RESUMEN

This study investigated the proteome modulated by oncogenic KRAS in immortalized airway epithelial cells. Chloride intracellular channel protein 4 (CLIC4), S100 proteins (S100A2 and S100A11), tropomyosin 2, cathepsin L1, integrinsα3, eukaryotic elongation factor 1, vimentin, and others were discriminated. We here focused on CLIC4 to investigate its potential involvement in carcinogenesis in the lung because previous studies suggested that some chloride channels and chloride channel regulators could function as tumor suppressors. CILC4 protein levels were reduced in some lung cancer cell lines. The restoration of CLIC4 in lung cancer cell lines in which CLIC4 expression was reduced attenuated their growth activity. The immunohistochemical expression of the CLIC4 protein was weaker in primary lung cancer cells than in non-tumorous airway epithelial cells and was occasionally undetectable in some tumors. CLIC4 protein levels were significantly lower in a subtype of mucinous ADC than in others, and were also significantly lower in KRAS-mutated ADC than in EGFR-mutated ADC. These results suggest that the alteration in CLIC4 could be involved in restrictedly the development of a specific fraction of lung adenocarcinomas. The potential benefit of the proteome modulated by oncogenic KRAS to lung cancer research has been demonstrated.

Asunto(s)

Carcinogénesis/metabolismo , Canales de Cloruro/metabolismo , Neoplasias Pulmonares/metabolismo , Proteoma/metabolismo , Proteómica , Proteínas Proto-Oncogénicas/genética , Proteínas ras/genética , Carcinogénesis/patología , Extractos Celulares , Línea Celular Tumoral , Supervivencia sin Enfermedad , Humanos , Neoplasias Pulmonares/patología , MicroARNs/metabolismo , Proteínas Proto-Oncogénicas p21(ras) , ARN Interferente Pequeño/metabolismo , Transducción Genética

RESUMEN

Settlement of larvae of Crassostrea gigas on shell chips (SC) prepared from shells of 11 different species of mollusks was investigated. Furthermore, the settlement inducing compound in the shell of C. gigas was extracted and subjected to various treatments to characterize the chemical cue. C. gigas larvae settled on SC of all species tested except on Patinopecten yessoensis and Atrina pinnata. In SC of species that induced C. gigas larvae to settle, settlement was proportionate to the amount of SC supplied to the larvae. When compared to C. gigas SC, all species except Crassostrea nippona showed lower settlement inducing activities, suggesting that the cue may be more abundant or in a more available form to the larvae in shells of conspecific and C. nippona than in other species. The settlement inducing activity of C. gigas SC remained intact after antibiotic treatment. Extraction of C. gigas SC with diethyl ether (Et2O-ex), ethanol (EtOH-ex), and water (Aq-ex) did not induce larval settlement of C. gigas larvae. However, extraction of C. gigas SC with 2N of hydrochloric acid (HCl-ex) induced larval settlement that was at the same level as the SC. The settlement inducing compound in the HCl-ex was stable at 100°C but was destroyed or degraded after pepsin, trypsin, PNGase F and trifluoromethanesulfonic acid treatments. This chemical cue eluted between the molecular mass range of 45 and 150 kDa after gel filtration and revealed a major band at 55 kDa on the SDS-PAGE gel after staining with Stains-all. Thus, a 55 kDa glycoprotein component in the organic matrix of C. gigas shells is hypothesized to be the chemical basis of larval settlement on conspecifics.

Asunto(s)

Crassostrea/efectos de los fármacos , Crassostrea/fisiología , Glicoproteínas/farmacología , Análisis de Varianza , Exoesqueleto , Animales , Antibacterianos/farmacología , Cromatografía en Gel , Electroforesis en Gel de Poliacrilamida , Etanol/farmacología , Éter/farmacología , Liofilización , Calor , Ácido Clorhídrico/farmacología , Larva/efectos de los fármacos , Larva/fisiología , Océano Pacífico , Pepsina A/farmacología , Soluciones , Especificidad de la Especie , Temperatura , Tripsina/farmacología

RESUMEN

The metamorphic response of pediveliger larvae of Mytilus galloprovincialis to the neurotransmitter blockers chlorpromazine, amitriptyline, rauwolscine, idazoxan, atenolol and butoxamine, and to tetraethylammonium chloride (TEA) was investigated through a series of bioassays. Chlorpromazine, amitriptyline and idazoxin inhibited larval metamorphosis induced by 10⁻4 M epinephrine. The concentration that inhibited metamorphosis by 50% (IC50) for chlorpromazine and amitriptyline was 1.6 x 10⁻6 M and 6.6 x 10⁻5 M, respectively. Idazoxan was less effective with an IC50 of 4.4 x 10¹³ M. Moreover, these three inhibitors showed no toxicity at any of the concentrations tested. The larval metamorphic response to K+ was not inhibited by 10⁻³ M tetraethylammonium chloride after 96 h. Thus, the neurotransmitter blockers chlorpromazine and amitriptyline are inhibitors of larval metamorphosis, and will be useful tools for antifouling studies.

Asunto(s)

Incrustaciones Biológicas/prevención & control , Metamorfosis Biológica/efectos de los fármacos , Mytilus/efectos de los fármacos , Inhibidores de la Captación de Neurotransmisores/farmacología , Tetraetilamonio/farmacología , Animales , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Larva/metabolismo , Mytilus/crecimiento & desarrollo , Mytilus/metabolismo

RESUMEN

Gene silencing by promoter hypermethylation plays an important role in molecular pathogenesis. We previously reported that insulin-like growth factor (IGF) binding protein-4 (IGFBP-4), which inhibits IGF-dependent growth, is expressed via early growth response-1 (EGR-1) and is often silenced in cultivated lung cancer cells. The purpose of the present study was to clarify clinicopathological factors associated with IGFBP-4 gene silencing in lung adenocarcinomas. Seventy-six surgically resected adenocarcinomas (20 well-, 35 moderately-, and 21 poorly-differentiated) were subjected to methylation-specific polymerase chain reaction (PCR) analysis for EGR-1-binding sites located in the IGFBP-4 promoter and immunohistochemistry for IGFBP-4, EGR-1, and Ki-67. Thirty-two adenocarcinomas (42%) revealed IGFBP-4 promoter hypermethylation, and the severity inversely correlated with the level of IGFBP-4 expression (P < 0.0001) and tumor differentiation (well versus poor, P = 0.0278; well/moderate versus poor, P = 0.0395). Furthermore, there was a negative correlation between Ki-67 labeling index and IGFBP-4 expression (P = 0.0361). These findings suggest that the expression of IGFBP-4 in adenocarcinoma cells in vivo is downregulated by epigenetic silencing in association with tumor differentiation, resulting in disruption of the mechanism of IGFBP-4-mediated growth inhibition.

Asunto(s)

Adenocarcinoma/genética , Silenciador del Gen , Proteína 4 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Neoplasias Pulmonares/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Sitios de Unión , Metilación de ADN , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Humanos , Inmunohistoquímica , Proteína 4 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Antígeno Ki-67/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas

RESUMEN

Lung cancer, like other cancers, is considered to develop through the accumulation of genetic alterations. Mutation of the KRAS gene is one of the most important events in carcinogenesis of the lung. The KRAS gene, belonging to the RAS gene family, encodes a membrane-bound 21-kd guanosine triphosphate (GTP)-binding protein. Single point mutations in this protein result in continuous activation to transmit excessive signals, promoting a variety of biological events. In lung cancers, the mutations concentrate at codon 12 and mostly affect adenocarcinomas (ADCs). They also affect atypical adenomatous hyperplasia, the precursor of ADCs. Therefore, mutation of the KRAS gene is suggested to confer a growth advantage to airway epithelial cells enabling them to expand clonally early in the development of ADCs. The mutation is also a reliable marker of an unfavorable response to certain molecular-targeting therapies. Furthermore, patients with ADCs affected by mutations have been reported to exhibit a significantly higher risk of postoperative disease recurrence. Thus, the significance of KRAS gene mutations has been investigated extensively. However, not all the details emerged. In this review, particulars that have been established are introduced, and important issues remaining to be resolved are discussed, with special reference to carcinogenesis of the lung.

Asunto(s)

Carcinoma/genética , Neoplasias Pulmonares/genética , Proteínas Proto-Oncogénicas/genética , Proteínas ras/genética , Carcinoma/patología , Humanos , Neoplasias Pulmonares/patología , Mutación , Estadificación de Neoplasias , Proteínas Proto-Oncogénicas p21(ras)

RESUMEN

Vascular endothelial growth factor-A (VEGF-A) is crucial for angiogenesis, vascular permeability, and metastasis during tumor development. We demonstrate here that early growth response-1 (EGR-1), which is induced by the extracellular signal-regulated kinase (ERK) pathway activation, activates VEGF-A in lung cancer cells. Increased EGR-1 expression was found in adenocarcinoma cells carrying mutant K-RAS or EGFR genes. Hypoxic culture, siRNA experiment, luciferase assays, chromatin immunoprecipitation, electrophoretic mobility shift assays, and quantitative RT-PCR using EGR-1-inducible lung cancer cells demonstrated that EGR-1 binds to the proximal region of the VEGF-A promoter, activates VEGF-A expression, and enhances hypoxia inducible factor 1alpha (HIF-1alpha)-mediated VEGF-A expression. The EGR-1 modulator, NAB-2, was rapidly induced by increased levels of EGR-1. Pathology samples of human lung adenocarcinomas revealed correlations between EGR-1/HIF-1alpha and VEGF-A expressions and relative elevation of EGR-1 and VEGF-A expression in mutant K-RAS- or EGFR-carrying adenocarcinomas. Both EGR-1 and VEGF-A expression increased as tumors dedifferentiated, whereas HIF-1alpha expression did not. Although weak correlation was found between EGR-1 and NAB-2 expressions on the whole, NAB-2 expression decreased as tumors dedifferentiated, and inhibition of DNA methyltransferase/histone deacetylase increased NAB-2 expression in lung cancer cells despite no epigenetic alteration in the NAB-2 promoter. These findings suggest that EGR-1 plays important roles on VEGF-A expression in lung cancer cells, and epigenetic silencing of transactivator(s) associated with NAB-2 expression might also contribute to upregulate VEGF-A expression.

Asunto(s)

Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Neoplasias Pulmonares/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Animales , Azacitidina/análogos & derivados , Azacitidina/farmacología , Línea Celular Tumoral/efectos de los fármacos , Línea Celular Tumoral/metabolismo , Decitabina , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Inhibidores Enzimáticos/farmacología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Regulación Neoplásica de la Expresión Génica , Genes ras , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Regiones Promotoras Genéticas , Interferencia de ARN , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética

RESUMEN

We have established a concise sub-typing system suitable for predicting the postoperative outcome in cases of stage I lung adenocarcinoma (ADC), using morphometric profiling. The association between postoperative disease recurrence and a variety of morphological features including histological architecture, cell type, cytoplasmic color/internal structure, nuclear shape/size, chromatin pattern, and nucleoli count/remarkableness, was analyzed. Histological architecture had the most prognostic value and could be subdivided into low-grade (bronchioloalveolar, papillary and tubular: "tubular" in this paper is defined as a tubular or glandular structure lined with single-layered neoplastic cells) and high-grade (acinar and solid: "acinar" is defined as a tubular or glandular structure lined with poly-layered neoplastic cells or as a fused glandular structure such as the cribriform pattern) components. The subgroups separated based on a cut-off value, 71.5% of the high-grade component comprised by a tumor, which was calculated according to a relative operating characteristic curve, exhibited a significant difference in disease recurrence [estimated 5-year disease-free survival rate, 95.3% in the low-grade group versus 66.7% in the high-grade group, hazard ratio 7.35, Log-rank test p = 0.002]. The sub-grouping system is concise and suitable for practical use. It will improve the histological classification of ADC.

Asunto(s)

Adenocarcinoma/clasificación , Adenocarcinoma/patología , Neoplasias Pulmonares/clasificación , Neoplasias Pulmonares/patología , Adenocarcinoma/mortalidad , Supervivencia sin Enfermedad , Humanos , Inmunohistoquímica , Estimación de Kaplan-Meier , Neoplasias Pulmonares/mortalidad , Estadificación de Neoplasias , Pronóstico

RESUMEN

The traditional histologic classification of lung cancer is not satisfactory to describe the morphologic characteristics of individual tumors, because it does not fully cover cytologic features. This paper describes a novel typing system using morphometric profiling that covers a variety of morphologic features including histologic architecture, cell type, cytoplasmic color and internal structure, nuclear outline, chromatin pattern, nucleoli count and remarkableness, and average and deviation of nuclear size and circularity. In all, 201 cases of lung tumors (whose sizes are <20 mm) were examined. Results of a hierarchical clustering analysis were used to draw a dendrogram. We here tentatively focused on 8 morphometric clusters and analyzed their potential association with a variety of clinicopathologic and molecular genetic features. Significant differences in postoperative recurrent risk, growth activity, oncogenic mutation (EGFR or KRAS), impairments of tumor suppressors (p53 and p16), sex predisposition, and smoking status were found among the 8 clusters. The system has the potential to improve histopathologic diagnosis and our understanding of carcinogenesis in the lung.

Asunto(s)

Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Células Pequeñas/genética , Carcinoma de Células Pequeñas/patología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Biomarcadores de Tumor/análisis , Carcinoma de Pulmón de Células no Pequeñas/clasificación , Carcinoma de Células Pequeñas/clasificación , Nucléolo Celular/patología , Núcleo Celular/patología , Citoplasma/patología , Análisis Mutacional de ADN , ADN de Neoplasias/análisis , Femenino , Humanos , Técnicas para Inmunoenzimas , Neoplasias Pulmonares/clasificación , Masculino , Recurrencia Local de Neoplasia , Estadificación de Neoplasias

RESUMEN

We present a case of a polypoid tumor located in the right middle lobe bronchus. The tumor was composed of bi-layered glandular or ductular structures consisting of inner cuboidal cells and outer multipolar cells. Immunohistochemical examinations confirmed epithelial and myoepithelial differentiation in the inner and outer components, respectively. Consequently, the tumor was diagnosed as an epithelial-myoepithelial carcinoma. Epithelial-myoepithelial carcinomas of the bronchus are very rare neoplasms with low-grade malignant potential. To date, including our case, only 27 cases have been reported in the English literature. Here, we review the reported cases and compare them with other salivary gland-type carcinomas regarding clinical, biological, and genetic features.

Asunto(s)

Neoplasias de los Bronquios/patología , Carcinoma/patología , Neoplasias de los Bronquios/genética , Neoplasias de los Bronquios/metabolismo , Carcinoma/genética , Carcinoma/metabolismo , Análisis Mutacional de ADN , Receptores ErbB/genética , Femenino , Humanos , Inmunohistoquímica , Rayos Láser , Microdisección , Persona de Mediana Edad , Mutación , Neumonectomía , Reacción en Cadena de la Polimerasa , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas p21(ras) , Proteínas ras/genética

RESUMEN

CD133 is one of the most representative cancer stem cell markers. This study evaluated the potential prognostic value of CD133 expression in stage I lung adenocarcinomas (ADC). Tumors from 177 patients were immunohistochemically examined for CD133 expression, and their associations with disease recurrence were analyzed. Also, the potential prognostic value of combining CD133 expression with proliferating activity measured by immunohistochemical expression of Ki-67 and vessel involvement was evaluated. CD133 high expressers showed a significantly higher risk of recurrence than CD133 low expressers: 5-year disease-free survival (DFS) rate 77.2% vs. 95.1% (p=0.004), adjusted Hazard ratio (HR) 4.37, 95% Confidence Interval (CI) 1.30-14.71 (p=0.017). CD133 high expressers having strong proliferating activity and/or with vessel invasion showed a higher risk of recurrence: 5-year DFS rate 66.5% in CD133 high/Ki-67 high expressers vs. 93.2% in the other types (p<0.001), adjusted HR 8.39, 95% CI 2.65-26.54 (p<0.001): 5-year DFS rate 51.0% in CD133 high expressers with vessel invasion vs. 92.9% in the other types (p<0.001), adjusted HR 4.50, 95% CI 1.51-13.34 (p=0.007): 5-year DFS rate 53.9% in CD133 high/Ki-67 high expressers with vessel invasion vs. 91.2% in the other types (p<0.001), adjusted HR 9.32, 95% CI 3.42-25.39 (p<0.001). In conclusion, the level of CD133 expression is an independent prognostic marker and its combination with proliferating activity and/or vessel invasion could have excellent prognostic value to predict postoperative recurrence in patients with stage I lung ADC.

Asunto(s)

Adenocarcinoma/metabolismo , Antígenos CD/metabolismo , Glicoproteínas/metabolismo , Neoplasias Pulmonares/metabolismo , Péptidos/metabolismo , Antígeno AC133 , Adenocarcinoma/mortalidad , Adenocarcinoma/patología , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/metabolismo , Proliferación Celular , Supervivencia sin Enfermedad , Femenino , Humanos , Antígeno Ki-67/metabolismo , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Recurrencia Local de Neoplasia , Estadificación de Neoplasias , Pronóstico , Tasa de Supervivencia

RESUMEN

Bronchioloalveolar carcinoma (BAC) arising in the peripheral lung is the prototype of human lung adenocar-cinoma and is considered to develop, at least in part, from its precursor atypical adenomatous hyperplasia (AAH). Molecular genetics investigations have revealed the significant roles of mutations in KRAS and epidermal growth factor receptor (EGFR) genes in the pathogenesis of AAH and BAC. Recently, selective molecular targeting therapies, such as those using EGFR tyrosine kinase inhibitors, have been introduced with remarkable success. In spite of the accumulation of research results into BAC/AAH, there remain three important issues to be addressed; 1) the etiology of BAC and AAH, 2) the genetic and/or epigenetic alteration(s) responsible for the progression of AAH to BAC, 3) the genetic backgrounds speculated as the cause of multiple AAH/BAC. These three issues are briefly reviewed and discussed, along with the murine pulmonary carcinogenesis model which is potentially useful for solving these issues.

Asunto(s)

Adenocarcinoma Bronquioloalveolar/patología , Neoplasias Pulmonares/patología , Adenocarcinoma Bronquioloalveolar/genética , Adenoma/genética , Adenoma/patología , Animales , Modelos Animales de Enfermedad , Receptores ErbB/genética , Hiperplasia/genética , Hiperplasia/patología , Neoplasias Pulmonares/genética , Ratones , Mutación , Lesiones Precancerosas/genética , Lesiones Precancerosas/patología , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas p21(ras) , Proteínas ras/genética

RESUMEN

FXYD3 is a FXYD-containing Na,K-ATPase ion channel regulator first identified as a protein overexpressed in murine breast tumors initiated by oncogenic ras or neu. However, our preliminary study revealed that FXYD3 expression was down-regulated in oncogenic KRAS-transduced airway epithelial cells. This contradiction led us to investigate the role of FXYD3 in carcinogenesis of the lung. FXYD3 mRNA and protein levels were lower in most of the lung cancer cell lines than in either the noncancerous lung tissue or airway epithelial cells. Protein levels were also lower in a considerable proportion of primary lung cancers than in nontumoral airway epithelia; FXYD3 expression levels decreased in parallel with the dedifferentiation process. Also, a somatic point mutation, g55c (D19H), was found in one cell line. Forced expression of the wild-type FXYD3, but not the mutant, restored the well-demarcated distribution of cortical actin in cancer cells that had lost FXYD3 expression, suggesting FXYD3 plays a role in the maintenance of cytoskeletal integrity. However, no association between FXYD3 expression and its promoter's methylation status was observed. Therefore, inactivation of FXYD3 through a gene mutation or unknown mechanism could be one cause of the atypical shapes of cancer cells and play a potential role in the progression of lung cancer.

Asunto(s)

Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Proteínas de la Membrana/biosíntesis , Proteínas de la Membrana/genética , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/genética , Secuencia de Aminoácidos , Western Blotting , Línea Celular Tumoral , Metilación de ADN/genética , Análisis Mutacional de ADN , Regulación hacia Abajo , Expresión Génica , Silenciador del Gen , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/patología , Datos de Secuencia Molecular , Regiones Promotoras Genéticas/genética , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa

RESUMEN

The cancer stem cell (CSC) theory is currently central to the field of cancer research, because it is not only a matter of academic interest but also crucial in cancer therapy. CSCs share a variety of biological properties with normal somatic stem cells in terms of self-renewal, the propagation of differentiated progeny, the expression of specific cell markers and stem cell genes, and the utilization of common signaling pathways and the stem cell niche. However, CSCs differ from normal stem cells in their tumorigenic activity. Thus, CSCs are also termed cancer initiating cells. In this paper, we briefly review hitherto described study results and refer to some excellent review articles to understand the basic properties of CSCs. In addition, we focus upon CSCs of lung cancers, since lung cancer is still increasing in incidence worldwide and remains the leading cause of cancer deaths. Understanding the properties of, and exploring cell markers and signaling pathways specific to, CSCs of lung cancers, will lead to progress in therapy, intervention, and improvement of the prognosis of patients with lung cancer. In the near future, the evaluation of CSCs may be a routine part of practical diagnostic pathology.

Asunto(s)

Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/terapia , Células Madre Neoplásicas , Carcinoma Pulmonar de Células Pequeñas/patología , Animales , Antígenos de Diferenciación/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/terapia , Diagnóstico Diferencial , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/metabolismo , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Transducción de Señal , Carcinoma Pulmonar de Células Pequeñas/diagnóstico , Carcinoma Pulmonar de Células Pequeñas/metabolismo , Carcinoma Pulmonar de Células Pequeñas/terapia , Nicho de Células Madre

RESUMEN

Small cell lung cancer (SCLC) exhibits insulin-like growth factor-dependent growth. SCLC is the most aggressive among known in vivo lung cancers, whereas in vitro growth of SCLC is paradoxically slow as compared with that of non-SCLC (NSCLC). In this study, we demonstrate that SCLC cells overexpress insulin-like growth factor binding protein (IGFBP)-2 via NeuroD, a neuroendocrine cell-specific transcription factor. Chromatin immunoprecipitation, electrophoretic mobility shift, and IGFBP-2 promoter assays all revealed that NeuroD binds to the E-box in the 5'-untranslated region of IGFBP-2. A NeuroD transgene in both airway epithelial and NSCLC cells up-regulated the transcription of IGFBP-2 and retarded cell growth. Recombinant IGFBP-2 repressed the growth of both airway epithelial and NSCLC cells in a dose-dependent manner. A NeuroD-specific small interfering RNA repressed IGFBP-2 expression in SCLC, and neutralization of IGFBP-2 and an IGFBP-2-specific small interfering RNA increased SCLC cell growth. Pathological samples of SCLC also expressed IGFBP-2 abundantly, as compared with NSCLC, and showed only rare (8%) IGFBP-2 promoter methylation, whereas the IGFBP-2 promoter was methylated in 71% of adenocarcinomas and 29% of squamous cell carcinomas. These findings suggest that 1) SCLC has an IGFBP-2 overexpression mechanism distinct from NSCLC, 2) secreted IGFBP-2 contributes to the slow growth of SCLC in vitro, and 3) the epigenetic alterations in the IGFBP-2 promoter contribute to the striking differences in IGFBP-2 expression between SCLC and NSCLC in vivo.

Asunto(s)

Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Proteína 2 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Carcinoma Pulmonar de Células Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular Transformada , Línea Celular Tumoral , Metilación de ADN , ADN de Neoplasias/metabolismo , Células Epiteliales/metabolismo , Células Epiteliales/patología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Proteína 2 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Proteína 2 de Unión a Factor de Crecimiento Similar a la Insulina/farmacología , Pulmón/metabolismo , Pulmón/patología , Neoplasias Pulmonares/patología , Sistemas Neurosecretores/metabolismo , Sistemas Neurosecretores/patología , Regiones Promotoras Genéticas , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacología , Carcinoma Pulmonar de Células Pequeñas/patología , Transfección , Regulación hacia Arriba

RESUMEN

Our preliminary studies revealed that oncogenic KRAS (KRAS/V12) dramatically suppressed the growth of immortalized airway epithelial cells (NHBE-T, with viral antigen-inactivated p53 and RB proteins). This process appeared to be a novel event, different from the so-called premature senescence that is induced by either p53 or RB, suggesting the existence of a novel tumor suppressor that functions downstream of oncogenic KRAS. After a comprehensive search for genes whose expression levels were modulated by KRAS/V12, we focused on DUSP6, a pivotal negative feedback regulator of the RAS-ERK pathway. A dominant-negative DUSP6 mutant, however, failed to rescue KRAS/V12-induced growth suppression, but conferred a stronger anchorage-independent growth activity to the surviving subpopulation of cells generated from KRAS/V12-transduced NHBE-T. DUSP6 expression levels were found to be weaker in most lung cancer cell lines than in NHBE-T, and DUSP6 restoration suppressed cellular growth. In primary lung cancers, DUSP6 expression levels decreased as both growth activity and histological grade of the tumor increased. Loss of heterozygosity of the DUSP6 locus was found in 17.7% of cases and was associated with reduced expression levels. These results suggest that DUSP6 is a growth suppressor whose inactivation could promote the progression of lung cancer. We have here identified an important factor involved in carcinogenesis through a comprehensive search for downstream targets of oncogenic KRAS.

Asunto(s)

Transformación Celular Neoplásica/genética , Fosfatasa 6 de Especificidad Dual/genética , Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares/genética , Proteínas Proto-Oncogénicas/metabolismo , Proteínas ras/metabolismo , Desequilibrio Alélico , Línea Celular Tumoral , Proliferación Celular , Transformación Celular Neoplásica/patología , Islas de CpG , Metilación de ADN , Regulación hacia Abajo , Humanos , Neoplasias Pulmonares/patología , Mutación , Regiones Promotoras Genéticas , Biosíntesis de Proteínas/genética , Proteínas Proto-Oncogénicas p21(ras) , Activación Transcripcional

RESUMEN

Small cell lung cancer (SCLC) exhibits highly aggressive behavior and has a poor prognosis. While numerous investigations have been carried out, the exact mechanism of its carcinogenesis and aggressiveness is still unclear. SCLC is categorized as a neuroendocrine neoplasia and has a genetic profile characterized by universal alterations of the RB and TP53 genes. Epidemiological studies indicate the majority of SCLCs to be caused by smoking and the TP53 mutational pattern to be consistent with that evoked by smoke carcinogens; however, there is no direct evidence that such carcinogens induce alterations to RB in SCLC. While the importance of these alterations in the carcinogenesis of SCLC is strongly suggested, the exact molecular mechanism has been only little elucidated. SCLC cells almost always express mammalian achaete-scute homolog-1 (MASH1) and thyroid transcription factor-1 (TTF-1). MASH1 plays a critical role in neuroendocrine differentiation. TTF-1 is a characteristic marker of distal airway cells and pulmonary adenocarcinomas, but is also expressed in extrapulmonary neuroendocrine cancers. Thus, TTF-1 may well play a significant role in the development of neuroendocrine cancers. Recent studies indicate that the airway stem cell is committed to the neuroendocrine lineage through MASH1 and Notch signaling and that only RB-deleted neuroendocrine cells selectively proliferate in response to E2F3, eventually undergoing transformation to neuroendocrine cancer cells, probably in concert with TP53 gene aberrations. Thus, alterations of both the RB and TP53 genes are central to the carcinogenesis of SCLC, while many other factors including MASH1 and TTF-1 contribute to the development and biological behavior of SCLC.

Asunto(s)

Genes de Retinoblastoma , Neoplasias Pulmonares/genética , Proteínas Nucleares/genética , Carcinoma Pulmonar de Células Pequeñas/genética , Factores de Transcripción/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Progresión de la Enfermedad , Factor de Transcripción E2F1/genética , Genes Relacionados con las Neoplasias , Humanos , Invasividad Neoplásica , Fenotipo , Factor Nuclear Tiroideo 1 , Activación Transcripcional

RESUMEN

The present study investigated the potential difference between EGFR-mutated lung adenocarcinoma (ADC) and KRAS-mutated ADC in relation to past illness and family history. Among the 153 tumors examined, 33 (21.6%) were EGFR-mutated, and 22 (14.4%) were KRAS-mutated. The EGFR-mutated cases showed a significantly higher prevalence of past illness involving the gastric cancer in males (EGFR 3/8 (37.5%), KRAS 0/13 (0.0%), no mutation (NONE) 1/57 (1.8%); Fisher's exact test, P=0.0064) or uterine myoma in females (EGFR 8/25 (32.0%), KRAS 0/9 (0.0%), NONE 3/41 (7.3%); Fisher's exact test, P=0.0139). No association between the mutations and family history was found. The EGFR-mutated ADC is therefore likely to develop through a distinct carcinogenetic pathway from the others, but genetic backgrounds seemed unlikely to be determinant predisposing to the EGFR-mutated ADC.

Asunto(s)

Adenocarcinoma/genética , Genes erbB-1/genética , Neoplasias Pulmonares/genética , Mioma/genética , Mioma/patología , Neoplasias Primarias Secundarias/genética , Proteínas Proto-Oncogénicas/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Neoplasias Uterinas/genética , Neoplasias Uterinas/patología , Proteínas ras/genética , Adenocarcinoma/epidemiología , Adenocarcinoma/patología , Factores de Edad , Análisis Mutacional de ADN , Femenino , Estudios de Asociación Genética , Humanos , Neoplasias Pulmonares/epidemiología , Neoplasias Pulmonares/patología , Masculino , Mutación , Mioma/epidemiología , Neoplasias Primarias Secundarias/patología , Prevalencia , Proteínas Proto-Oncogénicas p21(ras) , Factores de Riesgo , Fumar , Neoplasias Gástricas/epidemiología , Neoplasias Uterinas/epidemiología

RESUMEN

The purpose of the present study was to establish accurate prognostic markers to predict the post-operative recurrence of stage I lung adenocarcinomas (ADC). One-hundred and ninety cases of stage I ADC were examined for KRAS mutations and Ki-67 expression, and their associations with disease recurrence were analyzed. KRAS-mutated cases showed a significantly higher risk of recurrence than cases without mutations (5-year disease-free survival (DFS) 61.0% vs. 85.8%, P=0.017: adjusted Hazard ratio (HR) 4.55, 95% Confidence Interval (CI) 1.61-12.82, P=0.004). Ki-67 high-expressers (labeling index >10%) also showed a higher risk of recurrence than low-expressers (5-year DFS 68.7% vs. 93.2%, P<0.001: adjusted HR 3.84, 95% CI 1.18-12.45, P=0.025). Ki-67 high-expressers with KRAS mutations showed an additional higher risk of recurrence compared to low-expressers without mutations (5-year DFS 37.5% vs. 93.3%, P<0.001: adjusted HR 16.82, 95% CI 3.77-74.98, P<0.001) and their 5-year DFS was nearly equivalent to that of stage II non-small cell lung cancer (NSCLC) in our facility (37.5% vs. 37.2% for stage II NSCLC, p=0.577). The combined use of KRAS status and Ki-67 expression level could be an excellent prognostic marker to predict the post-operative recurrence of stage I ADC.

Asunto(s)

Adenocarcinoma/diagnóstico , Adenocarcinoma/genética , Biomarcadores de Tumor/metabolismo , Antígeno Ki-67/biosíntesis , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Mutación , Proteínas Proto-Oncogénicas/genética , Proteínas ras/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Adenocarcinoma/fisiopatología , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Análisis Mutacional de ADN , Femenino , Estudios de Seguimiento , Humanos , Inmunohistoquímica , Antígeno Ki-67/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/fisiopatología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas p21(ras) , Recurrencia , Proteínas ras/metabolismo

RESUMEN

The authors' previous study demonstrated that oncogenic KRAS modulates the shape and motility of airway epithelial cells. To explore detailed mechanism mediating these events, the possible involvement of phosphatidylinositides (PIP) was investigated. The intracellular localization of PIP was visualized with a pleckstrin homology domain-enhanced green fluorescent protein (EGFP) construct. PIP accumulated at the leading edges of polarizing epithelial cells, while they co-localized with cortical actin at cell-cell contacts, suggesting that PIP play important roles in the cytoskeletal organization. Transduction of oncogenic KRAS induced multiple pseudopodia and disrupted cortical actin, enhancing motility. A mitogen activated protein kinase kinase (MEK) inhibitor reduced the accumulation of PIP at membranes and development of pseudopodia, and restored stable cortical actin, reducing the motility. A phosphoinositide 3-kinase (PI3K) inhibitor also reduced accumulation of PIP at membranes, formation of pseudopodia and motility, but its effect on cortical actin was indistinct. The KRAS V12/S35 mutant, activating only the MEK pathway, induced multiple pseudopodia and disrupted the cortical actin. The KRAS V12/C40 mutant, activating only the PI3K pathway, also induced pseudopodia, but its effect on cortical actin was obscure. Taken together, oncogenic KRAS could cause the accumulation of PIP via the PI3K and MEK pathways and modulate the cell shape and migration.

Asunto(s)

Citoesqueleto/ultraestructura , Células Epiteliales/ultraestructura , Fosfatidilinositoles/metabolismo , Proteínas Proto-Oncogénicas/genética , Mucosa Respiratoria/ultraestructura , Proteínas ras/genética , Western Blotting , Línea Celular , Movimiento Celular/efectos de los fármacos , Movimiento Celular/fisiología , Citoesqueleto/química , Citoesqueleto/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Células Epiteliales/química , Células Epiteliales/efectos de los fármacos , Humanos , Quinasas Quinasa Quinasa PAM/efectos de los fármacos , Quinasas Quinasa Quinasa PAM/metabolismo , Microscopía Fluorescente , Fosfatidilinositol 3-Quinasas/efectos de los fármacos , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfatidilinositoles/química , Proteínas Proto-Oncogénicas p21(ras) , Mucosa Respiratoria/química , Mucosa Respiratoria/efectos de los fármacos

RESUMEN

BACKGROUNDS/AIMS: It has been reported that urinary oxidative stress markers are higher in diabetic patients with proteinuria. We performed the present study to elucidate the relationship between urinary excretion of oxidative stress markers, albumin excretion, and histological changes, and to confirm the potential utility of oxidative stress markers for clinical treatment. METHODS: Diabetic db/db mice or nondiabetic db/m mice were administered candesartan (10 mg/kg/day) or hydralazine (50 mg/kg/day) for 18 weeks. RESULTS: Thirty-week-old male db/db mice treated with control vehicle revealed elevated urinary excretion and immunohistological levels of 8-hydroxydeoxyguanosine in glomeruli when compared to db/m mice. Treatment with candesartan, but not hydralazine, reduced these values to levels in db/m mice. Increased mesangial expansion, urinary excretion of albumin and 8-isoprostane, and glomerular immunohistological levels of nitrotyrosine in db/db mice were also decreased markedly by candesartan but not hydralazine. Interestingly, correlations between levels of albumin and oxidative stress markers in urine were very high, even when groups undergoing long-term (44 weeks) treatment were included (correlation coefficient 0.767 with respect to 8-hydroxydeoxyguanosine, 0.888 with respect to 8-isoprostane). CONCLUSION: It is anticipated that urinary concentrations of oxidative stress markers will be direct barometers of glomerulus-derived oxidative stress and glomerular injury in diabetic nephropathy.

Asunto(s)

Bloqueadores del Receptor Tipo 1 de Angiotensina II/uso terapéutico , Bencimidazoles/uso terapéutico , Desoxiguanosina/análogos & derivados , Nefropatías Diabéticas/tratamiento farmacológico , Nefropatías Diabéticas/orina , Dinoprost/análogos & derivados , Tetrazoles/uso terapéutico , Tirosina/análogos & derivados , 8-Hidroxi-2'-Desoxicoguanosina , Albuminuria/orina , Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacocinética , Animales , Antihipertensivos/uso terapéutico , Bencimidazoles/farmacocinética , Biomarcadores/orina , Compuestos de Bifenilo , Desoxiguanosina/orina , Diabetes Mellitus/fisiopatología , Diabetes Mellitus/orina , Nefropatías Diabéticas/fisiopatología , Dinoprost/orina , Modelos Animales de Enfermedad , Hidralazina/uso terapéutico , Glomérulos Renales/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Estrés Oxidativo/fisiología , Tetrazoles/farmacocinética , Resultado del Tratamiento , Tirosina/orina