301
|
Kitlinska J. Neuropeptide Y (NPY) in neuroblastoma: effect on growth and vascularization. Peptides 2007; 28:405-12. [PMID: 17229489 DOI: 10.1016/j.peptides.2006.08.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Accepted: 08/08/2006] [Indexed: 10/23/2022]
Abstract
Neuroblastomas are pediatric tumors of sympathetic origin, expressing neuronal markers, such as NPY and its receptors. Due to this, neuroblastomas are often associated with elevated plasma levels of NPY, which correlates with poor clinical outcome of the disease. This clinical data corroborates the recent discovery of growth-promoting actions of NPY in neuroblastomas. The peptide has been shown to stimulate proliferation of neuroblastoma cells in an autocrine manner and induce tumor vascularization. Since both processes are mediated by the same Y2 and Y5 receptors, targeting this pathway may be a potential bidirectional therapy for these children's tumors.
Collapse
Affiliation(s)
- Joanna Kitlinska
- Department of Physiology and Biophysics, Georgetown University Medical Center, Basic Science Building Rm. 234, Washington, DC 20057, United States.
| |
Collapse
|
302
|
Rende M, Pistilli A, Stabile AM, Terenzi A, Cattaneo A, Ugolini G, Sanna P. Role of nerve growth factor and its receptors in non-nervous cancer growth: efficacy of a tyrosine kinase inhibitor (AG879) and neutralizing antibodies antityrosine kinase receptor A and antinerve growth factor: an in-vitro and in-vivo study. Anticancer Drugs 2007; 17:929-41. [PMID: 16940803 DOI: 10.1097/01.cad.0000224459.13651.fd] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Neurotrophins, originally identified as neuronal survival and differentiation factors, exert their actions through tyrosine kinase receptors such as TrKA, in the case of the nerve growth factor. Neurotrophins also interact with p75, a common receptor devoid of kinase activity and connected to apoptosis. Here we show that nerve growth factor, TrKA and p75 are expressed in cell lines of human cancers of various non-neuronal lineages, including a panel of muscular sarcomas, and we show that all cell lines investigated actively release nerve growth factor into the medium. Treatment by AG879 (a tyrosine kinase inhibitor that inhibits TrKA phosphorylation, but not TrKB and TrKC) or by neutralizing antibodies anti-nerve growth factor and anti-TrKA dramatically decreases their proliferation with a variable increase in apoptosis. Similarly, p75 transfection induced a significant increase in apoptosis. Furthermore, for the first time we have determined by high-performance liquid chromatography the pharmacokinetic profile of a novel preparation of AG879 and we have established an optimal plasmatic concentration for in-vivo administration. Treatment with AG879 in immunodepressed mice grafted with leiomyosarcoma or promyelocytic leukemia cells resulted in dramatic reductions in tumor sizes. In conclusion, our data have a novel preclinical potential for revealing a possible therapeutical utility in targeting in-vivo nerve growth factor/TrKA by AG879 or neutralizing antibody anti-TrKA in cancer proliferation and in muscle sarcomas, in particular.
Collapse
Affiliation(s)
- Mario Rende
- Section of Anatomy, Department of Experimental Medicine, University of Perugia School of Medicine, Via del Giochetto, 06122 Perugia, Italy.
| | | | | | | | | | | | | |
Collapse
|
303
|
El Zein N, Badran BM, Sariban E. The neuropeptide pituitary adenylate cyclase activating protein stimulates human monocytes by transactivation of the Trk/NGF pathway. Cell Signal 2007; 19:152-62. [PMID: 16914291 DOI: 10.1016/j.cellsig.2006.05.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Revised: 05/17/2006] [Accepted: 05/17/2006] [Indexed: 11/18/2022]
Abstract
Transactivation is a process whereby stimulation of G-protein-coupled receptors (GPCR) activates signaling from receptors tyrosine kinase (RTK). In neuronal cells, the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) acting through the GPCR VPAC-1 exerts trophic effects by transactivating the RTK TrkA receptor for the nerve growth factor (NGF). Both PACAP and NGF have pro-inflammatory activities on monocytes. We have tested the possibility that in monocytes, PACAP, as reported in neuronal cells, uses NGF/TrkA signaling pathway. In these cells, PACAP increases TrkA tyrosine phosphorylations through a PI-3kinase dependent but phospholipase C independent pathway. K252a, an inhibitor of TrkA decreases PACAP-induced Akt and ERK phosphorylation and calcium mobilisation resulting in decreases in intracellular H2O2 production and membrane upregulation of CD11b expression, both functions being inhibited after anti-NGF or anti-TrkA antibody treatment. K252a also inhibits PACAP-associated NF-KB activity. Monocytes increase in NGF production is seen after micromolar PACAP exposure while nanomolar treatment which desensitizes cells to high dose of PACAP prevents PACAP-induced TrkA phosphorylation, H2O2 production and CD11b expression. Finally, NGF-dependent ERK activation and H2O2 production is pertussis toxin sensitive. Altogether these data indicate that in PACAP-activated monocytes some pro-inflammatory activities occur through transactivation mechanisms involving VPAC-1, NGF and TrkA-associated tyrosine kinase activity.
Collapse
Affiliation(s)
- Nabil El Zein
- Laboratory of Pediatric Oncology, Hôpital des Enfants, 1020 Brussels, Belgium
| | | | | |
Collapse
|
304
|
Ødegaard E, Staff AC, Abeler VM, Kopolovic J, Onsrud M, Lazarovici P, Davidson B. The activated nerve growth factor receptor p-TrkA is selectively expressed in advanced-stage ovarian carcinoma. Hum Pathol 2007; 38:140-6. [PMID: 16996570 DOI: 10.1016/j.humpath.2006.06.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 06/27/2006] [Accepted: 06/28/2006] [Indexed: 11/16/2022]
Abstract
The objective of this study was to compare the expression of the nerve growth factor (NGF) receptors TrkA and p75 in ovarian borderline tumors, International Federation of Gynecology and Obstetrics (FIGO) stage I carcinomas and advanced-stage (FIGO stage III-IV) carcinomas, and to assess a possible association between NGF receptor expression and mitogen-activated protein kinase (MAPK) activation in borderline tumors and FIGO stage I carcinomas. Sections from 119 borderline tumors, 57 FIGO stage I invasive ovarian carcinomas, and 56 advanced-stage carcinomas were evaluated for expression of activated phospho-TrkA (p-TrkA) and p75 using immunohistochemistry. MAPK activation was analyzed in stage I carcinomas and borderline tumors using phospho-specific antibodies against the extracellular-regulated kinase (p-ERK), the high osmolarity glycerol response kinase (p-p38), and the c-jun amino-terminal kinase (p-JNK). p-TrkA membrane expression was significantly more frequent in advanced-stage carcinomas compared with both borderline and stage I carcinomas (P < .001). p75 membrane expression was comparable in the 3 groups (P > .05). p-ERK and p-p38 expression was comparable in borderline and stage I carcinomas, whereas p-JNK was more frequently expressed in stage I ovarian carcinomas (P < .001). NGF receptor expression showed no association with MAPK activation in borderline and stage I carcinomas. In conclusion, expression of biologically active p-TrkA receptor at the cell membrane is up-regulated along tumor progression in ovarian carcinoma, whereas p75 expression remains unaltered. These data provide further evidence regarding the clinical role of p-TrkA in ovarian carcinoma. NGF receptors probably signal via MAPK-independent pathways in ovarian carcinoma.
Collapse
Affiliation(s)
- Elin Ødegaard
- Department of Gynecology, Ulleval University Hospital, University of Oslo, N-0407 Oslo, Norway
| | | | | | | | | | | | | |
Collapse
|
305
|
Botchkarev VA, Yaar M, Peters EMJ, Raychaudhuri SP, Botchkareva NV, Marconi A, Raychaudhuri SK, Paus R, Pincelli C. Neurotrophins in Skin Biology and Pathology. J Invest Dermatol 2006; 126:1719-27. [PMID: 16845411 DOI: 10.1038/sj.jid.5700270] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Neurotrophins (NTs) belong to a family of growth factors, which control the development, maintenance, and apoptotic death of neurons and also fulfill multiple regulatory functions outside the nervous system. Biological effects induced by NTs strongly depend on the pattern of NT receptor/co-receptors expression in target cells, as well as on the set of intracellular adaptor molecules that link NT signalling to distinct biochemical pathways. In this review, we summarize data on the molecular mechanisms underlying the involvement of NTs in the control of non-neuronal functions in normal skin (e.g. keratinocyte proliferation, melanocyte development and apoptosis, hair growth). We also review the data on the role for NTs and their receptors in a number of pathological skin conditions (stress-induced hair loss, psoriasis, atopic dermatitis). Although additional efforts are required to fully understand mechanisms underlying the involvement of NTs and their receptors in controlling functions of normal and pathologically altered skin cells, substantial evidence suggests that modulation of NT signalling by NTs receptor agonists/antagonists may be developed as intervention modalities in distinct skin and hair growth pathologies.
Collapse
Affiliation(s)
- Vladimir A Botchkarev
- Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
306
|
Lippa B, Morris J, Corbett M, Kwan TA, Noe MC, Snow SL, Gant TG, Mangiaracina M, Coffey HA, Foster B, Knauth EA, Wessel MD. Discovery of novel isothiazole inhibitors of the TrkA kinase: Structure–activity relationship, computer modeling, optimization, and identification of highly potent antagonists. Bioorg Med Chem Lett 2006; 16:3444-8. [PMID: 16632359 DOI: 10.1016/j.bmcl.2006.04.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2006] [Revised: 03/31/2006] [Accepted: 04/03/2006] [Indexed: 10/24/2022]
Abstract
The design, synthesis, and biological evaluation of potent inhibitors of the TrkA kinase is presented. A homology model is created to aid in the enhancement of potency and selectivity of isothiazole inhibitors found during a high-throughput screen. Three different syntheses are utilized to make diverse analogs within this series. Aminoheterocycles are found to be good urea surrogates, whereas bicyclic substituents on the C3 thio group were found to be extremely potent TrkA inhibitors in kinase and cell assays.
Collapse
Affiliation(s)
- Blaise Lippa
- Pfizer Inc., PGRD Groton, MS-8220-2203 Eastern Point Rd., Groton, CT 06340, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
307
|
Uccini S, Colarossi C, Scarpino S, Boldrini R, Natali PG, Nicotra MR, Perla FM, Mannarino O, Altavista P, Boglino C, Cappelli CA, Cozzi D, Donfrancesco A, Kokai G, Losty PD, McDowell HP, Dominici C. Morphological and molecular assessment of apoptotic mechanisms in peripheral neuroblastic tumours. Br J Cancer 2006; 95:49-55. [PMID: 16755292 PMCID: PMC2360487 DOI: 10.1038/sj.bjc.6603212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Multiple defects in apoptotic pathways have been described in peripheral neuroblastic tumours (NTs). Mitosis–karyorrhexis index (MKI) is a reliable morphological marker identifying favourable and unfavourable NTs. The extent to which apoptotic processes contribute to determine the clinical significance of MKI is still undefined. Apoptosis was investigated in a series of 110 peripheral NTs by comparing MKI to immunohistochemical and molecular apoptotic features. High MKI was found in 55 out of 110 NTs (50%) and was associated with advanced stage (P=0.007), neuroblastoma (NB) histological category (P=0.024), MYCN amplification (P<0.001), and poor outcome (P=0.011). Overall survival probability was 45% in patients with high MKI compared to 73% in patients with low MKI. In the same 110 NTs, the expression of Bcl-2, Bcl-XL, Bax and Mcl-1 was studied by immunohistochemistry, but no significant associations were found with clinicohistological features. Microarray analysis of apoptotic genes was performed in 40 out of 110 representative tumours. No significant association was found between the expression of apoptotic genes and MKI or clinicohistological features. Proliferative activity was assessed in 60 out of 110 representative tumours using Ki67 immunostaining, but no significant correlations with MKI or clinicobiological features were found. In NTs, the combination of apoptosis and proliferation as expressed by MKI is a significant prognostic parameter, although neither of them is per se indicative of the clinicobiological behaviour and outcome.
Collapse
Affiliation(s)
- S Uccini
- Department of Experimental Medicine & Pathology, La Sapienza University, Viale Regina Elena 324, Rome I-00161, Italy.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
308
|
Kitlinska J. Neuropeptide Y in neural crest-derived tumors: effect on growth and vascularization. Cancer Lett 2006; 245:293-302. [PMID: 16513255 DOI: 10.1016/j.canlet.2006.01.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2005] [Revised: 01/14/2006] [Accepted: 01/16/2006] [Indexed: 11/17/2022]
Abstract
Neuropeptide Y (NPY) is a sympathetic neurotransmitter recently found to be a potent growth and angiogenic factor. The peptide and its receptors are abundant in neural crest-derived tumors, such as sympathetic neuroblastomas and pheochromocytomas, as well as parasympathetic Ewing's sarcoma family of tumors. NPY regulates their growth directly, by an autocrine activation of tumor cell proliferation or apoptosis, and indirectly, by its angiogenic activity. The overall effect of the peptide on tumor growth depends on a balance between these processes and the type of receptors expressed in the tumor cells. Thus, NPY and its receptors may become targets for the treatment of neural tumors, directed against both tumor cell proliferation and angiogenesis.
Collapse
MESH Headings
- Animals
- Cell Proliferation
- Humans
- Models, Biological
- Neoplasms, Nerve Tissue/metabolism
- Neoplasms, Nerve Tissue/pathology
- Neoplasms, Nerve Tissue/physiopathology
- Neovascularization, Pathologic/metabolism
- Neovascularization, Pathologic/pathology
- Neovascularization, Pathologic/physiopathology
- Neural Crest/metabolism
- Neural Crest/pathology
- Neuroblastoma/metabolism
- Neuroblastoma/pathology
- Neuroblastoma/physiopathology
- Neuropeptide Y/biosynthesis
- Neuropeptide Y/physiology
- Sarcoma, Ewing/metabolism
- Sarcoma, Ewing/pathology
- Sarcoma, Ewing/physiopathology
Collapse
Affiliation(s)
- Joanna Kitlinska
- Department of Physiology and Biophysics, Georgetown Universitty Medical Center, Basic Science Building Rm. 234, Washington, DC 20057.
| |
Collapse
|
309
|
Machida T, Fujita T, Ooo ML, Ohira M, Isogai E, Mihara M, Hirato J, Tomotsune D, Hirata T, Fujimori M, Adachi W, Nakagawara A. Increased expression of proapoptotic BMCC1, a novel gene with the BNIP2 and Cdc42GAP homology (BCH) domain, is associated with favorable prognosis in human neuroblastomas. Oncogene 2006; 25:1931-42. [PMID: 16288218 DOI: 10.1038/sj.onc.1209225] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Differential screening of the genes obtained from cDNA libraries of primary neuroblastomas (NBLs) between the favorable and unfavorable subsets has identified a novel gene BCH motif-containing molecule at the carboxyl terminal region 1 (BMCC1). Its 350 kDa protein product possessed a Bcl2-/adenovirus E1B nineteen kDa-interacting protein 2 (BNIP2) and Cdc42GAP homology domain in the COOH-terminus in addition to P-loop and a coiled-coil region near the NH2-terminus. High levels of BMCC1 expression were detected in the human nervous system as well as spinal cord, brain and dorsal root ganglion in mouse embryo. The immunohistochemical study revealed that BMCC1 was positively stained in the cytoplasm of favorable NBL cells but not in unfavorable ones with MYCN amplification. The quantitative real-time reverse transcription-PCR using 98 primary NBLs showed that high expression of BMCC1 was a significant indicator of favorable NBL. In primary culture of newborn mice superior cervical ganglion (SCG) neurons, mBMCC1 expression was downregulated after nerve growth factor (NGF)-induced differentiation, and upregulated during the NGF-depletion-induced apoptosis. Furthermore, the proapoptotic function of BMCC1 was also suggested by increased expression in CHP134 NBL cells undergoing apoptosis after treatment with retinoic acid, and by an enhanced apoptosis after depletion of NGF in the SCG neurons obtained from newborn mice transgenic with BMCC1 in primary culture. Thus, BMCC1 is a new member of prognostic factors for NBL and may play an important role in regulating differentiation, survival and aggressiveness of the tumor cells.
Collapse
Affiliation(s)
- T Machida
- Division of Biochemistry, Chiba Cancer Center Research Institute, Chiba, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
310
|
Verpoorten N, De Jonghe P, Timmerman V. Disease mechanisms in hereditary sensory and autonomic neuropathies. Neurobiol Dis 2006; 21:247-55. [PMID: 16183296 DOI: 10.1016/j.nbd.2005.08.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Revised: 08/16/2005] [Accepted: 08/17/2005] [Indexed: 10/25/2022] Open
Abstract
Inherited peripheral neuropathies are common monogenically inherited diseases of the peripheral nervous system. In the most common variant, i.e., the hereditary motor and sensory neuropathies, both motor and sensory nerves are affected. In contrast, sensory abnormalities predominate or are exclusively present in hereditary sensory and autonomic neuropathies (HSAN). HSAN are clinically and genetically heterogeneous and are subdivided according to mode of inheritance, age of onset and clinical evolution. In recent years, 6 disease-causing genes have been identified for autosomal dominant and recessive HSAN. However, vesicular transport and axonal trafficking seem important common pathways leading to degeneration of sensory and autonomic neurons. This review discusses the HSAN-related genes and their biological role in the disease mechanisms leading to HSAN.
Collapse
Affiliation(s)
- Nathalie Verpoorten
- Peripheral Neuropathy Group, Department of Molecular Genetics, Flanders Interuniversity Institute for Biotechnology, Institute Born-Bunge, University of Antwerp, Universiteitsplein 1, B-2610 Antwerpen, Belgium
| | | | | |
Collapse
|
311
|
Davidson B, Risberg B, Berner A, Bedrossian CWM, Reich R. The biological differences between ovarian serous carcinoma and diffuse peritoneal malignant mesothelioma. Semin Diagn Pathol 2006; 23:35-43. [PMID: 17044194 DOI: 10.1053/j.semdp.2006.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Recent improvements in immunohistochemistry panels used for differentiating ovarian serous carcinoma/primary peritoneal carcinoma (OC/PPC) from diffuse malignant peritoneal mesothelioma (DMPM) have resulted in improved diagnostic rates for these tumors in both cytological and histological material. However, little is known about the biological characteristics that differentiate these two cancer types. We performed a comparative analysis of cancer-associated molecule expression data for a cohort consisting of up to 270 serous OC/PPC specimens (only peritoneal lesions) and 32 peritoneal MM. The molecules studied were nerve growth factor receptors (p75, p-TrkA), angiogenic factors (VEGF, IL-8, bFGF, heparanase), laminin receptors (the 67-kDa receptor and the alpha 6 integrin subunit), proteases (MMP-2), immune response mediators (HLA-G), and signaling molecules (the MAPK members ERK, JNK, and p38). The methods used were immunohistochemistry, Western blotting, and RT-PCR. DMPM specimens showed significantly higher expression of p75 (P < 0.001), p-TrkA (P < 0.001), and bFGF (P < 0.001), and significantly lower expression of the 67-kDa receptor (P < 0.001), alpha 6 integrin subunit (P = 0.025), VEGF (P < 0.001), IL-8 (P < 0.001), and HLA-G (P = 0.039) compared with OC/PPC. DMPM specimens showed higher activation ratio (phosphorylated/total enzyme ratio) of all three MAPK members (ERK, P = 0.017; JNK, P < 0.001; p38, P = 0.009) compared with OC/PPC. These data document significant differences in the expression of cancer- and metastasis-associated molecules in MM compared with ovarian carcinoma, and suggest that different biological pathways are involved in tumorigenesis and disease progression in these two tumors.
Collapse
Affiliation(s)
- Ben Davidson
- Department of Pathology, Norwegian Radium Hospital-National Hospital, University of Oslo, Oslo, Norway.
| | | | | | | | | |
Collapse
|
312
|
Escobar MA, Grosfeld JL, Powell RL, West KW, Scherer LR, Fallon RJ, Rescorla FJ. Long-term outcomes in patients with stage IV neuroblastoma. J Pediatr Surg 2006; 41:377-81. [PMID: 16481255 DOI: 10.1016/j.jpedsurg.2005.11.032] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM OF STUDY Long-term outcome studies in survivors with stage IV neuroblastoma (NB) are sparse. This review evaluates late complications and long-term outcomes in stage IV NB survivors. METHODS A retrospective review of stage IV NB survivors was performed to analyze outcomes, including long-term morbidity, recurrence, and survival. MAIN RESULTS Of 153 patients with stage IV NB, 52 (34%) survived (male-female, 26:26). Age at diagnosis was 29.1 +/- 31.7 months in survivors. Eighteen were 1 year or younger and 34 were older than 1 year compared with 10 nonsurvivors 1 year or younger and 91 older than 1 year (P = .0003, Fisher's Exact test). Primary tumor sites were adrenal (35), retroperitoneal (11), mediastinal (3), pelvic (2), and no primary with tumor metastases identified (1). Ten survivors had favorable and 16 had unfavorable histology compared with 1 favorable and 18 unfavorable in nonsurvivors (P = .01). Four survivors had MYCN amplification (> or = 10 copies) and 2 deletions of 1p and 11q. Sites of metastasis in survivors and nonsurvivors were similar. Treatment in survivors included surgery in 51 (75% [39/51] complete tumor resection [CTR]); chemotherapy, 50; radiation, 17; stem cell transplantation, 20; and bone marrow transplant, 1. In nonsurvivors, 13 (25%) of 53 (P < < .0001) had CTR, 18 stem cell transplantation, and 12 bone marrow transplant. Six patients had tumor recurrence but survived (mean, 9.3 +/- 8.3 years; range, 6 months-24 years). Recurrence was local (1), distant (2), and both (3) and was treated by resection, chemotherapy, and radiation. The mean age of survivors was 12.4 +/- 8.3 years (range, 2-34 years). In all stage IV cases, event-free survival was 30% and overall survival was 34%. Long-term complications occurred in 23 (44%) survivors, including endocrine disturbances (7), orthopedic (5), cataracts (2), adhesive bowel obstruction (2), hypertension (1), bronchiolitis (1), blindness (1), peripheral neuropathy (1), nonfunctioning kidney (1), cholelithiasis (1), and thyroid nodule (1). CONCLUSION Only 34% of patients with stage IV NB survived despite aggressive multimodal therapy. Age of younger than 1 year, favorable pathology, CTR, and no recurrence were the only statistically significant factors that favored survival. Forty-four percent of survivors experienced late morbidity, and tumor recurred in 6 (11.5%) of 52. Patients should be monitored for tumor recurrence and long-term sequelae. New methods of treatment are required to achieve better outcomes.
Collapse
Affiliation(s)
- Mauricio A Escobar
- Department of Surgery, Indiana University School of Medicine, JW Riley Hospital for Children, Indianapolis, IN 46202, USA
| | | | | | | | | | | | | |
Collapse
|
313
|
Li Y, Lal B, Kwon S, Fan X, Saldanha U, Reznik TE, Kuchner EB, Eberhart C, Laterra J, Abounader R. The scatter factor/hepatocyte growth factor: c-met pathway in human embryonal central nervous system tumor malignancy. Cancer Res 2005; 65:9355-62. [PMID: 16230398 DOI: 10.1158/0008-5472.can-05-1946] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Embryonal central nervous system (CNS) tumors, which comprise medulloblastoma, are the most common malignant brain tumors in children. The role of the growth factor scatter factor/hepatocyte growth factor (SF/HGF) and its tyrosine kinase receptor c-Met in these tumors has been until now completely unknown. In the present study, we show that human embryonal CNS tumor cell lines and surgical tumor specimens express SF/HGF and c-Met. Furthermore, c-Met mRNA expression levels statistically significantly correlate with poor clinical outcome. Treatment of medulloblastoma cells with SF/HGF activates c-Met and downstream signal transduction as evidenced by c-Met, mitogen-activated protein kinase, and Akt phosphorylation. SF/HGF induces tumor cell proliferation, anchorage-independent growth, and cell cycle progression beyond the G1-S checkpoint. Using dominant-negative Cdk2 and a degradation stable p27 mutant, we show that cell cycle progression induced by SF/HGF requires Cdk2 function and p27 inhibition. SF/HGF also protects medulloblastoma cells against apoptosis induced by chemotherapy. This cytoprotective effect is associated with reduction of proapoptotic cleaved poly(ADP-ribose) polymerase and cleaved caspase-3 proteins and requires phosphoinositide 3-kinase activity. SF/HGF gene transfer to medulloblastoma cells strongly enhances the in vivo growth of s.c. and intracranial tumor xenografts. SF/HGF-overexpressing medulloblastoma xenografts exhibit increased invasion and morphologic changes that resemble human large cell anaplastic medulloblastoma. This first characterization establishes SF/HGF:c-Met as a new pathway of malignancy with multifunctional effects in human embryonal CNS tumors.
Collapse
Affiliation(s)
- Yunqing Li
- Department of Neurology, Johns Hopkins University School of Medicine, MD 21205, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
314
|
Ricci A, Graziano P, Mariotta S, Cardillo G, Sposato B, Terzano C, Bronzetti E. Neurotrophin system expression in human pulmonary carcinoid tumors. Growth Factors 2005; 23:303-12. [PMID: 16338793 DOI: 10.1080/08977190500233813] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Neurotrophin (NT) and NT receptor expression was assessed in 12 typical (TC) and 8 atypical (AC) human pulmonary carcinoids by Western blot and immunohistochemistry. TC and AC carcinoid express to different extent NT and NT receptor proteins. Nerve growth factor (NGF) was expressed by 83% of the TC but not by the AC carcinoids. Brain derived neurotrophic factor (BDNF) was expressed by 33 and 100% of TC and AC carcinoids, respectively. NT-3 was expressed by 58% of the TC and 38% of AC carcinoids. TC carcinoids express high affinity NT receptors while 50% of the AC carcinoids express the TrkB receptor. Our results demonstrate that NGF/TrkA and BDNF/TrkB signaling need to be considered as regulatory pathways that may address survival, differentiation and/or aggressiveness of human pulmonary carcinoids. Contrarily to the BDNF/TrkB, expression of the NGF/TrkA signaling may overcome aggressiveness of carcinoid cells. NTs may be useful as markers in the clinic.
Collapse
Affiliation(s)
- Alberto Ricci
- Università La Sapienza, Azienda Ospedaliera Sant'Andrea, Dipartimento di Scienze Cardiovascolari e Respiratorie, Roma, Italy.
| | | | | | | | | | | | | |
Collapse
|
315
|
Yang ZL, Deng XH, Yang LP, Li QL, Fan WT, Liang S, Miao XY. Expression of nerve growth factor messenger RNA in pancreatic cancer tissues in Sprague Dawley rats. Shijie Huaren Xiaohua Zazhi 2005; 13:2227-2230. [DOI: 10.11569/wcjd.v13.i18.2227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To establish a model of pancreatic cancer in Sprague-Dawley(SD)rats and to explore the expression and its significance of nerve growth factor(NGF)mRNA in pancreatic cancer and non-cancer tissues.
METHODS: Ninety rats were randomly divided into A (n = 40), B (n = 40) and C (n = 10) group. For group A and B, dimethylbenzanthrancene (DMBA) was directly implanted into the parenchyma of the rat pancreas to establish pancreatic cancer model. The rats in group B were treated with trichostatin(TSA). The rats in group C served as the controls. The rats were executed within 3-5 mo, and the carcinogenesis of the rats was observed by pathological methods. In situ hybridization was used to detect the expression of NGF mRNA in the formalin-fixed and routinely paraffin-embedded sections of pancreatic cancer and non-cancer tissues.
RESULTS: The prevalence rate of pancreatic cancer in group A was 48.7%(18/37) within 3-5 mo, 28.6%(2/7) at mo, 40.0%(4/10) at 4 mo and 60%(12/20) at 5 mo (P > 0.05), and that in group B was 33.3%(12/36), 16.7%(1/6), 30.0%(3/10) and (40.0%)8/20, respectively (P > 0.05). The prevalence rate in group A was higher than that of group B (P > 0.05). The diameters of tumor mass in group A were significantly larger than those in group B (group A: 0.5-1.0 cm 7 cases, 1.0-2.0 cm 10 cases, > 2 cm 1 case vs group B: 0.5-1.0 cm 9 case, 1.0-2.0 cm 2 cases, >2.0 cm 1 case, P < 0.05). No tumor formed in the pancreas of the rats in group C or in other main organs of the rats in group A and B. The positive rate of NGF mRNA expression in the pancreatic ductal cancer tissues was significantly higher than that in non-cancer tissues (67.9% vs 18.6%, P < 0.01), and severely atypical hyperplasia was observed in the positive non-cancer pancreatic tissues of ductal epithelium. The positive rate of NGF mRNA expression in ductal adenocarcinoma was markedly higher in group A than that in group B (P = 0.052). The positive rate of NGF mRNA in the rats with tumor maximal diameter ≤ 1.0 cm was lower than that in the ones with tumor maximal diameter > 1.0 cm (P > 0.05).
CONCLUSION: Direct implantation of DMBA in the parenchyma of pancreas can induce pancreatic cancer with a high occurrence rate in a short time. NGF may play an important role in the carcinogenesis of pancreatic cancer. TSA can inhibit the occurrence and progression of pancreatic cancer by inhibiting NGF expression.
Collapse
|
316
|
Sobue S, Hagiwara K, Banno Y, Tamiya-Koizumi K, Suzuki M, Takagi A, Kojima T, Asano H, Nozawa Y, Murate T. Transcription factor specificity protein 1 (Sp1) is the main regulator of nerve growth factor-induced sphingosine kinase 1 gene expression of the rat pheochromocytoma cell line, PC12. J Neurochem 2005; 95:940-9. [PMID: 16135093 DOI: 10.1111/j.1471-4159.2005.03399.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sphingosine kinase (SPHK) is known to exert an anti-apoptic role in various cells and cell lines. We previously reported that human brain is rich in SPHK1 (Murate et al. 2001). After showing a high expression of SPHK1 in rat brain, we examined the gene expression mechanism using nerve growth factor (NGF)-stimulated rat PC12 cells. With RT-PCR, we found that both rat brain and PC12 utilized exon 1d mostly out of eight untranslated first exons. NGF induced an increase in SPHK enzyme activity and protein about double those in PC12 cells, and NGF-induced SPHK1 mRNA was three times higher than in the control. The minimal 5' promoter was determined, and TrkA specific inhibitor K252a inhibited the NGF-induced promoter activity of SPHK1. The truncation or mutation of putative transcription factor-binding motifs revealed that one specificity protein 1 (Sp1) binding motif of the 5' region of exon 1d is prerequisite. Electrophoresis mobility shift assay confirmed the promoter analysis, indicating increased Sp1 protein binding to this motif after NGF treatment. Chromatin immunoprecipitation assay also showed the binding of Sp1 and the promoter region in vivo. These results suggest the signal transduction pathway from NGF receptor TrkA to transcription factor Sp1 protein binding to the promoter Sp1-like motif in NGF-induced rat SPHK1 gene expression.
Collapse
Affiliation(s)
- S Sobue
- Nagoya University Graduate School of Medicine, Nagoya University School of Health Sciences, Daiko-minami, Nagoya, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
317
|
Lavoie JF, Lesauteur L, Kohn J, Wong J, Furtoss O, Thiele CJ, Miller FD, Kaplan DR. TrkA Induces Apoptosis of Neuroblastoma Cells and Does So via a p53-dependent Mechanism*[boxs]. J Biol Chem 2005; 280:29199-207. [PMID: 15961390 DOI: 10.1074/jbc.m502364200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neuroblastoma (NB) is the most frequent solid extracranial tumor in children. Its clinical prognosis correlates with the expression of members of the Trk neurotrophin receptor family, which includes TrkA and TrkB. TrkA expression is associated with favorable prognosis, whereas TrkB expression is associated with poor prognosis. Here we show that TrkA expression induces the apoptosis of NB cells and does so by modulating the levels or activities of a number of proteins involved in regulating cell survival and apoptosis, including p53, Bcl-2, and caspase-3. TrkA increased the expression of p53 target proteins and failed to induce apoptosis in cells where p53 was inactivated by mutation or via expression of dominant inhibitory p53 or E1B55K, indicating that TrkA mediates apoptosis, at least in part, through p53. Treatment with a caspase inhibitor or overexpression of Bcl-X(L) also prevented TrkA from inducing apoptosis. In contrast, elevated expression of TrkA in non-transformed sympathetic neurons resulted in the suppression of p53 levels and enhanced survival. These results identify apoptosis as a novel biological response of TrkA in NB cells and imply that TrkA is a good prognosis marker for NB due in part to its ability to mediate apoptosis when expressed at sufficient levels.
Collapse
Affiliation(s)
- Jean-François Lavoie
- Cancer Research Program, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | | | | | | | | | | | | | | |
Collapse
|
318
|
Lee S, Nakamura E, Yang H, Wei W, Linggi MS, Sajan MP, Farese RV, Freeman RS, Carter BD, Kaelin WG, Schlisio S. Neuronal apoptosis linked to EglN3 prolyl hydroxylase and familial pheochromocytoma genes: developmental culling and cancer. Cancer Cell 2005; 8:155-67. [PMID: 16098468 DOI: 10.1016/j.ccr.2005.06.015] [Citation(s) in RCA: 400] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2005] [Revised: 04/29/2005] [Accepted: 06/07/2005] [Indexed: 01/11/2023]
Abstract
Germline NF1, c-RET, SDH, and VHL mutations cause familial pheochromocytoma. Pheochromocytomas derive from sympathetic neuronal precursor cells. Many of these cells undergo c-Jun-dependent apoptosis during normal development as NGF becomes limiting. NF1 encodes a GAP for the NGF receptor TrkA, and NF1 mutations promote survival after NGF withdrawal. We found that pheochromocytoma-associated c-RET and VHL mutations lead to increased JunB, which blunts neuronal apoptosis after NGF withdrawal. We also found that the prolyl hydroxylase EglN3 acts downstream of c-Jun and is specifically required among the three EglN family members for apoptosis in this setting. Moreover, EglN3 proapoptotic activity requires SDH activity because EglN3 is feedback inhibited by succinate. These studies suggest that failure of developmental apoptosis plays a role in pheochromocytoma pathogenesis.
Collapse
Affiliation(s)
- Sungwoo Lee
- Department of Medical Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
319
|
Fuller GN, Su X, Price RE, Cohen ZR, Lang FF, Sawaya R, Majumder S. Many human medulloblastoma tumors overexpress repressor element-1 silencing transcription (REST)/neuron-restrictive silencer factor, which can be functionally countered by REST-VP16. Mol Cancer Ther 2005; 4:343-9. [PMID: 15767543 DOI: 10.1158/1535-7163.mct-04-0228] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Medulloblastoma, one of the most malignant pediatric brain tumors, is believed to arise from the undifferentiated external granule-layer cells in the cerebellum. It is a heterogeneous cancer, and the mechanism of tumorigenesis for the majority of types is unknown. Repressor element-1 silencing transcription/neuron-restrictive silencer factor (REST/NRSF) is a transcriptional repressor that can block transcription of a battery of neuronal differentiation genes by binding to a specific consensus DNA sequence present in their regulatory region. Previously, we found that some medulloblastoma cell lines express REST/NRSF at high levels compared with either neuronal progenitor cells or fully differentiated neurons. However, it is not known if REST/NRSF is indeed overexpressed in human medulloblastoma tumor specimens and in what frequency. Here, we did an immunohistochemical analysis of such tumor specimens using an anti-REST antibody. We show that among 21 human medulloblastoma tumors, 17 expressed REST/NRSF (6 strongly and 11 weakly). In contrast, adjacent normal cerebellum tissue sections and four of the tumor specimens did not express REST/NRSF, indicating that abnormal expression of REST/NRSF is observed in the majority of human medulloblastoma tumors. To determine whether countering REST/NRSF activity blocks tumorigenicity of medulloblastoma cells, especially in the intracranial (i.c.) environment, we found that adenovirus-mediated expression of REST-VP16, a recombinant transcription factor that can compete with REST/NRSF and activate REST/NRSF target genes instead of repressing them, blocked the i.c. tumorigenic potential of medulloblastoma cells and inhibited growth of established tumors in nude mice, suggesting that REST/NRSF may serve as a therapeutic target for medulloblastoma and that forced expression of neuronal differentiation genes in medulloblastoma cells through agents, such as REST-VP16, can interfere with their tumorigenicity.
Collapse
Affiliation(s)
- Gregory N Fuller
- Brain Tumor Center, University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Box 11, Houston, TX 77030, USA
| | | | | | | | | | | | | |
Collapse
|
320
|
Peruzzi F, Bergonzini V, Aprea S, Reiss K, Sawaya BE, Rappaport J, Amini S, Khalili K. Cross talk between growth factors and viral and cellular factors alters neuronal signaling pathways: implication for HIV-associated dementia. ACTA ACUST UNITED AC 2005; 50:114-25. [PMID: 15936090 DOI: 10.1016/j.brainresrev.2005.05.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2004] [Revised: 03/10/2005] [Accepted: 05/02/2005] [Indexed: 12/14/2022]
Abstract
HIV-associated dementia (HAD) is a serious neurological disorder affecting about 7% of people with AIDS. In the brain, HIV-1 infects a restricted number of cell types, being primarily present in macrophages and microglial cells, less abundant in astrocytes, and rarely seen in oligodendrocytes and neurons. Lack of a productive HIV-1 infection of neuronal cells suggests the presence of an indirect pathway by which the virus may determine the brain pathology and neuronal dysfunction seen in AIDS patients. Among the participants in this event, viral proteins including gp120 and Tat, along with host factors including cytokines, chemokines, and several signaling pathways have received considerable attention. In this article, we discuss the most recent concepts pertaining to the mechanisms of HIV-1-induced neuronal dysfunction by highlighting the interplay between signal transduction pathways activated by viral and host factors and their consequences in neuronal cell function.
Collapse
Affiliation(s)
- Francesca Peruzzi
- Center for Neurovirology and Cancer Biology, Temple University, 1900 12th North Street, Philadelphia, PA 19122, USA.
| | | | | | | | | | | | | | | |
Collapse
|
321
|
Evangelopoulos ME, Weis J, Krüttgen A. Signalling pathways leading to neuroblastoma differentiation after serum withdrawal: HDL blocks neuroblastoma differentiation by inhibition of EGFR. Oncogene 2005; 24:3309-18. [PMID: 15735700 DOI: 10.1038/sj.onc.1208494] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Neuroblastoma is the second most common pediatric malignancy, characterized by a high rate of unexplained spontaneous remissions. Much progress has been made in understanding neuroblastoma differentiation triggered by certain agents such as retinoic acid. However, little is known about the signalling pathways that lead to differentiation of neuroblastoma cells due to serum withdrawal. We found that in Neuro2a neuroblastoma cells, EGFR, ERK1/2 and Akt showed increased phosphorylation after serum withdrawal, and that the activation of EGFR was necessary for the activation of Akt and ERK1/2. Inhibition of EGFR, ERK1/2 and PI3K blocked neuroblastoma differentiation after serum withdrawal. Interestingly, addition of high-density lipoprotein (HDL) abrogated serum-withdrawal induced neuroblastoma differentiation, as well as the activation of EGFR. Our results demonstrate a novel role for serum-derived lipoproteins in the control of receptor tyrosine kinase activity.
Collapse
|
322
|
Chen X, Agate RJ, Itoh Y, Arnold AP. Sexually dimorphic expression of trkB, a Z-linked gene, in early posthatch zebra finch brain. Proc Natl Acad Sci U S A 2005; 102:7730-5. [PMID: 15894627 PMCID: PMC1140405 DOI: 10.1073/pnas.0408350102] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2004] [Indexed: 12/23/2022] Open
Abstract
Sexual differentiation of the zebra finch (Taeniopygia guttata) neural song circuit is thought to be initiated by sex differences in sex chromosome gene expression in brain cells. One theory is that Z-linked genes, present in the male's ZZ genome at double the dose of females' (ZW), are expressed at higher levels and trigger masculine patterns of development. We report here that trkB (tyrosine kinase receptor B) is Z-linked in zebra finches. trkB is the receptor for neurotrophic factors BDNF and neurotrophin 4, and mediates their influence on neuronal survival, migration, and specification. trkB mRNA is expressed at a higher level in the male telencephalon or whole brain than in corresponding regions of the female in adulthood, and at posthatch day (P) 6, when the song circuit is undergoing sexual differentiation. Moreover, this expression is higher in the song nucleus high vocal center (HVC) than in the surrounding telencephalon at P6, and in males relative to females. In addition, trkB protein is expressed more highly in male than female whole brain at P6. These results establish trkB as a candidate factor that contributes to masculine differentiation of HVC because of its Z-linkage, which leads to sex differences in expression. BDNF is known to be stimulated by estrogen and to be expressed at higher levels in males than females at later ages in HVC. Thus, the trkB-BDNF system may be a focal point for convergent masculinizing influences of Z-linked factors and hormones.
Collapse
Affiliation(s)
- Xuqi Chen
- Department of Physiological Science, University of California, Los Angeles, CA 90095, USA
| | | | | | | |
Collapse
|
323
|
Dobson T, Minic A, Nielsen K, Amiott E, Krushel L. Internal initiation of translation of the TrkB mRNA is mediated by multiple regions within the 5' leader. Nucleic Acids Res 2005; 33:2929-41. [PMID: 15908588 PMCID: PMC1133793 DOI: 10.1093/nar/gki605] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Translational regulation of the dendritically localized mRNA encoding for the neurotrophin receptor TrkB has important ramifications for synaptic function. We examined whether the TrkB mRNA is translated through an internal initiation entry site (IRES). The human TrkB 5′ leaders are derived from the use of alternative promoters and alternative splicing, but all 5′ leaders share a common exon. Insertion of a full-length 5′ leader, as well as the common exon into the intercistronic region of a dicistronic luciferase construct, yielded luciferase activity generated from the second cistron that was either equivalent or higher than that observed from the encephalomyocarditis virus IRES. Moreover, inhibiting cap-dependent translation ex vivo and in in vitro lysates had only a minimal effect on the translation of mRNA containing the TrkB 5′ leader. Dissecting the 5′ leader showed that the IRES is located in the exon common to all TrkB 5′ leaders. Moreover, six regions ranging from 2 to 25 nt were identified that either promoted or inhibited IRES activity. Taken together, these results suggest that the 5′ leader of the human TrkB mRNA contains multiple cis-elements that regulate internal initiation of translation and that this mechanism may contribute significantly to the translation of the TrkB mRNA in neuronal dendrites.
Collapse
Affiliation(s)
| | | | | | | | - Les Krushel
- To whom correspondence should be addressed. Tel: +1 303 724 3646; Fax: +1 303 724 3647;
| |
Collapse
|
324
|
Cavaliere F, Nestola V, Amadio S, D'Ambrosi N, Angelini DF, Sancesario G, Bernardi G, Volonté C. The metabotropic P2Y4 receptor participates in the commitment to differentiation and cell death of human neuroblastoma SH-SY5Y cells. Neurobiol Dis 2005; 18:100-9. [PMID: 15649700 DOI: 10.1016/j.nbd.2004.09.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2004] [Revised: 08/31/2004] [Accepted: 09/07/2004] [Indexed: 01/19/2023] Open
Abstract
Extracellular nucleotides exert a variety of biological actions through different subtypes of P2 receptors. Here we characterized in the human neuroblastoma SH-SY5Y cells the simultaneous presence of various P2 receptors, belonging to the P2X ionotropic and P2Y metabotropic families. Western blot analysis detected the P2X1,2,4,5,6,7 and P2Y1,2,4,6, but not the P2X3 and P2Y12 receptors. We then investigated which biological effects were mediated by the P2Y4 subtype and its physiological pyrimidine agonist UTP. We found that neuronal differentiation of the SH-SY5Y cells with dibutiryl-cAMP increased the expression of the P2Y4 protein and that UTP itself was able to positively interfere with neuritogenesis. Moreover, transient transfection and activation of P2Y4 also facilitated neuritogenesis in SH-SY5Y cells, as detected by morphological phase contrast analysis and confocal examination of neurofilament proteins NFL. This was concurrent with increased transcription of immediate-early genes linked to differentiation such as cdk-5 and NeuroD6, and activity of AP-1 transcription family members such as c-fos, fos-B, and jun-D. Nevertheless, a prolonged activation of the P2Y4 receptor by UTP also induced cell death, both in naive, differentiated, and P2Y4-transfected SH-SY5Y cells, as measured by direct count of intact nuclei and cytofluorimetric analysis of damaged DNA. Taken together, our data indicate that the high expression and activation of the P2Y4 receptor participates in the neuronal differentiation and commitment to death of SH-SY5Y cells.
Collapse
|
325
|
Liu HY, MacDonald JIS, Hryciw T, Li C, Meakin SO. Human Tumorous Imaginal Disc 1 (TID1) Associates with Trk Receptor Tyrosine Kinases and Regulates Neurite Outgrowth in nnr5-TrkA Cells. J Biol Chem 2005; 280:19461-71. [PMID: 15753086 DOI: 10.1074/jbc.m500313200] [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: 11/06/2022] Open
Abstract
The human tumorous imaginal disc 1 (TID1) proteins including TID1(L) and TID1(S), members of the DnaJ domain protein family, are involved in multiple intracellular signaling pathways such as apoptosis induction, cell proliferation, and survival. Here we report that TID1 associates with the Trk receptor tyrosine kinases and regulates nerve growth factor (NGF)-induced neurite outgrowth in PC12-derived nnr5 cells. Binding assays and transfection studies showed that the carboxyl-terminal end of TID1 (residues 224-429) bound to Trk at the activation loop (Tyr(P)(683)-Tyr(684)(P)(684) in rat TrkA) and that TID1 was tyrosine phosphorylated by Trk both in yeast and in transfected cells. Moreover endogenous TID1 was also tyrosine phosphorylated by and co-immunoprecipitated with Trk in neurotrophin-stimulated primary rat hippocampal neurons. Overexpression studies showed that both TID1(L) and TID1(S) significantly facilitated NGF-induced neurite outgrowth in TrkA-expressing nnr5 cells possibly through a mechanism involving increased activation of mitogen-activated protein kinase. Consistently knockdown of endogenous TID1, mediated with specific short hairpin RNA, significantly reduced NGF-induced neurite growth in nnr5-TrkA cells. These data provide the first evidence that TID1 is a novel intracellular adaptor that interacts with the Trk receptor tyrosine kinases in an activity-dependent manner to facilitate Trk-dependent intracellular signaling.
Collapse
Affiliation(s)
- Hui-Yu Liu
- Cell Biology Group, Robarts Research Institute, London, Ontario, Canada
| | | | | | | | | |
Collapse
|
326
|
Kitlinska J, Abe K, Kuo L, Pons J, Yu M, Li L, Tilan J, Everhart L, Lee EW, Zukowska Z, Toretsky JA. Differential effects of neuropeptide Y on the growth and vascularization of neural crest-derived tumors. Cancer Res 2005; 65:1719-28. [PMID: 15753367 DOI: 10.1158/0008-5472.can-04-2192] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Neuropeptide Y (NPY) is a sympathetic neurotransmitter recently found to be potently angiogenic and growth promoting for endothelial, vascular smooth muscle and neuronal cells. NPY and its cognate receptors, Y1, Y2 and Y5, are expressed in neural crest-derived tumors; however, their role in regulation of growth is unknown. The effect of NPY on the growth and vascularization of neuroendocrine tumors was tested using three types of cells: neuroblastoma, pheochromocytoma, and Ewing's sarcoma family of tumors (ESFT). The tumors varied in expression of NPY receptors, which was linked to differential functions of the peptide. NPY stimulated proliferation of neuroblastoma cells via Y2/Y5Rs and inhibited ESFT cell growth by Y1/Y5-mediated apoptosis. In both tumor types, NPY receptor antagonists altered basal growth levels, indicating a regulatory role of autocrine NPY. In addition, the peptide released from the tumor cells stimulated endothelial cell proliferation, which suggests its paracrine angiogenic effects. In nude mice xenografts, exogenous NPY stimulated growth of neuroblastoma tumors, whereas it increased apoptosis and reduced growth of ESFT. However, in both tumors, NPY treatment led to an increase in tumor vascularization. Taken together, this is the first report of NPY being a growth-regulatory factor for neuroendocrine tumors, acting both by autocrine activation of tumor cell proliferation or apoptosis and by angiogenesis. NPY and its receptors may become targets for novel approaches in the treatment of these diseases, directed against both tumor cell proliferation and angiogenesis.
Collapse
Affiliation(s)
- Joanna Kitlinska
- Department of Physiology, Lombardi Cancer Center, Georgetown University Medical Center, Washington, District of Columbia 20057, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
327
|
Arnold JM, Phipps MW, Chen J, Phipps J. Cellular sublocalization of Cx43 and the establishment of functional coupling in IMR-32 neuroblastoma cells. Mol Carcinog 2005; 42:159-69. [PMID: 15605363 DOI: 10.1002/mc.20072] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Neuroblastoma (NB) is the most common solid pediatric tumor. IMR-32 cells are a highly malignant human NB cell line with uncontrolled proliferation but with the potential to be differentiated under specific conditions. Preliminary research indicated that connexin 43 (Cx43), the most widespread of the Cx family, is aberrantly located in IMR-32 cells, which renders these cells incapable of gap junction (GJ) intercellular communication. Functioning GJ intercellular communication has been strongly associated with growth control and a decrease in tumorigenicity. 8-br-cAMP, known to initiate the differentiation process in cancer cells, was used to examine changes in Cx43 localization and expression via immunocytochemistry, Western blot analysis, and flow cytometry. Exposure of IMR-32 cells to 8-br-cAMP decreased cell proliferation, restored the abnormally localized Cx43 from around the nucleus to the cell membrane, increased de novo Cx43 protein expression, and appeared to phosphorylate Cx43 on serine (Ser) 255 and Ser262. Forskolin, an activator of cAMP dependent protein kinase (PKA), produced identical results to 8-br-cAMP demonstrating the effect that was not unique to a cAMP analog. The use of a PKA inhibitor further confirmed the specificity of 8-br-cAMP and forskolin's effect on Cx43. The cellular relocation of Cx43, combined with the increased protein expression, established first ever GJ intercellular communication between IMR-32 cells as revealed by scrape loading. These results suggest that the GJ-mediated return of growth control, as a prerequisite for further differentiation, offers a new therapeutic avenue in the treatment of NB.
Collapse
Affiliation(s)
- Jennifer M Arnold
- SIMS, PharmaGap, National Research Council of Canada, Ottawa, Ontario, Canada
| | | | | | | |
Collapse
|
328
|
Tacconelli A, Farina AR, Cappabianca L, Desantis G, Tessitore A, Vetuschi A, Sferra R, Rucci N, Argenti B, Screpanti I, Gulino A, Mackay AR. TrkA alternative splicing: a regulated tumor-promoting switch in human neuroblastoma. Cancer Cell 2004; 6:347-60. [PMID: 15488758 DOI: 10.1016/j.ccr.2004.09.011] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2004] [Revised: 07/22/2004] [Accepted: 09/07/2004] [Indexed: 12/14/2022]
Abstract
We identify a novel alternative TrkA splice variant, TrkAIII, with deletion of exons 6, 7, and 9 and functional extracellular IG-C1 and N-glycosylation domains, that exhibits expression restricted to undifferentiated early neural progenitors, human neuroblastomas (NBs), and a subset of other neural crest-derived tumors. This NGF-unresponsive isoform is oncogenic in NIH3T3 cells and promotes tumorigenic NB cell behavior in vitro and in vivo (cell survival, xenograft growth, angiogenesis) resulting from spontaneous tyrosine kinase activity and IP3K/Akt/NF-kappaB but not Ras/MAPK signaling. TrkAIII antagonizes NGF/TrkAI signaling, which is responsible for NB growth arrest and differentiation through Ras/MAPK, and its expression is promoted by hypoxia at the expense of NGF-responsive receptors, providing a mechanism for converting NGF/TrkA/Ras/MAPK antioncogenic signals to TrkAIII/IP3K/Akt/NF-kappaB tumor-promoting signals during tumor progression.
Collapse
Affiliation(s)
- Antonella Tacconelli
- Department of Experimental Medicine, University of L'Aquila, Via Vetoio, Coppito 2, 67100 L'Aquila, Italy
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
329
|
Wood ER, Kuyper L, Petrov KG, Hunter RN, Harris PA, Lackey K. Discovery and in vitro evaluation of potent TrkA kinase inhibitors: oxindole and aza-oxindoles. Bioorg Med Chem Lett 2004; 14:953-7. [PMID: 15013000 DOI: 10.1016/j.bmcl.2003.12.002] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2003] [Revised: 11/21/2003] [Accepted: 12/02/2003] [Indexed: 01/22/2023]
Abstract
The discovery, synthesis, potential binding mode, and in vitro kinase profile of 3-(3-bromo-4-hydroxy-5-(2'-methoxyphenyl)-benzylidene)-5-bromo-1,3-dihydro-pyrrolo[2,3-b]pyridin-2-one, 3-[(1-methyl-1H-indol-3-yl)methylene]-1,3-dihydro-2H-pyrrolo[3,2-b]-pyridin-2-one as potent TrkA inhibitors are discussed.
Collapse
Affiliation(s)
- Edgar R Wood
- GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27709, USA
| | | | | | | | | | | |
Collapse
|
330
|
Antonelli A, Chiaretti A, Piastra M, Vigneti E, Aloe L. In vitro human ependymoblastoma cells differentiate after exposure to nerve growth factor. ACTA ACUST UNITED AC 2004; 33:503-15. [PMID: 15906158 DOI: 10.1007/s11068-004-0513-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2004] [Revised: 10/18/2004] [Accepted: 10/20/2004] [Indexed: 10/25/2022]
Abstract
Nerve Growth Factor (NGF) has a prominent action on immature crest-derived nerve cells and on differentiation and survival of neurons in central and peripheral nervous system. NGF is produced by a variety of neuronal and non-neuronal cells, including neoplastic cells. Its role in tumor cells is largely unknown and controversial. The aim of the present study was to investigate the effect of NGF on brain neoplastic cells using primary cultures from ependymoblastoma (EP) tissue. Human EP tissues were cultured to obtain in vitro cells and their structural, biochemical, and molecular responses to NGF were investigated. The results showed that under basal conditions, human EP cells are characterized by low presence of high-affinity NGF-receptors. Time-course and dose-response studies revealed that EP cells undergo differentiation after exposure to NGF. Our findings showed that in human EP cells, NGF exerts a marked action on differentiation rather than proliferation.
Collapse
MESH Headings
- Adolescent
- Antibodies/pharmacology
- Brain Neoplasms/drug therapy
- Brain Neoplasms/metabolism
- Brain Neoplasms/physiopathology
- Cell Differentiation/drug effects
- Cell Differentiation/physiology
- Cell Proliferation/drug effects
- Cell Shape/drug effects
- Cell Shape/physiology
- Cell Transformation, Neoplastic/drug effects
- Cell Transformation, Neoplastic/metabolism
- DNA-Binding Proteins/metabolism
- Erythroid-Specific DNA-Binding Factors
- Humans
- Nerve Growth Factor/antagonists & inhibitors
- Nerve Growth Factor/metabolism
- Neuroectodermal Tumors, Primitive/drug therapy
- Neuroectodermal Tumors, Primitive/metabolism
- Neuroectodermal Tumors, Primitive/physiopathology
- Protein Binding/drug effects
- Protein Binding/physiology
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Receptor, trkA/agonists
- Receptor, trkA/genetics
- Receptor, trkA/metabolism
- Transcription Factors/metabolism
- Tumor Cells, Cultured
Collapse
Affiliation(s)
- A Antonelli
- Institute of Neurobiology and Molecular Medicine, Neurobiology section CNR, Rome, Italy
| | | | | | | | | |
Collapse
|
331
|
Hansford LM, Thomas WD, Keating JM, Burkhart CA, Peaston AE, Norris MD, Haber M, Armati PJ, Weiss WA, Marshall GM. Mechanisms of embryonal tumor initiation: distinct roles for MycN expression and MYCN amplification. Proc Natl Acad Sci U S A 2004; 101:12664-9. [PMID: 15314226 PMCID: PMC515113 DOI: 10.1073/pnas.0401083101] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2004] [Indexed: 01/19/2023] Open
Abstract
The mechanisms causing persistence of embryonal cells that later give rise to tumors is unknown. One tumorigenic factor in the embryonal childhood tumor neuroblastoma is the MYCN protooncogene. Here we show that normal mice developed neuroblast hyperplasia in paravertebral ganglia at birth that completely regressed by 2 weeks of age. In contrast, ganglia from MYCN transgenic (TH-MYCN) mice demonstrated a marked increase in neuroblast hyperplasia and MycN expression during week 1. Regression of neuroblast hyperplasia was then delayed and incomplete before neuroblastoma tumor formation at 6 and 13 weeks in homo- and hemizygote mice, respectively. Paravertebral neuronal cells cultured from perinatal TH-MYCN mice exhibited 3- to 10-fold resistance to nerve growth factor (NGF) withdrawal, compared with normal mice. Both low- and high-affinity NGF receptors were expressed in perinatal neuroblast hyperplasia but not in neuroblastoma tumor tissue. MYCN transgene amplification was present at low levels in perinatal neuroblast hyperplasia from both homo- and hemizygote TH-MYCN mice. However, only in hemizygous mice did tumor formation correlate with a stepwise increase in the frequency of MYCN amplification. These data suggest that inappropriate perinatal MycN expression in paravertebral ganglia cells from TH-MYCN mice initiated tumorigenesis by altering the physiologic process of neural crest cell deletion. Persisting embryonal neural crest cells underwent further changes, such as MYCN amplification and repression of NGF receptor expression, during tumor progression. Our studies provide a model for studying perinatal factors influencing embryonal tumor initiation.
Collapse
Affiliation(s)
- Loen M Hansford
- Children's Cancer Institute Australia for Medical Research, Randwick 2031, Australia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
332
|
Davidson B, Reich R, Lazarovici P, Ann Flørenes V, Nielsen S, Nesland JM. Altered expression and activation of the nerve growth factor receptors TrkA and p75 provide the first evidence of tumor progression to effusion in breast carcinoma. Breast Cancer Res Treat 2004; 83:119-28. [PMID: 14997042 DOI: 10.1023/b:brea.0000010704.17479.8a] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The aim of this study was to characterize phenotypic alterations along the progression of breast carcinoma from primary tumor to pleural effusion through analysis of the expression of nerve growth factor (NGF) and its receptors phospho-TrkA (p-TrkA activated receptor) and p75. Sections from 42 malignant pleural effusions from breast cancer patients and 65 corresponding solid tumors (34 primary, 31 metastatic) were evaluated for protein expression of the activated p-TrkA receptor. The majority of lesions were additionally studied for NGF and p75 expression. Six effusions and four breast carcinoma cell lines were studied for expression of p-TrkA using immunoblotting (IB). Membrane expression of p-TrkA was high in carcinoma cells in effusions (39/42, 93%) and locoregional recurrences (12/13, 92%), with significantly lower expression in both primary tumors (14/34, 41%) and lymph node metastases (8/18, 44%), respectively (p < 0.001 for effusions vs. primary tumors; p = 0.001 for effusions vs. lymph nodes). In contrast, p75 expression was less frequent in effusions compared to both primary tumors and lymph node metastases, significantly so for the latter (p = 0.019). NGF expression was comparable at all sites, but its expression in tumor cells in effusions (7/21 cases) was limited to cases in which time to progression (TTP) to effusion occurred within 5 years or less from primary operation. In univariate analysis of survival, mean and median TTP were 6.3 and 6 years for NGF-negative effusions, compared to 3 and 4 years for NGF-positive cases (p = 0.013). IB confirmed expression of p-TrkA in five of six effusions, while all four breast cancer cell lines were p-TrkA-negative. Our data provide the first documented evidence of molecular events that occur along tumor progression of breast carcinoma from primary tumors to effusion. The almost universal expression of p-TrkA in cancer cells in effusions and late recurrences is in full agreement with our recent report linking this factor with poor prognosis in ovarian cancer. Furthermore, the rapid progression to effusion in cases showing NGF expression in tumor cells underscores the aggressive clinical behavior of tumors that are able to utilize this pathway in an autocrine manner.
Collapse
MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Breast Neoplasms/genetics
- Breast Neoplasms/mortality
- Breast Neoplasms/pathology
- Cell Line, Tumor
- Disease Progression
- Female
- Gene Expression Regulation, Neoplastic
- Humans
- Immunoblotting
- Lymphatic Metastasis
- Middle Aged
- Neoplasm Metastasis
- Neoplasm Recurrence, Local/genetics
- Neoplasm Recurrence, Local/mortality
- Neoplasm Recurrence, Local/pathology
- Pleural Effusion, Malignant/genetics
- Pleural Effusion, Malignant/mortality
- Pleural Effusion, Malignant/pathology
- Receptor, Nerve Growth Factor
- Receptor, trkA/genetics
- Receptors, Nerve Growth Factor/genetics
- Survival Analysis
Collapse
Affiliation(s)
- Ben Davidson
- Department of Pathology, The Norwegian Radium Hospital, University of Oslo, Montebello, Oslo, Norway.
| | | | | | | | | | | |
Collapse
|
333
|
Davidson B, Reich R, Lazarovici P, Flørenes VA, Risberg B, Nielsen S, Sert B, Bedrossian C. Expression of the nerve growth factor receptors TrkA and p75 in malignant mesothelioma. Lung Cancer 2004; 44:159-65. [PMID: 15084380 DOI: 10.1016/j.lungcan.2003.11.014] [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] [Received: 08/04/2003] [Revised: 11/03/2003] [Accepted: 11/17/2003] [Indexed: 10/26/2022]
Abstract
The objective of the present report was to study the expression of the low affinity nerve growth factor (NGF) receptor p75 and of the activated high-affinity NGF receptor TrkA in malignant mesothelioma (MM). In addition, to analyze whether expression of these receptors is site-related (pleural versus peritoneal MM, solid lesions versus effusions). Sections from 81 MM (57 biopsies, 24 effusions) were analyzed. Sixty-one mesotheliomas were of pleural origin, while the remaining 20 were peritoneal. Effusion specimens consisted of 6 peritoneal and 18 pleural effusions, while biopsies consisted of 14 peritoneal and 43 pleural lesions. Specimens were immunohistochemically stained using antibodies against p75 and phospho-TrkA (p-TrkA). Six effusions were additionally analyzed for p-TrkA expression using immunoblotting (IB). p-TrkA membrane expression (66/81 specimens; 81%) was by far more frequent than that of p75 (26/81 specimens; 32%). In addition, p-TrkA expression was significantly higher in peritoneal MM compared to their pleural counterparts (20/20 versus 46/61 positive tumors; P = 0.014). p-TrkA membrane expression was marginally higher in effusions (P = 0.058), while the opposite was true for p75 membrane expression (P = 0.008) and p-TrkA cytoplasmic expression (P = 0.003). In conclusion, our results document for the first time frequent expression of p-TrkA and lower expression of p75 in MM, in agreement with the biological aggressiveness of this tumor. The enhanced expression of p-TrkA in peritoneal MM, tumors that appear in younger patients, and in effusions as compared to solid tumors, suggest that p-TrkA plays a significant role in the biology of this disease and may aid in defining tumor progression in this setting.
Collapse
Affiliation(s)
- Ben Davidson
- Department of Pathology, The Norwegian Radium Hospital, Montebello N-0310 Oslo, University of Oslo, Oslo, Norway.
| | | | | | | | | | | | | | | |
Collapse
|
334
|
Bennasroune A, Gardin A, Aunis D, Crémel G, Hubert P. Tyrosine kinase receptors as attractive targets of cancer therapy. Crit Rev Oncol Hematol 2004; 50:23-38. [PMID: 15094157 DOI: 10.1016/j.critrevonc.2003.08.004] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2003] [Indexed: 12/24/2022] Open
Abstract
Receptor tyrosine kinases (RTKs) are the main mediators of the signaling network that transmit extracellular signals into the cell, and control cellular differentiation and proliferation. Recent and rapid advances in our understanding of cellular signaling by receptor tyrosine kinases, in normal and malignant cells, have brought to light the potential of RTKs as selective anti-cancer targets. Their activity is normally tightly controlled and regulated. Overexpression of RTK proteins or functional alterations caused by mutations in the corresponding genes or abnormal stimulation by autocrine growth factor loops contribute to constitutive RTK signaling, resulting in dysregulated cell growth and cancer. The mechanisms of uncontrolled RTK signaling that leads to cancer has provided the rationale for anti-RTK drug development. Herceptin, Gleevec, and Iressa are the first examples of drugs which have successfully translated basic research on oncogenes into cancer therapeutics. RTKs can be viewed as multifunctional targets, and strategies towards the prevention and inhibition of RTK signaling include antibodies, antagonist ligands, small molecule inhibitors of protein kinase activity, and inhibitors of protein-protein interactions. Progresses in the field of rational drug design and computational chemistry will vastly benefit from the availability of increasing structural knowledge of both the kinase domains and the ligand-binding sites of these receptors.
Collapse
Affiliation(s)
- Amar Bennasroune
- INSERM Unit 575, 5 rue Blaise Pascal, 67084 Strasbourg Cedex, France
| | | | | | | | | |
Collapse
|
335
|
Tabakman R, Lecht S, Sephanova S, Arien-Zakay H, Lazarovici P. Interactions between the cells of the immune and nervous system: neurotrophins as neuroprotection mediators in CNS injury. PROGRESS IN BRAIN RESEARCH 2004; 146:387-401. [PMID: 14699975 DOI: 10.1016/s0079-6123(03)46024-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Inflammatory processes in the central nervous system (CNS) are considered neurotoxic, although recent studies suggest that they also can be beneficial and confer neuroprotection (neuroprotective autoimmunity). Cells from the immune system have been detected in CNS injury and found to produce and secrete a variety of neurotrophins such as NGF, BDNF, NT-3 and NT-4/5, and to express (similarly to neuronal cells), members of the tyrosine kinase (Trk) receptor family such as TrkA, TrkB and TrkC. Indeed, autocrine and paracrine interactions are observed at the site of CNS injury, resulting in a variety of homologic-heterologic modulations of immune and neuronal cell function. The end result of the inflammatory process, neurotoxicity and/or neuroprotection, is a function of the fine balance between the two cellular systems, i.e., of the complex signaling relationships between anti-inflammatory neuroprotective factors (neurotrophins and other chemical mediators) and proinflammatory neurotoxic factors (TNF, free radicals, certain cytokines, etc.). Autoimmune neuroprotection is a novel therapeutic approach aimed at shifting the balance between the immune and neuronal cells towards survival pathways in a variety of CNS injuries. This review focuses on data supporting this concept and its future therapeutical implications for optic nerve injury and multiple sclerosis.
Collapse
Affiliation(s)
- Rinat Tabakman
- Department of Pharmacology, School of Pharmacy, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | | | | | | | | |
Collapse
|
336
|
Affiliation(s)
- Mookda Pattarawarapan
- Texas A & M University, Department of Chemistry, PO Box 30012, College Station, Texas 77841-3012, USA
| | | |
Collapse
|
337
|
Nakagawara A. Neural crest development and neuroblastoma: the genetic and biological link. PROGRESS IN BRAIN RESEARCH 2004; 146:233-42. [PMID: 14699967 DOI: 10.1016/s0079-6123(03)46015-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Neuroblastoma is one of the most common pediatric solid tumors originating from the sympathoadrenal lineage of neural crest. The tumor shows extremely different clinical phenotypes such as spontaneous regression on one hand and aggressive growth on the other hand. The different biological behavior of neuroblastoma appears to be determined by the genetic abnormalities including amplification of MYCN oncogene, DNA ploidy and some allelic imbalances. However, the spontaneous regression of neuroblastoma mimics the programmed cell death normally occurring in developing sympathetic cells expressing both TrkA tyrosine kinase A and p75NTR neurotrophin receptor. Indeed, TrkA expression is the most important factor related to the induction of tumor cell differentiation and/or programmed cell death because without its expression spontaneous regression of neuroblastoma never occurs. Thus, the enigmatic clinical behaviors of neuroblastoma are strictly linked to the molecular mechanism of neural crest development.
Collapse
Affiliation(s)
- Akira Nakagawara
- Division of Biochemistry, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuoh-ku, Chiba 260-8717, Japan.
| |
Collapse
|
338
|
Abstract
Serous effusions are a frequently encountered clinical manifestation of metastatic disease, with breast, ovarian, and lung carcinomas and malignant mesothelioma (MM) leading the list. Recently, extensive research has resulted in expansion of the antibody panel that is available for effusion diagnosis, thereby reducing the risk for error. Despite this progress, relatively little has been done in way of understanding the biology of cancer cells in effusions, especially those of nonovarian origin. The diagnosis of a malignant effusion signifies disease progression and is associated with a worse prognosis regardless of the tumor site of origin. However, survival is much more variable with ovarian cancer compared with other tumors. Furthermore, cancer cells of different origins differ considerably in their biology and have unique phenotypic and genotypic characteristics. This review summarizes the current knowledge in this field and presents a model for the study of tumor metastasis and disease progression, through large comparative studies of malignant cells in effusions, primary tumors, and solid metastases. The case also is made for potential applications of this rapidly evolving body of knowledge in the diagnosis, classification, and prediction of biological behavior of processes resulting in cryptic effusions at the clinical level.
Collapse
Affiliation(s)
- Ben Davidson
- Department of Pathology, The Norwegian Radium Hospital, University of Oslo, Montebello N-0310 Oslo, Norway.
| |
Collapse
|
339
|
Abstract
Neurotrophins are a family of growth factors critical for the development and functioning of the nervous system. Although originally identified as neuronal survival factors, neurotrophins elicit many biological effects, ranging from proliferation to synaptic modulation to axonal pathfinding. Recent data indicate that the nature of the signaling cascades activated by neurotrophins, and the biological responses that ensue, are specified not only by the ligand itself but also by the temporal pattern and spatial location of stimulation. Studies on neurotrophin signaling have revealed variations in the Ras/MAP kinase, PI3 kinase, and phospholipase C pathways, which transmit spatial and temporal information. The anatomy of neurons makes them particularly appropriate for studying how the location and tempo of stimulation determine the signal cascades that are activated by receptor tyrosine kinases such as the Trk receptors. These signaling variations may represent a general mechanism eliciting specificity in growth factor responses.
Collapse
Affiliation(s)
- Rosalind A Segal
- Departments of Neurobiology and Pediatric Oncology, Harvard Medical School and Dana-Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, USA.
| |
Collapse
|
340
|
Zhang PJ, Weber R, Liang HH, Pasha TL, LiVolsi VA. Growth factors and receptors in juvenile nasopharyngeal angiofibroma and nasal polyps: an immunohistochemical study. Arch Pathol Lab Med 2003; 127:1480-4. [PMID: 14567719 DOI: 10.5858/2003-127-1480-gfarij] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Juvenile nasopharyngeal angiofibroma is a rare nasopharyngeal tumor that occurs exclusively in adolescent boys. It is a histologically benign but locally persistent growth of stromal and vascular tissue. Although male hormones and some growth factors, such as transforming growth factor beta1 (TGF-beta1), insulin-like growth factor II (IGF-II), and, lately, the proto-oncogene beta-catenin, have been implicated in the histogenesis of the tumor, the biologic signaling pathways that drive this peculiar fibrovascular proliferation are still nuclear. OBJECTIVE To evaluate immunoexpressions of beta-catenin, c-Kit, p130Cas, TGF-beta3, bone morphogenic protein 4, nerve growth factor (NGF), and the IGF receptor (IGF-1R) in a series of juvenile nasopharyngeal angiofibromas and to compare to that of a group of nasal polyps. DESIGN A standard immunohistochemical technique was used on paraffin sections of 12 sporadic juvenile nasopharyngeal angiofibromas and 15 nasal polyps with microwave or steam antigen retrieval. Immunoreactivity was analyzed semiquantitatively in stromal cells and endothelial cells of each case. RESULTS The expressions of beta-catenin (nuclear), c-Kit (cytoplasmic), and NGF (cytoplasmic) were higher and more frequent in stromal cells of juvenile nasopharyngeal angiofibromas than those of nasal polyps. Both juvenile nasopharyngeal angiofibromas and nasal polyps showed similarly frequent and strong immunoreactivity for p130Cas and TGF-beta3 and weak immunoreactivity for bone morphogenic protein 4 in both stromal cells and endothelial cells. No IGF-1R immunoreactivity was detected in any case of either group. CONCLUSIONS Our results support the role of beta-catenin in juvenile nasopharyngeal angiofibromas and suggest a potential involvement of c-Kit and NGF signaling pathways in the juvenile nasopharyngeal angiofibromas. Although the biologic significance of c-Kit in juvenile nasopharyngeal angiofibromas has yet to be defined, the finding of frequent and high c-Kit expression might have therapeutic importance for patients with juvenile nasopharyngeal angiofibromas.
Collapse
Affiliation(s)
- Paul J Zhang
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, Philadelphia, USA.
| | | | | | | | | |
Collapse
|
341
|
Boelaert K, Tannahill LA, Bulmer JN, Kachilele S, Chan SY, Kim D, Gittoes NJL, Franklyn JA, Kilby MD, McCabe CJ. A potential role for PTTG/securin in the developing human fetal brain. FASEB J 2003; 17:1631-9. [PMID: 12958169 DOI: 10.1096/fj.02-0948com] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Human securin, known also as PTTG, has established oncogenic and cell cycle regulatory functions. PTTG/securin transforms cells in vitro, inhibits sister chromatid separation, and regulates secretion of fibroblast growth factor-2. FGF-2 is a key regulator of CNS development and PTTG/securin expression has been reported in murine fetal brain. We examined the expression and function of securin and FGF-2 in the developing human fetal brain and in a fetal neuronal cell line (NT 2). Securin expression was significantly reduced in first and second trimester fetal cerebral cortex compared with adult cerebral cortex, where immunocytochemistry revealed intense securin staining in neuronal cell bodies. FGF-2 protein was concordantly lower in fetal cortex, whereas pretranslational expression of PTTG binding factor (PBF) was not significantly altered in fetal brain compared with adult. PCNA expression demonstrated that high securin levels in adult cortex were associated with absent cell proliferation. In NT-2 cells, securin stimulated FGF-2 expression, which could be abrogated by a carboxyl-terminal mutation. Low transient expression of securin resulted in a significant proliferative effect, whereas high levels of securin expression inhibited cell turnover. We propose a potential role for human PTTG/securin in modulating cell proliferation and FGF-2 expression during human neurogenesis.
Collapse
Affiliation(s)
- K Boelaert
- Division of Medical Sciences, University of Birmingham, Queen Elizabeth Hospital, Birmingham, B15 2TH, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
342
|
Abstract
Neuroblastoma is the most frequently occurring solid tumour in children, with an incidence of 1.3 cases per 100000 children aged 0-14 years. Despite many advances during the past three decades, neuroblastoma has remained an enigmatic challenge to clinical and basic scientists. 20 years ago, the MYCN gene was found to be amplified in neuroblastomas, and research since then has focused on the search for other genetic markers. It has emerged that neuroblastoma cells, like cells of many other tumour types, often suffer from extensive, non-random genetic damage at multiple genetic loci. Elucidation of the exact molecular make-up of neuroblastomas will enable researchers to analyse how much specific markers, alone or in combination, can help to stratify disease in prospective studies; at present, stratification is based on age, stage, MYCN, and Shimada pathology. Neuroblastoma may be one of the first examples of the use of genetic tumour markers as a tool for defining tumour behaviour and to aid clinical staging.
Collapse
|
343
|
Abstract
Genetic investigation of neuroblastoma has provided few clues to account for the variability in clinical phenotype which is such a characteristic feature of this tumour. Indeed, efforts to identify the primary genetic event(s) responsible for tumour development have been overwhelmed by the number and range of different genetic abnormalities observed, particularly in the more aggressive neuroblastoma subtypes. Since neuroblastoma is a consequence of aberrant development of the sympathetic nervous system (SNS), investigation of the genetic components known to be involved in the control of SNS developmental, may provide the key to understanding tumour behaviour. The neurotrophins and the glial family ligands both play very significant roles in different stages of SNS development and merit more detailed investigation as to how they might influence neuroblastoma tumorigenesis.
Collapse
Affiliation(s)
- Carmel M McConville
- Department of Paediatrics and Child Health, University of Birmingham, Vincent Drive, B15 2TT Birmingham, UK.
| | | |
Collapse
|
344
|
Hogarty MD. The requirement for evasion of programmed cell death in neuroblastomas with MYCN amplification. Cancer Lett 2003; 197:173-9. [PMID: 12880978 DOI: 10.1016/s0304-3835(03)00103-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Neuroblastoma is a tumour of the peripheral nervous system that accounts for 15% of cancer-related deaths in childhood. Amplification and overexpression of the MYCN proto-oncogene occurs in 25% of neuroblastomas and is highly correlated with treatment failure and mortality. MYCN stimulates cell cycle entry but does not alleviate the requirement for ongoing mitogenic signalling to support this proliferation. In fact, deregulated MYCN potently heightens cell sensitivity to myriad stressors that induce programmed cell death, although the mechanisms of this effect are poorly understood. To circumvent this safeguard against oncogene-driven neoplasia, cancer cells with deregulated MYC frequently exhibit defects in apoptotic pathways. It is similarly proposed that neuroblasts with MYCN amplification have obligate defects in pathways that engage or execute apoptosis, and these defects contribute to the malignant phenotype. Investigations into the molecular genetics of both primary human neuroblastomas with MYCN amplification, as well as tumours arising in genetically engineered mice with targeted MYCN overexpression, should help to define these cooperating genetic lesions. Elucidating the mechanisms whereby non-transformed neural cells engage MYCN-primed apoptosis, as well as the mechanisms neuroblasts with MYCN amplification use to evade this process, will define useful targets for biological therapeutics that exploit the inherent apoptosis-priming function of deregulated MYCN.
Collapse
Affiliation(s)
- Michael D Hogarty
- Division of Oncology, The Children's Hospital of Philadelphia and the Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-4318, USA.
| |
Collapse
|
345
|
Du JJ, Dou KF, Peng SY, Qian BZ, Xiao HS, Liu F, Wang WZ, Guan WX, Gao ZQ, Liu YB, Han ZG. Expression of NGF family and their receptors in gastric carcinoma: A cDNA microarray study. World J Gastroenterol 2003; 9:1431-4. [PMID: 12854135 PMCID: PMC4615477 DOI: 10.3748/wjg.v9.i7.1431] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the expression of NGF family and their receptors in gastric carcinoma and normal gastric mucosa, and to elucidate their effects on gastric carcinoma.
METHODS: RNA of gastric cancer tissues and normal gastric tissues was respectively isolated and mRNA was purified. Probes of both mRNA reverse transcription product cDNAs labled with α-33P dATP were respectively hybridized with Atlas Array membrane where NGF and their family genes were spotted on. Hybridized signal images were scanned on phosphor screen with ImageQuant 5.1 software after hybridization. Normalized values on spots were analyzed with ArrayVersion 5.0 software. Differential expression of NGF family and their receptors mRNA was confirmed between hybridized Atlas Array membranes of gastric cancer tissues and normal gastric mucosa, then their effects on gastric carcinoma were investigated.
RESULTS: Hybridization signal images on Atlas Array membrane appeared in a lower level of nonspecific hybridization. Both of NGF family and their receptors Trk family mRNA were expressed in gastric cancer and normal gastric mucosa. But adversely up-regulated expression in other tissues and organs. NGF, BDGF, NT-3, NT-4/5, NT-6 and TrkA, B and C were down-regulated simultaneously in gastric carcinoma in comparison with normal gastric mucosa. Degrees of down-regulation in NGF family were greater than those in their receptors Trk family. Down-regulation of NT-3 and BDGF was the most significant, and TrkC down-regulation level was the lowest in receptors Trk family.
CONCLUSION: Down-regulated expression of NGF family and their receptors Trk family mRNA in gastric cancer is confirmed. NGF family and their receptors Trk family probably play a unique role in gastric cancer cell apoptosis by a novel Ras or Raf signal transduction pathway. Their synchronous effects are closely associated with occurrence and development of gastric carcinoma induced by reduction of signal transduction of programmed cell death.
Collapse
Affiliation(s)
- Jian-Jun Du
- Department of General Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shanxi Province, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
346
|
Hornstein I, Pikarsky E, Groysman M, Amir G, Peylan-Ramu N, Katzav S. The haematopoietic specific signal transducer Vav1 is expressed in a subset of human neuroblastomas. J Pathol 2003; 199:526-33. [PMID: 12635144 DOI: 10.1002/path.1314] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vav1 is a signal transducer protein expressed exclusively in the haematopoietic system, where it plays a pivotal role in growth factor-induced differentiation and proliferation. Vav1 couples tyrosine kinase signals with the activation of the Rho/Rac GTPases, leading to cell differentiation and/or proliferation. Vav1 was originally detected as an oncogene, but its involvement in human malignancies has not been reported thus far. We report here that Vav1 is expressed in a neuroblastoma cell line, SK-N-MC. Molecular analysis indicated that there are no gross rearrangements or mutations in the Vav1 gene in SK-N-MC cells. Vav1 protein from SK-N-MC cells was similar to wild-type Vav1 in apparent molecular weight, phosphorylation state, and ability to associate with active EGFR. We also analysed the expression of Vav1 in 42 specimens of human neuroblastoma. Vav1 was expressed in the majority of these tumours. Our results suggest that Vav1 may play a role in the neoplastic process in a subset of neuroblastomas.
Collapse
Affiliation(s)
- Idit Hornstein
- Hubert H Humphrey Centre for Experimental Medicine and Cancer Research, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | | | | | | | | | | |
Collapse
|
347
|
Abstract
Neuroblastic tumors are a broad biological and clinical spectrum of neoplastic disease that has long captured the attention of clinicians and scientists alike. It is the most common solid extracranial tumor in children and accounts for 8-10% of all childhood tumors. Tumors are derived from neural crest cells and neural differentiation is common. Neuroblastoma is unique in that it presents with at least three distinct patterns of disease. Locoregional disease (Stage 1, 2, 3) does not metastasize to bone or bone marrow. Stage 4 is a systemic disease with widespread metastasis that responds to chemotherapy but many develop resistance. Stage 4s presents in infancy, is widespread and can spontaneously regress with no intervention, leaving a focus of fibrosis or calcification. Prognosis correlates with age, stage and tumor biological profile. The goal of this review is to provide an overview of the disease and highlight diagnostic, prognostic and therapeutic advances in neuroblastoma. Recommendations and resources for the evaluation and treatment of this disease are outlined.
Collapse
Affiliation(s)
- Orit Oppenheimer
- Departments of Pathology and Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
| | | | | |
Collapse
|
348
|
Wang Y, Gu X. Evolutionary and expression profiles of gene families crucial for central nervous system development. Inf Sci (N Y) 2002. [DOI: 10.1016/s0020-0255(02)00233-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
349
|
Ellison D. Classifying the medulloblastoma: insights from morphology and molecular genetics. Neuropathol Appl Neurobiol 2002; 28:257-82. [PMID: 12175339 DOI: 10.1046/j.1365-2990.2002.00419.x] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Significant advances in the treatment of the medulloblastoma (MB) have been made in the last 30 years, reducing mortality by 2-fold. Further improvements in the cure rate require an increased understanding of the biology of MBs, and this will translate into refinements in their classification. Scrutiny of the cytological variation found among MBs has recently led to the concept of the anaplastic MB, which overlaps the large-cell variant and appears to share its poor prognosis. In contrast, the MB with extensive nodularity, a distinctive nodular/desmoplastic variant occurring in infants, has a better outcome than most MBs in these young patients. Building on cytogenetic studies that have drawn attention to abnormalities on chromosome 17 in over a third of MBs, research shows non-random losses on chromosomes 8, 9, 10, 11 and 16, and gains on chromosomes 1, 7 and 9. Overexpression of ErbB2 receptors and losses on chromosome 17p have been proposed as independent indicators of aggressive behaviour, while high TrkC receptor expression indicates a favourable outcome. There is a strong association between anaplastic/large-cell tumours and MYC amplification, which has previously been linked with aggressive disease, but associations between abnormalities on chromosome 17 and anaplastic/large-cell MBs and between abnormalities in the shh/PTCH pathway and the desmoplastic variant are more controversial. Classification of the MB histopathologically and according to profiles of molecular abnormalities will help both to rationalize approaches to therapy, increasing the cure rate and reducing long-term side-effects, and to suggest novel treatments.
Collapse
Affiliation(s)
- D Ellison
- Northern Institute for Cancer Research, University of Newcastle-upon-Tyne, Newcastle-upon-Tyne, UK.
| |
Collapse
|
350
|
Tanabe A, Kurita M, Oshima K, Osada S, Nishihara T, Imagawa M. Functional analysis of zinc finger proteins that bind to the silencer element in the glutathione transferase P gene. Biol Pharm Bull 2002; 25:970-4. [PMID: 12186428 DOI: 10.1248/bpb.25.970] [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: 11/22/2022]
Abstract
Glutathione transferase P (GST-P) gene expression is repressed in normal rats but markedly promoted during the early stage of chemical hepatocarcinogenesis. We have previously identified a silencer region in this gene promoter. The silencer is composed of several cis-elements to which at least three proteins (Silencer factor-A, -B, and -C: SF-A, SF-B, and SF-C) are known to bind. We cloned and characterized the nuclear factor 1 family and the CCAAT/enhancer-binding protein family as SF-A and SF-B, respectively. Recently, zinc finger proteins as candidates for SF-C, which binds to GST-P silencer 2 (GPS2), were isolated. These proteins include four Krüppel-like proteins (BTEB2, EZF, LKLF, and TIEG1) and other factors containing multiple zinc finger motifs (TFIIIA and MZFP). In the present study, we found that the zinc finger proteins showed the same DNA-binding affinities to GPS2. Moreover, transfection analyses revealed that BTEB2, EZF, and TIEGI repressed the GST-P promoter activity. Therefore, these three factors might contribute to the repression of the GST-P gene expression in normal rat liver.
Collapse
Affiliation(s)
- Atsuhiro Tanabe
- Laboratory of Environmental Biochemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka, Suita, Japan
| | | | | | | | | | | |
Collapse
|