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Boruah N, Singh CS, Swargiary P, Dkhar H, Chatterjee A. Securin overexpression correlates with the activated Rb/E2F1 pathway and histone H3 epigenetic modifications in raw areca nut-induced carcinogenesis in mice. Cancer Cell Int 2022; 22:30. [PMID: 35033090 PMCID: PMC8761315 DOI: 10.1186/s12935-022-02442-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 01/01/2022] [Indexed: 12/22/2022] Open
Abstract
Background Raw areca nut (RAN) consumption induces oral, esophageal and gastric cancers, which are significantly associated with the overexpression of pituitary tumor transforming gene 1/securin and chromosomal instability (CIN). An association of Securin/PTTG1 upregulation and gastric cancer in human was also demonstrated earlier. Since the molecular mechanism underlying securin upregulation remains unclear, this study intended to investigate the association of securin upregulation with the Rb-E2F1 circuit and epigenetic histone (H3) modification patterns both globally and in the promoter region of the securin gene. Methods Six groups of mice were used, and in the treated group, each mouse consumed 1 mg of RAN extract with lime per day ad libitum in the drinking water for 60 days, after which the dose was increased by 1 mg every 60 days. Histopathological evaluation of stomach tissues was performed and securin expression was analysed by immunoblotting as well as by immunohistochemistry. ChIP-qPCR assays were performed to evaluate the recruitment of different histone modifications in the core promoter region of securin gene as well as its upstream and downstream regions. Results All mice developed gastric cancer with securin overexpression after 300 days of feeding. Immunohistochemistry data revealed hyperphosphorylation of Rb and upregulation of E2F1 in the RAN-treated samples. Increased trimethylation of H3 lysine 4 and acetylation of H3 lysine 9 and 18 both globally and in the promoter region of the securin gene were observed by increasing the levels of lysine-N-methyltransferase 2A, lysine-acetyltransferase, EP-300 and PCAF after RAN treatment. ChIP-qPCR data revealed that the quantity of DNA fragments retrieved from the immunoprecipitated samples was maximum in the -83 to -192 region than further upstream and the downstream of the promoter for H3K4Me3, H3K9ac, H3K18ac and H3K9me3. Conclusions RAN-mediated pRb-inactivation induced securin upregulation, a putative E2F1 target, by inducing misregulation in chromatin remodeling in its promoter region, which led to transcriptional activation and subsequent development of chromosomal instability. Therefore, present results have led to the hypothesis that RAN-induced changes in the epigenetic landscape, securin overexpression and subsequent elevation of chromosomal instability is probably byproducts of inactivation of the pRb pathway. Supplementary Information The online version contains supplementary material available at 10.1186/s12935-022-02442-z.
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Affiliation(s)
- Nabamita Boruah
- Molecular Genetics Laboratory, Department of Biotechnology & Bioinformatics, North-Eastern Hill University, Shillong, Meghalaya, 793022, India
| | - Chongtham Sovachandra Singh
- Molecular Genetics Laboratory, Department of Biotechnology & Bioinformatics, North-Eastern Hill University, Shillong, Meghalaya, 793022, India
| | - Pooja Swargiary
- Molecular Genetics Laboratory, Department of Biotechnology & Bioinformatics, North-Eastern Hill University, Shillong, Meghalaya, 793022, India
| | - Hughbert Dkhar
- Histopathology Division, Nazareth Hospital, Laitumkhrah, Shillong, 793003, India
| | - Anupam Chatterjee
- Molecular Genetics Laboratory, Department of Biotechnology & Bioinformatics, North-Eastern Hill University, Shillong, Meghalaya, 793022, India.
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Bello SF, Xu H, Guo L, Li K, Zheng M, Xu Y, Zhang S, Bekele EJ, Bahareldin AA, Zhu W, Zhang D, Zhang X, Ji C, Nie Q. Hypothalamic and ovarian transcriptome profiling reveals potential candidate genes in low and high egg production of white Muscovy ducks (Cairina moschata). Poult Sci 2021; 100:101310. [PMID: 34298381 PMCID: PMC8322464 DOI: 10.1016/j.psj.2021.101310] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 05/24/2021] [Accepted: 06/01/2021] [Indexed: 01/16/2023] Open
Abstract
In China, the low egg production rate is a major challenge to Muscovy duck farmers. Hypothalamus and ovary play essential role in egg production of birds. However, there are little or no reports from these tissues to identify potential candidate genes responsible for egg production in White Muscovy ducks. A total of 1,537 laying ducks were raised; the egg production traits which include age at first egg (days), number of eggs at 300 d, and number of eggs at 59 wk were recorded. Moreover, 4 lowest (LP) and 4 highest producing (HP) were selected at 59 wk of age, respectively. To understand the mechanism of egg laying regulation, we sequenced the hypothalamus and ovary transcriptome profiles in LP and HP using RNA-Seq. The results showed that the number of eggs at 300 d and number of eggs at 59 wk in the HP were significantly more (P < 0.001) than the LP ducks. In total, 106.98G clean bases were generated from 16 libraries with an average of 6.68G clean bases for each library. Further analysis showed 569 and 2,259 differentially expressed genes (DEGs) were identified in the hypothalamus and ovary between LP and HP, respectively. The KEGG pathway enrichment analysis revealed 114 and 139 pathways in the hypothalamus and ovary, respectively which includes Calcium signaling pathway, ECM-receptor interaction, Focal adhesion, MAPK signaling pathway, Apoptosis and Apelin signaling pathways that are involved in egg production. Based on the GO terms and KEGG pathways results, 10 potential candidate genes (P2RX1, LPAR2, ADORA1, FN1, AKT3, ADCY5, ADCY8, MAP3K8, PXN, and PTTG1) were identified to be responsible for egg production. Further, protein-protein interaction was analyzed to show the relationship between these candidate genes. Therefore, this study provides useful information on transcriptome of hypothalamus and ovary of LP and HP Muscovy ducks.
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Affiliation(s)
- Semiu Folaniyi Bello
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, Guangdong, China
| | - Haiping Xu
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, Guangdong, China
| | - Lijin Guo
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, Guangdong, China
| | - Kan Li
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, Guangdong, China
| | - Ming Zheng
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, Guangdong, China
| | - Yibin Xu
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, Guangdong, China
| | - Siyu Zhang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, Guangdong, China
| | - Endashaw Jebessa Bekele
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, Guangdong, China
| | - Ali Abdalla Bahareldin
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, Guangdong, China
| | - Weijian Zhu
- Wens Foodstuff Group Co. Ltd., Yunfu, 527400 Guangdong, China
| | - Dexiang Zhang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, Guangdong, China; Wens Foodstuff Group Co. Ltd., Yunfu, 527400 Guangdong, China
| | - Xiquan Zhang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, Guangdong, China
| | - Congliang Ji
- Wens Foodstuff Group Co. Ltd., Yunfu, 527400 Guangdong, China
| | - Qinghua Nie
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, Guangdong, China; Wens Foodstuff Group Co. Ltd., Yunfu, 527400 Guangdong, China.
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Fuertes M, Sapochnik M, Tedesco L, Senin S, Attorresi A, Ajler P, Carrizo G, Cervio A, Sevlever G, Bonfiglio JJ, Stalla GK, Arzt E. Protein stabilization by RSUME accounts for PTTG pituitary tumor abundance and oncogenicity. Endocr Relat Cancer 2018; 25:665-676. [PMID: 29622689 DOI: 10.1530/erc-18-0028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 04/05/2018] [Indexed: 11/08/2022]
Abstract
Increased levels of the proto-oncogene pituitary tumor-transforming gene 1 (PTTG) have been repeatedly reported in several human solid tumors, especially in endocrine-related tumors such as pituitary adenomas. Securin PTTG has a critical role in pituitary tumorigenesis. However, the cause of upregulation has not been found yet, despite analyses made at the gene, promoter and mRNA level that show that no mutations, epigenetic modifications or other mechanisms that deregulate its expression may explain its overexpression and action as an oncogene. We describe that high PTTG protein levels are induced by the RWD-containing sumoylation enhancer (RWDD3 or RSUME), a protein originally identified in the same pituitary tumor cell line in which PTTG was also cloned. We demonstrate that PTTG and RSUME have a positive expression correlation in human pituitary adenomas. RSUME increases PTTG protein in pituitary tumor cell lines, prolongs the half-life of PTTG protein and regulates the PTTG induction by estradiol. As a consequence, RSUME enhances PTTG transcription factor and securin activities. PTTG hyperactivity on the cell cycle resulted in recurrent and unequal divisions without cytokinesis, and the consequential appearance of aneuploidies and multinucleated cells in the tumor. RSUME knockdown diminishes securin PTTG and reduces its tumorigenic potential in a xenograft mouse model. Taken together, our findings show that PTTG high protein steady state levels account for PTTG tumor abundance and demonstrate a critical role of RSUME in this process in pituitary tumor cells.
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Affiliation(s)
- M Fuertes
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck SocietyBuenos Aires, Argentina
| | - M Sapochnik
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck SocietyBuenos Aires, Argentina
| | - L Tedesco
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck SocietyBuenos Aires, Argentina
| | - S Senin
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck SocietyBuenos Aires, Argentina
| | - A Attorresi
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck SocietyBuenos Aires, Argentina
| | - P Ajler
- Servicio de NeurocirugíaHospital Italiano, Buenos Aires, Argentina
| | - G Carrizo
- Servicio de NeurocirugíaHospital Italiano, Buenos Aires, Argentina
| | - A Cervio
- Departamento de NeurocirugíaFundación Para la Lucha Contra las Enfermedades Neurológicas de la Infancia (FLENI), Buenos Aires, Argentina
| | - G Sevlever
- Departamento de NeurocirugíaFundación Para la Lucha Contra las Enfermedades Neurológicas de la Infancia (FLENI), Buenos Aires, Argentina
| | - J J Bonfiglio
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck SocietyBuenos Aires, Argentina
| | - G K Stalla
- Department of Clinical ResearchMax Planck Institute of Psychiatry, Munich, Germany
| | - E Arzt
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck SocietyBuenos Aires, Argentina
- Departamento de Fisiología y Biología Molecular y CelularFacultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
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Abstract
The pituitary tumor-transforming gene (PTTG1) encodes a multifunctional protein (PTTG) that is overexpressed in numerous tumours, including pituitary, thyroid, breast and ovarian carcinomas. PTTG induces cellular transformation in vitro and tumourigenesis in vivo, and several mechanisms by which PTTG contributes to tumourigenesis have been investigated. Also known as the human securin, PTTG is involved in cell cycle regulation, controlling the segregation of sister chromatids during mitosis. This review outlines current information regarding PTTG structure, expression, regulation and function in the pathogenesis of neoplasia. Recent progress concerning the use of PTTG as a prognostic marker or therapeutic target will be considered. In addition, the PTTG binding factor (PBF), identified through its interaction with PTTG, has also been established as a proto-oncogene that is upregulated in several cancers. Current knowledge regarding PBF is outlined and its role both independently and alongside PTTG in endocrine and related cancers is discussed.
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Panguluri SK, Yeakel C, Kakar SS. PTTG: an important target gene for ovarian cancer therapy. J Ovarian Res 2008; 1:6. [PMID: 19014669 PMCID: PMC2584053 DOI: 10.1186/1757-2215-1-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Accepted: 10/20/2008] [Indexed: 12/13/2022] Open
Abstract
Pituitary tumor transforming gene (PTTG), also known as securin is an important gene involved in many biological functions including inhibition of sister chromatid separation, DNA repair, organ development, and expression and secretion of angiogenic and metastatic factors. Proliferating cancer cells and most tumors express high levels of PTTG. Overexpression of PTTG in vitro induces cellular transformation and development of tumors in nude mice. The PTTG expression levels have been correlated with tumor progression, invasion, and metastasis. Recent studies show that down regulation of PTTG in tumor cell lines and tumors in vivo results in suppression of tumor growth, suggesting its important role in tumorigenesis. In this review, we focus on PTTG structure, sub-cellular distribution, cellular functions, and role in tumor progression with suggestions on possible exploration of this gene for cancer therapy.
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Affiliation(s)
- Siva Kumar Panguluri
- Department of Physiology and Biophysics, James Graham Brown Cancer Center, University of Louisville, Louisville, KY 40202, USA
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Abstract
Pituitary tumor-transforming gene-1 (PTTG1) is overexpressed in a variety of endocrine-related tumors, especially pituitary, thyroid, breast, ovarian, and uterine tumors, as well as nonendocrine-related cancers involving the central nervous, pulmonary, and gastrointestinal systems. Forced PTTG1 expression induces cell transformation in vitro and tumor formation in nude mice. In some tumors, high PTTG1 levels correlate with invasiveness, and PTTG1 has been identified as a key signature gene associated with tumor metastasis. Increasing evidence supports a multifunctional role of PTTG1 in cell physiology and tumorigenesis. Physiological PTTG1 properties include securin activity, DNA damage/repair regulation and involvement in organ development and metabolism. Tumorigenic mechanisms for PTTG1 action involve cell transformation and aneuploidy, apoptosis, and tumorigenic microenvironment feedback. This paper reviews recent advances in our understanding of PTTG1 structure and regulation and addresses known mechanisms of PTTG1 action. Recent knowledge gained from PTTG1-null mouse models and transgenic animals and their potential application to subcellular therapeutic targeting PTTG1 are discussed.
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Affiliation(s)
- George Vlotides
- Department of Medicine, Cedars-Sinai Medical Center, University of California School of Medicine, Los Angeles, California 90048, USA
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Rajamannan NM, Subramaniam M, Abraham TP, Vasile VC, Ackerman MJ, Monroe DG, Chew TL, Spelsberg TC. TGFbeta inducible early gene-1 (TIEG1) and cardiac hypertrophy: Discovery and characterization of a novel signaling pathway. J Cell Biochem 2007; 100:315-25. [PMID: 16888812 PMCID: PMC3927779 DOI: 10.1002/jcb.21049] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cellular mechanisms causing cardiac hypertrophy are currently under intense investigation. We report a novel finding in the TGFbeta inducible early gene (TIEG) null mouse implicating TIEG1 in cardiac hypertrophy. The TIEG(-/-) knock-out mouse was studied. Male mice age 4-16 months were characterized (N = 86 total) using echocardiography, transcript profiling by gene microarray, and immunohistochemistry localized upregulated genes for determination of cellular mechanism. The female mice (N = 40) did not develop hypertrophy or fibrosis. The TIEG(-/-) knock-out mouse developed features of cardiac hypertrophy including asymmetric septal hypertrophy, an increase in ventricular size at age 16 months, an increase (214%) in mouse heart/weight body weight ratio TIEG(-/-), and an increase in wall thickness in TIEG(-/-) mice of (1.85 +/- 0.21 mm), compared to the control (1.13 +/- 0.15 mm, P < 0.04). Masson Trichrome staining demonstrated evidence of myocyte disarray and myofibroblast fibrosis. Microarray analysis of the left ventricles demonstrated that TIEG(-/-) heart tissues expressed a 13.81-fold increase in pituitary tumor-transforming gene-1 (Pttg1). An increase in Pttg1 and histone H3 protein levels were confirmed in the TIEG(-/-) mice hearts tissues. We present evidence implicating TIEG and possibly its target gene, Pttg1, in the development of cardiac hypertrophy in the TIEG null mouse.
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Affiliation(s)
- Nalini M Rajamannan
- Division of Cardiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA.
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Boylan MO, Jepeal LI, Wolfe MM. Sp1/Sp3 binding is associated with cell-specific expression of the glucose-dependent insulinotropic polypeptide receptor gene. Am J Physiol Endocrinol Metab 2006; 290:E1287-95. [PMID: 16403775 DOI: 10.1152/ajpendo.00535.2005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The physiological effects of glucose-dependent insulinotropic polypeptide (GIP) are mediated through specific receptors expressed on target cells. Because aberrant GIP receptor (GIPR) expression has been implicated in abnormal GIP responses associated with type 2 diabetes mellitus and food-induced Cushing's syndrome, we sought to identify factors that regulate the GIPR. We previously demonstrated that sequences between -1 and -100 of the GIPR gene were sufficient to direct transcription in a rat insulinoma cell line (RIN38). In the present study, we compared the 5'-flanking regions of the rat and human GIPR gene and demonstrated 88% identity within the first 92 bp. Subsequent serial deletion analyses showed that the region between -85 and -40 is essential for maximal promoter activity. Within this region, we identified three putative Sp1 binding motifs, located at positions -77, -60, and -50, that can specifically bind both Sp1 and Sp3. Whereas mutation of the Sp1 sites at -50 and -60 led to 36 and 40% reduction in promoter activity, respectively, mutation of the Sp1 motif at -70 did not affect promoter activity. Cotransfection of S2 Schneider cells with GIPR-luciferase chimeric constructs and either Sp1 or Sp3 expression vectors indicated that both Sp1 and the long form of Sp3 activate transcription through binding to the Sp1 sites located between -100 and -40. Lastly, chromatin immunoprecipitation analyses revealed that both Sp1 and Sp3 bind to the GIPR promoter region in RIN38 cells. These results indicate that cell-specific expression of GIPR is associated with the binding of the transcription factors Sp1 and Sp3 to the GIPR promoter.
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Affiliation(s)
- Michael O Boylan
- Section of Gastroenterology, Boston Medical Center, 650 Albany St., Boston, MA 02118, USA
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Rehfeld N, Geddert H, Atamna A, Rohrbeck A, Garcia G, Kliszewski S, Neukirchen J, Bruns I, Steidl U, Fenk R, Gabbert HE, Kronenwett R, Haas R, Rohr UP. The influence of the pituitary tumor transforming gene-1 (PTTG-1) on survival of patients with small cell lung cancer and non-small cell lung cancer. J Carcinog 2006; 5:4. [PMID: 16426442 PMCID: PMC1360069 DOI: 10.1186/1477-3163-5-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2005] [Accepted: 01/20/2006] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND PTTG-1 (pituitary tumor transforming gene) is a novel oncogene that is overexpressed in tumors, such as pituitary adenoma, breast and gastrointestinal cancers as well as in leukemia. In this study, we examined the role of PTTG-1 expression in lung cancer with regard to histological subtype, the correlation of PTTG-1 to clinical parameters and relation on patients' survival. METHODS Expression of PTTG-1 was examined immunohistochemically on formalin-fixed, paraffin-embedded tissue sections of 136 patients with small cell lung cancer (SCLC) and 91 patients with non-small cell lung cancer (NSCLC), retrospectively. The intensity of PTTG-1 expression as well as the proportion of PTTG-1 positive cells within a tumor was used for univariate and multivariate analysis. RESULTS PTTG-1 expression was observed in 64% of SCLC tumors and in 97.8% of NSCLC tumors. In patients with SCLC, negative or low PTTG-1 expression was associated with a shorter mean survival time compared with patients with strong PTTG-1 expression (265 +/- 18 days vs. 379 +/- 66 days; p = 0.0291). Using the Cox regression model for multivariate analysis, PTTG-1 expression was a significant predictor for survival next to performance status, tumor stage, LDH and hemoglobin. In contrast, in patients with NSCLC an inverse correlation between survival and PTTG-1 expression was seen. Strong PTTG-1 expression was associated with a shorter mean survival of 306 +/- 58 days compared with 463 +/- 55 days for those patients with no or low PTTG-1 intensities (p = 0.0386). Further, PTTG-1 expression was associated with a more aggressive NSCLC phenotype with an advanced pathological stage, extensive lymph node metastases, distant metastases and increased LDH level. Multivariate analysis using Cox regression confirmed the prognostic relevance of PTTG-1 expression next to performance status and tumor stage in patients with NSCLC. CONCLUSION Lung cancers belong to the group of tumors expressing PTTG-1. Dependent on the histological subtype of lung cancer, PTTG-1 expression was associated with a better outcome in patients with SCLC and a rather unfavourable outcome for patients with NSCLCs. These results may reflect the varying role of PTTG-1 in the pathophysiology of the different histological subtypes of lung cancer.
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Affiliation(s)
- Nina Rehfeld
- Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Helene Geddert
- Institut für Pathologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Abedelsalam Atamna
- Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Astrid Rohrbeck
- Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Guillermo Garcia
- Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Slawek Kliszewski
- Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Judith Neukirchen
- Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Ingmar Bruns
- Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Ulrich Steidl
- Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Roland Fenk
- Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Helmut E Gabbert
- Institut für Pathologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Ralf Kronenwett
- Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Rainer Haas
- Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Ulrich-Peter Rohr
- Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
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Clem AL, Hamid T, Kakar SS. Characterization of the role of Sp1 and NF-Y in differential regulation of PTTG/securin expression in tumor cells. Gene 2004; 322:113-21. [PMID: 14644503 DOI: 10.1016/j.gene.2003.08.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Pituitary tumor transforming gene (PTTG), also known as securin, is a regulator of cell division that is overexpressed in many tumors. Its expression is cell cycle regulated, although its transcriptional regulation is yet to be determined. The 5' RACE analysis of the human testis mRNA revealed the existence of a previously unreported transcription start site at 317 bp upstream of the translation start site (ATG). This gene is known to be composed of five exons and four introns, which is now changed to six exons and five introns. To map the promoter region, and to understand its regulation, we designed several fusion constructs of the 5' flanking region of PTTG including the sequence from nucleotide -1373 to -3 (relative to the translation start site) to a luciferase reporter gene. Transient transfection of these constructs in prostate cancer cell line (PC-3) and fibroblast cell line (HS27) confirmed the existence of promoter for PTTG between nucleotides -161 and -3 (in relation to translation start site). The 5' and 3' deletion analysis of the PTTG flanking region and electrophoretic mobility shift assays revealed binding of Sp1 and NF-Y transcription factors within nucleotides -540 to -500. Chromatin immunoprecipitation (ChIP) assays of the HS27 and PC-3 cells revealed the binding of Sp1 protein to PTTG promoter sequence in vivo. Site-directed mutagenesis of the Sp1 consensus sequence resulted in approximately 70% reduction of the overall transcriptional activation of the PTTG promoter, whereas mutation of the NF-Y sequence resulted in approximately 25% reduction. Deletion of both Sp1 and NF-Y consensus sequences resulted in 90% loss of PTTG promoter activity. It was further observed, by Western blot analysis, that the levels of Sp1 protein are higher in PC-3 cells when compared to levels in HS27 cells, possibly contributing to a tissue-specific effect. Our studies indicate an important role of Sp1 in transcription regulation of PTTG expression in tumors.
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Affiliation(s)
- Amy L Clem
- Department of Medicine and James Graham Brown Cancer Center, University of Louisville, Louisville, KY 40202, USA
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Wen CY, Nakayama T, Wang AP, Nakashima M, Ding YT, Ito M, Ishibashi H, Matsuu M, Shichijo K, Sekine I. Expression of pituitary tumor transforming gene in human gastric carcinoma. World J Gastroenterol 2004; 10:481-3. [PMID: 14966902 PMCID: PMC4716965 DOI: 10.3748/wjg.v10.i4.481] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM: Pituitary tumor transforming gene (PTTG1) is overexpressed in a variety of tumors, including carcinomas of the lung, breast, colon, as well as in leukemia, lymphoma and pituitary adenomas. However, there is little information on its expression in gastric carcinoma. We sought to investigate the expression of PTTG1 in gastric carcinoma and to explore the relationship between its expression and clinicopathological factors.
METHODS: We studied 75 primary human gastric adenocarcinomas, including 17 mucosal carcinomas, 21 submucosal infiltrative carcinomas, 12 carcinomas invading proprial muscle layers, 6 carcinomas reaching the subserosa, and 19 carcinomas penetrating the serosal surface. Immunohistochemical analysis was performed using paraffin-embedded sections of gastric adenocarcinomas.
RESULTS: PTTG1 was expressed heterogeneously in carcinomas. Positive PTTG1 staining was observed in 65.3% of the carcinomas (49 of 75). Its expression did not correlate significantly with either the histological type or the depth of infiltration of the gastric carcinomas. However, a statistical analysis showed significant differences between the primary adenocarcinomas and the associated metastatic lymph nodes.
CONCLUSION: The results of this study demonstrate that PTTG1 expression is enhanced in metastatic lymph nodes in comparison to that in primary carcinomas. We suggest that PTTG1 may contribute to lymph node metastases in gastric carcinoma.
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Affiliation(s)
- Chun-Yang Wen
- Department of Molecular Pathology, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
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Mu YM, Oba K, Yanase T, Ito T, Ashida K, Goto K, Morinaga H, Ikuyama S, Takayanagi R, Nawata H. Human pituitary tumor transforming gene (hPTTG) inhibits human lung cancer A549 cell growth through activation of p21(WAF1/CIP1 ). Endocr J 2003; 50:771-81. [PMID: 14709851 DOI: 10.1507/endocrj.50.771] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Pituitary tumor transforming gene (PTTG) is a proto-oncogene cloned from rat GH4 cells. This gene was able to induce cell transformation in vitro and is also associated with p53-dependent and -independent apoptosis. In this study, we cloned human PTTG (hPTTG) from a pituitary tumor and then stably transfected the hPTTG into HeLa and A549 cells. An overexpression of hPTTG significantly inhibited cell growth, which was determined by the adherent cell growth properties, colony formation in soft agar and [3H] thymidine incorporation, respectively, in HeLa and A549 cells. The inhibitory effect on cell growth was associated with the activation of p21WAF1/CIP1 in A549 cells, but not in HeLa cells. The hPTTG overexpression increased both the p21WAF1/CIP1 mRNA and protein expression levels as determined by both Northern and Western blot analysis, respectively, in A549 cells. The increased expression of p21WAF1/CIP1 mRNA was regulated at the transcription level and was independent on p53 expression because the luciferase activity increased after the co-transfection of hPTTG and p21WAF1/CIP1 promoter fragments with and without a p53 binding sequence. The subcellular distribution of hPTTG was dependent on cell type, and was predominantly in the nucleus in HeLa, Cos-7 and DU145 cells, but showed a diffuse distribution in both the nucleus and cytoplasm in A549, DLD-1 and NIH3T3 cells. These results indicate that an overexpression of hPTTG inhibits the cell growth due to different mechanisms, which are p21WAF1/CIP1 -dependent and -independent.
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Affiliation(s)
- Yi-Ming Mu
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Science, Kyushu University, Fukuoka, Japan
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Tfelt-Hansen J, Schwarz P, Terwilliger EF, Brown EM, Chattopadhyay N. Calcium-sensing receptor induces messenger ribonucleic acid of human securin, pituitary tumor transforming gene, in rat testicular cancer. Endocrinology 2003; 144:5188-93. [PMID: 12970167 DOI: 10.1210/en.2003-0520] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pituitary tumor transforming gene (PTTG), the human ortholog of securin, is an oncogene. Few normal tissues express PTTG, although in the testis, it is more abundantly expressed. In cancer, however, its wide expression has been directly correlated with the proliferation and angiogenesis, although very little is known about the overall regulation of the PTTG gene. In this study, we investigate the role of the calcium-sensing receptor (CaR), a G protein-coupled receptor (GPCR), in regulating PTTG in a widely used model of humoral hypercalcemia of malignancy, the rat H-500 Leydig cell testicular cancer. We show that extracellular calcium (Ca2+o) up-regulates PTTG mRNA. This up-regulation has a rapid onset, starting at 0.5 h, and remains up-regulated until 40 h. The up-regulation was also Ca2+o concentration dependent, with increases (mean +/- se) of 4.22 +/- 1.61-fold, 5.11 +/- 1.11-fold, and 5.64 +/- 1.92-fold at 5, 7.5, and 10 mm calcium, respectively, compared with 0.5 mm Ca2+o. This effect was abolished by overexpression of a dominant-negative CaR (R185Q), thereby confirming that the effect of high Ca2+o is CaR mediated. Another GPCR agonist, ADP, had no effect on PTTG expression. Because PTTG has been reported to induce angiogenesis, we investigated the effect of elevated Ca2+o on vascular endothelial growth factor (VEGF) expression. Indeed high calcium up-regulated VEGF mRNA by 1.59 +/- 0.22-fold. In conclusion, we show for the first time that a GPCR, the CaR, stimulates the synthesis of PTTG mRNA in a nonmetastasizing model for humoral hypercalcemia of malignancy and, in the process, might induce angiogenesis via VEGF.
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Affiliation(s)
- Jacob Tfelt-Hansen
- Endocrine-Hypertension Division, Department of Medicine and Membrane Biology Program, Brigham and Women's Hospital and Harvard Medical School, 221 Longwood Avenue, Boston, Massachusetts 02115, USA.
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Jin ZY, Cheng RX, Zheng CL, Zheng H. Expression of PTTG and c-myc gene in human primary hepatocellular carcinoma. Shijie Huaren Xiaohua Zazhi 2003; 11:1677-1681. [DOI: 10.11569/wcjd.v11.i11.1677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the relationship between expressions of PTTG and c-myc genes and oncogenesis in human hepatocellular carcinomas(HCC).
METHODS In situ hybridization (DNA-RNA) and immunohistochemistry (SP method) methods were used to detect the expressions of PTTG and c-myc genes in 61 cases of human hepatocellular carcinomas.
RESULTS The distributions of positive cells of PTTG mRNA and PTTG protein in HCC were diffuse, aggregate or scattered. The positive stainings of PTTG mRNA and PTTG protein were plasma and submembrane types. The positive rates of PTTG mRNA and PTTG protein were 72.1% (44/61) and 78.7% (48/61) in HCC, and 93.4% (57/61) and 91.8% (56/61) in pericarcinomatous liver tissues. The expressions of PTTG mRNA and PTTG protein in HCC were significantly lower than those in paracancerous tissues (P<0.005, P<0.05). The expression of PTTG gene was significantly correlated with that of c-myc gene (P<0.005).
CONCLUSION Overexpression of PTTG is related to human hepatocellular carcinogenesis. C-myc gene activated by PTTG protein may play an important role in hepatocellular transformation and carcinogenesis.
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Affiliation(s)
- Zhong-Yuan Jin
- Department of Pathology, Xiangya School of Medicine, Zhongnan University, Changsha 410078, Hunan Province, China
| | - Rui-Xue Cheng
- Department of Pathology, Xiangya School of Medicine, Zhongnan University, Changsha 410078, Hunan Province, China
| | - Chang-Li Zheng
- Department of Pathology, Xiangya School of Medicine, Zhongnan University, Changsha 410078, Hunan Province, China
| | - Hui Zheng
- Department of Pathology, Xiangya School of Medicine, Zhongnan University, Changsha 410078, Hunan Province, China
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Yao YQ, Xu JS, Lee WM, Yeung WSB, Lee KF. Identification of mRNAs that are up-regulated after fertilization in the murine zygote by suppression subtractive hybridization. Biochem Biophys Res Commun 2003; 304:60-6. [PMID: 12705884 DOI: 10.1016/s0006-291x(03)00537-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Transcriptions occur in mouse preimplantation embryos as early as one-cell stage. However, our understanding on gene expression at this stage is lacking. The present study applied suppression subtractive hybridization (SSH) to compared gene expression profiles of mouse zygote and oocyte. Forty-four differentially expressed genes were selected and shown positive signals by reverse dot-blot hybridization. DNA sequences comparison of these putative clones with the GenBank/EMBL databases using BLAST search identified 38 clones with >90% identity to known genes and six novel clones with less than 70% homology to the databases. Eleven out of the 44 differentially expressed clones were either originally isolated from male embryo or testis-specific genes, suggesting that these genes may be derived from paternal genome. Five differentially expressed genes of interest, including bromodomain-containing protein BP75, spindlin, radixin, pituitary tumor-transforming gene (PTTG), and proteoglycan core protein (serglycin) were further studied by semi-quantitative RT-PCR. It is noted that spindlin which involves in cell division is highly expressed in zygote, suggesting that this protein may play an important role in zygotic gene activation (ZGA) and early stage development in 1-cell stage mouse embryos.
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Affiliation(s)
- Yuan-Qing Yao
- Department of Obstetrics and Gynaecology, The University of Hong Kong, Hong Kong, SAR, China
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18
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Kanakis D, Kirches E, Mawrin C, Dietzmann K. Promoter mutations are no major cause of PTTG overexpression in pituitary adenomas. Clin Endocrinol (Oxf) 2003; 58:151-5. [PMID: 12580929 DOI: 10.1046/j.1365-2265.2003.01683.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE The pituitary tumour transforming gene (PTTG) was proven to cause transformation of NIH3T3 fibroblasts, which produce tumours when transplanted into immunodeficient mice. PTTG is overexpressed in about 90% of pituitary adenomas. The reason for its overexpression is still unclear. DESIGN Because promoter mutations may play a role for an altered regulation of PTTG transcription in the pituitary adenomas, we analysed two promoter regions which were characterized previously as functionally important. PATIENTS Twenty-five patients of both sexes with pituitary adenomas, mainly null-cell adenomas, were included in this study. MEASUREMENTS Both DNA regions were amplified from paraffin sections by PCR and analysed for small deletions or insertions on polyacrylamide gels in all patients. In 16 cases both DNA regions were sequenced to detect base substitutions. RESULTS No deletions/insertions and no tumour-specific substitutions were found. In three homopolymeric regions a polymorphism was detected, which also occurred in control sequences. In addition, these tracts showed some degree of length instability. CONCLUSIONS Promoter mutations do not play a major role for the enhanced PTTG transcription in pituitary adenomas. Therefore, DNA-binding proteins, hypomethylation or other epigenetic factors may be responsible for PTTG overexpression.
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Affiliation(s)
- D Kanakis
- Department of Neuropathology, University of Magdeburg, Magdeburg, Germany.
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Yin H, Fujimoto N, Maruyama S, Asano K. Strain difference in regulation of pituitary tumor transforming gene (PTTG) in estrogen-induced pituitary tumorigenesis in rats. Jpn J Cancer Res 2001; 92:1034-40. [PMID: 11676853 PMCID: PMC5926607 DOI: 10.1111/j.1349-7006.2001.tb01057.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Recently a novel oncogene, PTTG (pituitary tumor transforming gene) was isolated from a rat pituitary tumor cell line whose expression is apparently correlated with pituitary tumorigenesis. In the rat, estradiol (E(2)) is known to induce anterior pituitary hyperplasia. The effects of E(2), however, vary greatly among rat strains. Therefore we examined the expression of PTTG and its regulation by E(2) in F344, Wistar, Brown-Norway and Donryu rats. Four-week-old females were ovariectomized and a pellet containing 10 mg of E(2) was given s.c. Total RNA was isolated from the pituitary gland and PTTG mRNA was measured with a competitive RT-PCR technique. The F344 strain was the most susceptible to E(2) induction of pituitary tumorigenesis, followed by Wistar and Brown-Norway, while no increase in pituitary weight was noted in Donryu rats. PTTG mRNA in the gland was induced by E(2) within 48 - 72 h in F344 and Wistar, but not in Brown-Norway or Donryu strains. These data suggest that PTTG expression may at least in part be responsible for strain differences in E(2)-induced pituitary tumorigenesis.
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Affiliation(s)
- H Yin
- Department of Cancer Research, RIRBM, Hiroshima University, Minami-ku, Hiroshima 734-8553
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20
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Abstract
Pituitary tumors constitute 10% of intracranial neoplasms and are mostly benign, monoclonal adenomas derived from single mutant cells. Pituitary oncogenes have been intensively studied and three of them, gsp, ccnd1, and PTTG are abundant in significant numbers of cases. gsp is present in approximately 40% of Caucasian patients with GH-secreting tumors and results from a mutated, constitutively active alpha subunit of Gs protein. Persistent activation of the cAMP-PKA-CREB pathway may lead to uncontrolled cell proliferation and GH secretion. ccnd1 is overexpressed cyclin D1, and cyclin D1 gene is amplified in some pituitary tumors. PTTG is expressed in most pituitary tumors. PTTG is localized to both the nucleus and cytoplasm and interacts with several protein partners. At least three tumorigenesis mechanisms are proposed for human PTTG. 1) PTTG and FGF form a positive feedback loop and stimulate tumor vascularity. 2) PTTG transactivates c-myc or other pro-proliferation genes. 3) PTTG overexpression causes aneuploidy. PTTG expression activates p53 and causes p53-dependent and -independent apoptosis. Due to lack of functional human pituitary cell cultures and appropriate animal models for pituitary tumors, many of the results reviewed here are obtained from heterologous systems.
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Affiliation(s)
- Run Yu
- Cedars‐Sinai Research Institute‐UCLA School of Medicine, Los Angeles, CA 90048
| | - Shlomo Melmed
- Cedars‐Sinai Research Institute‐UCLA School of Medicine, Los Angeles, CA 90048
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21
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Liu ZP, Nakagawa O, Nakagawa M, Yanagisawa H, Passier R, Richardson JA, Srivastava D, Olson EN. CHAMP, a novel cardiac-specific helicase regulated by MEF2C. Dev Biol 2001; 234:497-509. [PMID: 11397016 DOI: 10.1006/dbio.2001.0277] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
MEF2C is a MADS-box transcription factor required for cardiac myogenesis and morphogenesis. In MEF2C mutant mouse embryos, heart development arrests at the looping stage (embryonic day 9.0), the future right ventricular chamber fails to form, and cardiomyocyte differentiation is disrupted. To identify genes regulated by MEF2C in the developing heart, we performed differential array analysis coupled with subtractive cloning using RNA from heart tubes of wild-type and MEF2C-null embryos. Here, we describe a novel MEF2C-dependent gene that encodes a cardiac-restricted protein, called CHAMP (cardiac helicase activated by MEF2 protein), that contains seven conserved motifs characteristic of helicases involved in RNA processing, DNA replication, and transcription. During mouse embryogenesis, CHAMP expression commences in the linear heart tube at embryonic day 8.0, shortly after initiation of MEF2C expression in the cardiogenic region. Thereafter, CHAMP is expressed specifically in embryonic and postnatal cardiomyocytes. At the trabeculation stage of heart development, CHAMP expression is highest in the trabecular region in which cardiomyocytes have exited the cell cycle and is lowest in the proliferative compact zone. These findings suggest that CHAMP acts downstream of MEF2C in a cardiac-specific regulatory pathway for RNA processing and/or transcriptional control.
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Affiliation(s)
- Z P Liu
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, Texas 75390-9148, USA
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22
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Pei L. Identification of c-myc as a down-stream target for pituitary tumor-transforming gene. J Biol Chem 2001; 276:8484-91. [PMID: 11115508 DOI: 10.1074/jbc.m009654200] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Pituitary tumor-transforming gene (PTTG) encodes a protein implicated in cellular transformation and transcriptional regulation. To identify downstream target genes, I established cell lines with tightly regulated inducible expression of PTTG. DNA arrays were used to analyze gene expression profiles after PTTG induction. I identified c-myc oncogene as a major PTTG target. Induction of PTTG resulted in increased cell proliferation through activation of c-myc. I showed that PTTG activates c-myc transcription in transfected cells. PTTG binds to c-myc promoter near the transcription initiation site in a protein complex containing the upstream stimulatory factor (USF1). I have defined the PTTG DNA-binding site and mapped PTTG DNA binding domain to a region between amino acids 61 and 118. Furthermore, I demonstrated that PTTG DNA binding is required for its transcriptional activation function. These results definitively established the role of PTTG as a transcription activator and indicate that PTTG is involved in cellular transformation and tumorigenesis through activation of c-myc oncogene.
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Affiliation(s)
- L Pei
- Division of Endocrinology and Metabolism, Cedars-Sinai Research Institute, UCLA School of Medicine, Los Angeles, California 90048, USA.
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23
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Pei L. Activation of mitogen-activated protein kinase cascade regulates pituitary tumor-transforming gene transactivation function. J Biol Chem 2000; 275:31191-8. [PMID: 10906323 DOI: 10.1074/jbc.m002451200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pituitary tumor-transforming gene (PTTG) is a recently characterized oncogene that can act as a transcriptional activator. In this study, we have characterized the transactivation domain of PTTG. Transient transfection of fusion constructs containing GAL4 DNA-binding domain and different parts of PTTG indicated the transactivation domain of PTTG is located between amino acids 119 and 164. Mitogen-activated protein (MAP) kinase cascade is important in the regulation of cell growth, apoptosis, and differentiation. Therefore, we have explored the possibility that this kinase cascade plays a role in regulating PTTG transactivation function. Activation of the MAP kinase cascade by epidermal growth factor or an expression vector for a constitutively active form of the MAP kinase kinase (MEK1) led to stimulation of PTTG transactivation activity. We showed that PTTG is phosphorylated in vitro on Ser(162) by MAP kinase and that this phosphorylation site plays an essential role in PTTG transactivation function. We demonstrated that PTTG interacts directly with MEK1 through a putative SH3 domain-binding site located between amino acids 51 and 54 and that this interaction is crucial for PTTG transactivation function. In addition, we showed that activation of MAP kinase phosphorylation cascade resulted in nuclear translocation of PTTG. Together, our data establish that a growth factor-stimulated MAP kinase plays an important role in modulating PTTG function.
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Affiliation(s)
- L Pei
- Division of Endocrinology and Metabolism, Cedars-Sinai Research Institute-UCLA School of Medicine, Los Angeles, California 90048, USA.
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Chien W, Pei L. A novel binding factor facilitates nuclear translocation and transcriptional activation function of the pituitary tumor-transforming gene product. J Biol Chem 2000; 275:19422-7. [PMID: 10781616 DOI: 10.1074/jbc.m910105199] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pituitary tumor-transforming gene (PTTG) is a recently characterized oncogene whose expression product contains a transcriptional activation domain at the C terminus. To understand the mechanisms involved in PTTG biological functions, we used yeast two-hybrid screening to identify proteins that interact with PTTG. This study reports the isolation and characterization of a novel PTTG-binding factor (PBF). PBF contains an open reading frame of 179 amino acids with a predicted molecular mass of 22 kDa. In Northern blot analyses, PBF mRNA was ubiquitously expressed in human tissues. Glutathione S-transferase pull-down and co-immunoprecipitation assays demonstrate that PBF interacts specifically with PTTG under both in vitro and in vivo conditions. The PTTG binding domain in PBF was located within the C-terminal 30-amino acid region that contain a nuclear localization signal. Immunofluorescence and subcellular fractionation studies showed that PTTG is predominantly expressed in the cytoplasm with partial nuclear localization, whereas PBF is localized both in the cytoplasm and the nucleus. The interaction between PBF and PTTG facilitated PTTG translocation from the cytoplasm to the nucleus. Furthermore, PBF is required for transcriptional activation of basic fibroblast growth factor by PTTG. In summary, we have characterized a novel PTTG-binding protein that facilitates PTTG nuclear translocation and potentiates its transcriptional activation function.
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Affiliation(s)
- W Chien
- Division of Endocrinology and Metabolism, Cedars-Sinai Research Institute, UCLA School of Medicine, Los Angeles, California 90048, USA
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Ramos-Morales F, Domínguez A, Romero F, Luna R, Multon MC, Pintor-Toro JA, Tortolero M. Cell cycle regulated expression and phosphorylation of hpttg proto-oncogene product. Oncogene 2000; 19:403-9. [PMID: 10656688 DOI: 10.1038/sj.onc.1203320] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We recently isolated a cDNA for hpttg, the human homolog of rat pituitary tumor transforming gene. Now we have analysed the expression of hpttg as a function of cell proliferation. hPTTG protein level is up-regulated in rapidly proliferating cells, is down-regulated in response to serum starvation or cell confluence, and is regulated in a cell cycle-dependent manner, peaking in mitosis. In addition, we show that hPTTG is phosphorylated during mitosis. Immunodepletion and in vitro phosphorylation experiments, together with the use of a specific inhibitor, indicate that Cdc2 is the kinase that phosphorylates hPTTG. These results suggest that hpttg is induced by, and may have a role in, regulatory pathways involved in the control of cell proliferation.
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Affiliation(s)
- F Ramos-Morales
- Departamento de Microbiología, Facultad de Biología, Universidad de Seville, Spain
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Kakar SS. Molecular cloning, genomic organization, and identification of the promoter for the human pituitary tumor transforming gene (PTTG). Gene 1999; 240:317-24. [PMID: 10580151 DOI: 10.1016/s0378-1119(99)00446-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Recently, we cloned and sequenced cDNA of a potent pituitary tumor transforming gene (PTTG) from human testis and showed that this gene is expressed highly in various human tumors, including tumors of the pituitary and adrenal glands, and the liver, kidney, endometrium, uterus, and ovary. To determine the genomic organization of the PTTG and its transcriptional regulation in tumors, we isolated the gene. The PTTG spans more than 10kb and contains five exons and four introns. Primer extension and RNA protection assays indicated a transcription start site at an adenine residue at 37 bases upstream of the translation start site (ATG). Analysis of the 5' flanking region of the gene revealed the existence of three SP1/GC boxes, three AP1 and one AP2 binding sequences, a cyclic AMP response element sequence, and an insulin response element sequence. The promoter activity of the PTTG was evaluated by transfecting a human ovarian tumor cell line (SKOV3) and a mouse fibroblast cell line (NIH 3T3) with a chimeric fusion construct containing the 5' flanking sequence (nucleotide from -1336 to +34) and luciferase reporter gene (pluc 1370). The promoter activity of this construct was 210-fold higher in SKOV3 and 20-fold higher in NIH 3T3 cells than the promoterless vector. Deletion of sequences at the 5' end of the pluc 1370 construct from nucleotide -1336 to -1157 (pluc 1190), from nucleotide -1336 to -977 (pluc 1010) and from nucleotide -1336 to -707 (pluc 740) further increased luciferase activity. Further deletion of the 5' sequence from nucleotide -1336 to -407 (pluc 440), and from nucleotide -1336 to -127 (pluc 160) decreased activity by 95%. These results suggest that the sequence from nucleotide -126 to +34 is sufficient for PTTG promoter activity and that the sequence between nucleotide -706 and -407 contains an enhancer element. PTTG promoter activity was eight- to ten-fold higher in SKOV3 cells than NIH 3T3 cells, suggesting a basis for the tumor-specific expression of the PTTG. Knowledge of the genomic organization and the promoter region of the human tumor transforming gene will allow further studies of possible disorders of the PTTG as well as facilitate elucidation of the transcriptional control of PTTG expression in human tumors.
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Affiliation(s)
- S S Kakar
- Department of Physiology, University of Alabama at Birmingham, Birmingham, AL, USA.
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Pei L. Pituitary tumor-transforming gene protein associates with ribosomal protein S10 and a novel human homologue of DnaJ in testicular cells. J Biol Chem 1999; 274:3151-8. [PMID: 9915854 DOI: 10.1074/jbc.274.5.3151] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pituitary tumor-transforming gene (PTTG) is a recently characterized proto-oncogene that is expressed specifically in adult testis. In this study, we have used in situ hybridization and developmental Northern blot assays to demonstrate that PTTG mRNA is expressed stage-specifically in spermatocytes and spermatids during rat spermatogenic cycle. We have used the yeast two-hybrid system to identify proteins that interact with PTTG in testicular cells. Two positive clones were characterized. One of the clones is the ribosomal protein S10, the other encodes a novel human DnaJ homologue designated HSJ2. Northern blot analysis showed that testis contains higher levels of HSJ2 mRNA than other tissues examined, and the expression pattern of HSJ2 mRNA in postnatal rat testis is similar to PTTG. S10 mRNA levels do not vary remarkably among different tissues and remains unchanged during testicular germ cell differentiation. In vitro binding assays demonstrated that both S10 and HSJ2 bind to PTTG specifically and that PTTG can be co-immunoprecipitated with S10 and HSJ2 from transfected cells. Moreover, the binding sites for both proteins were located within the C-terminal 75 amino acids of the PTTG protein. These results suggest that PTTG may play a role in spermatogenesis.
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Affiliation(s)
- L Pei
- Division of Endocrinology, Cedars-Sinai Research Institute, UCLA School of Medicine, Los Angeles, California 90048, USA
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