Expressions of heparanase and upstream stimulatory factor in hepatocellular carcinoma

USF1 modulates transcription and cellular functions by regulating multiple transcription factors in Huh7 cells

Liver cancer, including hepatocellular carcinoma (HCC), is a malignant tumor that has high rates of metastasis and mortality worldwide. Upstream transcription factor 1 (USF1) is a canonical transcription factor (TF) and is associated with the pathogenesis of several cancers, but its biological functions and molecular targets in HCC remain unclear. Huh7 cells that overexpress USF1 were used with whole transcriptome profiling through RNA sequencing and chromatin immunoprecipitation (ChIP) sequencing methods to investigate the downstream targets of USF1. Reverse transcription-quantitative PCR was then used to validate the downstream targets. The results showed that USF1 significantly regulates 350 differentially expressed genes (DEGs). The upregulated DEGs were primarily protein-coding genes enriched in immune and inflammation response pathways, while the downregulated DEGs were mainly coding long non-coding (lnc)RNAs, indicating the regulatory function of USF1. It was also demonstrated that USF1 directly binds to the promoter region of 2,492 genes, which may be involved in the viral progression and cell proliferation pathways. By integrating these two datasets, 16 overlapped genes were detected, including downregulated lncRNA-NEAT1 and upregulated TF-ETV5. The downregulated lncRNA-NEAT1 showed reverse expression pattern and prognosis result compared with that of USF1 in patients with liver cancer, while upregulated TF-ETV5 showed consistent results with USF1. Promoter region motif analysis indicated that ETV5 has more binding motifs and genes than USF1 itself for USF1-regulated DEGs, indicating that USF1 may indirectly modulate gene expression by regulating ETV5 expression in Huh7 cells. The study also validated the direct interaction between USF1 and the promoter of ETV5 using ChIP-qPCR. In summary, the results demonstrated that USF1 binds to the promoter region of thousands of genes and affects a large part of DEGs indirectly. Downstream genes, including lncRNA-NEAT1 and TF-ETV5, may also have potential functions in the regulated network by USF1 and have potential functions in the progression of HCC. The present findings suggested that USF1 and its downstream targets could be potential targets for HCC therapy in the future.

Silencing RPL8 inhibits the progression of hepatocellular carcinoma by down-regulating the mTORC1 signalling pathway

This study aimed to explore the role of ribosomal protein L8 (RPL8) in controlling hepatocellular carcinoma (LIHC) development. We measured RPL8 expression, apoptosis, cell viability, proliferation, migration, invasion, glucose uptake, lactate production, and the ATP/ADP ratio of LIHC cells to investigate the effect of RPL8 on LIHC. Bioinformatic analysis was employed to analyse RPL8 expression and its potential mechanism in LIHC. RPL8 was upregulated in LIHC tissues and cells. RPL8 silencing accelerated apoptosis and suppressed viability, growth, and movement of LIHC cells. Additionally, RPL8 silencing inhibited glycolysis in LIHC cells. Bioinformatic analysis revealed that RPL8 is regulated by the upstream transcription factor upstream stimulating factor 1 (USF1) and activates the mTORC1 signalling pathway. USF1 overexpression eliminated the inhibitory effect of RPL8 silencing in LIHC cells. RPL8 overexpression increased cell growth, movement, and glycolysis in LIHC. However, inhibition of the mTORC1 signalling pathway eliminated the effect of RPL8 overexpression on LIHC cells. In conclusion, RPL8 may affect LIHC progression by regulating the mTORC1 signalling pathway.

Heparanase-1: From Cancer Biology to a Future Antiviral Target

Heparan sulfate proteoglycans (HSPGs) are a major constituent of the extracellular matrix (ECM) and are found to be implicated in viral infections, where they play a role in both cell entry and release for many viruses. The enzyme heparanase-1 is the only known endo-beta-D-glucuronidase capable of degrading heparan sulphate (HS) chains of HSPGs and is thus important for regulating ECM homeostasis. Heparanase-1 expression is tightly regulated as the uncontrolled cleavage of HS may result in abnormal cell activation and significant tissue damage. The overexpression of heparanase-1 correlates with pathological scenarios and is observed in different human malignancies, such as lymphoma, breast, colon, lung, and hepatocellular carcinomas. Interestingly, heparanase-1 has also been documented to be involved in numerous viral infections, e.g., HSV-1, HPV, DENV. Moreover, very recent reports have demonstrated a role of heparanase-1 in HCV and SARS-CoV-2 infections. Due to the undenied pro-carcinogenic role of heparanase-1, multiple inhibitors have been developed, some reaching phase II and III in clinical studies. However, the use of heparanase inhibitors as antivirals has not yet been proposed. If it can be assumed that heparanase-1 is implicated in numerous viral life cycles, its inhibition by specific heparanase-acting compounds should result in a blockage of viral infection. This review addresses the perspectives of using heparanase inhibitors, not only for cancer treatment, but also as antivirals. Eventually, the development of a novel class antivirals targeting a cellular protein could help to alleviate the resistance problems seen with some current antiretroviral therapies.

USF2-mediated upregulation of TXNRD1 contributes to hepatocellular carcinoma progression by activating Akt/mTOR signaling

Thioredoxin reductase 1 (TXNRD1) is one of the major redox regulators in mammalian cells, which has been reported to be involved in tumorigenesis. However, its roles and regulatory mechanism underlying the progression of HCC remains poorly understood. In this study, we demonstrated that TXNRD1 was significantly upregulated in HCC tumor tissues and correlated with poor survival in HCC patients. Functional studies indicated TXNRD1 knockdown substantially suppressed HCC cell proliferation and metastasis both in vitro and in vivo, and its overexpression showed opposite effects. Mechanistically, TXNRD1 attenuated the interaction between Trx1 and PTEN which resulting in acceleration of PTEN degradation, thereby activated Akt/mTOR signaling and its target genes which conferred to elevated HCC cell mobility and metastasis. Moreover, USF2 was identified as a transcriptional suppressor of TXNRD1, which directly interacted with two E-box sites in TXNRD1 promoter. USF2 functioned as tumor suppressor through the downstream repression of TXNRD1. Further clinical data revealed negative co-expression correlations between USF2 and TXNRD1. In conclusion, our findings reveal that USF2-mediated upregulation of TXNRD1 contributes to hepatocellular carcinoma progression by activating Akt/mTOR signaling.

Computational modeling of chromatin accessibility identified important epigenomic regulators

Chromatin accessibility is essential for transcriptional activation of genomic regions. It is well established that transcription factors (TFs) and histone modifications (HMs) play critical roles in chromatin accessibility regulation. However, there is a lack of studies that quantify these relationships. Here we constructed a two-layer model to predict chromatin accessibility by integrating DNA sequence, TF binding, and HM signals. By applying the model to two human cell lines (GM12878 and HepG2), we found that DNA sequences had limited power for accessibility prediction, while both TF binding and HM signals predicted chromatin accessibility with high accuracy. According to the HM model, HM features determined chromatin accessibility in a cell line shared manner, with the prediction power attributing to five core HM types. Results from the TF model indicated that chromatin accessibility was determined by a subset of informative TFs including both cell line-specific and generic TFs. The combined model of both TF and HM signals did not further improve the prediction accuracy, indicating that they provide redundant information in terms of chromatin accessibility prediction. The TFs and HM models can also distinguish the chromatin accessibility of proximal versus distal transcription start sites with high accuracy.

Liver-Metastasis-Related Genes are Potential Biomarkers for Predicting the Clinical Outcomes of Patients with Pancreatic Adenocarcinoma

It is widely acknowledged that metastasis determines the prognosis of pancreatic adenocarcinoma (PAAD), and the liver is the most primary distant metastatic location of PAAD. It is worth exploring the value of liver-metastasis-related genetic prognostic signature (LM-PS) in predicting the clinical outcomes of PAAD patients post R0 resection. We collected 65 tumors and 165 normal pancreatic data from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression project (GTEx), respectively. Differentially expressed genes (DEGs) between primary tumor and normal pancreatic samples were intersected with DEGs between primary tumor samples with liver metastasis and those without new tumor events. The intersected 45 genes were input into univariate Cox regression analysis to identify the prognostic genes. Thirty-three prognostic liver-metastasis-related genes were identified and included in least absolute shrinkage and selection operator (LASSO) analysis to develop a seven-gene LM-PS, which included six risk genes (ANO1, FAM83A, GPR87, ITGB6, KLK10, and SERPINE1) and one protective gene (SMIM32). The PAAD patients were grouped into low- and high-risk groups based on the median value of risk scores. The LM-PS harbored an independent predictive ability to distinguish patients with a high-risk of death and liver metastasis after R0 resection. Moreover, a robust prognostic nomogram based on LM-PS, the number of positive lymph nodes, and histologic grade were established to predict the overall survival of PAAD patients. Besides, a transcription factor‐microRNA coregulatory network was constructed for the seven LM-PS genes, and the immune infiltration and genomic alterations were systematically explored in the TGCA-PAAD cohort.

Heparanase induces necroptosis of microvascular endothelial cells to promote the metastasis of hepatocellular carcinoma

Heparanase (HPSE) is a kind of multifunctional extracellular hydrolase, and related to metastasis of hepatocellular carcinoma (HCC). Endothelial necroptosis promotes the metastasis of cancer cells. It is not clear whether HPSE could mediate necroptosis of microvascular endothelial cells (MVECs) to promote HCC metastasis. Here we found HPSE expression was up-regulated in HCC tissues and its over-expression was correlated with multiple tumor foci, microvascular invasion, and poor outcome of HCC patients. Non-contact co-culture experiments showed high-expressed HPSE in HCC cells mediated the necroptosis of human umbilical vein endothelial cells (HUVECs) and elevated the expression levels of syndecan-1 (SDC-1) and tumor necrosis factor-α (TNF-α) in vitro. As a result of necroptosis, trans-endothelial migration (TEM) of HCC cells was increased. Conversely, both HPSE and SDC-1 knockdowns reversed necroptosis and decreased TNF-α expression level, while HPSE over-expression increased SDC-1 and TNF-α expression and aggravated necroptosis. Animal experiments found that the nude mice, intraperitoneally injected with HPSE high expressing HCC cells, had obvious necroptosis of MVECs and high intrahepatic metastasis rate, which could be relieved by inhibitor of necroptosis. Morever, HPSE elevated the expression levels of p38 mitogen-activated protein kinase (p38 MAPK) rather than nuclear factor kappa B in vitro. Our data suggest that HPSE induces necroptosis of MVECs to promote the metastasis of HCC by activating HPSE/SDC-1/TNF-α axis and p38 MAPK pathway.

Cyclin-Dependent Kinase 5 (CDK5)-Mediated Phosphorylation of Upstream Stimulatory Factor 2 (USF2) Contributes to Carcinogenesis

The transcription factor USF2 is supposed to have an important role in tumor development. However, the regulatory mechanisms contributing to the function of USF2 are largely unknown. Cyclin-dependent kinase 5 (CDK5) seems to be of importance since high levels of CDK5 were found in different cancers associated with high USF2 expression. Here, we identified USF2 as a phosphorylation target of CDK5. USF2 is phosphorylated by CDK5 at two serine residues, serine 155 and serine 222. Further, phosphorylation of USF2 at these residues was shown to stabilize the protein and to regulate cellular growth and migration. Altogether, these results delineate the importance of the CDK5-USF2 interplay in cancer cells.

Suppression of metastasis through inhibition of chitinase 3-like 1 expression by miR-125a-3p-mediated up-regulation of USF1

Rationale: Chitinase 3-like 1 (Chi3L1) protein is up-regulated in various diseases including solid cancers. According to Genome-Wide Association Study (GWAS)/Online Mendelian Inheritance in Man (OMIM)/Differentially Expressed Gene (DEG) analyses, Chi3L1 is associated with 38 cancers, and more highly associated with cancer compared to other oncogenes such as EGFR, TNFα, etc. However, the mechanisms and pathways by which Chi3L1 is associated with cancer are not clear. In current study, we investigated the role of Chi3L1 in lung metastasis. Methods: We performed the differentially expressed gene analysis to explore the genes which are associated with Chi3L1 using the web-based platform from Biomart. We investigated the metastases in lung tissues of C57BL/6 mice injected with B16F10 melanoma following treatment with Ad-shChi3L1. We also investigated the expression of USF1 and Chi3L1 in Chi3L1 KD mice lung tissues by Western blotting and IHC. We also analyzed lung cancer cells metastases induced by Chi3L1 using migration and cell proliferation assay in human lung cancer cell lines. The involvement of miR-125a-3p in Chi3L1 regulation was determined by miRNA qPCR and luciferase reporter assay. Results: We showed that melanoma metastasis in lung tissues was significantly reduced in Chi3L1 knock-down mice, accompanied by down-regulation of MMP-9, MMP-13, VEGF, and PCNA in Chi3L1 knock-down mice lung tissue, as well as in human lung cancer cell lines. We also found that USF1 was conversely expressed against Chi3L1. USF1 was increased by knock-down of Chi3L1 in mice lung tissues, as well as in human lung cancer cell lines. In addition, knock-down of USF1 increased Chi3L1 levels in addition to augmenting metastasis cell migration and proliferation in mice model, as well as in human cancer cell lines. Moreover, in human lung tumor tissues, the expression of Chi3L1 was increased but USF1 was decreased in a stage-dependent manner. Finally, Chi3L1 expression was strongly regulated by the indirect translational suppressing activity of USF1 through induction of miR-125a-3p, a target of Chi3L1. Conclusion: Metastases in mice lung tissues and human lung cancer cell lines were decreased by KD of Chi3L1. USF1 bound to the Chi3L1 promoter, however, Chi3L1 expression was decreased by USF1, despite USF1 enhancing the transcriptional activity of Chi3L1. We found that USF1 induced miR-125a-3p levels which suppressed Chi3L1 expression. Ultimately, our results suggest that lung metastasis is suppressed by knock-down of Chi3L1 through miR-125a-3p-mediated up-regulation of USF1.

Heparanase Contributes To Trans-Endothelial Migration of Hepatocellular Carcinoma Cells

The overall outcome of patients with hepatocellular carcinoma (HCC) is still very poor due to its high metastasis and recurrence rate. During metastasis, trans-endothelial migration (TEM) of HCC cells is a key step. Heparanase (HPSE) is an endo-beta-glucuronidase and exerts prometastatic properties for normal and tumor-derived cells. However, it is remains unclear that HPSE contributes to TEM of HCC cells. In this study, human umbilical vein endothelial cells-C (HUVEC-C) was used to simulate vascular endothelial cells (VECs), and the HCCLM3 cells with high HPSE expression were chosen and used for in vitro TEM assay and in vivo experiment. As results, we found that HCCLM3 cells showed higher TEM rate compared with other HCC cells. Downregulation or inhibition of HPSE activity resulted in suppression of TEM of HCC cells both in vitro and in vivo. Our findings suggest that HPSE contributes to TEM of HCC cells, which may be a new biological function of HPSE.

Downregulation of Heparanase Expression Results in Suppression of Invasion, Migration, and Adhesion Abilities of Hepatocellular Carcinoma Cells

Objective. Heparanase (HPSE) is high-expressed in most malignant tumors including hepatocellular carcinoma (HCC) and promotes cancer cell invasion and migration. The aim of the study is to explore whether HPSE enhances adhesion in metastasis of HCC cells. Methods. HPSE expressions in human HCC cells were measured with real-time RT-PCR and Western blot analysis. Four recombinant miRNA vectors pcDNATM6.2-GW/EmGFP-miR-HPSE (pmiR-HPSE) were transfected into HCCLM3 cell. HPSE expression in transfected cell was measured. The cell invasion, migration, and adhesion abilities were detected, respectively. Results. Both HPSE mRNA and protein relative expression levels were higher in HepG2, BEL-7402, and HCCLM3 cells than those in normal hepatocyte (P < 0.05). HPSE showed highest expression level in HCCLM3 cell (P < 0.05). Transfection efficiencies of four miRNA vectors were 75%–85%. The recombinant vectors significantly decreased HPSE expression in transfected HCCLM3 cells (P < 0.01), and pmiR-HPSE-1 showed best interference effect (P < 0.05). pmiR-HPSE-1 significantly decreased the penetrated and migrating cells numbers and adherence rate of HCCLM3 cells (P < 0.05). Conclusion. HPSE is a potentiator of cell adhesion in metastasis of HCC.

High glucose-induced intestinal epithelial barrier damage is aggravated by syndecan-1 destruction and heparanase overexpression

Syndecan-1 (Sdc1) and its endo-beta-d-glucuronidase heparanase (HPSE) are implicated in maintenance of intestinal epithelial barrier (IEB), but their alterations and roles in high-glucose/hyperglycaemia (HG) conditions have not been fully investigated. This study aimed to determine the expression pattern, the possible regulation mechanism of Sdc1 and HPSE in HG conditions, and their potential effects on IEB. Therefore, diabetic mice/cell models were developed, and tissue/serum samples, cell lysate and culture supernatants were harvested. The expression of Sdc1 and HPSE in control, HG and designated interventions groups were detected. Phosphorylations of mitogen-activated protein kinase signalling pathway (MAPK), the expressions of Occludin and ZO-1, and the levels of transepithelial electrical resistance (TEER) were measured and monitored. The results showed that in HG conditions, intestinal tissue and cellular Sdc1 were significantly decreased, but the expression of HPSE, and soluble Sdc1 in serum and culture supernatants were remarkably increased. Such alterations of Sdc1 and HPSE were associated with solely p38 MAPK activation, and were correlated with the reductions of Occludin, ZO-1 and TEER. Heparin (Sdc1 analogue) and SB203580 (a p38 MAPK inhibitor), instead of insulin, alleviated Sdc1 destruction and HPSE overexpression, and effectively prevented against the reductions of tight junctions and the abnormality of intestinal permeability in HG conditions. In conclusion, we confirm the unique alterations of Sdc1 and HPSE in HG conditions, and found their interactions with p38 MAPK activation and IEB. These indicate that Sdc1/HPSE modulation can be viewed as an important complementary treatment for relieving HG-induced gastrointestinal damage.

Differential mRNA expression profiles between hepatocellular carcinoma and adjacent normal liver tissue

AIM: To identify differentially expressed genes between hepatocellular carcinoma and normal liver tissues and to carry out bioinformatics analysis.

METHODS: Agilent 8×60 K microarray was used to detect the changes of gene expression between hepatocellular carcinoma and adjacent normal liver tissues. Bioinformatics methods were used to identify differentially expressed genes and perform GO pathway analysis. Real-time PCR was applied to verify microarray data.

RESULTS: Microarray analysis screened a total of up-regulated 924 mRNAs and 1770 down-regulated mRNAs in hepatocellular carcinoma tissues compared with the normal tissues. GO pathway analysis demonstrated that these mRNAs are involved in transcription, redox, signal transduction, ion transport, immune response, cell adhesion, and binding functions. The results of real-time PCR were in high concordance with microarray results.

CONCLUSION: Differentially expressed genes identified in this study may be involved in signal transduction, immune response and other key biological processes. These genes may provide new targets for targeted therapy.