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2.
Neuroscience ; 124(2): 351-66, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14980385

RESUMO

UNLABELLED: FK506 and its non-immunosuppressive derivatives represent a class of pharmacological agents referred to as immunophilin ligands that have been reported to promote neuroregeneration and survival in several experimental models; however their cellular and molecular mechanisms of action have not been well established. Here we characterize a new immunophilin ligand that interacts with both FK506 binding protein 12 (FKBP12) and FKBP52, and demonstrate that JNJ460 induces neurite outgrowth from freshly explanted dorsal root ganglia (DRG) in a Schwann cell-dependent manner. Purified cultures of neurons fail to respond to these drugs, but cultures containing Schwann cells and neurons respond with neurite outgrowth, as do neurons grown in conditioned medium from JNJ460-treated Schwann cells. Using microarray analysis and a transcription reporter assay, we show that JNJ460 induces a series of transcriptional changes that occur in a temporal cascade. Among the Schwann cell-expressed genes upregulated following JNJ460 treatment is the POU transcription factor SCIP, which has been shown to regulate Schwann cell gene transcription and differentiation. JNJ460 potentiated transforming growth factor beta (TGF-beta)-induced transcriptional activation and SCIP induction in Schwann cells, by altering the interaction between FKBP12 and the TGF-beta type I receptor, TbetaR1. Finally, to test whether JNJ460 enhances neurite regeneration in vivo, we treated animals with JNJ460 for 30 days following mechanical transection of the sciatic nerve and demonstrated myelin and axonal hypertrophy at the ultrastructural level. Collectively, these data suggest that Schwann cells play an important role in the biological effects of immunophilin ligands by affecting neuron-glial signaling during regeneration. SUMMARY: The cellular and molecular mechanisms responsible for the regenerative effects of immunophilin ligands are not well understood. Here we show that the neuritogenic effects of JNJ460 in a DRG model depend on interactions between neurons and Schwann cells. Treatment of purified Schwann cells with JNJ460 alters Schwann cell gene expression, and promotes the generation of factors that act on neurons. These data indicate that Schwann cells play an important role in the actions of immunophilin ligands.


Assuntos
Gânglios Espinais/citologia , Regeneração Nervosa/efeitos dos fármacos , Células de Schwann/efeitos dos fármacos , Tacrolimo/farmacologia , Animais , Animais Recém-Nascidos , Axônios/efeitos dos fármacos , Axônios/ultraestrutura , Northern Blotting/métodos , Western Blotting/métodos , Células Cultivadas , Técnicas de Cocultura/métodos , Meios de Cultivo Condicionados/farmacologia , Relação Dose-Resposta a Droga , Interações Medicamentosas , Indução Enzimática , Imunofluorescência/métodos , Imunofilinas/farmacologia , Imunossupressores/farmacologia , Imunossupressores/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica/métodos , Modelos Moleculares , Fator de Crescimento Neural/farmacologia , Fator 6 de Transcrição de Octâmero , Análise de Sequência com Séries de Oligonucleotídeos/métodos , RNA Mensageiro/biossíntese , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Células de Schwann/fisiologia , Células de Schwann/ultraestrutura , Neuropatia Ciática/tratamento farmacológico , Tacrolimo/análogos & derivados , Tacrolimo/uso terapêutico , Proteínas de Ligação a Tacrolimo/química , Proteínas de Ligação a Tacrolimo/metabolismo , Fatores de Tempo , Fatores de Transcrição/metabolismo , Transfecção/métodos , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Triptofano/metabolismo
3.
Cancer Genet Cytogenet ; 129(2): 131-7, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11566343

RESUMO

To determine the pathogenic role of chromosomes 11 and 17 in the carcinogenesis of human ovarian cancers, neo(R)-tagged chromosome 11 or 17 was transferred from cell lines A9H11 or A9H17, respectively, into the ovarian carcinoma cell line SKOV-3 using microcell-mediated chromosome transfer. The chromosome transfer was verified by polymerase chain reaction detection of the neo(R) gene, fluorescence in situ hybridization detection of an extra chromosome 11, and microsatellite polymorphism detection of an exogeneous chromosome 11. Five SKOV-3/A9H11 hybrids and five SKOV-3/A9H17 hybrid clones were generated. For the chromosome 11 transfer, complete suppression of tumorigenicity was observed in four clones, (11)9-8 and 11(H)7-2, 11(H)8-3, and 11(H)7-2, 100 days post implantation. For the chromosome 17 transfer, no complete suppression of tumorigenicity was observed. However, an increased latency period ranging from 25 to 49 days in contrast to 7 days for the SKOV-3 parental line, and a significant reduction in tumor size was observed. There was no correlation between the in vitro growth rate and the tumorigenicity or length of latency period. Our results demonstrate functionally that chromosome 11 may carry a tumor suppressor gene(s) while chromosome 17 may carry a tumor growth-inhibitor gene(s) for the ovarian carcinoma cell line, SKOV-3.


Assuntos
Carcinoma/genética , Cromossomos Humanos Par 11/genética , Técnicas de Transferência de Genes , Genes Supressores de Tumor/genética , Neoplasias Ovarianas/genética , Animais , Divisão Celular/genética , Cromossomos Humanos Par 17/genética , Células Clonais , Progressão da Doença , Feminino , Marcadores Genéticos , Humanos , Hibridização in Situ Fluorescente , Camundongos , Camundongos SCID , Transplante de Neoplasias , Reação em Cadeia da Polimerase , Fatores de Tempo , Células Tumorais Cultivadas
4.
Cancer Genet Cytogenet ; 114(2): 136-43, 1999 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-10549271

RESUMO

Homogeneous staining region (hsr), a cytogenetic indicator of gene amplification, has been frequently found in ovarian carcinoma (ovc). To identify the origin of the hsr, chromosome microdissection combined with polymerase chain reaction and fluorescence in situ hybridization (FISH) was applied to two human ovarian cancer cell lines, GR and MLS/P. The hsr probes were labeled with biotin or digoxigenin and hybridized to normal metaphase spreads to elucidate the chromosomal origin and regional localization of the amplified genes. FISH to normal metaphase spreads with the probe generated from the whole hsr-bearing chromosome from GR hybridized to 8q24, 2p13-->2q11.2, 10pter-->10p15, 10p12-->10q11.2, 5q23-->5q31, and 5q33-->5qter. For MLS/P, the hsr-bearing marker chromosome hybridized to 8q and 15q. In both cases, detailed FISH analysis revealed enhanced signal intensity at the 8q24 locus, which coincides with the chromosomal location of the C-MYC oncogene. To verify the involvement of C-MYC in hsr formation, in situ hybridization with a probe specific for the C-MYC oncogene was conducted and confirmed the amplification of C-MYC as the origin of the hsr. The whole hsr-bearing chromosome for GR is designated as rev ish der(10) (10pter-->10p15::8q24hsr:: 10p12-->10q11.2::8q24::2q11.2-->2p13::2p13 -->2q11.2::8q24::10q11-->10p11.2:: 5q23-->5q31::5q33-->5qter (wcp10+,D10Z1++,wcp2+,D2Z++,wcp5+,wcp8+ ,C-MYC++/hsr). The hsr-bearing marker for MLS/P is designated as rev ish der(8)(qter-->8q24::8q24::8q24-->8q10:: 8q10-->8q24::8q24::8q24-->8qter:: 15q11-->15qter)(wcp8+, D8Z1+,wcp15+,C-MYC++. FISH with the probe generated from the hsr of GR also painted the hsr in MLS/P, indicating that the two hsrs have shared homology, which indicates that the amplification of 8q24/C-MYC as the origin of hsr may be a nonrandom genomic alteration in ovc.


Assuntos
Bandeamento Cromossômico , Amplificação de Genes/genética , Genes myc/genética , Hibridização in Situ Fluorescente , Neoplasias Ovarianas/genética , Cromossomos Humanos/genética , Sondas de DNA , Feminino , Marcadores Genéticos/genética , Humanos , Reação em Cadeia da Polimerase , Células Tumorais Cultivadas
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