RESUMEN

Collagen triple helix repeat containing-1 (CTHRC1) is a secreted glycoprotein that activates the planar cell polarity pathway of Wnt signaling. Using microarray analysis, we found that the CTHRC1 gene is overexpressed in hepatocellular carcinoma (HCC). The level of CTHRC1 mRNA was measured in 201 surgically resected HCCs using real time reverse transcription-polymerase chain reaction. Overexpression of CTHRC1 in HCC was associated with large tumor size and advanced tumor stage. Furthermore, expression of CTHRC1 as was identified as an independent prognostic factors in the multivariate analysis. Suppression of CTHRC1 expression inhibited tumor migration and invasion whereas overexpression of CTHRC1 promoted tumor invasion. Activation of RhoA, but not Rac1 or Cdc42, was found to play a crucial role in CTHRC1-induced cell migration. CTHRC1 promoted adhesion of cancer cells to extracellular matrix through induction of integrin ß1 expression and activation of focal adhesion kinase. These results suggest CTHRC1 promotes tumor invasion and metastasis by enhancing the adhesion and migratory abilities of tumor cells. It is also a promising biomarker for predicting the prognosis of patients with HCC.

Asunto(s)

Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Proteínas de la Matriz Extracelular/genética , Expresión Génica , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Adulto , Anciano , Carcinoma Hepatocelular/mortalidad , Adhesión Celular/genética , Movimiento Celular/genética , Matriz Extracelular/metabolismo , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Integrina beta1/genética , Integrina beta1/metabolismo , Neoplasias Hepáticas/mortalidad , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Invasividad Neoplásica , Estadificación de Neoplasias , Oportunidad Relativa , Pronóstico , Proteína de Unión al GTP rhoA/metabolismo

RESUMEN

Cell division in eukaryotes depends on a fine control of the dynamic changes of microtubules. Nucleolar and spindle-associated protein (NuSAP) is a microtubule-binding and -bundling protein essential for the integrity of the anaphase spindle and cell division. NuSAP contains two consensus cdk phosphorylation sites in its microtubule-binding domain. Here we show NuSAP is phosphorylated by cdk1 in early mitosis. This phosphorylation inhibits the binding of NuSAP to microtubules. During metaphase-to anaphase transition, NuSAP is dephosphorylated to promote spindle midzone formation and cell cycle progression. Expression of cdk1 phosphorylation-null mutant causes extensive bundling of microtubules in the prometaphase spindle. Our results suggest that phosphorylation and dephosphorylation of NuSAP during progression of mitosis regulate spindle organization through modulation of the dynamics of microtubules.

Asunto(s)

Proteína Quinasa CDC2/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteínas Asociadas a Microtúbulos/metabolismo , Microtúbulos/metabolismo , Mitosis , Dominios y Motivos de Interacción de Proteínas , Sitios de Unión , Proteína Quinasa CDC2/genética , Células HEK293 , Células HeLa , Humanos , Inmunoprecipitación , Lentivirus/genética , Lentivirus/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Microtúbulos/genética , Mutagénesis Sitio-Dirigida , Fosforilación , Huso Acromático/genética , Huso Acromático/metabolismo , Treonina/metabolismo

RESUMEN

UNLABELLED: Insulin-like growth factor II mRNA-binding protein 3 (IMP3) is an RNA-binding protein expressed in embryonic tissues and multiple cancers. To investigate the role of IMP3 in hepatocellular carcinoma (HCC), its protein expression in the surgically resected unifocal tumors of 377 HCC patients (296 men and 81 women) with ages ranging from 7 to 88 years (mean, 55.49 years) was analyzed by immunohistochemistry. IMP3 was expressed in 255 (67.6%) of 377 resected unifocal primary HCCs. IMP3 protein was predominantly expressed in tumor border and invasive front, and it was more abundant in the satellite nodules and tumor thrombi than in the main tumors. The expression correlated with high alpha-fetoprotein (>200 ng/mL, P < 1 x 10(-7)), larger tumor size (>5 cm, P = 0.006), high tumor grade (P < 1 x 10(-7)), and high tumor stage with vascular invasion and various degrees of intrahepatic metastasis (P < 1 x 10(-7)). IMP3 expression predicted early tumor recurrence (P < 1 x 10(-7)) and was a strong indicator of poor prognosis (P < 0.0001). Depletion of IMP3 with RNA interference in HCC cell line HA22T caused a decrease in cell motility, invasion, and transendothelial migration. Microarray analysis revealed that IMP3 depletion was associated with downregulation of multiple genes involved in tumor invasion. CONCLUSION: Our results indicate that IMP3 plays an important role in tumor invasion and metastasis and is a strong prognostic factor for patients with HCC.

Asunto(s)

Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Proteínas de Neoplasias/metabolismo , Recurrencia Local de Neoplasia/metabolismo , Recurrencia Local de Neoplasia/patología , Proteínas de Unión al ARN/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Hepatocelular/diagnóstico , Línea Celular Tumoral , Movimiento Celular , Niño , Femenino , Proteína HMGA2/metabolismo , Humanos , Estimación de Kaplan-Meier , Neoplasias Hepáticas/diagnóstico , Masculino , Persona de Mediana Edad , Análisis Multivariante , Invasividad Neoplásica , Recurrencia Local de Neoplasia/diagnóstico , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Pronóstico , Estudios Retrospectivos

RESUMEN

BACKGROUND: Carcinoid tumors are a group of heterogeneous tumors with neuroendocrine differentiation and are mainly located in the gastrointestinal tract. A high frequency of cytoplasmic accumulation and/or nuclear translocation of beta-catenin with frequent mutations of exon 3 of beta-catenin gene in gastrointestinal carcinoid tumor has been previously described, but the role of Wnt/beta-catenin/APC pathway in the genesis of carcinoid tumor remains largely unknown. METHODS: To further characterize the role of Wnt/beta-catenin/APC pathway, we investigated 91 gastrointestinal carcinoid tumors and, for comparison, 26 extragastrointestinal carcinoid tumors by immunohistochemical detection of beta-catenin protein and direct sequencing of exon 3 of the beta-catenin gene and exon 15 of the APC gene. RESULTS: Cytoplasmic accumulation and/or nuclear translocation of beta-catenin were found in 27 gastrointestinal carcinoid tumors (29.7%) but not in any extragastrointestinal carcinoid tumors. Interestingly, neither beta-catenin nor APC gene mutation was detected in all of the cases with nuclear expression of beta-catenin. CONCLUSIONS: Our results indicate that the role beta-catenin plays in the genesis of gastrointestinal and extragastrointestinal carcinoid tumors is different. Nuclear expression of beta-catenin does not occur in extragastrointestinal carcinoid tumors, and mutation of exon 3 of beta-catenin gene and exon 15 of APC gene does not contribute to the activation of Wnt/beta-catenin/APC pathway in gastrointestinal carcinoid tumors.

Asunto(s)

Proteína de la Poliposis Adenomatosa del Colon/genética , Tumor Carcinoide/genética , Núcleo Celular/metabolismo , Neoplasias Gastrointestinales/genética , Mutación/genética , beta Catenina/genética , Proteína de la Poliposis Adenomatosa del Colon/metabolismo , Tumor Carcinoide/metabolismo , Citoplasma/metabolismo , Exones/genética , Neoplasias Gastrointestinales/metabolismo , Humanos , Transporte de Proteínas , Fracciones Subcelulares , beta Catenina/metabolismo