially made a diagnosis of primary hyperparathyroidism concomitant with HHM due to gastric cancer, diagnostic imaging studies, such as echography, CT, sestamibi scintigraphy, and autopsy findings, did not reveal evidence of any parathyroid tumors or ectopic parathyroid glands in the mediastinum. Both primary and metastatic tumor cells showed positive staining with PTH-specific antibody as well as PTHrP-specific antibody on immunohistochemical examination. PTH concentration in the cytosolic fraction of the metastatic tumor was elevated compared to that from a control patient with no calcium metabolic disorders in vitro. These findings indicated that PTH secreted ectopically by gastric cancer cells, not by parathyroid glands, caused hypercalcemia in this patient. To our knowledge, this is the first case report of PTH-secreting gastric carcinoma cells. We report the case and a review of the previous reported PTH-secreting non-parathyroid tumors along with the mechanisms of secretion.
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Affiliation(s)
- Koji Nakajima
- Department of Internal Medicine, Iida Municipal Hospital, Iida 395-8502, Japan.
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Li J, Dong S, Townsend SD, Dean T, Gardella TJ, Danishefsky SJ. Chemistry as an Expanding Resource in Protein Science: Fully Synthetic and Fully Active Human Parathyroid Hormone-Related Protein (1-141). Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201207603] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Li J, Dong S, Townsend SD, Dean T, Gardella TJ, Danishefsky SJ. Chemistry as an expanding resource in protein science: fully synthetic and fully active human parathyroid hormone-related protein (1-141). Angew Chem Int Ed Engl 2012; 51:12263-7. [PMID: 23124999 DOI: 10.1002/anie.201207603] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Indexed: 01/08/2023]
Affiliation(s)
- Jianfeng Li
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, NY 10065, USA
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Tov AB, Mandel D, Weissman Y, Dollberg S, Taxir T, Lubetzky R. Changes in serum parathyroid hormone-related protein in breastfed preterm infants. Breastfeed Med 2012; 7:50-3. [PMID: 21492018 DOI: 10.1089/bfm.2010.0101] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Parathyroid hormone-related protein (PTHrP) has the ability to activate parathyroid hormone receptors and cause hypercalcemia. In a previous study we have demonstrated high concentrations of PTHrP in both term and preterm human milk (HM). PTHrP intestinal absorption and its influence upon calcium homeostasis of the preterm infant have not been studied yet. This study assessed the correlation between PTHrP concentrations in preterm HM and PTHrP in maternal and neonatal serum. STUDY DESIGN We collected samples of expressed HM obtained from 16 mothers of preterm infants (25-34 weeks of gestation) and drew blood samples from both mothers and infants on postpartum days 2 and 10. PTHrP concentrations were measured by two-site immunoradiometric assay. Blood calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP) concentrations were also measured. RESULTS Neither maternal nor neonatal PTHrP serum concentrations varied significantly after 10 days of breastfeeding. There was a correlation between PTHrP concentrations in maternal serum and HM concentrations (R² = 0.24, p = 0.04), but not between HM and neonatal serum concentrations or between PTHrP concentrations in HM and preterm serum concentrations of Ca, P, and ALP. CONCLUSIONS Despite high concentrations of PTHrP in preterm HM, serum concentrations of PTHrP of breastfed preterm infants did not increase over time. There was no correlation between PTHrP concentrations in HM and neonatal serum Ca concentration.
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Affiliation(s)
- Amir Ben Tov
- Department of Neonatology, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Israel
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Alamoudi OS. Lung cancer at a University Hospital in Saudi Arabia: A four-year prospective study of clinical, pathological, radiological, bronchoscopic, and biochemical parameters. Ann Thorac Med 2011; 5:30-6. [PMID: 20351958 PMCID: PMC2841806 DOI: 10.4103/1817-1737.58957] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Accepted: 11/16/2009] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES AND BACKGROUND Lung cancer accounts for 4% of all newly diagnosed cancers in Saudi Arabia. The pattern of presentation is unknown. The objectives of this study were to assess the clinical, radiological, pathological, biochemical and bronchoscopic abnormalities in lung cancer patients and to compare our findings with those reported in the literature. METHODS A total of 114 patients with proven lung cancer were selected for the study. A questionnaire concerning patients' demographic data was obtained; the abnormalities and the cell types of lung cancer were recorded prospectively in each subject. RESULTS A total of 114 patients with lung cancer were studied. Mean age ± SD was (59.8 ± 10.8) years, and (71.1%) were smokers and 95.1% of them were male, (90.1%) smoked >20 pack/yr (96.2%) for 20 years or more. Cough (76.3%) and clubbing (40.4%) were the most common symptom and physical abnormality respectively. The right lung (64.9%) was more commonly affected than the left (37.7%). Metastases were present in (49.1%) at presentation. The right and left upper bronchi (24% vs. 16%) were the mostly affected. Hypercalcemia was more common in squamous cell, while hyponatremia was more common in adenocarcinoma, and small cell. Squamous cell carcinoma was the most common cell type (51.8%) and significantly associated with smoking (P ≤ 0.001) CONCLUSION Squamous cell carcinoma was the most common cell type, and significantly associated with smoking. The incidence of metastasis was high at presentation. The right lung and right upper bronchus were often affected. Hypercalcemia and hyponatremia were the most common biochemical abnormalities.
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Affiliation(s)
- Omer S Alamoudi
- Department of Medicine, King Abdulaziz University Hospital, (KAUH), Jeddah, Saudi Arabia.
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16
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Phillips DJ, Harding PE, Bach LA. The history of the Endocrine Society of Australia. The first fifty years. HEALTH AND HISTORY 2011; 13:90-106. [PMID: 21932745 DOI: 10.5401/healthhist.13.1.0090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The Endocrine Society of Australia was formed in 1958 with the aims of advancing knowledge and practice in endocrinology (the study of hormones) and to bring together physicians and scientists in this area of study. It was one of the first medical specialist societies in Australia. From humble beginnings with ninety-nine foundation members, it has flourished to a society with almost 950 members which annually runs three successful clinical and scientific meetings, and provides scholarships, research grants, and travel grants for its young members. Members have received international and national recognition within the field and more generally. Collaboration between scientists and physicians has been a key strength of the Society.
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Dobolyi A, Palkovits M, Usdin TB. The TIP39-PTH2 receptor system: unique peptidergic cell groups in the brainstem and their interactions with central regulatory mechanisms. Prog Neurobiol 2010; 90:29-59. [PMID: 19857544 PMCID: PMC2815138 DOI: 10.1016/j.pneurobio.2009.10.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 10/11/2009] [Accepted: 10/14/2009] [Indexed: 01/01/2023]
Abstract
Tuberoinfundibular peptide of 39 residues (TIP39) is the recently purified endogenous ligand of the previously orphan G-protein coupled parathyroid hormone 2 receptor (PTH2R). The TIP39-PTH2R system is a unique neuropeptide-receptor system whose localization and functions in the central nervous system are different from any other neuropeptides. TIP39 is expressed in two brain regions, the subparafascicular area in the posterior thalamus, and the medial paralemniscal nucleus in the lateral pons. Subparafascicular TIP39 neurons seem to divide into a medial and a lateral cell population in the periventricular gray of the thalamus, and in the posterior intralaminar complex of the thalamus, respectively. Periventricular thalamic TIP39 neurons project mostly to limbic brain regions, the posterior intralaminar thalamic TIP39 neurons to neuroendocrine brain areas, and the medial paralemniscal TIP39 neurons to auditory and other brainstem regions, and the spinal cord. The widely distributed axon terminals of TIP39 neurons have a similar distribution as the PTH2R-containing neurons, and their fibers, providing the anatomical basis of a neuromodulatory action of TIP39. Initial functional studies implicated the TIP39-PTH2R system in nociceptive information processing in the spinal cord, in the regulation of different hypophysiotropic neurons in the hypothalamus, and in the modulation of affective behaviors. Recently developed novel experimental tools including mice with targeted mutations of the TIP39-PTH2R system and specific antagonists of the PTH2R will further facilitate the identification of the specific roles of TIP39 and the PTH2R.
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Affiliation(s)
- Arpád Dobolyi
- Department of Anatomy, Histology and Embryology, HAS-Semmelweis University, Budapest, Hungary.
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Parathyroid Hormone and Parathyroid Hormone–Related Peptide in the Regulation of Calcium Homeostasis and Bone Development. Endocrinology 2010. [DOI: 10.1016/b978-1-4160-5583-9.00056-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Landa MS, García SI, Liberjen L, Schuman ML, Finkielman S, Pirola CJ. Parathyroid Hormone-Related Protein Overexpression Decreases Blood Pressure in Spontaneously Hypertensive Rats. Clin Exp Hypertens 2009. [DOI: 10.1081/ceh-57435] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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20
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Expression of parathyroid hormone-related protein in the partially obstructed and reversed rabbit bladder. Int Urol Nephrol 2008; 41:505-11. [DOI: 10.1007/s11255-008-9485-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Accepted: 09/23/2008] [Indexed: 01/05/2023]
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Spiro SG, Gould MK, Colice GL. Initial evaluation of the patient with lung cancer: symptoms, signs, laboratory tests, and paraneoplastic syndromes: ACCP evidenced-based clinical practice guidelines (2nd edition). Chest 2007; 132:149S-160S. [PMID: 17873166 DOI: 10.1378/chest.07-1358] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND This chapter of the guidelines is intended to provide an evidence-based assessment of the initial evaluation of patients recognized as having lung cancer and the recognition of paraneoplastic syndromes. METHODS The current medical literature that is applicable to this issue was identified by a computerized search and was evaluated using standardized methods. Recommendations were framed using the approach described by the Health and Science Policy Committee of the American College of Chest Physicians. RESULTS Patients with lung cancer usually present with multiple symptoms, both respiratory related and constitutional. There is usually a time delay between symptom recognition by the patient and the ultimate diagnosis of lung cancer by the physician. Whether this time delay impacts prognosis is unclear, but delivering timely and efficient care is an important component in its own right. Lung cancer may be accompanied by a variety of paraneoplastic syndromes. These syndromes may not necessarily preclude treatment with a curative intent. CONCLUSIONS The initial evaluation of the patient with known or suspected lung cancer should include an assessment of symptoms, signs, and laboratory test results in a standardized manner as a screen for identifying those patients with paraneoplastic syndromes and a higher likelihood of metastatic disease.
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Affiliation(s)
- Stephen G Spiro
- Department of Respiratory Medicine, University College Hospital, Grafton Way, London WC1E 6AU, UK.
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Godler DE, Stein AN, Bakharevski O, Lindsay MML, Ryan PFJ. Parathyroid hormone-related peptide expression in rat collagen-induced arthritis. Rheumatology (Oxford) 2005; 44:1122-31. [DOI: 10.1093/rheumatology/keh690] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Morley P, Whitfield JF, Willick G. Parathyroid hormone analogues for treatment of osteoporosis and hypercalcaemia. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.8.1.31] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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24
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Schievano E, Mammi S, Carretta E, Fiori N, Corich M, Bisello A, Rosenblatt M, Chorev M, Peggion E. Conformational and biological characterization of human parathyroid hormone hPTH(1-34) analogues containing beta-amino acid residues in positions 17-19. Biopolymers 2004; 70:534-47. [PMID: 14648764 DOI: 10.1002/bip.10508] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The N-terminal 1-34 fragment of parathyroid hormone (PTH) elicits the full spectrum of bone-related biological activities of the intact native sequences. It has been suggested that the structural elements essential for bioactivity are two helical segments located at the N-terminal and C-terminal sequences, connected by hinges or flexible points around positions 12 and 19. In order to assess the relevance of the local conformation around Gly(18) upon biological function, we synthesized and characterized the following human (h) PTH(1-34) analogues containing beta-amino acid residues: [analogues: see text]. Biological activity and binding affinity of analogue I are one order of magnitude lower than those of the parent compound. In analogue II, both binding affinity and biological activity are partially recovered. Analogues III and V have no binding affinity and very low biological activity. Both bioactivity and binding affinity are partially recovered in analogue IV. The conformational properties of the analogues in aqueous solution containing dodecylphosphocholine micelles were studied by CD, 2D-nuclear magnetic resonance and molecular dynamics calculations. The results confirmed the presence in all analogues of two helical segments located at the N-terminal and C-terminal sequences. The insertion of beta-amino acid residues around position 18 does not cause appreciable conformational differences in the five analogues. The differences in biological activity and binding affinity among the five analogues cannot be related to structural differences in the membrane mimetic environment reported in this study. Our results stress the importance of the side-chain functionalities in the sequence 17-19 for biological function.
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Affiliation(s)
- E Schievano
- Department of Organic Chemistry, University of Padova, Institute of Biomolecular Chemistry, C.N.R, Via Marzolo 1, 35131 Padova, Italy
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Power DM, Ingleton PM, Clark MS. Application of comparative genomics in fish endocrinology. INTERNATIONAL REVIEW OF CYTOLOGY 2003; 221:149-90. [PMID: 12455748 DOI: 10.1016/s0074-7696(02)21012-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
This review discusses the ways in which comparative genomics can contribute to the study of fish endocrinology. First, the phylogenetic position of fish and an overview of their specific endocrine systems are presented. The emphasis will be on teleosts because they are the most abundant fishes and because most data are available for this group. Second, the complexity of fish genomics is reviewed. With the vast array of genome sizes and ploidy levels, assignment of gene orthology is more difficult in fish, but this is an absolute prerequisite in functional analysis and it is important to be aware of such genome plasticity when cloning genes. The ease with which a gene is cloned at the genomic level is directly related to genome size and complexity, a factor that is not known in the majority of fish species. Finally, the methodology is presented along with specific examples of parathyroid hormone-related protein (PTHrP) (a previously unidentified hormone in fish), calcium-sensing receptor, and calcitonin (with a duplication of this particular ligand in Fugu rubripes). Preliminary data also suggest that there are further duplicated genes in the calcium regulatory system. Comparative genomics has provided a valuable approach for isolating and characterizing a range of fish genes involved in calcium regulation. However, for understanding the physiology and endocrine regulation of this system, particularly with regard to gene duplication, an alternative approach is required in which conventional endocrinology techniques will play a significant role.
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Affiliation(s)
- Deborah M Power
- CCMAR, Centre of Marine Sciences, Universidade do Algarve, Campus de Gambelas, 8000-810 Faro, Portugal
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Peggion E, Mammi S, Schievano E, Schiebler L, Corich M, Rosenblatt M, Chorev M. Structure-function relationship studies of bovine parathyroid hormone [bPTH(1-34)] analogues containing alpha-amino-iso-butyric acid (Aib) residues. Biopolymers 2003; 68:437-57. [PMID: 12601801 DOI: 10.1002/bip.10294] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The N-terminal 1-34 fragments of the parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP) elicit the full spectrum of bone-related biological activities of the intact native sequences. It has been suggested that the structural elements essential for bioactivity are two helical segments located at the N-terminal and C-terminal sequences, connected by hinges or flexible points around positions 12 and 19. In order to assess the relevance of the local conformation around Gly(12) upon biological function, we synthesized and characterized the following PTH(1-34) analogues containing Aib residues: (I) A-V-S-E-I-Q-F-nL-H-N-Aib-G-K-H-L-S-S-nL-E-R-V-E-Nal-L-R-K-K-L-Q-D-V-H-N-Y-NH(2) ([Nle(8,18), Aib(11), Nal(23),Tyr(34)]bPTH(1-34)-NH(2)); (II) A-V-S-E-I-Q-F-nL-H-N-L-Aib-K-H-L-S-S-nL-E-R-V-E-Nal-L-R-K-K-L-Q-D-V-H-N-Y-NH(2) ([Nle(8,18), Aib(12),Nal(23),Tyr(34)]bPTH(1-34)-NH(2)); (III) A-V-S-E-I-Q-F-nL-H-N-L-G-Aib-H-L-S-S-nL-E-R-V-E-Nal-L-R-K-K-L-Q-D-V-H-N-Y-NH(2) ([Nle(8,18), Aib(13), Nal(23),Tyr(34)]bPTH(1-34)-NH(2)); (IV) A-V-S-E-I-Q-F-nL-H-N-Aib-Aib-K-H-L-S-S-nL-E-R-V-E-Nal-L-R-K-K-L-Q-D-V-H-N-YNH(2) ([Nle(8,18), Aib(11,12), Nal(23),Tyr(34)]bPTH(1-34)-NH(2)); (V) A-V-S-E-I-Q-F-nL-H-N-L-Aib-Aib-H-L-S-S-nL-E-R-V-E-Nal-L-R-K-K-L-Q-D-V-H-N-Y-NH(2) ([Nle(8,18), Aib(12,13),Nal(23),Tyr(34)]bPTH(1-34)-NH(2)). (nL= Nle; Nal= L-(2-naphthyl)-alanine; Aib= alpha-amino-isobutyric acid.) The introduction of Aib residues at position 11 in analogue I or at positions 11 and 12 in analogue IV resulted in a 5-20-fold lower efficacy and a substantial loss of binding affinity compared to the parent compound [Nle(8,18), Nal(23),Tyr(34)]bPTH(1-34)-NH(2). Both binding affinity and adenylyl cyclase stimulation activity are largely restored when the Aib residues are introduced at position 12 in analogue II, 13 in analogue III, and 12-13 in analogue V. The conformational properties of the analogues in aqueous solution containing dodecylphosphocholine micelles were studied by CD, two-dimensional (2D) NMR and computer simulations. The results indicated the presence of two helical segments in all analogues, located at the N-terminal and C-terminal sequences. Insertion of Aib residues at positions 12 and 13, or of Aib dyads at positions 11-12 and 12-13, enhances the stability of the N-terminal helix of all analogues. In all analogues the Aib residues are included in the helical segments. These results confirmed the importance of the helical structure in the N-terminal activation domain, as well as of the presence of the Leu(11) hydrophobic side chain in the native sequence, for PTH-like bioactivity.
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Affiliation(s)
- E Peggion
- University of Padova, Department of Organic Chemistry, Institute of Biomolecular Chemistry, CNR, Via Marzolo 1, 35131 Padova, Italy.
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Beckles MA, Spiro SG, Colice GL, Rudd RM. Initial evaluation of the patient with lung cancer: symptoms, signs, laboratory tests, and paraneoplastic syndromes. Chest 2003; 123:97S-104S. [PMID: 12527569 DOI: 10.1378/chest.123.1_suppl.97s] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
This chapter describes the components of the initial evaluation for a patient either suspected or known to have lung cancer. The components of the initial evaluation are based on the recognized manifestations of localized lung cancer, ie, symptoms referable to the primary tumor, intrathoracic spread of lung cancer, and patterns of metastatic dissemination. Features of the history and physical signs may be useful indicators of the extent of disease. A standardized evaluation, relying on symptoms, signs, and routinely available laboratory tests, can serve as a useful screen for metastatic disease. Also described are the common features of the various paraneoplastic syndromes associated with lung cancer.
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Asadi F, Faraj M, Malakouti S, Kukreja SC. Effect of parathyroid hormone related protein, and dihydrotestosterone on proliferation and ornithine decarboxylase mRNA in human prostate cancer cell lines. Int Urol Nephrol 2002; 33:417-22. [PMID: 12230264 DOI: 10.1023/a:1019551021631] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVES Parathyroid hormone related protein (PTHrP) has been identified as the major hormone responsible for the syndrome of humoral hypercalcemia of malignancy (HHM). Recent studies have shown that a large number of prostate tumors demonstrate the presence of PTHrP despite the fact that prostate cancer is rarely associated with the HHM syndrome. Other studies have indicated that PTHrP behaves as an early response gene, which stimulates ornithine decarboxylase (ODC) enzyme activity, an enzyme, involved in the biosynthesis of polyamines. It is therefore possible that PTHrP regulates prostate tumor cell proliferation via ODC gene expression. METHODS In the present study, we evaluated the effects of PTHrP and/or dihydrotestosterone (DHT) treatment on DNA synthesis by thymidine incorporation in androgen-dependent (LnCaP) and androgen-independent (PC3) human prostate adenocarcinoma cell lines. In addition, we utilized Northern blot analysis to investigate the effect of PTHrP [1-34] alone or in combination with DHT on ODC mRNA. RESULTS PTHrP [1-34] treatment resulted in an increase in thymidine uptake in PC3 cells by 50%, whereas no such increase was seen in LnCaP cells. However, in the LnCaP cells, in the presence of DHT, PTHrP stimulated DNA synthesis to a level greater than that seen with DHT alone. DHT (10 nM) treatment resulted in an induction of PTHrP as well as ODC mRNAs in the androgen-dependent (LnCaP) but not in androgen-independent (PC3) cell line. PTHrP [1-34] treatment resulted in induction of ODC mRNA in the LnCaP cells. Addition of DHT resulted in a further increase in the ODC mRNA expression. CONCLUSIONS These data suggest that PTHrP may play a role in prostate cancer cell proliferation and the increased ODC gene expression may be one possible mechanisms responsible for this phenomenon.
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Affiliation(s)
- F Asadi
- Department of Medicine, VA West Side Medical Center and University of Illinois College of Medicine, Chicago, USA.
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29
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Pasquini GMF, Davey RAM, Ho PWM, Michelangeli VP, Grill V, Kaczmarczyk SJ, Zajac JD. Local secretion of parathyroid hormone-related protein by an osteoblastic osteosarcoma (UMR 106-01) cell line results in growth inhibition. Bone 2002; 31:598-605. [PMID: 12477574 DOI: 10.1016/s8756-3282(02)00872-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Parathyroid hormone-related protein (PTHrP) has been implicated as being important in the growth of tumor cells responsive to the peptide. We utilized a rat osteoblastic osteosarcoma cell line, UMR 106-01, which has PTHrP receptors and a PTHrP-responsive adenylate cyclase/cAMP messenger system, to produce a modified cell line that overexpresses PTHrP. The human PTHrP cDNA sequence was transfected by electroporation into UMR 106-01 cells and the stable cell lines UMR-36 and UMR-34 were established. The modified cell line, UMR-36, had increased levels of PTHrP mRNA compared with control cell lines and secreted PTHrP into the culture medium at levels of 0.01-0.1 pmol/10(7) cells in 12 h. The secreted peptide was biologically active as indicated by its ability to activate adenylate cyclase. The number of UMR-36 cells following 9 days in culture was reduced by up to 80% compared with control lines, which was associated with decreased (3)H-thymidine incorporation into genomic DNA. Addition of 1000-fold excess of the PTHrP antagonist, PTHrP(7-34), to UMR-36 cells resulted in the escape of growth inhibition and increased rate of growth. In vivo, tumors derived from UMR-36 cells were smaller in size compared with tumors derived from control cells. In conclusion, increased autocrine secretion of, and responsiveness to, PTHrP results in inhibited growth kinetics of an osteoblast-like bone tumor cell line in vitro and in vivo.
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Affiliation(s)
- G M F Pasquini
- Department of Medicine, University of Melbourne, Royal Melbourne Hospital, Victoria, Australia
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Wang Y, Yang SX, Tu P, Zhang B, Ma SQ. Expression of parathyroid hormone (PTH)/PTH-related peptide receptor messenger ribonucleic acid in mice hair cycle. J Dermatol Sci 2002; 30:136-41. [PMID: 12413769 DOI: 10.1016/s0923-1811(02)00074-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
There is increasing evidence that parathyroid hormone (PTH) and PTH-related peptide (PTHrP) are involved in normal skin cell growth, influence the proliferation and differentiation of the epidermis and hair follicle. PTHrP and PTH/PTHrP receptor show prominent cutaneous expression, may exert important paracrine and/or autocrine functions. The expression of PTH/PTHrP receptor in different stages of hair cycle is unknown. Therefore, we examined the amount of PTH/PTHrP mRNA in C57BL/6 mice skin at different stages of hair cycle by relatively quantitative reverse transcription-polymerase chain reaction (RT-PCR), and investigated the localization of this receptor in mice skin by in situ hybridization. The expression of PTH/PTHrP receptor mRNA were higher in anagen, but significantly lower in catagen and telogen. Then, the PTH/PTHrP receptor mRNA was located in the inner root sheath (IRS) in anagen and catagen, but was not detected in telogen hair follicles, although it was expressed weakly in dermis. The variety of the PTH/PTHrP receptor mRNA expression during hair cycling suggest that PTH, PTHrP and their receptors might participate in the regulation of hair cycle in mice skin.
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Affiliation(s)
- Ying Wang
- Department of Dermatology, The First Hospital of Peking University, Beijing 100034, People's Republic of China.
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31
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Chen HL, Demiralp B, Schneider A, Koh AJ, Silve C, Wang CY, McCauley LK. Parathyroid hormone and parathyroid hormone-related protein exert both pro- and anti-apoptotic effects in mesenchymal cells. J Biol Chem 2002; 277:19374-81. [PMID: 11897779 DOI: 10.1074/jbc.m108913200] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
During bone formation, multipotential mesenchymal cells proliferate and differentiate into osteoblasts, and subsequently many die because of apoptosis. Evidence suggests that the receptor for parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP), the PTH-1 receptor (PTH-1R), plays an important role in this process. Multipotential mesenchymal cells (C3H10T1/2) transfected with normal or mutant PTH-1Rs and MC3T3-E1 osteoblastic cells were used to explore the roles of PTH, PTHrP, and the PTH-1R in cell viability relative to osteoblastic differentiation. Overexpression of wild-type PTH-1R increased cell numbers and promoted osteocalcin gene expression versus inactivated mutant receptors. Furthermore, the effects of PTH and PTHrP on apoptosis were dramatically dependent on cell status. In preconfluent C3H10T1/2 and MC3T3-E1 cells, PTH and PTHrP protected against dexamethasone-induced reduction in cell viability, which was dependent on cAMP activation. Conversely, PTH and PTHrP resulted in reduced cell viability in postconfluent cells, which was also dependent on cAMP activation. Further, the proapoptotic-like effects were associated with an inhibition of Akt phosphorylation. These data suggest that parathyroid hormones accelerate turnover of osteoblasts by promoting cell viability early and promoting cell departure from the differentiation program later in their developmental scheme. Both of these actions occur at least in part via the protein kinase A pathway.
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Affiliation(s)
- Hen-Li Chen
- Department of Periodontics, Prevention, and Geriatrics, University of Michigan, Ann Arbor, Michigan 48109, USA
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Jüppner H, Potts JT. Roles of Parathyroid Hormone and Parathyroid Hormone–Related Peptide in Calcium Metabolism and Bone Biology: Biological Actions and Receptors. Compr Physiol 2000. [DOI: 10.1002/cphy.cp070317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Endo K, Katsumata K, Hirata M, Masaki T, Kubodera N, Nakamura T, Ikeda K, Ogata E. 1,25-dihydroxyvitamin D3 as well as its analogue OCT lower blood calcium through inhibition of bone resorption in hypercalcemic rats with continuous parathyroid hormone-related peptide infusion. J Bone Miner Res 2000; 15:175-81. [PMID: 10646127 DOI: 10.1359/jbmr.2000.15.1.175] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and its analogue 22-oxa-1,25(OH)2D3 (22-oxacalcitriol) (OCT) on calcium and bone metabolism were examined in an animal model of hypercalcemia with continuous infusion of parathyroid hormone-related peptide (PTHrP), to determine whether active vitamin D could counteract the skeletal action of PTHrP in addition to its reported effect in suppressing the production of PTHrP in cancer cells. Parathyroid glands were removed from 8-week-old Sprague-Dawley rats to eliminate the confounding effects of endogenous PTH. Animals were then continuously infused with human PTHrP(1-34) at a constant rate via osmotic minipumps for 2 weeks, and at the same time treated orally or intravenously with OCT or 1,25(OH)2D3 four to nine times during the 2-week period. Under these conditions, OCT and, surprisingly, 1,25(OH)2D3 alleviated hypercalcemia in a dose-dependent manner. 1,25(OH)2D3 and OCT suppressed the urinary excretion of deoxypyridinoline, although they did not affect renal calcium handling, suggesting that the antihypercalcemic effect is attributable to the inhibition of bone resorption. These active vitamin D compounds also counteracted the effects of PTHrP at the proximal renal tubules, as reflected by a decrease in phosphate excretion. Histomorphometric analysis of bone revealed a dose-related decrease in parameters of bone resorption. These results suggest that 1,25(OH)2D3 as well as OCT has the potential to alleviate hypercalcemia, at least in part, through the inhibition of bone resorption in hypercalcemic rats with constant PTHrP levels. We propose that the main function of active vitamin D in high bone-turnover states is to inhibit bone resorption, and this may have important implications for the understanding of the role of active vitamin D in the treatment of metabolic bone diseases, such as osteoporosis.
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Affiliation(s)
- K Endo
- Pharmaceutical Research Laboratory, Chugai Pharmaceutical Co. Ltd., Tokyo, Japan
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Iwamura M, Wu W, Muramoto M, Ohori M, Egawa S, Uchida T, Baba S. Parathyroid hormone-related protein is an independent prognostic factor for renal cell carcinoma. Cancer 1999; 86:1028-34. [PMID: 10491530 DOI: 10.1002/(sici)1097-0142(19990915)86:6<1028::aid-cncr19>3.0.co;2-g] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Parathyroid hormone-related protein (PTHrP) has been shown to be the principal cause of humoral hypercalcemia associated with renal cell carcinoma (RCC). Recent studies have demonstrated that the amino-terminal region of PTHrP has growth factor-like activities, suggesting it may play a role in the development of RCC. In this study, expression of the carboxy-terminal region of PTHrP was assessed immunohistochemically and its significance in predicting the prognosis of RCC was studied. METHODS Forty radical nephrectomy specimens were immunostained with a murine monoclonal antibody (9H7) against the carboxy-terminal region (amino acids 109-141) of PTHrP using the streptavidin-peroxidase enzyme conjugate method. Staining intensity was evaluated semiquantitatively and compared with clinicopathologic features of the corresponding RCC. RESULTS Immunoreactivity to 9H7 was observed to be localized to the cytosol of tumor cells at various staining intensities. There were 30 cases (75.0%) with strong staining and 10 cases (25.0%) in which staining was weak or nonexistent. Staining intensity showed no significant correlation with gender, tumor greatest dimension, stage, or grade. Tumors of the clear cell type expressed PTHrP to a significantly greater extent than tumors of the granular cell type. Tumor recurrence was significantly greater in the weakly stained or unstained group compared with the strongly stained group (P = 0.035). Multivariate analysis indicated that PTHrP expression and tumor stage were equally significant prognostic indicators in RCCs measuring <10 cm in greatest dimension. CONCLUSIONS Evident PTHrP(109-141) expression is present in the majority of RCCs. The results of the current study indicate PTHrP(109-141) may be a possible marker of cellular differentiation and may be useful for predicting recurrence free survival in RCC patients after radical nephrectomy.
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Affiliation(s)
- M Iwamura
- Department of Urology, Kitasato University School of Medicine, Kanagawa, Japan
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Bisello A, Behar V, Greenberg Z, Suva LJ, Rosenblatt M, Chorev M. Development of a photoreactive parathyroid hormone antagonist to probe antagonist-receptor bimolecular interaction. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 1999; 54:120-8. [PMID: 10461746 DOI: 10.1034/j.1399-3011.1999.00096.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Parathyroid hormone (PTH) and PTH-related protein (PTHrP) exert their calciotropic activities by binding to a specific seven-transmembrane-helix-containing G protein-coupled receptor mainly located in bone and kidney cells. In order to map in detail the nature of hormone-receptor interaction, we are employing 'photoaffinity scanning' of the bimolecular interface. To this end, we have developed photoreactive benzophenone (BP)-containing PTH analogs which can be specifically and efficiently cross-linked to the human (h) PTH/PTHrP receptor. In this report, we describe the photocross-linking of a BP-containing PTH antagonist, [Nle8,18,D-2-Nal12,Lys13(epsilon-BP),2-Nal23,Tyr34]bPT H(7-34)NH2 (ANT) to the recombinant hPTH/PTHrP receptor stably expressed in human embryonic kidney cells (HEK-293, clone C-21). This photoreactive antagonist has high affinity for the hPTH/PTHrP receptor and inhibits agonist-induced cyclase activity and intracellular calcium release. The photo-induced cross-linking of the radioiodinated antagonist (125I-ANT) to the recombinant hPTH/PTHrP receptor followed by SDS-PAGE analysis reveals a single radiolabeled band of approximately 85kDa, similar to that observed after cross-linking of a radioiodinated BP-containing agonist. The formation of this covalent 125I-ANT - hPTH/PTHrP receptor conjugate is competed dose-dependently by a variety of unlabelled PTH- and PTHrP-derived agonists and antagonists. This is the first report of a specific and efficient photocross-linking of a radioiodinated PTH antagonist to the hPTH/PTHrP receptor. Therefore, it provides the opportunity to study directly the nature of the bimolecular interaction of PTH antagonist with the hPTH/PTHrP receptor.
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Affiliation(s)
- A Bisello
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
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Jemtland R, Rian E, Olstad OK, Haug E, Bruland OS, Bucht E, Gautvik KM. Two human osteoblast-like osteosarcoma cell lines show distinct expression and differential regulation of parathyroid hormone-related protein. J Bone Miner Res 1999; 14:904-14. [PMID: 10352098 DOI: 10.1359/jbmr.1999.14.6.904] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Parathyroid hormone (PTH)-related protein (PTHrP) acts as a local regulator of osteoblast function via mechanisms that involve PTH/PTHrP receptors linked to protein kinase A (PKA) and C (PKC). However, the regulation of PTHrP production and mRNA expression in human osteoblasts is poorly understood. Here we have characterized alternative PTHrP mRNA 3' splicing variants, encoding PTHrP isoforms of 139, 141, and 173 amino acids, and studied the regulation of PTHrP and its mRNAs by activated PKA and PKC in two human osteoblast-like cell lines (KPDXM and TPXM). Using exon-specific Northern analysis and reverse transcriptase-coupled polymerase chain reaction, we identified mRNAs encoding PTHrP(1-139) and PTHrP(1-141) in both cell lines. PTHrP(1-139) mRNAs predominated in TPXM cells and PTHrP(1-173) mRNAs were only detected in TPXM cells. Activation of PKA or PKC resulted in different effects on PTHrP and its mRNAs in the two cell lines. In TPXM cells, peptide-specific immunoassays detected high basal levels of PTHrP, increasing by 2-fold in cell extracts and 4-fold in culture media at 7 h and 24 h after exposure to forskolin, respectively, paralleling changes in PTHrP mRNA expression. Phorbol ester 12-O-tetradecanoyl-phorbol 13-acetate (TPA), a PKC activator, had no effect. In KPDXM cells, PTHrP was not detected in culture media under basal experimental conditions, and barely detectable amounts were present in cell extracts of TPA-treated cells, although the mRNA levels increased substantially in response to TPA. In the responsive cell lines, the effects on mRNA levels were dose dependent, and increased by 6.9- to 10.5-fold and 2.0- to 4.1-fold at 4 h in TPXM and KPDXM cells after exposure to 10 microM forskolin and 150 nM TPA, respectively. PTHrP mRNA levels then declined but were sustained above controls also at 12 h in both cell lines, albeit at considerably higher levels in TPXM cells. The different responsiveness to agents activating PKA- and PKC-dependent pathways may depend on the cellular state of differentiation, or alternatively, cancer cell line-specific defects. Our data demonstrating distinct differences in mRNA species and the amounts of PTHrP produced by the two cell lines as compared with roughly equivalent overall mRNA levels may suggest that post-transcriptional mechanisms play an important role in limiting the production of intracellular and secreted PTHrPs in human osteoblastic cells.
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Affiliation(s)
- R Jemtland
- Institute of Medical Biochemistry, University of Oslo, Oslo, Norway
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Aya K, Tanaka H, Ichinose Y, Kobayashi M, Seino Y. Expression of parathyroid hormone-related peptide messenger ribonucleic acid in developing kidney. Kidney Int 1999; 55:1696-703. [PMID: 10231431 DOI: 10.1046/j.1523-1755.1999.00417.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Parathyroid hormone (PTH)-related peptide (PTHrP), originally identified as a causative agent of hypercalcemia of malignancy, has been implicated in the regulation of growth and differentiation of endochondral bone, hair follicle, and breast as an autocrine/paracrine factor. Although some experiments indicate that PTHrP works as a growth factor for primary renal cells in vitro, the role of PTHrP in the kidney in vivo is not yet known. METHODS We examined the amounts of PTHrP and PTH/ PTHrP receptor (PTHR) mRNA in the mouse kidney developmental process by reverse transcription-polymerase chain reaction, and investigated which cells produce PTHrP and PTHR in vivo by in situ hybridization. RESULTS We observed high levels of PTHrP mRNA during mouse kidney maturation. PTHrP mRNA was expressed in the collecting duct, urothelium of the pelvis, and immature elements in the cortex of the developing kidney, including the S-shaped body, ureteric bud, and glomerulus. However, the expression of PTHR mRNA was lower during maturation than after the completion of the maturation process, and it was not detected in the collecting duct, urothelium of the pelvis, or nephrogenic zone in embryonic day 16 or 0-day-old mouse kidneys. CONCLUSION These findings suggest that PTHrP has a role in mouse kidney maturation or glomerular development.
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Affiliation(s)
- K Aya
- Department of Pediatrics, Okayama University Medical School, Japan
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Lam MH, Briggs LJ, Hu W, Martin TJ, Gillespie MT, Jans DA. Importin beta recognizes parathyroid hormone-related protein with high affinity and mediates its nuclear import in the absence of importin alpha. J Biol Chem 1999; 274:7391-8. [PMID: 10066803 DOI: 10.1074/jbc.274.11.7391] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Parathyroid hormone-related protein (PTHrP), expressed in a range of tumors, has endocrine, autocrine/paracrine, and intracrine actions, some of which relate to its ability to localize in the nucleus. Here we show for the first time that extracellularly added human PTHrP (amino acids 1-108) can be taken up specifically by receptor-expressing UMR106.01 osteogenic sarcoma cells and accumulate to quite high levels in the nucleus and nucleolus within 40 min. Quantitation of recognition by the nuclear localization sequence (NLS)-binding importin subunits indicated that in contrast to proteins containing conventional NLSs, PTHrP is recognized exclusively by importin beta and not by importin alpha. The sequence of PTHrP responsible for binding was mapped to amino acids 66-94, which includes an SV40 large tumor-antigen NLS-like sequence, although sequence determinants amino-terminal to this region were also necessary for high affinity binding (apparent dissociation constant of approximately 2 nM for importin beta). Nuclear import of PTHrP was assessed in vitro using purified components, demonstrating that importin beta, together with the GTP-binding protein Ran, was able to mediate efficient nuclear accumulation in the absence of importin alpha, whereas the addition of nuclear transport factor NTF2 reduced transport. The polypeptide ligand PTHrP thus appears to be accumulated in the nucleus/nucleolus through a novel, NLS-dependent nuclear import pathway independent of importin alpha and perhaps also of NTF2.
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Affiliation(s)
- M H Lam
- Department of Biochemistry and Molecular Biology, John Curtin School of Medical Research, Canberra, A.C.T.2601, Australia
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Weidler M, Marx UC, Seidel G, Schäfer W, Hoffmann E, Esswein A, Rösch P. The structure of human parathyroid hormone-related protein(1-34) in near-physiological solution. FEBS Lett 1999; 444:239-44. [PMID: 10050767 DOI: 10.1016/s0014-5793(98)01658-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Parathyroid hormone-related protein plays a major role in the pathogenesis of humoral hypercalcemia of malignancy. Under normal physiological conditions, parathyroid hormone-related protein is produced in a wide variety of tissues and acts in an autocrine or paracrine fashion. Parathyroid hormone-related protein and parathyroid hormone bind to and activate the same G-protein-coupled receptor. Here we present the structure of the biologically active NH2-terminal domain of human parathyroid hormone-related protein(1-34) in near-physiological solution in the absence of crowding reagents as determined by two-dimensional proton magnetic resonance spectroscopy. An improved strategy for structure calculation revealed the presence of two helices, His-5-Leu-8 and Gln-16-Leu-27, connected by a flexible linker. The parathyroid hormone-related protein(1-34) structure and the structure of human parathyroid hormone(1-37) as well as human parathyroid hormone(1-34) are highly similar, except for the well defined turn, His-14-Ser-17, present in parathyroid hormone. Thus, the similarity of the binding affinities of parathyroid hormone and parathyroid hormone-related protein to their common receptor may be based on their structural similarity.
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Affiliation(s)
- M Weidler
- Lehrstuhl für Biopolymere, Universität Bayreuth, Germany
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Garcia SI, Clemens TL, Fagin JA, Finkielman S, Pirola CJ. Parathyroid hormone-related protein expression in vascular smooth muscle of spontaneously hypertensive rats: evidence for lack of response to angiotensin II. J Hypertens 1998; 16:1467-74. [PMID: 9814617 DOI: 10.1097/00004872-199816100-00010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE We studied the expression of parathyroid hormone (PTH)-related protein in vascular smooth muscle cells of spontaneously hypertensive rats (SHR) using Wistar-Kyoto (WKY) and Sprague-Dawley rats as normotensive controls. METHODS Aortae from 4- and 18-week-old SHR versus age-matched WKY and Sprague-Dawley rats were excised to obtain total RNA or smooth muscle cells. The cells were subcultured in Dulbecco's Modified Eagle's Medium containing 10% fetal calf serum, then serum-deprived for 72 h and stimulated with 0.1 micromol/I angiotensin II. PTH-related protein, c-myc and angiotensin II type qa receptor (AT1aR) messenger (m)RNA levels were measured by Northern blot, using total RNA extracted by phenol/chloroform. The effects of PTH-related protein(1-34)NH2 intravenous injections on arterial blood pressure and the heart rate were studied in anesthetized SHR and WKY rats. RESULTS The Northern blots showed a significantly higher abundance of PTH-related protein mRNA in aortae of SHR versus WKY rats in the prehypertensive state but no significant difference in adult animals. In cultured aortic smooth muscle cells, angiotensin II induced a four- to sixfold increase in PTH-related protein mRNA levels in smooth muscle cells from normotensive animals, but failed to elicit a significant response in smooth muscle cells derived from SHR in either the prehypertensive or the hypertensive state. This lack of response to angiotensin II in SHR smooth muscle cells was not due to decreased expression or responsiveness of the AT1aR, since SHR smooth muscle cells had more AT1aR mRNA than Sprague-Dawley smooth muscle cells, and angiotensin II-induced activation of c-myc was faster and greater in smooth muscle cells derived from 4- or 18-week-old SHR than in Sprague-Dawley smooth muscle cells. In contrast, PTH-related protein(1-34)NH2 induced a long-lasting dose-dependent hypotensive and tachycardic response in both SHR and WKY rats, indicating that SHR retained responsiveness to the vasodilator. CONCLUSIONS PTH-related protein gene expression in response to angiotensin II is impaired in SHR arteries. A deficiency in this potent local vasodilator may contribute to the development and/or maintenance of arterial hypertension in this model.
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MESH Headings
- Angiotensin II/pharmacology
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/metabolism
- Blotting, Northern
- Hemodynamics/drug effects
- Hypertension/metabolism
- Injections, Intravenous
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Parathyroid Hormone/metabolism
- Parathyroid Hormone-Related Protein
- Proteins/genetics
- Proteins/metabolism
- Proto-Oncogene Proteins c-myc/genetics
- Proto-Oncogene Proteins c-myc/metabolism
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred SHR
- Rats, Inbred WKY
- Rats, Sprague-Dawley
- Receptor, Angiotensin, Type 1
- Receptor, Angiotensin, Type 2
- Receptors, Angiotensin/genetics
- Receptors, Angiotensin/metabolism
- Vasoconstrictor Agents/pharmacology
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Affiliation(s)
- S I Garcia
- Departamento de Sustancias Vasoactivas, Instituto de Investigaciones Médicas A. Lanari, Universidad de Buenos Aires, Argentina
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Steers WD, Broder SR, Persson K, Bruns DE, Ferguson JE, Bruns ME, Tuttle JB. Mechanical stretch increases secretion of parathyroid hormone-related protein by cultured bladder smooth muscle cells. J Urol 1998; 160:908-12. [PMID: 9720586 DOI: 10.1097/00005392-199809010-00087] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Parathyroid hormone-related protein (PTHrP) immunoreactivity has been detected in the bladder and increases in response to dilatation secondary to obstruction. The hypothesis that PTHrP could be increased solely by stretch rather than other possible in vivo variables was tested by stretching cultured bladder smooth muscle cells and analyzing the culture medium for this protein. In response to mechanical stretch, PTHrP was increased in smooth muscle cell cultures. Immunoradiometric assay revealed maximal rates of secretion for the first eight hours. Comparison of percent change in PTHrP secretion of flexed cells for the various flex parameters revealed a difference (p = .006) when the degree of stretch (i.e. percent elongation) was altered. The protein synthesis inhibitor cycloheximide inhibited basal and stretch-induced PTHrP secretion. PTHrP (1-100 nM) relaxed carbachol-contracted bladder body and base by 15% and 45% respectively. PTHrP did not affect bladder contractions induced by potassium (124 mM) or alpha-beta MeATP (10 microM). Increased PTHrP secretion in response to stretch of smooth muscle raises the possibility of an autocrine action to relax the bladder during filling. PTHrP may also exert a paracrine action on vessels regulating blood flow during bladder filling or it may modulate neural activity.
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Affiliation(s)
- W D Steers
- Department of Urology, University of Virginia School of Medicine, Charlottesville, USA
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Steers WD, Broder SR, Persson K, Bruns DE, Ferguson JE, Bruns ME, Tuttle JB. Mechanical stretch increases secretion of parathyroid hormone-related protein by cultured bladder smooth muscle cells. J Urol 1998; 160:908-12. [PMID: 9720586 DOI: 10.1016/s0022-5347(01)62831-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Parathyroid hormone-related protein (PTHrP) immunoreactivity has been detected in the bladder and increases in response to dilatation secondary to obstruction. The hypothesis that PTHrP could be increased solely by stretch rather than other possible in vivo variables was tested by stretching cultured bladder smooth muscle cells and analyzing the culture medium for this protein. In response to mechanical stretch, PTHrP was increased in smooth muscle cell cultures. Immunoradiometric assay revealed maximal rates of secretion for the first eight hours. Comparison of percent change in PTHrP secretion of flexed cells for the various flex parameters revealed a difference (p = .006) when the degree of stretch (i.e. percent elongation) was altered. The protein synthesis inhibitor cycloheximide inhibited basal and stretch-induced PTHrP secretion. PTHrP (1-100 nM) relaxed carbachol-contracted bladder body and base by 15% and 45% respectively. PTHrP did not affect bladder contractions induced by potassium (124 mM) or alpha-beta MeATP (10 microM). Increased PTHrP secretion in response to stretch of smooth muscle raises the possibility of an autocrine action to relax the bladder during filling. PTHrP may also exert a paracrine action on vessels regulating blood flow during bladder filling or it may modulate neural activity.
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Affiliation(s)
- W D Steers
- Department of Urology, University of Virginia School of Medicine, Charlottesville, USA
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Yoshida T, Horiuchi T, Sakamoto H, Inoue H, Takayanagi H, Nishikawa T, Yamamoto S, Koshihara Y. Production of parathyroid hormone-related peptide by synovial fibroblasts in human osteoarthritis. FEBS Lett 1998; 433:331-4. [PMID: 9744821 DOI: 10.1016/s0014-5793(98)00940-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Synovial fibroblasts from patients with osteoarthritis in culture produced parathyroid hormone-related peptide (PTHrP) on treatment with phorbol ester (TPA) in a dose- and time-dependent manner. The levels of PTHrP immunoreactivity in the conditioned medium of synovial fibroblast cultures were measured using specific PTHrP antibody. The maximum production was obtained at a concentration of 10(-8) M and 24 h after TPA treatment. But sensitivity to TPA of synovial fibroblasts differed among four patients from slight to marked. PTHrP production was also induced with inflammatory cytokines, such as 1 ng/ml of IL-1alpha, IL-1beta, IL-6 and TNF-alpha, and 10(-6) M prostaglandin E2, after 24 h treatment. The expression of PTHrP was confirmed by reverse-transcriptase polymerase chain reaction. Since the synovial fibroblasts isolated from osteoarthritic patients produce high levels of IL-6 and IL-8, typical cytokines produced in synovial fibroblasts, production of PTHrP may provide new insight into the pathophysiology of joint disorder.
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Affiliation(s)
- T Yoshida
- Department of Clinical Chemistry, Hoshi College of Pharmacy, Tokyo, Japan
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Parathyroid Hormone-Related Protein-Induced Hypercalcemia in SCID Mice Engrafted With Adult T-Cell Leukemia Cells. Blood 1998. [DOI: 10.1182/blood.v91.12.4747] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractParathyroid hormone-related protein (PTHrP) is considered to be one of the main causes of hypercalcemia associated with adult T-cell leukemia (ATL). To clarify the role of PTHrP and bone remodeling in the development of hypercalcemia in ATL, we examined the SCID mouse model of ATL that has previously been shown to mimic the disease in humans. Using this model, we found clear elevations in serum levels of calcium and C-terminal PTHrP (C-PTHrP). PTHrP mRNA was highly expressed in ATL cells proliferating in vivo. After the development of hypercalcemia, ATL mice were killed and bone histomorphometric analysis was performed. Bone volume was clearly decreased in the ATL mice. In comparison to control SCID mice, bone formation indices were very low in the ATL mice. Surprisingly, no significant difference was detected between the ATL mice and the control SCID mice in eroded surface/bone surface (ES/BS), a parameter of bone resorption. To our knowledge, the model presented here is the first animal model of ATL with humoral hypercalcemia. This is in contrast to previously reported, well-characterized animal models of human solid tumors associated with humoral hypercalcemia of malignancy (HHM). Furthermore, this model not only provides us with the opportunity to study the mechanisms underlying development of elevated calcium levels in ATL, but also allows us to test new therapeutic agents designed to treat hypercalcemia.
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Abstract
Parathyroid hormone-related protein (PTHrP) is considered to be one of the main causes of hypercalcemia associated with adult T-cell leukemia (ATL). To clarify the role of PTHrP and bone remodeling in the development of hypercalcemia in ATL, we examined the SCID mouse model of ATL that has previously been shown to mimic the disease in humans. Using this model, we found clear elevations in serum levels of calcium and C-terminal PTHrP (C-PTHrP). PTHrP mRNA was highly expressed in ATL cells proliferating in vivo. After the development of hypercalcemia, ATL mice were killed and bone histomorphometric analysis was performed. Bone volume was clearly decreased in the ATL mice. In comparison to control SCID mice, bone formation indices were very low in the ATL mice. Surprisingly, no significant difference was detected between the ATL mice and the control SCID mice in eroded surface/bone surface (ES/BS), a parameter of bone resorption. To our knowledge, the model presented here is the first animal model of ATL with humoral hypercalcemia. This is in contrast to previously reported, well-characterized animal models of human solid tumors associated with humoral hypercalcemia of malignancy (HHM). Furthermore, this model not only provides us with the opportunity to study the mechanisms underlying development of elevated calcium levels in ATL, but also allows us to test new therapeutic agents designed to treat hypercalcemia.
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Sharpe GR, Dillon JP, Durham B, Gallagher JA, Fraser WD. Human keratinocytes express transcripts for three isoforms of parathyroid hormone-related protein (PTHrP), but not for the parathyroid hormone/PTHrP receptor: effects of 1,25(OH)2 vitamin D3. Br J Dermatol 1998; 138:944-51. [PMID: 9747354 DOI: 10.1046/j.1365-2133.1998.02259.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Parathyroid hormone-related protein (PTHrP) is strongly expressed in the epidermis and has been implicated in the regulation of growth and differentiation of keratinocytes. PTHrP has N-terminal sequence homology with parathyroid hormone (PTH) and binds to the type I PTH/PTHrP receptor, but earlier reports suggest that keratinocytes do not possess this cell surface receptor. In order to determine which PTHrP mRNA isoforms are expressed by keratinocytes and whether the type I receptor mRNA is present, we designed specific primers for reverse transcriptase-polymerase chain reaction. The interaction of PTHrP with other promoters of keratinocyte differentiation is unclear. In particular, 1,25(OH)2D3 is also fundamental in calcium homeostasis and induces changes in intracellular calcium. We therefore investigated the effect of 1,25(OH)2D3 on PTHrP mRNA expression and protein production in cultured human keratinocytes. Cells were incubated for 3 days at concentrations of 1.25(OH)2D3 of 10(-10)-10(-6) mol/L. PTHrP in culture supernatant, measured by two site immunoradiometric assay, was 915 +/- 98 PTHrP fmol/mg of cell layer protein in untreated cultures decreasing to 570 +/- 113 with 10(-8) mol/L and 402 +/- 24 with 10(-6) mol/L 1,25(OH)2D3 (mean +/- SEM, P < 0.01, n = 6). Transcripts for all three PTHrP isoforms (139, 141 and 173 amino acids) were detectable in keratinocyte mRNA. Corresponding to the decrease in PTHrP protein we demonstrated a reduction in all three PTHrP mRNA transcripts after 3 days' incubation with 1,25(OH)2D3 over a concentration range 10(-10)-10(-6) mol/L. Repeated studies failed to detect type I PTH/PTHrP receptor mRNA in human keratinocytes, either in control cultures or in the presence of 1,25(OH)2D3. We have shown that keratinocytes produce abundant PTHrP and that this is modulated by 1,25(OH)2D3, suggesting a physiological role. Further studies are required to investigate the relative expression of PTHrP isoforms, their role in keratinocyte signalling and the receptors involved.
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Affiliation(s)
- G R Sharpe
- Department of Dermatology, University of Liverpool, U.K.
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Abstract
The genomes of all organisms contain an abundance of DNA repeats which are at-risk for causing genetic change. We have used the yeast Saccharomyces cerevisiae to investigate various repeat categories in order to understand their potential for causing genomic instability and the role of DNA metabolism factors. Several types of repeats can increase enormously the likelihood of genetic changes such as mutation or recombination when present either in wild type or mutants defective in replication or repair. Specifically, we have investigated inverted repeats, homonucleotide runs, and short distant repeats and the consequences of various DNA metabolism mutants. Because the at-risk motifs (ARMs) that we characterized are sensitive indicators, we have found that they are useful tools to reveal new genetic factors affecting genome stability as well as to distinguish subtle differences between alleles.
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Affiliation(s)
- D A Gordenin
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, 101 Alexander Dr., P.O. Box 12233, Research Triangle Park, NC 27709, USA.
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Wu G, Iwamura M, di Sant'Agnese PA, Deftos LJ, Cockett AT, Gershagen S. Characterization of the cell-specific expression of parathyroid hormone-related protein in normal and neoplastic prostate tissue. Urology 1998; 51:110-20. [PMID: 9610565 DOI: 10.1016/s0090-4295(98)00077-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Parathyroid hormone-related protein (PTHrP) is a primary factor in the pathogenesis of malignancy-associated hypercalcemia. By alternative splicing, the human PTHrP gene can generate three different species of mRNA that encode three initial translational isoforms of 139, 173, and 141 amino acids. We recently reported that PTHrP was present in normal prostatic neuroendocrine cells and was overexpressed in prostate cancer tissue as demonstrated by immunostaining. This study was undertaken to further clarify the complex expression of PTHrP gene in normal prostate tissue and prostate cancer. METHODS PTHrP mRNA in samples prepared from normal prostate tissue, prostate cancer, and three prostate cancer cell lines, PC3, LNCaP, and DU145 was assessed using Northern hybridization. Expressed PTHrP isoforms were deduced from differential reverse transcription-polymerase chain reaction (RT-PCR) assays with exon-specific primers. Further localization of different species of PTHrP mRNA was performed using nonradioactive in situ hybridization with exon-specific probes on consecutive sections of normal and neoplastic prostate tissue. RESULTS Northern hybridization showed that the PTHrP expression level was higher in prostate cancer than in normal prostate tissue. All three PTHrP isoforms could be detected in normal prostate tissues and prostate cancer with differential RT-PCR. Further analysis using in situ hybridization with exon-specific probes revealed that all three PTHrP isoforms were present in prostatic neuroendocrine cells and only PTHrP-1-139 isoform could be clearly detected in prostate cancer tissue. Two androgen-insensitive cell lines, PC3 and DU145, derived from a bone metastasis and a brain metastasis, respectively, expressed all three mRNA species encoding for the three isoforms, but DU145 cells expressed less than PC3 cells. Androgen-sensitive LNCaP cells exhibited a low level of expression of mRNA species encoding for PTHrP-1-139 and PTHrP-1-173, and no expression of PTHrP1-141 isoform. CONCLUSIONS All three initial translational isoforms of PTHrP are produced by prostatic neuroendocrine cells. The mature products of PTHrP might exert their effects on other prostatic epithelial cells in a paracrine fashion and also participate in the homeostatic regulation of the ejaculate. In prostate cancer, differential expression of these three isoforms is evident and PTHrP-1-139 isoform is more abundant than the other two forms. These findings are valuable for designing future research studies to further elucidate the biological functions of PTHrP in normal prostatic glands and prostate cancer.
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Affiliation(s)
- G Wu
- Department of Urology, University of Rochester Medical Center, New York 14642, USA
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Kawashima-Ohya Y, Satakeda H, Kuruta Y, Kawamoto T, Yan W, Akagawa Y, Hayakawa T, Noshiro M, Okada Y, Nakamura S, Kato Y. Effects of parathyroid hormone (PTH) and PTH-related peptide on expressions of matrix metalloproteinase-2, -3, and -9 in growth plate chondrocyte cultures. Endocrinology 1998; 139:2120-7. [PMID: 9529001 DOI: 10.1210/endo.139.4.5941] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The roles of PTH and PTH-related peptide (PTH-rp) in the expression of matrix metalloproteinases (MMPs) during endochondral bone formation were investigated, using various cartilages obtained from young rabbits and rabbit chondrocyte cultures. Immunohistochemical, immunoblotting, zymographical, and/or Northern blot analyses showed that MMP-2 and -9 levels were much higher in the growth plate than in permanent cartilage in vivo. In growth plate chondrocyte cultures, PTH, PTH-rp, and (Bu)2cAMP increased the amount of MMP-2 present in the culture medium, as revealed by zymograms and immunoblots, whereas the other tested growth factors or cytokines, including bone morphogenetic protein-2 and interleukin-1, did not increase the MMP-2 level. PTH also increased the MMP-2 messenger RNA level within 24 h. In addition, PTH increased MMP-3 and -9 levels in the growth plate chondrocyte cultures. However, in articular chondrocyte cultures, PTH had little effect on the levels of MMP-2, -3, and -9. In contrast to PTH, interleukin-1 induced MMP-3 and -9, but not MMP-2, in growth plate and articular chondrocytes. These findings suggest that in ossifying cartilage, PTH/PTH-rp plays a pivotal role in the induction of various MMPs, including MMP-2 (which is considered to be a constitutive enzyme), and that PTH/PTH-rp is involved in the control of cartilage-matrix degradation during endochondral bone formation.
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Affiliation(s)
- Y Kawashima-Ohya
- Department of Biochemistry, Hiroshima University School of Dentistry, Japan
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Nagai Y, Yamato H, Akaogi K, Hirose K, Ueyama Y, Ikeda K, Matsumoto T, Fujita T, Ogata E. Role of interleukin-6 in uncoupling of bone in vivo in a human squamous carcinoma coproducing parathyroid hormone-related peptide and interleukin-6. J Bone Miner Res 1998; 13:664-72. [PMID: 9556066 DOI: 10.1359/jbmr.1998.13.4.664] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OCC tumor has been established from a human squamous carcinoma associated with humoral hypercalcemia of malignancy (HHM) and shown to overproduce parathyroid hormone-related peptide (PTHrP) and cause aggressive hypercalcemia when implanted into nude rats. In the present study, we have demonstrated by reverse transcription-polymerase chain reaction and Northern blot analysis that OCC tumor also overexpressed interleukin 6 (IL-6) mRNA and that tumor-bearing animals exhibited a marked increase in plasma IL-6 as well as PTHrP concentrations. When a monoclonal antibody against human IL-6 was injected to block the activities of tumor-derived IL-6, bone loss in tumor-bearing animals was significantly prevented. Quantitative bone histomorphometric analysis revealed that treatment with anti-IL-6 antibody caused a substantial decrease in both osteoclast number and eroded surface (as parameters of bone resorption) and also a significant increase in the mineral apposition rate, but little effect on the osteoblastic surface. These results provide in vivo evidence suggesting that in tumors coproducing IL-6 and PTHrP, IL-6 is involved not only in the acceleration of osteoclastic bone resorption but also, at least in part, in the suppression of osteoblastic functions in HHM syndrome.
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Affiliation(s)
- Y Nagai
- Biomedical Research Laboratories, Kureha Chemical Industry, Co., Ltd., Tokyo, Japan
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