RESUMEN
Non-small cell lung cancer (NSCLC) represents 75-80% of all lung carcinomas, which is the most common cause of death from cancer. Tumour suppressor candidate 3 (TUSC3) is pivotal in many biochemical functions and cytological processes. Dis-regulation of TUSC3 is frequently observed in epithelial cancers. In this study, we observed up-regulated TUSC3 expression at the mRNA and protein levels in clinical NSCLC samples compared with adjacent non-tumorous lung tissues. The expression level of TUSC3 is significantly correlated with tumour metastasis and patient survival. Overexpression of TUSC3 in NSCLC cells led to increased proliferation, migration, and invasion in vitro and accelerated xenograft tumour growth in vivo, while the opposite effects were achieved in TUSC3-silenced cells. Increased GLI1, SMO, PTCH1, and PTCH2 abundance were observed in TUSC3 overexpressed cells using western blotting. Co-immunoprecipitation and immunofluorescence analyses further revealed interaction between TUSC3 and GLI1. In conclusion, our study demonstrated an oncogenic role of TUSC3 in NSCLC and showed that dis-regulation of TUSC3 may affect tumour cell invasion and migration through possible involvement in the Hedgehog (Hh) signalling pathway.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteínas Hedgehog/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas de la Membrana/biosíntesis , Transducción de Señal , Proteínas Supresoras de Tumor/biosíntesis , Células A549 , Animales , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Movimiento Celular/genética , Proliferación Celular , Femenino , Proteínas Hedgehog/genética , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Masculino , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Invasividad Neoplásica/genética , Proteínas Supresoras de Tumor/genética , Proteína con Dedos de Zinc GLI1/genética , Proteína con Dedos de Zinc GLI1/metabolismoRESUMEN
Colorectal cancer (CRC) is one of the most common malignancies and is the second leading cause of cancer death in humans. Tumour suppressor candidate 3 (TUSC3) plays an important role in embryogenesis and metabolism. Deletion of TUSC3 often causes non-syndromic mental retardation. Even though TUSC3 deregulation is frequently observed in epithelial cancers, the function of TUSC3 in CRC has remained unknown. In this study, we observed greater expression of TUSC3 at the mRNA and protein level in clinical colorectal tumour samples compared with paired normal tissues. Gain- and loss-of-function analyses were performed to evaluate the functional significance of TUSC3 in CRC initiation and progression. Immunoblotting, immunofluorescence, and co-immunoprecipitation analyses were used to identify potential pathways with which TUSC3 might be involved. Overexpression of TUSC3 in CRC cells induced epithelial-mesenchymal transition (EMT) in CRC cells, accompanied by down-regulation of the epithelial marker, E-cadherin, and up-regulation of the mesenchymal marker, vimentin. Increased proliferation, migration, and invasion, as well as accelerated xenograft tumour growth, were observed in TUSC3-overexpressing CRC cells, while opposite effects were achieved in TUSC3-silenced cells. In conclusion, our study demonstrated the oncogenic role of TUSC3 in CRC and showed that TUSC3 may be responsible for alternations in the proliferation ability, aggressiveness, and invasive/metastatic potential of CRC through regulating the MAPK, PI3K/Akt, and Wnt/ß-catenin signalling pathways.