RESUMO
In patients with hepatocellular carcinoma (HCC), disease progression and associated bone metastasis (BM) can markedly reduce quality of life. While the long non-coding RNA (lncRNA) zinc finger E-box binding homeobox 1 antisense 1 (ZEB1-AS1) has been shown to function as a key regulator of oncogenic processes in HCC and other tumor types, whether it plays a role in controlling HCC BM remains to be established. In the current study, we detected the significant upregulation of lncZEB1-AS1 in HCC tissues, and we found this expression to be associated with BM progression. When we knocked down this lncRNA in HCC cells, we found that this significantly reduced their migratory, invasive, and metastatic activity both in vitro and in vivo. At a mechanistic level, we found that lncZEB1-AS1 was able to target miR-302b and to thereby increase PI3K-AKT pathway activation and EGFR expression, resulting in the enhanced expression of downstream matrix metalloproteinase genes in HCC cells. In summary, our results provide novel evidence that lncZEB1-AS1 can promote HCC BM through a mechanism dependent upon the activation of PI3K-AKT signaling, thus highlighting a potentially novel therapeutic avenue for the treatment of such metastatic progression in HCC patients.
RESUMO
In hepatocellular carcinoma (HCC), the hypoxic tumor microenvironment can drive enhance tumor malignancy and recurrence. The microRNA (miRNA) miR-196-5p has been shown to modulate the progression of several cancer types, but its roles in HCC remain uncertain. In the present report we observed significant miR-196-5p downregulation in HCC tissues and cells, and we found that the expression of this miRNA significantly impaired the proliferation and metastatic potential of HCC in vitro and in vivo. We identified high-mobility group AT-hook 2 (HMGA2) as a miR-196-5p target gene that was associated with the ability of miR-196-5p to modulate the progression of HCC. Expression of miR-196-5p and HMGA2 were correlated with the clinical characteristics and poor outcomes in patients with HCC. Finally, we found that hypoxic conditions were linked with reduced miR-196-5p expression in the context of HCC. Together these results highlight the role for miR-196-5p as an inhibitor of the proliferation and metastasis of HCC via the targeting of HMGA2, with this novel hypoxia/miR-196-5p/HMGA2 pathway serving as a potential target for future therapeutic intervention.
Assuntos
Carcinoma Hepatocelular/patologia , Regulação para Baixo , Proteína HMGA2/genética , Neoplasias Hepáticas/patologia , MicroRNAs/genética , Regiões 3' não Traduzidas , Animais , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Masculino , Camundongos , Transplante de Neoplasias , Hipóxia TumoralRESUMO
The mechanism of hepatocellular carcinoma (HCC) metastasis remains poorly understood. Tropomodulin 3 (TMOD3) is a member of the pointed end capping protein family that contributes to invasion and metastasis in several types of malignancies. It has been found to be crucial for the membranous skeleton and embryonic development, although, its role in HCC progression remains largely unclear. We observed increased levels of Tmod3 in HCCs, especially in extrahepatic metastasis. High Tmod3 expression correlated with aggressive carcinoma and poor patient with HCC survival. Loss-of-function studies conducted by us determined Tmod3 as an oncogene that promoted HCC growth and metastasis. Mechanistically, Tmod3 increases transcription of matrix metalloproteinase-2, -7, and -9 which required PI3K-AKT. Interaction between Tmod3 and epidermal growth factor receptor (EGFR) that supports the activation of EGFR phosphorylation, is essential for signaling activation of PI3K-AKT viral oncogene homolog. These findings reveal that Tmod3 enhances aggressive behavior of HCC both in vitro and in vivo by interacting with EFGR and by activating the PI3K-AKT signaling pathway.
Assuntos
Carcinoma Hepatocelular/genética , Proliferação de Células/genética , Neoplasias Hepáticas/genética , Tropomodulina/genética , Animais , Carcinoma Hepatocelular/patologia , Progressão da Doença , Intervalo Livre de Doença , Transição Epitelial-Mesenquimal/genética , Receptores ErbB/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Xenoenxertos , Humanos , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Pessoa de Meia-Idade , Metástase Neoplásica , Proteína Oncogênica v-akt/genética , Fosfatidilinositol 3-Quinases/genética , Transdução de Sinais/genéticaRESUMO
UNLABELLED: Systemic analyses using large-scale genomic profiles have successfully identified cancer-driving somatic copy number variations (SCNVs) loci. However, functions of vast focal SCNVs in "protein-coding gene desert" regions are largely unknown. The integrative analysis of long noncoding RNA (lncRNA) expression profiles with SCNVs in hepatocellular carcinoma (HCC) led us to identify the recurrent deletion of lncRNA-PRAL (p53 regulation-associated lncRNA) on chromosome 17p13.1, whose genomic alterations were significantly associated with reduced survival of HCC patients. We found that lncRNA-PRAL could inhibit HCC growth and induce apoptosis in vivo and in vitro through p53. Subsequent investigations indicated that the three stem-loop motifs at the 5' end of lncRNA-PRAL facilitated the combination of HSP90 and p53 and thus competitively inhibited MDM2-dependent p53 ubiquitination, resulting in enhanced p53 stability. Additionally, in vivo lncRNA-PRAL delivery efficiently reduced intrinsic tumors, indicating its potential therapeutic application. CONCLUSIONS: lncRNA-PRAL, one of the key cancer-driving SCNVs, is a crucial stimulus for HCC growth and may serve as a potential target for antitumor therapy.
