RESUMO
BACKGROUND: The recently identified TMPRSS2: ERG fusion gene is a candidate oncogene for prostate cancer (PCa). SUBJECTS AND METHODS: We have tested for the presence of this gene in tumor samples from 84 patients who had radical prostatectomy in 1998-2000. Sixty patients (group A) had surgery only; 24 patients (group B) received androgen ablation therapy for 3 months before surgery. The occurrence of the rearrangement was evaluated by RT-PCR and by fluorescent in situ hybridization analysis. RESULTS: A TMPRSS2:ERG fusion gene was present and expressed, as demonstrated by RT-PCR, in 84% of patients in group A and in 54% of patients in group B (p=0.01). The presence of TMPRSS2:ERG transcripts and the levels of ERG RNA, measured by quantitative Real Time-PCR, did not correlate significantly with clinical and pathologic characteristics of the tumors. In patients of group A, but not in those of group B, ERG expression showed a negative correlation with the Gleason score (p=0.0001). Histochemical analysis showed that ERG expression is limited to tumor cells, and in group A patients (but not in group B patients) it is limited to those glands that express TMPRSS2:ERG. CONCLUSION: The lower proportion of patients expressing TMPRSS2: ERG in group B suggests that androgen ablation inhibits the expression of TMPRSS2:ERG. Moreover, in group B, but not in group A, patients with expression of the fusion gene had earlier prostate specific antigen recurrence (p=0.007). Although preliminary, the data indicate that tumors in which pre-surgery androgen ablation fails to suppress expression of the fusion gene have a higher risk of recurrence.
Assuntos
Antagonistas de Androgênios/uso terapêutico , Proteínas de Fusão Oncogênica/genética , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/genética , Neoplasias da Próstata/prevenção & controle , Neoplasias da Próstata/terapia , Técnicas de Ablação , Idoso , Animais , Fusão Gênica , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Proteínas de Fusão Oncogênica/metabolismo , Prostatectomia , Neoplasias da Próstata/sangue , Recidiva , Resultado do TratamentoRESUMO
Thyroid hormone plays an important role on myocardial development and function. The local effects of thyroid hormone are mediated by the receptor isoforms ultimately driving the expression of cardiac-specific genes. Although overt and subclinical thyroid dysfunction causes well-known changes in the cardiovascular system, little is known about local thyroid hormone action in normal and failing human myocardium. With a newly developed multiplex competitive RT-PCR method, we evaluated the expression of thyroid hormone receptor (TR) isoforms alpha-1, alpha-2, and beta-1 in normal human hearts and in end-stage congestive heart failure. A statistically significant difference in the expression of all three TR isoforms was observed among samples from normal subjects, ischemic heart disease (IHD), and dilated cardiomyopathy (DCM). In DCM, compared with normal, the studied TR isoforms were significantly increased. In IHD, the increased expression was found significant only for alpha-1 and alpha-2 isoforms. No differences were observed between the pathologic groups. In conclusion, a coordinated increment in the expression of the TR isoforms was observed in both DCM and IHD by multiplex competitive RT-PCR. The observed changes could represent a compensatory mechanism to myocardial failure or to locally altered thyroid hormone action.
Assuntos
Insuficiência Cardíaca/metabolismo , Miocárdio/metabolismo , Receptores dos Hormônios Tireóideos/genética , Adulto , Idoso , Western Blotting , Feminino , Regulação da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Isoformas de Proteínas/genética , Receptores dos Hormônios Tireóideos/análise , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
OBJECTIVE: The selenoenzyme type 2 iodothyronine 5' deiodinase (DII) catalyzes the conversion of thyroxine into its active form tri-iodothyronine (T3), modulating thyroid hormone homeostasis in a local, tissue-specific manner. The amphibian, rodent and human cDNAs encoding this enzyme have been recently cloned and expressed. At present, little information regarding the genomic structure of mammalian DII is available. DESIGN AND METHODS: The complete structure, including intron-exon junctions, of the human DII (hDII) gene was obtained by long PCR and rapid amplification of cDNA ends (RACE). Chromosomal assignment of the hDII gene was performed by fluorescence in situ hybridization using a highly specific probe. RESULTS AND CONCLUSIONS: Our data demonstrated that hDII is a single copy gene located on chromosome 14, position 14q24.3. The gene spans over 15 kb, and the 7 kb transcript is encoded by three exons of 149 bp, 273 bp and 6.6 kb separated respectively by two 274 bp and 7.4 kb introns. A restriction map of the hDII gene is also reported. These data will help in further studies of the role of DII in the maintenance of peripheral thyroid hormone homeostasis.
Assuntos
Mapeamento Cromossômico , DNA Complementar/química , Iodeto Peroxidase/genética , Processamento Alternativo , Sequência de Bases , Cromossomos Humanos Par 14 , Éxons , Humanos , Hibridização in Situ Fluorescente , Íntrons , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , Mapeamento por Restrição , Homologia de SequênciaAssuntos
Poli A , RNA Mensageiro/análise , RNA/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ligação Competitiva , Biópsia por Agulha , RNA Polimerases Dirigidas por DNA/metabolismo , Humanos , Miocárdio/química , Plasmídeos/genética , RNA/química , Receptores dos Hormônios Tireóideos/genética , Sensibilidade e Especificidade , Proteínas ViraisRESUMO
Prostate cancer, the most frequent non-cutaneous malignancy in men from industrialized countries, is a growing medical problem, representing the second leading cause of male cancer deaths. In the last decade, converging evidence from epidemiological and biological studies suggests that the Insulin-like Growth Factor (IGF) axis is involved in the tumorigenesis and neoplastic growth of prostate cancer. Epidemiological observations indicated that circulating IGF-I levels are positively associated with the increased risk of prostate cancer. The activation of type I IGF receptor (IGF-IR) by IGF-I and/or IGF-II, has mitogenic and antiapoptotic effects on normal and malignant prostate cells. Altered expression of IGF axis components has also been reported in vitro and in animal models of prostate cancer, as well as in human prostate cancer tissue samples. In this review we address and analyze epidemiological studies, in vitro and in vivo cancer models, and human ex vivo prostate cancer researches performed to date supporting the role of IGF axis in prostate cancer.
Assuntos
Neoplasias da Próstata , Somatomedinas/metabolismo , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Valor Preditivo dos Testes , Neoplasias da Próstata/epidemiologia , Neoplasias da Próstata/etiologia , Neoplasias da Próstata/metabolismo , Risco , Somatomedinas/análise , Somatomedinas/genéticaRESUMO
Anatomy studies normally precede physiology. While the anatomy of the penis and the biochemical and molecular regulation of erection are largely known, the exact anatomical description of the human clitoris was produced in 1998, the taxonomy of female sexual dysfunctions classified in 1999, and biochemistry of female excitation described only in 2002. There are various reasons for this. Female sexual physiology is much more complex than that of the male, and cultural and religious considerations have discouraged the scientific study of female sexuality. However, it is now apparent that modern sexology cannot be truly 'medical' if female sexual anatomy and the physiology of female sexual response are unknown.