RESUMEN

At present, there are still many poorly understood aspects of the mechanisms underlying hepatocellular carcinoma (HCC) invasion and metastasis. Invadopodia are important structures for cancer cell invasion and metastasis. We determined that high T-lymphoma invasion and metastasis 1 (Tiam1) expression is associated with HCC invasion and metastasis and poor patient prognosis after surgery. Gain- and loss-of-function studies confirmed that Tiam1 promotes invadopodia formation in HCC by activating Rac1. A series of biochemical experiments confirmed that this effect is regulated by the PI3K/Akt signaling pathway. We also confirmed that PIP2 facilitates this effect. In summary, these findings reveal that Tiam1 plays an important role in invadopodia formation in HCC.

Asunto(s)

Carcinoma Hepatocelular/patología , Regulación Neoplásica de la Expresión Génica , Neoplasias Hepáticas/patología , Fosfatidilinositol 3-Quinasas/metabolismo , Podosomas/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteína 1 de Invasión e Inducción de Metástasis del Linfoma-T/metabolismo , Animales , Apoptosis , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Movimiento Celular , Proliferación Celular , Femenino , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Masculino , Ratones , Ratones Desnudos , Persona de Mediana Edad , Fosfatidilinositol 3-Quinasas/genética , Podosomas/metabolismo , Pronóstico , Proteínas Proto-Oncogénicas c-akt/genética , Tasa de Supervivencia , Proteína 1 de Invasión e Inducción de Metástasis del Linfoma-T/genética , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto

RESUMEN

BACKGROUND: In sepsis, reorganization of the actin cytoskeleton in the epithelium during inflammation will lead to a breakdown of epithelial barrier integrity, and contribute to the pathogenesis of sepsis, but the exact changes of various components regulating the actin cytoskeleton pathway remain unclear. METHODS: We used lipopolysaccharide (LPS) challenged primary epithelial cells cultured at the air-liquid interface (ALI) to mimic epithelial barrier dysfunction during sepsis. Then we detected differential expression of T-lymphoma invasion and metastasis 1 (TIAM1) gene in lung epithelial cells and septic models. RESULTS: LPS induced barrier dysfunction in human tracheobronchial epithelial cells (HTBEs) as measured by statistically significant changes in ionic and macromolecular permeability. We observed differential expression of TIAM1 gene. The protein expression of TIAM1 was decreased after LPS challenge, in human bronchial epithelial cells. Furthermore, the expression levels of both TIAM1 mRNA and protein were decreased in lungs of septic rodent models. CONCLUSIONS: Given that expression levels of TIAM1 have been associated with mortality among sepsis patients, our findings have the potential for the development of diagnostic and treatment strategies relevant for patient management.

RESUMEN

T lymphoma invasion and metastasis 1 (Tiam1) is a guanine nucleotide exchange factor (GNEF) family member, and is considered to be involved in many important cellular processes and oncogenesis. In this study, we investigated Tiam1 expression differences between normal tissue and malignant tissue using tissue microarray (TMA), and further studied the Tiam1 mRNA and protein level in 9 hepatoma lines. Forty-nine tumor tissue and 47 normal tissue samples were detected via TMA by immunohistochemistry with polyclonal antibody. Tiam1 expression in 9 human hepatoma cell lines, namely Huh-7, HepG2, Hep3B, SMMC-7721, QGy-7701, QGy-7703, BEL-7402, BEL-7404 and BEL-7405, and 1 normal primary human hepatocyte, HL-7702, was compared by means of fluorescence quantitative PCR, immunocytochemistry assay and Western blotting. We found that Tiam1 was significantly expressed in various malignancies. Tiam1 mRNA and protein levels were significantly elevated in the 9 human hepatoma cell lines compared to the normal primary human hepatocyte. Our results suggest that Tiam1 overexpression in malignant neoplasms could be a novel effective supplementary biomarker for tumors, including hepatocellular carcinoma.

Asunto(s)

Biomarcadores de Tumor/metabolismo , Regulación Neoplásica de la Expresión Génica , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/metabolismo , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/metabolismo , Línea Celular , Humanos , Inmunohistoquímica , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/metabolismo , Análisis por Micromatrices , ARN Mensajero/metabolismo , Proteína 1 de Invasión e Inducción de Metástasis del Linfoma-T

RESUMEN

Objective To explore the expression of Tiaml in clear cell renal cell carcinoma and analyze its correlations to pathology of disease and prognosis.Methods The expressions of Tiam1 protein in 107 specimens of human clear cell renal cell carcinoma and 20 specimens of normal renal tissues were detected by immunohistochemical staining and its clinical significance was then analyzed.Results The expression of Tiam1 protein was higher in renal cancers than in the adjacent normal tissues ( P ＜ 0.01 ).Tiam1 protein expression rates were 47.6％ and 72.7％ in Ⅰ - Ⅱ and Ⅲ - Ⅳ tumors,while 49.3％ and 76.5％ in T1 - T2 and T3 - T4 tumors,respectively ( P ＜ 0.01 ).Expression of Tiam1 protein was higher in lymph node positive renal carcinoma tissues than in lymph node negative renal carcinoma tissues ( 71.7％ versus 47.5％,P ＜ 0.05 ).The expression of Tiam1 in carcinoma tissues showed a positive relationship with tumor vascular invasion (81.3％ versus 48.0％,P ＜ 0.01 ).In patients followed-up 5 - 8 years,Kaplan-meier analysis and the log-rank test showed that the 5-year survival was significantly different between the group of lower and higher Tiaml expression groups ( 84.4％ versus 46.8％,P ＜ 0.05 ).Conclusions The expression of Tiaml protein was higher in human primary renal carcinoma than in normal renal tissues.The positive rate of Tiam1 protein expression was related to classification,TNM stage,lymph node metastasis and vascular invasion.The detection of the expression of Tiaml protein may be helpful in the diagnosis and prognosis of renal carcinoma.