RESUMO
Previously regarded as a rare neoplasm, the incidence of esophageal adenocarcinoma has risen rapidly in recent decades. It is often discovered late in the disease process and has a dismal prognosis. Current prognostic markers including clinical, radiographic, and histopathologic findings have limited utility and do not consider the biology of this deadly disease. Genome-wide analyses have identified SMAD4 inactivation in a subset of tumors. Although Smad4 has been extensively studied in other gastrointestinal malignancies, its role in esophageal adenocarcinoma remains to be defined. Herein, we show, in a large cohort of esophageal adenocarcinomas, Smad4 loss by immunohistochemistry in 21 of 205 (10%) tumors and that Smad4 loss correlated with increased postoperative recurrence (P=0.040). Further, patients whose tumors lacked Smad4 had shorter time to recurrence (TTR) (P=0.007) and poor overall survival (OS) (P=0.011). The median TTR and OS of patients with Smad4-negative tumors was 13 and 16 months, respectively, as compared with 23 and 22 months, respectively, among patients with Smad4-positive tumors. In multivariate analyses, Smad4 loss was a prognostic factor for both TTR and OS, independent of histologic grade, lymphovascular invasion, perineural invasion, tumor stage, and lymph node status. Considering Smad4 loss correlated with postoperative locoregional and/or distant metastases, Smad4 was also assessed in a separate cohort of 5 locoregional recurrences and 43 metastatic esophageal adenocarcinomas. In contrast to primary tumors, a higher prevalence of Smad4 loss was observed in metastatic disease (44% vs. 10%). In summary, loss of Smad4 protein expression is an independent prognostic factor for TTR and OS that correlates with increased propensity for disease recurrence and poor survival in patients with esophageal adenocarcinoma after surgical resection.
Assuntos
Adenocarcinoma/química , Biomarcadores Tumorais/análise , Neoplasias Esofágicas/química , Recidiva Local de Neoplasia , Proteína Smad4/análise , Adenocarcinoma/mortalidade , Adenocarcinoma/secundário , Adenocarcinoma/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Intervalo Livre de Doença , Regulação para Baixo , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/cirurgia , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Análise Serial de Tecidos , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Nodal is a growth factor of the transforming growth factor ß superfamily that is expressed in high turnover tissues, such as the human endometrium, and in several malignancies. The effects of Nodal are modulated by the coreceptor Cripto and mediated by SMAD proteins. This study evaluated the gene and protein expression of Nodal, Cripto, total and phosphorylated (p) SMAD3, and SMAD4 in the proliferative endometrium of women with and without endometriosis. METHOD: Total RNA was isolated and complementary DNA synthesized from eutopic endometrium of women with (n = 15) and without (n = 12) endometriosis, followed by quantitative real-time polymerase chain reaction (PCR) to evaluate the gene expression of Nodal, Cripto, SMAD3, and SMAD4. Western blot was used to evaluate the protein levels of Nodal and Cripto, and immunohistochemistry was performed to localize SMAD3, pSMAD3, and SMAD4. RESULTS: Although Nodal expression was unchanged in women with endometriosis, real-time PCR indicated lower gene expression of Cripto (fold change 0.27, P < .05) in the endometriosis group. This difference, however, was not maintained at protein expression level as assessed by Western blot. The immunostaining of total SMAD3 was reduced in the endometriosis group (P < .01), but the localization of pSMAD3 and the nuclear staining of SMAD4 were unchanged. CONCLUSION: These findings suggest that the Nodal signaling pathway has subtle changes in the endometrium of women with endometriosis, but this imbalance may not cause functional damage as it seems not to affect the nuclear expression of SMAD4.
Assuntos
Proliferação de Células , Endometriose/metabolismo , Endométrio/química , Proteínas Ligadas por GPI/análise , Peptídeos e Proteínas de Sinalização Intercelular/análise , Proteínas de Neoplasias/análise , Proteína Nodal/análise , Proteína Smad3/análise , Proteína Smad4/análise , Adulto , Western Blotting , Estudos de Casos e Controles , Endometriose/diagnóstico , Endometriose/genética , Endométrio/patologia , Feminino , Proteínas Ligadas por GPI/genética , Regulação da Expressão Gênica , Humanos , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteínas de Neoplasias/genética , Proteína Nodal/genética , Fosforilação , RNA Mensageiro/análise , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais , Proteína Smad3/genética , Proteína Smad4/genética , Adulto JovemRESUMO
INTRODUCTION: During root formation, Smad-4 plays a key role during the epithelial-mesenchymal interactions and the Hertwig's epithelial root sheath (HERS) apical proliferation. The root formation and eruption of rat molars is impeded by alendronate treatment due to the inhibition of bone resortion by this drug. The present study aimed to examine the structures affected in the developing root and immunodetect the presence of Smad-4 in rats treated with alendronate. METHODS: Newborn Wistar rats were daily injected 2.5 mg/kg alendronate (ALN) during 9, 12 and 30 days. The controls (CON) were injected with saline. The maxillae were fixed and embedded in paraffin or Spurr resin. Paraffin sections were incubated in Smad-4 antibody that was labelled with DAB. The ultrathin sections were examined in a transmission electron microscope. RESULTS: In ALN, a short portion of root dentine was formed; the epithelial diaphragm (ED) and the dental follicle (DF) were disorganized by the contact of bone trabeculae. The (CON) molar roots developed normally. Smad-4 labelling was detected in the cytoplasm of fibroblasts and cementoblasts adjacent to the cementum in CON; in ALN group, few ED cells presented weak immunolabelling. Ultrastructurally, the ED and DF appeared disrupted due to the presence of thin bone trabeculae between its cells. It resulted in the lack of apical proliferation of HERS and, consequently, arrest of root formation. CONCLUSION: The immunodetection of Smad-4 in the DF cells of ALN specimens indicates that the signalling for the differentiation of these cells into cementum-forming fibroblasts and cementoblasts occurs, despite the impairment of root elongation.
Assuntos
Alendronato/efeitos adversos , Reabsorção Óssea/etiologia , Cementogênese/efeitos dos fármacos , Cemento Dentário/efeitos dos fármacos , Dente Molar/efeitos dos fármacos , Proteína Smad4/análise , Raiz Dentária/efeitos dos fármacos , Animais , Proteínas Morfogenéticas Ósseas/efeitos dos fármacos , Proteínas Morfogenéticas Ósseas/metabolismo , Diferenciação Celular/efeitos dos fármacos , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Microscopia Eletrônica , Dente Molar/citologia , Dente Molar/crescimento & desenvolvimento , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Proteína Smad4/imunologia , Raiz Dentária/citologia , Raiz Dentária/crescimento & desenvolvimento , Fator de Crescimento Transformador beta1/efeitos dos fármacos , Fator de Crescimento Transformador beta1/metabolismoRESUMO
OBJECTIVE: To investigate the expression of SMAD proteins in human thyroid tissues since the inactivation of TGF-beta/activin signaling components is reported in several types of cancer. Phosphorylated SMAD 2 and SMAD3 (pSMAD2/3) associated with the SMAD4 induce the signal transduction generated by TGF-beta and activin, while SMAD7 inhibits this intracellular signaling. Although TGF-beta and activin exert antiproliferative roles in thyroid follicular cells, thyroid tumors express high levels of these proteins. MATERIALS AND METHODS: The protein expression of SMADs was evaluated in multinodular goiter, follicular adenoma, papillary and follicular carcinomas by immunohistochemistry. RESULTS: The expression of pSMAD2/3, SMAD4 and SMAD7 was observed in both benign and malignant thyroid tumors. Although pSMAD2/3, SMAD4 and SMAD7 exhibited high cytoplasmic staining in carcinomas, the nuclear staining of pSMAD2/3 was not different between benign and malignant lesions. CONCLUSIONS: The finding of SMADs expression in thyroid cells and the presence of pSMAD2/3 and SMAD4 proteins in the nucleus of tumor cells indicates propagation of TGF-beta/activin signaling. However, the high expression of the inhibitory SMAD7, mostly in malignant tumors, could contribute to the attenuation of the SMADs antiproliferative signaling in thyroid carcinomas.
Assuntos
Ativinas/fisiologia , Proteínas Smad Reguladas por Receptor/metabolismo , Neoplasias da Glândula Tireoide/metabolismo , Fator de Crescimento Transformador beta/fisiologia , Adenoma/metabolismo , Carcinoma Papilar, Variante Folicular/metabolismo , Bócio Nodular/metabolismo , Humanos , Transdução de Sinais/fisiologia , Proteína Smad2/análise , Proteína Smad3/análise , Proteína Smad4/análise , Proteína Smad7/análiseRESUMO
BACKGROUND/AIMS: CCN2 is present during tooth development. However, the relationship between CCN2 and the transforming growth factor beta (TGFbeta)/SMAD2/3 signaling cascade during early stages of tooth development is unclear. Here, we compare the expression of CCN2 and TGFbeta/SMAD2/3 components during tooth development, and analyze the functioning of TGFbeta/SMAD2/3 in wild-type (WT) and Ccn2 null (Ccn2-/-) mice. METHODS: Coronal sections of mice on embryonic day (E)11.5, E12.5, E13.5, E14.5 and E18.5 from WT and Ccn2-/- were immunoreacted to detect CCN2 and components of the TGFbeta signaling pathway and assayed for 5'-bromo-2'-deoxyuridine immunolabeling and proliferating cell nuclear antigen immunostaining. RESULTS: CCN2 and TGFbeta signaling components such as TGFbeta1, TGFbeta receptor II, SMADs2/3 and SMAD4 were expressed in inducer tissues during early stages of tooth development. Proliferation analysis in these areas showed that epithelial cells proliferate less than mesenchymal cells from E11.5 to E13.5, while at E14.5 they proliferate more than mesenchymal cells. We did not find a correlation between functioning of the TGFbeta1 cascade and CCN2 expression because Ccn2-/- mice showed neither a reduction in SMAD2 phosphorylation nor a difference in cell proliferation. CONCLUSION: CCN2 and the TGFbeta/SMAD2/3 signaling pathway are active in signaling centers of tooth development where proliferation is dynamic, but these mechanisms may act independently.