Recent Advances in Liver Cancer Stem Cells: Non-coding RNAs, Oncogenes and Oncoproteins

WNT/β-catenin signaling in hepatocellular carcinoma: The aberrant activation, pathogenic roles, and therapeutic opportunities

Hepatocellular carcinoma (HCC) is a liver cancer, highly heterogeneous both at the histopathological and molecular levels. It arises from hepatocytes as the result of the accumulation of numerous genomic alterations in various signaling pathways, including canonical WNT/β-catenin, AKT/mTOR, MAPK pathways as well as signaling associated with telomere maintenance, p53/cell cycle regulation, epigenetic modifiers, and oxidative stress. The role of WNT/β-catenin signaling in liver homeostasis and regeneration is well established, whereas in development and progression of HCC is extensively studied. Herein, we review recent advances in our understanding of how WNT/β-catenin signaling facilitates the HCC development, acquisition of stemness features, metastasis, and resistance to treatment. We outline genetic and epigenetic alterations that lead to activated WNT/β-catenin signaling in HCC. We discuss the pivotal roles of CTNNB1 mutations, aberrantly expressed non-coding RNAs and complexity of crosstalk between WNT/β-catenin signaling and other signaling pathways as challenging or advantageous aspects of therapy development and molecular stratification of HCC patients for treatment.

Dose Consideration of Lenvatinib's Anti-Cancer Effect on Hepatocellular Carcinoma and the Potential Benefit of Combined Colchicine Therapy

PURPOSE

The dose-dependent anti-cancer effect of lenvatinib on hepatocellular carcinoma (HCC) cells and the potential benefit of combined colchicine therapy were investigated.

METHODS

Four primary cultured HCC (S103, S143, S160, S176) cell lines were investigated by differential expressions of genes (11 lenvatinib target genes and NANOG) and anti-proliferative effect using clinically achievable plasma lenvatinib (250, 350 ng/mL) and colchicine (4 ng/mL) concentrations.

RESULTS

Colchicine showed an anti-proliferative effect on all cell lines. Lenvatinib at 250 ng/mL inhibited proliferation in all cell lines, but 350 ng/mL inhibited only three cell lines. For lenvatinib target genes, colchicine down-regulated more genes and up-regulated less genes than lenvatinib did in three cell lines. Lenvatinib up-regulated NANOG in all cell lines. Colchicine down-regulated NANOG in three cell lines but up-regulated NANOG with less magnitude than lenvatinib did in S103. Overall, combined colchicine and 250 ng/mL lenvatinib had the best anti-cancer effects in S143, with similar effects with combined colchicine and 350 ng/mL lenvatinib in S176 but less effects than combined colchicine and 350 ng/mL lenvatinib in S103 and S160.

CONCLUSIONS

Lenvatinib does not show a dose-dependent anti-cancer effect on HCC. Combined colchicine and lenvatinib can promote the total anti-cancer effects on HCC.

Cuproptosis-related prognostic signatures predict the prognosis and immunotherapy in HCC patients

Cuproptosis, an unusual type of programmed cell death mechanism of cell death, involved the disruption of specific mitochondrial metabolic enzymes in the occurrence and development of tumors. However, it was still unclear how the relationship between cuproptosis-related genes (CRGs) may contribute to hepatocellular carcinoma (HCC) potential the prognosis of HCC remained limited. Here, the landscape of 14 CRGs in HCC was evaluated using the Cancer Genome Atlas and International Cancer Genome Consortium datasets. And then, 4 CRGs (ATP7A, MTF1, GLS, and CDKN2A) were screened for the construction of risk signatures for prognosis and drug therapy. The HCC patients with CRGs high-risk showed poor prognosis than those with low risk. Moreover, the CRGs risk signature was shown to be an independent prognostic factor and associated with the immune microenvironment in HCC. Meanwhile, we constructed and verified a prognostic model based on cuproptosis-related lncRNAs (Cr-lncRNAs). We obtained 291 Cr-lncRNAs and constructed Cr-lncRNA prognosis signature based on 3 key Cr-lncRNAs (AC026356.1, NRAV, AL031985.3). The Cr-lncRNA prognosis signature was also an independent prognostic factor and associated with the immune microenvironment in HCC. Finally, the drug sensitivity database showed that 8 candidate drugs related to CRGs signature and Cr-lncRNAs signature. In summary, we evaluated and validated the CRGs and Cr-lncRNAs as potential predictive markers for prognosis, immunotherapy, and drug candidate with the personalized diagnosis and treatment of HCC.

Ciclopirox Olamine Induces Proliferation Inhibition and Protective Autophagy in Hepatocellular Carcinoma

Hepatocellular carcinoma is one of the most common fatal malignancies worldwide. Thus far, the hepatocellular carcinoma prognosis has been bleak due to deficiencies in the identification and diagnosis of early hepatocellular carcinoma. Ciclopirox olamine (CPX) is a synthetic antifungal agent and has been considered as an anti-cancer candidate drug recently, though the detailed mechanisms related to its anti-cancer effect in hepatocellular carcinoma have not yet been revealed. Here, we found that CPX could inhibit proliferation in HCC cells but not in intrahepatic cholangiocarcinoma cells by arresting the cell cycle. Moreover, the anti-cancer effects of CPX in HCC cells were also attributed to CPX-triggered ROS accumulation and DJ-1 downregulation. Additionally, CPX could promote complete autophagic flux, which alleviated the anti-cancer effect of CPX in HCC cells, whereas the ROS scavenger (NAC) would attenuate CPX-induced protective autophagy. Interestingly, CPX could also induce glycogen clustering in HCC cells. Altogether, this study provides a new insight into the detailed molecular mechanisms of CPX as an anti-cancer therapy and a strategy for treating hepatocellular carcinoma.

NUSAP1, a novel stemness-related protein, promotes early recurrence of hepatocellular carcinoma

Early recurrence (within 2 years after resection) is the primary cause of poor outcomes among hepatocellular carcinoma (HCC) patients, and liver cancer stem cells are the main contributors to postsurgical HCC recurrence. Nucleolar and spindle-associated protein 1 (NUSAP1) has been reported to be involved in tumor progression. We investigated the function and clinical value of NUSAP1 in early recurrence of HCC. Data from public datasets and our cohort were used to assess the association between NUSAP1 expression and early HCC recurrence. Gain- and loss-of-function experiments were carried out in vivo and in vitro. The predictive effect of NUSAP1 on early HCC recurrence was further evaluated by a validation cohort. We found that elevated NUSAP1 expression in HCC specimens was correlated with poor outcome, especially in cases with postoperative early recurrence. Functional studies indicated that NUSAP1 significantly promotes HCC progression. A postsurgical recurrence murine model further revealed that upregulated NUSAP1 dramatically increased the likelihood of HCC early recurrence. RNA sequencing data revealed that the gene sets of cancer stemness and the signal transducer and activator of transcription 3 (STAT3) pathway were enriched by NUSAP1 overexpression. Mechanistically, NUSAP1 enhanced cancer stemness through stimulating STAT3 nuclear translocation and activation through receptor of activated protein C kinase 1 (RACK1). In a validation cohort with 112 HCC patients, NUSAP1 effectively predicted HCC early recurrence. Our results indicated that NUSAP1 promotes early recurrence of HCC by sustaining cancer stemness and could serve as a valuable predictive indicator for postsurgical intervention in HCC patients.

Expression and prognostic signatures of m6A-related lncRNAs in hepatocellular carcinoma

BACKGROUND

N6-methyladenosine (m6A) is a common modification and plays an important role in various biological processes, but m6A-related lncRNA functions in hepatocellular carcinoma (HCC) have not been systematically clarified.

METHODS

The clinical data and RNA-seq transcriptome of 375 cases of HCC and 50 cases of normal tissues were obtained from the Cancer Gene Atlas database. Co-expression analysis was used to obtain m6A-related lncRNA. The independent prognostic factors were identified by univariate and multivariate Cox regression models. Kaplan-Meier method was used in survival analysis. The core gene of the mRNA-mRNA interaction network is related to m6A-related lncRNAs obtained by the CytoHubba plugin of Cytoscape. Gene ontology and Kyoto Gene Encyclopedia were analyzed to find out the potential mechanism. CIBERSORT algorithm was used to calculate the relative proportion of immune infiltrating cells.

RESULTS

We identified two subgroups (cluster 1 and cluster 2) according to the expression level. The survival analysis curve and receiver operating characteristic curve proved that this model could predict the prognosis of HCC patients. The univariate and multivariate Cox regression analyses showed the independent prognostic value. UBE2C was screened as the pivotal gene. The expression level of m6A-related lncRNAs causes changes in the tumor immune microenvironment.

CONCLUSION

The expression levels of m6A-related lncRNAs were significantly different and the prognostic value of m6A-related lncRNAs was confirmed. The m6A-related lncRNAs are expected to be prognostic signatures in HCC.

ALKBH5/MAP3K8 axis regulates PD-L1+ macrophage infiltration and promotes hepatocellular carcinoma progression

Hepatocellular carcinoma is one of the most common malignant tumors.M6A is a novel epigenetic modification that have been emerged as vital regulators for the progression of HCC. However, the regulatory role, clinical significance and the details of the modification, such as the impact on the local tumor environment, remain largely unclear. Our study showed that ALKBH5 was highly expressed in HCC and high ALKBH5 expression predicted a worse prognosis of HCC patients. Prediction of ALKBH5 function by tissue samples and single cell sequencing Gene Set Variation Analysis. Primary CD3 + T lymphocytes and bone marrow-derived macrophages were used to evaluate the effect of ALKBH5 on immune microenvironment. The results indicated that ALKBH5 promote HCC cell proliferation, metastasis and PD-L1+macrophage recruitment. Mechanistically the results showed that ALKBH5 regulates MAP3K8 expression in a m6A dependent manner which mediates the proliferation and metastasis of HCC cells. ALKBH5 also promotes the activation of JNK and ERK pathways through upregulating MAP3K8, thus regulating the expression of IL-8 and promoting macrophage recruitment. Taken together, these data show that ALKBH5 promotes HCC growth, metastasis and macrophage recruitment through ALKBH5/MAP3K8 axis and it may serve as a potential diagnostic marker and target for treatment of HCC patients.

miRNAs inspirations in hepatocellular carcinoma: Detrimental and favorable aspects of key performers

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related deaths worldwide. HCC initiation, progression, and therapy failure are all influenced by various variables, including microRNAs (miRNAs). miRNAs are short non-coding RNA sequences that modulate target mRNA expression by deteriorating or repressing translation. miRNAs play an imperative role in HCC pathogenesis by triggering the induction of cancer stem cells (CSCs) and their proliferation, while also delaying apoptosis, sustaining the cell cycle, and inspiring angiogenesis, invasion, and metastasis. Additionally, miRNAs modulate crucial HCC-related molecular pathways such as the p53 pathway, the Wnt/β-catenin pathway, VEGFR2, and PTEN/PI3K/AKT pathway. Consequently, the goal of this review was to give an up-to-date overview of oncogenic and tumor suppressor (TS) miRNAs, as well as their potential significance in HCC pathogenesis and treatment responses, highlighting their underpinning molecular pathways in HCC initiation and progression. Similarly, the biological importance and clinical application of miRNAs in HCC are summarized.

Circ_0064288 acts as an oncogene of hepatocellular carcinoma cells by inhibiting miR-335-5p expression and promoting ROCK1 expression

Background

Reportedly, circular RNA (circRNA) is a key modulator in the development of human malignancies. This work is aimed to probe the expression pattern, biological effects and mechanism of circ_0064288 on hepatocellular carcinoma (HCC) progression.

Methods

The differentially expressed circRNA was screened by analyzing the expression profiles of circRNAs in HCC tissues and normal tissues. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to examine the expression of circ_0064288, miR-335-5p and Rho associated coiled-coil containing protein kinase 1 (ROCK1) mRNA in HCC specimens. After circ_0064288 was overexpressed or knocked down in HCC cells, cell growth was detected by the CCK-8 experiment, and cell migration was evaluated using Transwell experiment and scratch healing experiment. The targeting relationship between miR-335-5p and circ_0064288 and ROCK1 mRNA was predicted and verified using bioinformatic analysis and dual-luciferase reporter gene experiments, respectively. Western blot was executed to examine ROCK1 protein expression in HCC cells.

Results

Circ_0064288 and ROCK1 expression was up-modulated in HCC, while miR-335-5p was down-modulated. High circ_0064288 expression was associated with shorter survival time of HCC patients. It was also revealed that circ_0064288 overexpression remarkably enhanced HCC cell growth and migration, while knockdown of circ_0064288 induced opposite effects. Additionally, circ_0064288 could competitively bind with miR-335-5p thereby up-modulate ROCK1 expression. MiR-335-5p overexpression partly counteracted the effect of circ_0064288 overexpression on HCC cells.

Conclusion

Circ_0064288 facilitates HCC cell growth and migration by modulating the miR-335-5p/ROCK1 axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09323-8.

Integrative bioinformatics and experimental analysis revealed TEAD as novel prognostic target for hepatocellular carcinoma and its roles in ferroptosis regulation

Objective: Transcriptional enhanced associate domain (TEAD) family consists of four members TEAD1/2/3/4 that regulate cell growth, stem cell functions and organ development. As the downstream of Hippo signaling pathway, TEAD family is involved in the progression of several cancers. However, the precise biology functions of TEAD family in hepatocellular carcinoma (HCC) have not been reported yet.

Methods: We apply bioinformatics analysis based on databases including UALCAN, Oncomine, GEPIA, Kaplan-Meier plotter, WebGestalt, cBioPortal, TIMER2.0, and in vitro experimental evidence to identify the exact roles of TEAD family in HCC.

Results: The results indicated that TEAD2/4 were significantly upregulated in HCC compared with normal tissues. Downregulated of TEAD2 could promote the death of HCC cells through inducing ferroptosis by iron accumulation and subsequent oxidative damage. According to the Kaplan-Meier plotter database, we found that the high expression of TEAD2 was significantly associated with poor disease-specific survival, overall survival, progression-free survival and relapse-free survival. In aspect of cancer immunity, Tumor Immune Estimation Resource algorithm showed that the expression of TEAD family members was obviously related to multiple of infiltrating immune cells including macrophages, neutrophils, dendritic cells, B cells, CD8+ T cells and CD4+ T cells. Finally, we conducted the functional enrichment analysis including protein-protein interaction network, gene ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway based on the TEAD family-associated coexpression genes.

Conclusion: The study provided deep insight information of TEAD family in the diagnostic and prognostic evaluation of HCC patients.

CDKN2A is a prognostic biomarker and correlated with immune infiltrates in hepatocellular carcinoma

Cyclin dependent kinase inhibitor 2A (CDKN2A) is an essential regulator of immune cell functionality, but the mechanisms whereby it drives immune infiltration in hepatocellular carcinoma (HCC) remain unclear. In the present study, we studied the association with CDKN2A expression and immune invasion with the risk of developing HCC. A totally of 2207 different genes were found between HCC and adjacent liver tissues from TCGA and GEO databases. CDKN2A was highly expressed in HCC and associated with poorer overall survival and disease-free survival. Notably, CDKN2A expression was positively correlated with infiltrating levels into purity, B cell, CD+8 T cell, CD+4 T cell, macrophage, neutrophil, and dendritic cells in HCC. CDKN2A expression showed strong correlations between diverse immune marker sets in HCC. These findings suggest that CDKN2A expression potentially contributes to regulation of tumor-associated macrophages and can be used as a prognostic biomarker for determining prognosis and immune infiltration in HCC.

Construction of a Ferroptosis-Related Nine-lncRNA Signature for Predicting Prognosis and Immune Response in Hepatocellular Carcinoma

Ferroptosis is an iron-dependent cell death process that plays important regulatory roles in the occurrence and development of cancers, including hepatocellular carcinoma (HCC). Moreover, the molecular events surrounding aberrantly expressed long non-coding RNAs (lncRNAs) that drive HCC initiation and progression have attracted increasing attention. However, research on ferroptosis-related lncRNA prognostic signature in patients with HCC is still lacking. In this study, the association between differentially expressed lncRNAs and ferroptosis-related genes, in 374 HCC and 50 normal hepatic samples obtained from The Cancer Genome Atlas (TCGA), was evaluated using Pearson's test, thereby identifying 24 ferroptosis-related differentially expressed lncRNAs. The least absolute shrinkage and selection operator (LASSO) algorithm and Cox regression model were used to construct and validate a prognostic risk score model from both TCGA training dataset and GEO testing dataset (GSE40144). A nine-lncRNA-based signature (CTD-2033A16.3, CTD-2116N20.1, CTD-2510F5.4, DDX11-AS1, LINC00942, LINC01224, LINC01231, LINC01508, and ZFPM2-AS1) was identified as the ferroptosis-related prognostic model for HCC, independent of multiple clinicopathological parameters. In addition, the HCC patients were divided into high-risk and low-risk groups according to the nine-lncRNA prognostic signature. The gene set enrichment analysis enrichment analysis revealed that the lncRNA-based signature might regulate the HCC immune microenvironment by interfering with tumor necrosis factor α/nuclear factor kappa-B, interleukin 2/signal transducers and activators of transcription 5, and cytokine/cytokine receptor signaling pathways. The infiltrating immune cell subtypes, such as resting memory CD4(+) T cells, follicular helper T cells, regulatory T cells, and M0 macrophages, were all significantly different between the high-risk group and the low-risk group as indicated in Spearman's correlation analysis. Moreover, a substantial increase in the expression of B7H3 immune checkpoint molecule was found in the high-risk group. Our findings provided a promising insight into ferroptosis-related lncRNAs in HCC and a personalized prediction tool for prognosis and immune responses in patients.

Upregulation of ubiquitin-conjugating enzyme E2T (UBE2T) predicts poor prognosis and promotes hepatocellular carcinoma progression

Reportedly, ubiquitin-conjugating enzyme E2T (UBE2T) is closely related to the progression of several malignancies. This work is aimed to probe the role of UBE2T in the progression of hepatocellular carcinoma (HCC) patients. The microarray analysis was executed to screen the differentially expressed genes (DEGs) in HCC tissues. The Cancer Genome Atlas (TCGA) and Gene Expression Profiling Interactive Analysis (GEPIA2) databases, PCR and immunohistochemistry were utilized to validate the dysregulation of UBE2T in HCC. Kaplan-Meier analysis was employed to determine the relationship between UBE2T expression and the prognosis of HCC patients. PCR was carried out to detect UBE2T protein expression in HCC cell lines. Cell Counting Kit-8 (CCK-8) assay and 5-bromo-2ʹ-deoxyuridine (BrdU) experiments were conducted to examine the proliferation of HCC cells. Scratch healing and Transwell experiments were conducted to examine the migration of HCC cells. Bioinformatics analysis and dual-luciferase reporter gene experiments predicted and validated the targeting relationship with miR-212-5p and UBE2T. We found that UBE2T expression was remarkably up-modulated in HCC tissues and cell lines, and its high expression was linked to a worse prognosis in HCC patients. UBE2T overexpression enhanced HCC cell proliferation and migration. Additionally, UBE2T was verified as a downstream target of miR-212-5p. In conclusion, UBE2T overexpression is markedly linked to unfavorable prognosis in HCC patients. UBE2T, regulated by miR-212-5p, significantly enhances the malignant phenotypes of HCC cells, which can be used as a target for HCC diagnosis and prognosis.

Role of chemokines in hepatocellular carcinoma (Review)

Hepatocellular carcinoma (HCC) is a prevalent malignant tumor worldwide, with an unsatisfactory prognosis, although treatments are improving. One of the main challenges for the treatment of HCC is the prevention or management of recurrence and metastasis of HCC. It has been found that chemokines and their receptors serve a pivotal role in HCC progression. In the present review, the literature on the multifactorial roles of exosomes in HCC from PubMed, Cochrane library and Embase were obtained, with a specific focus on the functions and mechanisms of chemokines in HCC. To date, >50 chemokines have been found, which can be divided into four families: CXC, CX3C, CC and XC, according to the different positions of the conserved N‑terminal cysteine residues. Chemokines are involved in the inflammatory response, tumor immune response, proliferation, invasion and metastasis via modulation of various signaling pathways. Thus, chemokines and their receptors directly or indirectly shape the tumor cell microenvironment, and regulate the biological behavior of the tumor. In addition, the potential application of chemokines in chemotaxis of exosomes as drug vehicles is discussed. Exosomes containing chemokines or expressing receptors for chemokines may improve chemotaxis to HCC and may thus be exploited for targeted drug delivery.