Interaction between ZBP-89 and p53 mutants and its contribution to effects of HDACi on hepatocellular carcinoma

A study on construction of a prognosis model for liver cancer based on analgesic targets and screening therapeutic drugs

BACKGROUND

Liver cancer is one of the most malignant liver diseases in the world, and the 5-year survival rate of such patients is low. Analgesics are often used to cure pain prevalent in liver cancer. The expression changes and clinical significance of the analgesic targets (ATs) in liver cancer have not been deeply understood.

OBJECTIVE

The purpose of this study is to clarify the expression pattern of ATs gene in liver cancer and its clinical significance. Through the comprehensive analysis of transcriptome data and clinical parameters, the prognosis model related to ATs gene is established, and the drug information sensitive to ATs is mined.

METHODS

The study primarily utilized transcriptomic data and clinical information from liver cancer patients sourced from The Cancer Genome Atlas (TCGA) database. These data were employed to analyze the expression of ATs, conduct survival analysis, gene set variation analysis (GSVA), immune cell infiltration analysis, establish a prognostic model, and perform other bioinformatic analyses. Additionally, data from liver cancer patients in the International Cancer Genome Consortium (ICGC) were utilized to validate the accuracy of the model. Furthermore, the impact of analgesics on key genes in the prognostic model was assessed using data from the Comparative Toxicogenomics Database (CTD).

RESULTS

The study investigated the differential expression of 58 ATs genes in liver cancer compared to normal tissues. Patients were stratified based on ATs expression, revealing varied survival outcomes. Functional enrichment analysis highlighted distinctions in spindle organization, centrosome, and spindle microtubule functions. Prognostic modeling identified low TP53 expression as protective, while elevated CCNA2, NEU1, and HTR2C levels posed risks. Commonly used analgesics, including acetaminophen and others, were found to influence the expression of these genes. These findings provide insights into potential therapeutic strategies for liver cancer and shed light on the molecular mechanisms underlying its progression.

CONCLUSIONS

The collective analysis of gene signatures associated with ATs suggests their potential as prognostic predictors in hepatocellular carcinoma patients. These findings not only offer insights into cancer therapy but also provide novel avenues for the development of indications for analgesics.

Identification and validation of three core genes in p53 signaling pathway in hepatitis B virus-related hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a common cancer and the leading cause is persistent hepatitis B virus (HBV) infection. We aimed to identify some core genes and pathways for HBV-related HCC.

METHODS

Gene expression profiles of GSE62232, GSE121248, and GSE94660 were available from Gene Expression Omnibus (GEO). The GSE62232 and GSE121248 profiles were the analysis datasets and GSE94660 was the validation dataset. The GEO2R online tool and Venn diagram software were applied to analyze commonly differentially expressed genes between HBV-related HCC tissues and normal tissues. Then, functional enrichment analysis using Gene Ontology (GO) and the Kyoto Encyclopedia of Gene and Genome (KEGG) as well as the protein-protein interaction (PPI) network was conducted. The overall survival rates and the expression levels were detected by Kaplan-Meier plotter and Gene Expression Profiling Interactive Analysis (GEPIA). Next, gene set enrichment analysis (GSEA) was performed to verify the KEGG pathway analysis. Furthermore, quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was performed to validate the levels of these three core genes in tumor tissues and adjacent non-tumor liver tissues from 12 HBV related HCC patients, HBV-associated liver cancer cell lines and normal liver cell lines, and HepG2 with p53 knockdown or deletion, respectively.

RESULTS

Fifteen highly expressed genes associated with significantly worse prognoses were selected and CCNB1, CDK1, and RRM2 in the p53 signaling pathway were identified as core genes. GSEA results showed that samples highly expressing three core genes were all enriched in the p53 signaling pathway in a validation dataset (P < 0.0001). The expression of these three core genes in tumor tissue samples was higher than that in relevant adjacent non-tumor liver tissues (P < 0.0001). Furthermore, we also found that the above genes were highly expressed in liver cancer cell lines compared with normal liver cells. In addition, we found that the expression of these three core genes in p53 knockdown or knockout HCC cell lines was lower than that in negative control HCC cell lines (P < 0.05).

CONCLUSIONS

CCNB1, CDK1, and RRM2 were enriched in the p53 signaling pathway and could be potential biomarkers and therapeutic targets for HBV-related HCC.

SPAG5 interacts with CEP55 and exerts oncogenic activities via PI3K/AKT pathway in hepatocellular carcinoma

Background

Deregulation of microtubules and centrosome integrity is response for the initiation and progression of human cancers. Sperm-associated antigen 5 (SPAG5) is essential for the spindle apparatus organization and chromosome segregation, but its role in hepatocellular carcinoma (HCC) remains undefined.

Methods

The expression of SPAG5 in HCC were examined in a large cohort of patients by RT-PCR, western blot and IHC. The clinical significance of SPAG5 was next determined by statistical analyses. The biological function of SPAG5 in HCC and the underlying mechanisms were investigated, using in vitro and in vivo models.

Results

Here, we demonstrated that SPAG5 exhibited pro-HCC activities via the activation of PI3K/AKT signaling pathway. SPAG5 expression was increased in HCC and correlated with poor outcomes in two independent cohorts containing 670 patients. High SPAG5 expression was associated with poor tumor differentiation, larger tumor size, advanced TNM stage, tumor vascular invasion and lymph node metastasis. In vitro and in vivo data showed that SPAG5 overexpression promoted tumor growth and metastasis, whereas SPAG5 knockdown led to the opposite phenotypes. SPAG5 interacted with centrosomal protein CEP55 to trigger the phosphorylation of AKT at Ser473. Inhibition of PI3K/AKT signaling markedly attenuated SPAG5-mediated cell growth. Furthermore, SPAG5 expression was suppressed by miR-363-3p which inhibited the activity of SPAG5 mRNA 3’UTR. Ectopic expression of SPAG5 partly abolished the miR-363-3p-caused cell cycle arrest and suppression of cell proliferation and migration.

Conclusions

Collectively, these findings indicate that SPAG5 serves a promising prognostic factor in HCC and functions as an oncogene via CEP55-mediated PI3K/AKT pathway. The newly identified miR-363-3p/SPAG5/CEP55 axis may represent a potential therapeutic target for the clinical intervention of HCC.

Electronic supplementary material

The online version of this article (10.1186/s12943-018-0872-3) contains supplementary material, which is available to authorized users.

Histone deacetylase inhibitor quisinostat activates caspase signaling and upregulates p53 acetylation to inhibit the proliferation of HepG2 cells

Histone deacetylase inhibitor (HDACi) has been a major target of anticancer agents. Quisinostat (JNJ‑26481585), a novel second‑generation HDACi, has previously demonstrated antiproliferative activity against non‑small cell lung cancer; however, the function of quisinostat in hepatocellular carcinoma (HCC) remains to be elucidated. In the present study, it was revealed that quisinostat suppressed the cell viability of HepG2 cells in vitro and in vivo. Increased cell apoptosis was observed in quisinostat‑treated HepG2 cells. The underlying mechanism revealed that quisinostat treatment activates the cleavage of caspase proteins. Furthermore, quisinostat upregulated p53 acetylation at K381/K382 sites by impairing the interaction between histone deacetylase 6 and p53, which resulted in the activation of p53, and triggered cell cycle arrest at the G1 phase. Collectively, the results of the present study demonstrated the antiproliferative effect of quisinostat on HepG2 cells; these results suggest that histone deacetylase may be a promising therapeutic target of HCC.

TRIM65 triggers β-catenin signaling via ubiquitylation of Axin1 to promote hepatocellular carcinoma

Deregulation of ubiquitin ligases contributes to the malignant progression of human cancers. Tripartite motif-containing protein 65 (TRIM65) is an E3 ubiquitin ligase and has been implicated in human diseases, but its role and clinical significance in hepatocellular carcinoma (HCC) remain unknown. Here, we showed that TRIM65 expression was increased in HCC tissues and associated with poor outcome in two independent cohorts containing 888 patients. In vitro and in vivo data demonstrated that overexpression of TRIM65 promoted cell growth and tumor metastasis, whereas knockdown of TRIM65 resulted in opposite phenotypes. Further studies revealed that TRIM65 exerted oncogenic activities via ubiquitylation of Axin1 to activate the β-catenin signaling pathway. TRIM65 directly bound to Axin1 and accelerated its degradation through ubiquitylation. Furthermore, HMGA1 was identified as an upstream regulator of TRIM65 in HCC cells. In clinical samples, TRIM65 expression was positively correlated with the expression of HMGA1 and nuclear β-catenin. Collectively, our data indicate that TRIM65 functions as an oncogene in HCC. The newly identified HMGA1/TRIM65/β-catenin axis serves as a promising prognostic factor and therapeutic target.

ZBP-89 reduces histone deacetylase 3 by degrading IkappaB in the presence of Pin1

BACKGROUND

Histone deacetylase 3 (HDAC3) is overexpressed in cancers and its inhibition enhances anti-tumor chemotherapy. ZBP-89, a transcription factor, can induce pro-apoptotic Bak and reduce HDAC3 but the mechanism is unknown. Pin1, a molecular switch that determines the fate of phosphoproteins, is known to interact with HDAC3. The aim of this study was to investigate the mechanism how ZBP-89 downregulated HDAC3.

METHODS

In this study, liver cells, Pin1-knockout Pin1(-/-) and Pin1 wild-typed Pin(+/+) cells were used to explore how ZBP-89 reduced HDAC3. The overexpression of ZBP-89 was achieved by infecting cells with Ad-ZBP-89, an adenoviral construct containing ZBP-89 gene. The role of NF-κB was determined using CAY10576, MG132 and SN50, the former two being inhibitors of IκB degradation and SN50 being an inhibitor of p65/p50 translocation. A xenograft tumor model was used to confirm the in vitro data.

RESULTS

ZBP-89 reduced HDAC3, and it could form a complex with IκB and induce IκB phosphorylation to inhibit IκB. Furthermore, ZBP-89-mediated HDAC3 reduction was suppressed by IκB degradation inhibitors CAY10576 and MG132 but not by p65/p50 translocation inhibitor SN50, indicating that IκB decrease rather than the elevated activity of NF-κB contributed to HDAC3 reduction. ZBP-89-mediated HDAC3 or IκB reduction was significantly less obvious in Pin1(-/-) cells compared with Pin1(+/+) cells. In Ad-ZBP-89-infected Pin1(+/+) cancer cells, Pin1 siRNA increased HDAC3 but decreased Bak, compared with cells without ZBP-89 infection. These findings indicate that Pin1 participates in ZBP-89-mediated HDAC3 downregulation and Bak upregulation. The cell culture result was confirmed by in vivo mouse tumor model experiments.

CONCLUSIONS

ZBP-89 attenuates HDAC3 by increasing IκB degradation. Such attenuation is independent of NF-κB activity but partially depends on Pin1. The novel pathway identified may help generate new anti-cancer strategy by targeting HDAC3 and its related molecules.

Epigenetic upregulation of Bak by ZBP-89 inhibits the growth of hepatocellular carcinoma

Zinc-binding protein-89 regulates Bak to facilitate apoptosis in cancer cells. This study examined if zinc-binding protein-89 regulates Bak through an epigenetic mechanism in hepatocellular carcinoma. We first demonstrated that the expression of Bak was reduced but the levels of deoxyribonucleic acid methyltransferase 1 and histone deacetylase 3 were increased in hepatocellular carcinoma cancer tissues compared to the corresponding non-cancer tissues. Moreover, there was a negative correlation between Bak expression and deoxyribonucleic acid methyltransferase 1 levels in hepatocellular carcinoma. Administration of zinc-binding protein-89 downregulated histone deacetylase 3 expression and suppressed the activities of histone deacetylase and deoxyribonucleic acid methyltransferase, which led to maintenance of histone acetylation status, inhibited the binding of methyl-CpG-binding protein 2 to genomic deoxyribonucleic acid and demethylated CpG islands in the Bak promoter in hepatocellular carcinoma cells. Using the xenograft mouse tumor model, we demonstrated that zinc-binding protein-89 or inhibitors of either epigenetic enzymes could stimulate Bak expression, induce apoptosis, and arrest tumor growth and that the maximal effort was achieved when zinc-binding protein-89 and the enzyme inhibitors were used in combination. Conclusively, zinc-binding protein-89 upregulates the expression of Bak by targeting multiple components of the epigenetic pathway in hepatocellular carcinoma.

Histone deacetylase inhibitors facilitate dihydroartemisinin-induced apoptosis in liver cancer in vitro and in vivo

Liver cancer ranks in prevalence and mortality among top five cancers worldwide. Accumulating interests have been focused in developing new strategies for liver cancer treatment. We have previously showed that dihydroartemisinin (DHA) exhibited antitumor activity towards liver cancer. In this study, we demonstrated that histone deacetylase inhibitors (HDACi) significantly augmented the antineoplastic effect of DHA via increasing apoptosis in vitro and in vivo. Inhibition of ERK phosphorylation contributed to DHA-induced apoptosis, due to the fact that inhibitor of ERK phosphorylation (PD98059) increased DHA-induced apoptosis. Compared with DHA alone, the combined treatment with DHA and HDACi reduced mitochondria membrane potential, released cytochrome c into cytoplasm, increased p53 and Bak, decreased Mcl-1 and p-ERK, activated caspase 3 and PARP, and induced apoptotic cells. Furthermore, we showed that HDACi pretreatment facilitated DHA-induced apoptosis. In Hep G2-xenograft carrying nude mice, the intraperitoneal injection of DHA and SAHA resulted in significant inhibition of xenograft tumors. Results of TUNEL and H&E staining showed more apoptosis induced by combined treatment. Immunohistochemistry data revealed the activation of PARP, and the decrease of Ki-67, p-ERK and Mcl-1. Taken together, our data suggest that the combination of HDACi and DHA offers an antitumor effect on liver cancer, and this combination treatment should be considered as a promising strategy for chemotherapy.