RESUMO
Cholangiocarcinoma (CCA) is a fatal disease with increasing morbidity and poor prognosis due to poor response to conventional chemotherapy or radiotherapy. Neurotensin (NTS) has long been recognized as an important factor in the central nervous system and as an endocrine agent in the peripheral circulation via NTS receptor (NTSR) mediated actions. In recent years, NTS has been implicated in the carcinogenesis of numerous cancers; however, its role in cholangiocarcinoma remains obscure. Here, we observed the expression of NTS in cholangiocarcinoma vs. non-cancerous tissues and found that up-regulation of NTS facilitated cholangiocarcinoma cell metastasis and down-regulation of NTS inhibited their migration ability. Mechanistically, NTS drove cholangiocarcinoma cell metastasis via the EGFR/AKT pathway. Both the PI3-K inhibitor LY294002 or EGFR inhibitor Erlotinib stopped the discrepant metastatic capacity between NTS-depleted cholangiocarcinoma cells and control cells, further confirming that EGFR/AKT was required in NTS-promoted cholangiocarcinoma cell metastasis. More importantly, overexpression of NTS predicted poor prognosis of CCA patients. In summary, NTS could promote cholangiocarcinoma cells metastasis by amplifying EGFR/AKT signaling and may therefore be useful to predict patient prognosis.
Assuntos
Neoplasias dos Ductos Biliares/patologia , Biomarcadores Tumorais/metabolismo , Colangiocarcinoma/secundário , Recidiva Local de Neoplasia/patologia , Neurotensina/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Apoptose , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/metabolismo , Biomarcadores Tumorais/genética , Estudos de Casos e Controles , Movimento Celular , Proliferação de Células , Colangiocarcinoma/genética , Colangiocarcinoma/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Seguimentos , Humanos , Metástase Linfática , Invasividade Neoplásica , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/metabolismo , Neurotensina/genética , Prognóstico , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais , Taxa de Sobrevida , Células Tumorais CultivadasRESUMO
MicroRNA (miRNA)-25 is a small non-coding RNA that has been implicated in the tumorigenesis of many cancers, but little is known on the role of miR-25 in HCC metastasis. We hereby found that miR-25 was significantly upregulated in clinical HCC tissues compared with normal liver tissues. We also revealed that miR-25 dramatically stimulates HCC cell growth and activates the epithelial-mesenchymal transition (EMT). MiR-25 is activated by the WNT/ß-catenin signaling pathway, and exerts its pro-metastatic function by directly inhibiting the Rho GDP dissociation inhibitor alpha (RhoGDI1). Downregulation of RhoGDI1 enhances expression of Snail, thereby promoting EMT. MiR-25 levels are positively correlated with ß-catenin expression, whereas negatively correlated with the level of RhoGDI1 in HCC. Our findings provide new insights into the role of miR-25 in HCC metastasis, and implicate the potential application of miR-25 in HCC therapy.
Assuntos
Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , MicroRNAs/genética , Inibidor alfa de Dissociação do Nucleotídeo Guanina rho/antagonistas & inibidores , Animais , Carcinoma Hepatocelular/metabolismo , Processos de Crescimento Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Feminino , Células Hep G2 , Xenoenxertos , Humanos , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Invasividade Neoplásica , Via de Sinalização Wnt , Inibidor alfa de Dissociação do Nucleotídeo Guanina rho/genética , Inibidor alfa de Dissociação do Nucleotídeo Guanina rho/metabolismoRESUMO
Mammalian target of rapamycin (mTOR) is frequently upregulated in hepatocellular carcinoma (HCC). Blockage of mTOR was found to induce marked reduction in HCC growth in preclinical models. In the present study, we tested a novel mTOR inhibitor, Torin-2, for its antitumor efficacy in HCC cell lines Hep G2, SNU-182 and Hep 3B2.1-7. The HCC cell lines were cultured in vitro. These cells were treated with Torin-2. Cell apoptosis was evaluated by Annexin V staining. Cell proliferation and cell cycle progression were determined by Ki67 staining and propidium iodide staining, respectively. mTOR signaling, autophagy induction and expression of ubiquitin-like containing PHD and RING finger domains 1 (UHRF1) were assessed by western blot analysis. The UHRF1 mRNA level was determined by real-time PCR. We found that Torin-2 effectively suppressed the growth and survival of HCC cell lines, demonstrated by reduced proliferation and a high rate of apoptosis. Further study elucidated that in addition to blocking mTOR complex 1 (mTORC1)-associated cell cycle progression and induction of autophagy, Torin-2 downregulated transcription of UHRF1, an essential regulator of DNA methylation that is highly expressed in HCC cell lines. Consistently, the level of DNA (cytosine-5)-methyltransferase 1 (DNMT1) was higher after treatment of the HCC cell lines with Torin-2. The downregulation of UHRF1 by Torin-1 was partially due to a decrease in the UHRF1 mRNA level. Torin-2 effectively inhibited HCC cell proliferation through induction of autophagy. Torin2-induced downregulation of UHRF1 expression may also contribute to its antitumor effect. Our research provides new clues regarding the antitumor effects of Torin-2 and sheds light on a novel therapeutic approach for HCC.