EVI1 promotes cell proliferation in HBx-induced hepatocarcinogenesis as a critical transcription factor regulating lncRNAs

Anti-hepatocellular carcinoma activity of the cyclin-dependent kinase inhibitor AT7519

Hepatocellular carcinoma (HCC) is one of the most common cancerous tumors and one of the leading causes of death among cancer-related disorders. Chemotherapy is ineffective in HCC patients, and the number of drugs that are in use is limited. Thus, new molecules are needed that could increase the effectiveness of anti-HCC regimens. Here, we show that AT7519, a CDK inhibitor, exerts positive effects on HCC cells: it inhibits proliferation, migration and clonogenicity. Detailed analysis of the transcriptomes of cells treated with this compound indicated that AT7519 affects a substantial portion of genes that are associated with HCC development and progression. Moreover, we showed that the concomitant use of AT7519 with gefitinib or cabozantinib sensitized HCC cells to these drugs. Thus, our research indicates that AT7519 is worth considering in monotherapy for hepatocellular carcinoma patients or in combination with other drugs, e.g., gefitinib or cabozantinib.

JAM-A signals through the Hippo pathway to regulate intestinal epithelial proliferation

JAM-A is a tight-junction-associated protein that contributes to regulation of intestinal homeostasis. We report that JAM-A interacts with NF2 and LATS1, functioning as an initiator of the Hippo signaling pathway, well-known for regulation of proliferation. Consistent with these findings, we observed increased YAP activity in JAM-A-deficient intestinal epithelial cells (IEC). Furthermore, overexpression of a dimerization-deficient mutant, JAM-A-DL1, failed to initiate Hippo signaling, phenocopying JAM-A-deficient IEC, whereas overexpression of JAM-A-WT activated Hippo signaling and suppressed proliferation. Lastly, we identify EVI1, a transcription factor reported to promote cellular proliferation, as a contributor to the pro-proliferative phenotype in JAM-A-DL1 overexpressing IEC downstream of YAP. Collectively, our findings establish a new role for JAM-A as a cell-cell contact sensor, raising implications for understanding the contribution(s) of JAM-A to IEC proliferation in the mammalian epithelium.

Long non‑coding RNAs in HBV‑related hepatocellular carcinoma (Review)

Hepatitis B virus (HBV)‑related hepatocellular carcinoma (HCC) is a global health problem that accounts for more than half of total liver cancer cases in developing countries. Despite the growing number of researches conducted, the molecular mechanism underlying the development of HCC remains elusive. Long non‑coding RNAs (lncRNAs), which are non‑coding RNAs >200 nt in length that were previously considered to be transcriptional noise, have been found to be dysregulated in HBV‑related HCC with the help of high‑throughput omics techniques. Subsequent investigations revealed that aberrant expression of lncRNAs may affect the risk of HBV‑related HCC through diverse mechanisms, including epigenetic silencing of transcriptional activation, alternative splicing, molecular sponging, modulating protein stability, and by serving as precursors of miRNAs. Although the sensitivity and specificity of lncRNAs must be further validated, a number of circulating lncRNAs have been identified as useful biomarkers for HBV‑related HCC. In addition to these findings, recent studies also unveiled that certain genetic polymorphisms in lncRNAs may affect the occurrence and prognosis of HBV‑related HCC. The aim of the present review was to provide an overview of the mechanisms underlying the involvement of lncRNAs in HBV‑related HCC. Subsequently, lncRNAs found to be dysregulated in HBV‑related HCC were focused on and current findings on circulating lncRNAs and their genetic polymorphisms were discussed.

ER stress regulating protein phosphatase 2A-B56γ, targeted by hepatitis B virus X protein, induces cell cycle arrest and apoptosis of hepatocytes

Hepatitis B virus X (HBx) protein contributes to the progression of hepatitis B virus (HBV)-related hepatic injury and diseases, but the exact mechanism remains unclear. Protein phosphatase 2 A (PP2A) is a major serine/threonine phosphatase involved in regulating many cellular phosphorylation signals that are important for regulation of cell cycle and apoptosis. Does HBx target to PP2A-B56γ and therefore affect HBx-induced hepatotoxicity? In the present study, the expression of B56γ positively correlated with the level of HBx in HBV-infected primary human hepatocytes in human-liver-chimeric mice, HBx-transgenic mice, HBV-infected cells, and HBx-expressing hepatic cells. B56γ promoted p53/p21-dependent cell cycle arrest and apoptosis. Mechanistically, B56γ was transactivated by AP-1, which was under the regulation of endoplasmic reticulum (ER) stress induced CREBH signaling in HBx-expressing hepatic cells. B56γ dephosphorylated p-Thr55-p53 to trigger p53/p21 pathway-dependent cell cycle G1 phase arrest, resulting in apoptosis of hepatic cells. In conclusion, this study provides a novel insight into a mechanism of B56γ mediating cell cycle arrest and apoptosis of HBx-expressing hepatic cells and a basis for B56γ being a potential therapeutic target for HBV-infected hepatic cells.

Prediction of early-stage hepatocellular carcinoma using OncoScan chromosomal copy number aberration data

AIM

To identify chromosomal copy number aberrations (CNAs) in early-stage hepatocellular carcinoma (HCC) and analyze whether they are correlated with patient prognosis.

METHODS

One hundred and twenty patients with early-stage HCC were enrolled in our study, with the collection of formalin fixed, paraffin-embedded (FFPE) specimens and clinicopathological data. Tumor areas were marked by certified pathologists on a hematoxylin and eosin-stained slide, and cancer and adjacent non-cancerous tissues underwent extraction of DNA, which was analyzed with the Affymetrix OncoScan platform to assess CNAs and loss of heterozygosity (LOH). Ten individuals with nonmalignant disease were used as the control group. Another cohort consisting of 40 patients with stage I/II HCC were enrolled to analyze gene expression and to correlate findings with the OncoScan data.

RESULTS

Copy number amplifications occurred at chromosomes 1q21.1-q44 and 8q12.3-24.3 and deletions were found at 4q13.1-q35.2, 8p 23.2-21.1, 16q23.3-24.3, and 17p13.3-12, while LOH commonly occurred at 1p32.3, 3p21.31, 8p23.2-21.1, 16q22.1-24.3, and 17p 13.3-11 in early-stage HCC. Using Cox regression analysis, we also found that a higher percentage of genome change (≥ 60%) was an independent factor for worse prognosis in early-stage HCC (P = 0.031). Among the 875 genes in the OncoScan GeneChip, six were independent predictors of worse disease-free survival, of which three were amplified (MYC, ELAC2, and SYK) and three were deleted (GAK, MECOM, and WRN). Further, patients with HCC who exhibited ≥ 3 CNAs involving these six genes have worse outcomes compared to those who had < 3 CNAs (P < 0.001). Similarly, Asian patients with stage I HCC from The Cancer Genome Atlas harboring CNAs with these genes were also predicted to have poorer outcomes.

CONCLUSION

Patients with early-stage HCC and increased genome change or CNAs involving MYC, ELAC2, SYK, GAK, MECOM, or WRN are at risk for poorer outcome after resection.

Linc00152 promotes cancer progression in hepatitis B virus-associated hepatocellular carcinoma

BACKGROUND

The X protein (HBx) plays as a key role in hepatocarcinogenesis associated with hepatitis B virus (HBV) infections. The study aimed to figure out the role of Linc00152 in hepatocellular carcinoma (HCC) and the association between the expression levels of Linc00152 and HBx.

METHODS

QRT-PCR assays were applied to analyzed the expression levels of Linc00152 and HBx. Kaplan-Meier survival curve was performed to identify the association between LINC00152 and the over survival time (OS) in HCC patients. Cell growth and invasion ability was evaluated by CCK8 cell proliferation and transwell invasion assays. Western-blot analysis was detected the protein expression. RNA immunoprecipitation (RIP), RNA-pull down and chromatin Immunoprecipitation (ChIP) assays was also been carried out.

RESULTS

We demonstrated that LINC00152 expression in hepatocellular carcinoma (HCC) patients was significantly higher compared with adjacent non-tumour tissues and positively correlated with tumor size, HBV infection (HBsAg) and tumor number. Patient with hepatitis B virus (HBV) infection HCC was higher expression than that without HBV. Furthermore, the expression levels of Linc00152 were positively correlated with HBx expression in HCC tissues and higher Linc00152 expression levels were correlated with poor prognosis of HCC patients. In vitro, Linc00152 was up-regulated in Huh-7 and SM7721 cells after overexpression of HBx and down-regulated after silencing HBx. Furthermore, silencing Linc00152 suppressed the cell proliferation and invasion. Moreover, we found that Linc00152 inhibited the E-cadherin expression via interacting with EZH2 and promoted the Epithelial-mesenchymal transition (EMT) phenomenon in HCC cells.

CONCLUSIONS

These results suggested that HBx enhanced LINC00152 expression and inhibition of LINC00152 could provide a therapeutic target for HCC.