No abstract

Astrocyte elevated gene-1 (AEG-1) is an important force in the development and progression of hepatocellular carcinoma (HCC). To extend our study, we examined here the role of AEG-1 in anti-metastatic effects of Huaier polysaccharide (HP) on the human HCC MHCC97-H cell line. AEG-1 shRNA contributed to the anti-proliferation effect of HP on MHCC97-H cells. Furthermore, results of Transwell insert chambers showed that low expression of AEG-1 could effectively facilitate HP to suppress MHCC97-H cell migration and invasion. We achieved this by reducing phosphoinositide 3-kinases (P13K) and phosphorylated Akt (pAkt) expression as well as enhancing natural killer (NK) cell activity. Taken together, our data strongly suggested that AEG-1 shRNA could block the carcinogenesis and progression of MHCC97-H cells and highlight the therapeutic potential of HP in HCC treatment, at least by part, by inhibiting the activation of the PI3K/Akt pathway and enhancing the NK cell-mediated immune response. These findings may provide a new strategy for HCC treatment.

Astrocyte elevated gene-1 (AEG-1) is involved in important biological processes including cell invasion, metastasis, and carcinogenesis. However, its clinical significance has remained largely unknown in hepatocellular carcinoma. Here, specimens from 144 patients with hepatocellular carcinomas in Beijing and Heilongjiang regions were investigated by immunohistochemical staining for AEG-1, vimentin, and E-cadherin expressions. A clinicopathological study revealed that AEG-1 expression level in tumor cells was significantly correlated with TNM stage (P = 0.001) and Edmonson grade (P < 0.0001). In addition, AEG-1, vimentin, and E-cadherin (epithelial-mesenchymal transition (EMT) biomarker) expressions were correlated with each other. These findings suggest that AEG-1 may be an epithelial-mesenchymal transition-associated biomarker in human hepatocellular carcinoma and play important roles in the progression of hepatocellular carcinoma. In addition, the AEG-1 gene is a potential target for elimination of hepatocellular carcinoma in the future.

Hepatocellular carcinoma (HCC) is one of the common cancers worldwide, especially in developing countries. Although the chronic infections of hepatitis B and C viruses have been established as the etiological factors of HCC, the mechanism for the tumorigenesis and development of HCC is still unclear. The liver-specific microRNA-122 (miR-122), an established tumor-suppressor miRNA, is often down-regulated in HCC, while the underlying mechanism is not well understood. Here we report that the AU-rich element-binding factor AUF1 suppresses the expression of Dicer1, the type III RNase that is required for microRNA maturation, leading to the inhibited biogenesis of miR-122. Overexpression of AUF1 led to the decreased expression of Dicer1 and miR-122, while the level of the miR-122 precursor (pre-miR-122) was increased. On the other hand, siRNA of AUF1 (siAUF1) increased the levels of Dicer1 mRNA and miR-122, but it reduced the abundance of pre-miR-122. Consistent with the reported data, this study demonstrated that AUF1 and Dicer1 showed opposite expression pattern in both human HCC tissues and cell lines. In addition, AUF1 inhibited the expression of Dicer1 by interacting with the 3′ untranslated region (3′UTR) and coding region of DICER1 mRNA. Moreover, the knockdown of AUF1 by siRNA altered the expression of other miRNAs and promoted HCC cell death. In conclusion, AUF1 down-regulates the expression miR-122 by interacting with the 3′UTR and coding region of DICER1 mRNA and suppressing Dicer1 expression. The AUF1/Dicer1/miR-122 pathway might play a critical role in the development of HCC.

RNA-binding factor 1 (AUF1) was found to be up-regulated in numerous tumors compared with untransformed tissues. Furthermore, it has been identified to regulate mRNAs en masse in hepatocellular carcinoma (HCC). Metadherin (MTDH) as a novel oncogene also promotes tumor progression and metastasis in HCC. Our study aimed to investigate the correlation between AUF1 and MTDH expressions by immunochemistry in 146 HCC patients from Heilongjiang region. AUF1 expression in HCC tumors was higher than that in the matched normal liver tissues. Particularly, AUF1 overexpression was closely associated with tumor size (P < 0.022), TNM stage (P < 0.003), hepatitis B surface antigen status, and AFP serum levels (P < 0.05). Furthermore, AUF1 overexpression led to poor outcome during 5-year follow-up (P < 0.001). Additionally, AUF1 and MTDH expressions were correlated with each other. Our findings suggest that the AUF1 gene may play an important role in HCC progression and be a novel biomarker in the future.