Weifeng Shen

Long noncoding RNA GIHCG promotes hepatocellular carcinoma progression through epigenetically regulating miR-200b/a/429

Long noncoding RNAs (lncRNAs) have been reported to play pivotal roles in a variety of cancers. However, lncRNAs involved in hepatocellular carcinoma (HCC) initiation and progression remain largely unclear. In this study, we identified an lncRNA gradually increased during hepatocarcinogenesis (lncRNA-GIHCG) using publicly available microarray data. Our results further revealed that GIHCG is upregulated in HCC tissues in comparison with adjacent non-tumor tissues. High GIHCG expression is correlated with large tumor size, microvascular invasion, advanced BCLC stage, and poor survival of HCC patients. Functional experiments showed that GIHCG promotes HCC cells proliferation, migration, and invasion in vitro, and promotes xenografts growth and metastasis in vivo. Mechanistically, we demonstrated that GIHCG physically associates with EZH2 and the promoter of miR-200b/a/429, recruits EZH2 and DNMT1 to the miR-200b/a/429 promoter regions, upregulates histone H3K27 trimethylation and DNA methylation levels on the miR-200b/a/429 promoter, and dramatically silences miR-200b/a/429 expression. Furthermore, the biological functions of GIHCG on HCC are dependent on the silencing of miR-200b/a/429. Collectively, our results demonstrated the roles and functional mechanisms of GIHCG in HCC, and indicated GIHCG may act as a prognostic biomarker and potential therapeutic target for HCC.Key MessagelncRNA-GIHCG is upregulated in HCC and associated with poor survival of patients.GIHCG significantly promotes tumor growth and metastasis of HCC.GIHCG physically associates with EZH2.GIHCG upregulates H3K27me3 and DNA methylation levels on the miR-200b/a/429 promoter.GIHCG epigenetically silences miR-200b/a/429 expression.

A let-7/Fas double-negative feedback loop regulates human colon carcinoma cells sensitivity to Fas-related apoptosis

Interferon-γ (IFN-γ) is considered essential for the regulation of anti-tumor reactions as it sensitizes Fas-related apoptosis in HT29 cells, but the mechanism is unclear. In the current study, our data demonstrated that IFN-γ stimulation and Fas activation suppressed Dicer processing and let-7 microRNA biogenesis, while let-7 microRNA strongly inhibited Fas expression by directly targeting Fas mRNA. Accordingly, our results indicate that Fas and let-7 microRNAs form a double-negative feedback loop in IFN-γ and Fas induced apoptosis in colon carcinoma cell line HT29, which may be an important synergistic mechanism in anti-tumor immune response. We also found that a let-7 microRNA inhibitor increased Fas expression and sensitized cells to Fas-related apoptosis, which may have future implications in colon carcinoma therapy.

Methylation patterns of estrogen receptor α promoter correlate with estrogen receptor α expression and clinicopathological factors in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the seventh most common type of cancer; notably, the incidence of HCC is four to eight times higher in men than women. Previous studies reported that the estrogen receptor (ER) signaling pathway is involved in the pathogenesis of HCC, although the extent of its involvement is unclear due to several conflicting reports. In the present study, tumor and paired adjacent non-cancerous tissues from 157 HCC patients were collected. Transcriptome sequencing and real-time quantitative polymerase chain reaction were used to quantify the ER α (ESR1) expression levels, and the Sequenom EpiTYPER assay was used to delineate the methylation patterns in the ESR1 promoter. We found that ESR1 expression was significantly reduced in tumor tissues (P < 0.001) compared to adjacent non-cancerous tissues. The CpG sites around the transcription start site were significantly hypermethylated in the tumor (P < 0.0001). This methylation pattern also correlated with the gene expression (P < 0.0001). Additionally, we found that the hypermethylation of ESR1 was associated with the presence of fibrous capsules (P = 1.2 × 10−4), the absence of microvascular invasions (P = 8.0 × 10−4), thin trabecular pattern (P = 0.025), and lower histologic gradings (P = 5.2 × 10−3). Thus, ESR1 expression is a candidate tumor suppressor gene in HCC. Further, promoter hypermethylation may be a mechanism by which expression of ESR1 is repressed, and the extent of hypermethylation of ESR1 may be a marker for HCC status and progression.

Overexpression of miR-218 inhibits hepatocellular carcinoma cell growth through RET

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world with poor prognosis. Here, we investigated the role of microRNA 218 (miR-218) in regulating human HCC development. Quantitative PCR (qPCR) was used to compare the expression levels of miR-218 between eight HCC and a normal liver cell lines, as well as nine primary HCC tissues and adjacent non-carcinoma tissues. HCC cell lines MHCC97L and Huh7 were transfected with lentiviral vector of miR-218 mimics. The effect of miR-218 overexpression on cancer cell growth, both in vitro and in vivo, as well as cancer cell invasion was examined. A bioinformatic method was used to predict the binding of miR-218 to RET proto-oncogene (RET). Small interfering RNA (SiRNA)-mediated genetic knock-down of RET was performed in MHCC97L and Huh7 cells, and its modulatory effect on miR-218-mediated HCC development was examined. miR-218 was found to be downregulated in HCC cell lines and primary HCC tissues. Overexpression of miR-218 in MHCC97L or Huh7 cells resulted in significant decrease in cell proliferation and invasion capability. Overexpression of miR-218 also reduced the tumor growth of xenografted Huh7 cells in vivo. The expression of endogenous RET was found to be upregulated by miR-218, and siRNA-induced RET downregulation resulted in phosphatase and tensin homolog deleted on chromosome 10 (PTEN) upregulation and reversal of the inhibitory effect of miR-218 upregulation on HCC proliferation. Our results indicate that miR-218 modulates HCC development, and this effect may be through RET and PTEN.

Potential Role of MicroRNA-210 as Biomarker in Human Cancers Detection: A Meta-Analysis.

We conducted this meta-analysis aimed to evaluate diagnostic accuracy of miR-210 in human cancers. A total of 673 cancer patients and 606 cancer-free individuals from 13 studies were contained in this meta-analysis. The overall diagnostic results in our study showed that the pooled sensitivity was 0.70, specificity was 0.76, and the AUC was 0.80. In addition, the PLR and NLR were 2.9 and 0.39, with DOR of 8. After the outliner exclusion detected by sensitivity analysis, these parameters had minimal change, which confirmed the stability of our work. The results in our studies showed that the miR-210 assay yielded relatively moderate accuracy in cancer patients and cancer-free individual differentiation. More basic researches are needed to highlight its role as supplement in clinical treatment.

PEG10 is imperative for TGF-β1-induced epithelial‑mesenchymal transition in hepatocellular carcinoma

Substantial evidence indicates that transforming growth factor-beta 1 (TGF-β1) plays a vital role in epithelial-mesenchymal transition (EMT). PEG10 has been shown involved in invasion and metastasis of tumors. The present study investigated the role of PEG10 in TGF-β1-triggered EMT in hepatocellular carcinoma (HCC) progression. Immunohistochemistry and real-time PCR were used to measure the expression level of PEG10 in clinical HCC tissues with or without lymph node metastasis, and normal tissues. The results showed that PEG10 expression is higher in HCC tissues and associated with overall survival (OS) and lymph node metastasis. Moreover, PEG10 expression level was remarkably higher in hepatic cancer cells than the normal hepatic cell line L02. In the present study, we constructed an adenovirus vector containing the coding area of PEG10 (Ad-PEG10) and infected HepG2 cells and found that overexpression of PEG10 promoted the cell migration, invasion ability and EMT of HepG2 cells. TGF-β1 acted on HepG2 cells by enhancing cell migration, invasion, EMT and upregulating PEG10 expression level. However, cells pretreated with adenovirus vector of PEG10 shRNAs (Ad-shRNA1 and Ad-shRNA2) did not occur EMT prior to TGF-β1 stimulation. Moreover, TGF-β1 did not increase the migration and invasion of cells with PEG10 knockdown and overexpression of PEG10 confers chemoresistance to HepG2 cells. Accordingly, sufficient PEG10 expression level is essential for TGF-β1 induced EMT and associated with the chemoresistance in HepG2 cells.