RAE1 is a prognostic biomarker and is correlated with clinicopathological characteristics of patients with hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a primary malignant tumor that accounts for approximately 90% of all cases of primary liver cancer worldwide. Microtubule alterations may contribute to the broad spectrum of resistance to chemotherapy, tumor development, and cell survival. This study aimed to assess the value of ribonucleic acid export 1 (RAE1), as a regulator of microtubules, in the diagnosis and prognosis of HCC, and to analyze its correlation with genetic mutations and pathways in HCC. RESULTS: The mRNA and protein levels of RAE1 were significantly elevated in HCC tissues compared with those in normal tissues. The high expression level of RAE1 was correlated with T stage, pathologic stage, tumor status, histologic grade, and alpha-fetoprotein level. HCC patients with a higher expression level of RAE1 had a poorer prognosis, and the expression level of RAE1 showed the ability to accurately distinguish tumor tissues from normal tissues (area under the curve (AUC) = 0.951). The AUC values of 1-, 3-, and 5-year survival rates were all above 0.6. The multivariate Cox regression analysis showed that RAE1 expression level was an independent prognostic factor for a shorter overall survival of HCC patients. The rate of RAE1 genetic alterations was 1.1% in HCC samples. Gene ontology and kyoto encyclopedia of genes and genomes pathway enrichment analyses indicated the co-expressed genes of RAE1 were mainly related to chromosome segregation, DNA replication, and cell cycle checkpoint. Protein-protein interaction analysis showed that RAE1 was closely correlated with NUP205, NUP155, NUP214, NUP54, and NXF1, all playing important roles in cell division and mitotic checkpoint. CONCLUSION: RAE1 can be a potential diagnostic and prognostic biomarker associated with microtubules and a therapeutic target for HCC.

EZH2-mediated H3K27me3 promotes autoimmune hepatitis progression by regulating macrophage polarization.

Autoimmune hepatitis (AIH) is a chronic progressive liver disease related to abnormal immune stimulation, leading to liver cirrhosis, liver cancer and liver failure. There is an urgent need to find novel biomarkers and potential drug targets for effective treatment of the disease. Although previous studies have shown that EZH2, as a histone methyltransferase, plays critical roles in tumor and autoimmune diseases, its role in autoimmune hepatitis remains largely unknown. In this study, we reported that the EZH2 and H3K27me3 expression level was significantly upregulated in liver tissues during the progression of AIH. High expression of EZH2 enhanced autoimmune hepatitis, immune response and liver fibrosis through H3K27me3. EZH2 inhibition induced the phenotype of hepatic macrophages to switch from M1 to M2 in the development of AIH. These findings indicated that EZH2-mediated H3K27me3 promoted autoimmune hepatitis by regulating the polarization of hepatic macrophages. EZH2 may be a promising therapeutic target for the prevention or treatment of autoimmune hepatitis.

IL-35 promotes EMT through STAT3 activation and induces MET by promoting M2 macrophage polarization in HCC.

The tumor microenvironment and interplay with cancer cells could promote tumor growth and metastasis. Here we report that polarization state of macrophages could affect epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET). IL-35 level secreted by M1 macrophage was significantly higher than M2 macrophage and it facilitated EMT process through activation of STAT3 in hepatocellular carcinoma cells. Interestingly, IL-35 could not directly promote MET, but it could indirectly induce MET of HCC cells through M2 macrophage polarization. These results indicated the level of IL-35 in tumor microenvironment may fluctuate at different stages of oncogenesis to regulate epithelial plasticity of HCC and provide potential therapeutic targets for tumor metastasis.

Chemical induced inflammation of the liver breaks tolerance and results in autoimmune hepatitis in Balb/c mice.

Autoimmune hepatitis (AIH) is a chronic liver disease mediated by immunity, and could lead to liver fibrosis and hepatocellular carcinoma. However, the mechanisms for breaking hepatic tolerance and driving AIH still remain elusive. We herein reported that the non-specific liver inflammation triggered by carbon tetrachloride (CCl4) recruited high numbers of CD4+T, CD8+T and B cells, and elevated the expression of proinflammaitory cytokines in Balb/c mice, further breaking liver tolerance and inducing autoimmune response, AIH inflammation and liver fibrosis in the presence of CYP2D6 antigen mimicry. In contrast, adenovirus infection could not break liver tolerance and induce AIH in Balb/c mice even in the presence of CYP2D6 antigen mimicry. These results suggested that genetic predisposition could determine liver tolerance in Balb/c mice. The chemical induced inflammation in the liver breaks tolerance and might be considered important for the initiation and development of AIH in Balb/c mice.

CRISPR/Cas9-mediated knockout of the PDEF gene inhibits migration and invasion of human gastric cancer AGS cells.

Gastric cancer is one of the most common malignant tumors worldwide and has the second highest incidence and mortality rate among malignant tumors in China. Prostate-derived Ets factor (PDEF) is a member of the Ets family of transcription factors. Although PDEF plays an important role in tumorigenesis, its biological function in gastric cancer is still unclear. Here, we evaluated PDEF expression in 30 cases of human gastric carcinoma and the corresponding peritumoral tissues, using immunohistochemistry and immunofluorescence. Significantly higher levels of PDEF were detected in tumors compared to peritumoral tissues. We then investigated PDEF expression in the gastric cancer cell lines SGC and AGS and the normal gastric epithelial cell line GES; The CRISPR/Cas9 genome-editing system was used to knockout PDEF in AGS cells as a model for gastric cancer. Cell proliferation, apoptosis, migration, and invasion of PDEF-knockout AGS cells were evaluated using CCK-8, flow cytometry, scratch wound, and transwell assays, respectively. The results illustrated that PDEF-knockout inhibited AGS cell proliferation, migration, and invasion. Taken together, the results imply that PDEF plays important roles in the proliferation, migration, and invasion of AGS cells and may serve as a new treatment target in gastric cancer.