RESUMO
Hepatocellular carcinoma (HCC) is a typical hypervascular solid tumor. Vasculogenic mimicry (VM) formed by aggressive tumor cells to mimic vasculogenic networks plays an important role in the tumor malignancy of HCC. Hsp90ß promotes endothelial cell-dependent angiogenesis in HCC. However, the relationship between Hsp90ß and VM formation is unclear. In this study, we found that Hsp90ß is positively correlated with VM and EMT marker proteins in HCC tissues and promotes tube formation, cell migration, and invasion in vitro. Hsp90ß interacts with Twist1 and promotes its deubiquitination and stabilization to nuclear translocation and enhances the VE-cadherin promoter activity. Results of in vitro analysis indicate that Hsp90ß enhances the tumor VM in tumor-burdened mice, and the Hsp90 inhibitor NVP-BEP800 suppresses VM formation by releasing Hsp90ß and Twist1 interaction. This study provides a potential antitumor therapy for inhibiting VM by targeting Hsp90ß in HCC.
Assuntos
Carcinoma Hepatocelular/patologia , Transição Epitelial-Mesenquimal , Proteínas de Choque Térmico HSP90/metabolismo , Neoplasias Hepáticas/patologia , Animais , Carcinoma Hepatocelular/metabolismo , Xenoenxertos , Humanos , Neoplasias Hepáticas/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neovascularização PatológicaRESUMO
Twist is a critical epithelial-mesenchymal transition (EMT)-inducing transcription factor that increases expression of vimentin. How Twist1 regulates this expression remains unclear. Here, we report that Twist1 regulates Cullin2 (Cul2) circular RNA to increase expression of vimentin in EMT. Twist1 bound the Cul2 promoter to activate its transcription and to selectively promote expression of Cul2 circular RNA (circ-10720), but not mRNA. circ-10720 positively correlated with Twist1, tumor malignance, and poor prognosis in hepatocellular carcinoma (HCC). Twist1 promoted vimentin expression by increasing levels of circ-10720, which can absorb miRNAs that target vimentin. circ-10720 knockdown counteracted the tumor-promoting activity of Twist1 in vitro and in patient-derived xenograft and diethylnitrosamine-induced TetOn-Twist1 transgenic mouse HCC models. These data unveil a mechanism by which Twist1 regulates vimentin during EMT. They also provide potential therapeutic targets for HCC treatment and provide new insight for circular RNA (circRNA)-based diagnostic and therapeutic strategies.Significance: A circRNA-based mechanism drives Twist1-mediated regulation of vimentin during EMT and provides potential therapeutic targets for treatment of HCC.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/15/4150/F1.large.jpg Cancer Res; 78(15); 4150-62. ©2018 AACR.
Assuntos
Carcinoma Hepatocelular/genética , Proteínas Culina/genética , Transição Epitelial-Mesenquimal/genética , Neoplasias Hepáticas/genética , Proteínas Nucleares/genética , RNA/genética , Proteína 1 Relacionada a Twist/genética , Vimentina/genética , Animais , Linhagem Celular , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/genética , Células HEK293 , Humanos , Camundongos , Regiões Promotoras Genéticas/genética , RNA Circular , Transdução de Sinais/genéticaRESUMO
The co-silencing of multiple tumor suppressor genes can lead to escalated malignancy in cancer cells. Given the limited efficacy of anticancer therapies targeting single tumor suppressor genes, we developed small circular single-stranded DNA (CSSD) that can up-regulate the expression of co-silenced tumor suppressor genes by sequestering microRNAs (miRNAs) that negatively regulate these genes. We found that cancer patients with low tumor expression of the tumor suppressor genes KLF17, CDH1, and LASS2 had shortened survival times. The up-regulation of these genes upon transfection of artificial CSSD-9 inhibited tumor proliferation and metastasis and promoted apoptosis in vitro as well as in ex vivo and patient-derived xenograft models. In addition, CSSD is more stable and effective than current miRNA inhibitors, and transfecting CSSDs via nanoparticles substantially improved delivery efficiency. The use of a single CSSD can promote the inhibition of multiple tumor suppressor genes. This study provides evidence for the possibility of using CSSDs as therapeutic miRNA inhibitors to target the co-silencing of multiple tumor suppressor genes.
