Emerging Regulatory Mechanisms Involved in Liver Cancer Stem Cell Properties in Hepatocellular Carcinoma

Ovatodiolide inhibited hepatocellular carcinoma stemness through SP1/MTDH/STAT3 signaling pathway

Hepatocellular carcinoma (HCC) is characterized with high recurrence and mortality, and the clinical treatments for HCC are very limited. Hepatocellular carcinoma stem cells are the root of HCC progress, recurrence, and multidrug resistance. Ovatodiolide (OVA) is a bioactive diterpenoid served as an inflammatory and immunotherapeutic responses modulator. In this research, we found OVA inhibited HCC stemness through inhibiting MTDH gene transcription. Moreover, we firstly discovered transcription factor SP1 bound to the promoter region of MTDH to transcriptionally regulate MTDH level. Mechanically, we demonstrated OVA decreased SP1 protein stability to transcriptionally inhibit MTDH gene, and inhibited the nuclear translocation of p65, and then diminished IL-6 level to suppress JAK/STAT3 signaling pathway, eventually decreases CD133 level and the stemness of HCC. Furthermore, we demonstrated ACT004, OVA derivative with high metabolic stability towards cytochrome P450 enzymes, showed no genotoxicity and no accumulative or delayed toxicities after long-term administration in rats. And the in vivo efficacy experiments indicated ACT004 inhibited tumor growth of hepatocellular carcinoma. In conclusion, we revealed the mechanism of OVA in regulating HCC stemness, detected the toxicity of OVA derivative and evaluated the in vivo efficacy which lays a foundation for further discovery of anti-HCC stem cell agents and provide a new strategy for the application of OVA in clinical treatment.

Promotion of hepatocellular carcinoma stemness and progression by abnormal spindle-like microcephaly-associated protein via the Wnt/β-catenin pathway

Background

Cancer stem cells (CSCs) play a crucial role in tumor recurrence and metastasis, which are the primary causes of death in patients with hepatocellular carcinoma (HCC). Currently, no drug effectively blocks the recurrence and metastasis of liver cancer, leading to a poor prognosis for patients. To enhance treatment outcomes, there is an urgent need to investigate the molecular mechanisms behind the recurrence and progression of liver cancer, with the aim of identifying effective therapeutic targets. Targeting HCC stemness can improve the prognosis of patients with HCC. Abnormal spindle-like microcephaly-associated protein (ASPM) plays a pivotal role in regulating neurogenesis and brain size, which is a centrosome protein. ASPM has been implicated in tumorigenesis and tumor progression, but its regulatory role in HCC stemness is not well understood. This study aims to investigate the role of ASPM in liver cancer stemness and elucidate its potential molecular mechanisms.

Methods

Bioinformatics analysis was used to study the expression of ASPM and its clinical significance in HCC. In vitro and in vivo assays were conducted to clarify the impact of ASPM knockdown on HCC cell stemness. The correlation between ASPM and the Wnt/β-catenin pathway was examined through analysis of online databases and in vitro experiments.

Results

The bioinformatics analysis revealed significant upregulation of ASPM was significantly upregulated in HCC samples, with expression correlating with poor prognosis. In vitro experimental data confirmed elevated ASPM expression in HCC cells compared to normal hepatocytes. Knockdown of ASPM suppressed HCC cell growth, clone formation, spheroid formation, migration, invasion, and the expression of CSC markers CD133 and CD44. This also inhibited the activation of the Wnt/β-catenin pathway. Reactivation of this pathway partially reversed the biological changes induced by ASPM knockdown in HCC cells. Additionally, in vivo data demonstrated that ASPM downregulation reduced the size and weight of xenografts in BALB/c mice, along with decreased expression of CSC markers.

Conclusions

These findings suggest that ASPM promotes HCC stemness and progression through the Wnt/β-catenin pathway. Targeting ASPM or the Wnt/β-catenin pathway may be a promising strategy to prevent HCC chemoresistance and recurrence, ultimately improving patient prognosis.

MicroRNAs in Hepatocellular Carcinoma Pathogenesis: Insights into Mechanisms and Therapeutic Opportunities

Hepatocellular carcinoma (HCC) presents a significant global health burden, with alarming statistics revealing its rising incidence and high mortality rates. Despite advances in medical care, HCC treatment remains challenging due to late-stage diagnosis, limited effective therapeutic options, tumor heterogeneity, and drug resistance. MicroRNAs (miRNAs) have attracted substantial attention as key regulators of HCC pathogenesis. These small non-coding RNA molecules play pivotal roles in modulating gene expression, implicated in various cellular processes relevant to cancer development. Understanding the intricate network of miRNA-mediated molecular pathways in HCC is essential for unraveling the complex mechanisms underlying hepatocarcinogenesis and developing novel therapeutic approaches. This manuscript aims to provide a comprehensive review of recent experimental and clinical discoveries regarding the complex role of miRNAs in influencing the key hallmarks of HCC, as well as their promising clinical utility as potential therapeutic targets.

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.

Stemness markers in hepatocellular carcinoma of Eastern vs. Western population: Etiology matters?

Hepatocellular carcinoma (HCC) is one of the most common cancers with a high mortality rate. HCC development is associated with its underlying etiologies, mostly caused by infection of chronic hepatitis B virus (HBV) and hepatitis C virus (HCV), alcohol, non-alcoholic fatty liver disease, and exposure to aflatoxins. These variables, together with human genetic susceptibility, contribute to HCC molecular heterogeneity, including at the cellular level. HCC initiation, tumor recurrence, and drug resistance rates have been attributed to the presence of liver cancer stem cells (CSC). This review summarizes available data regarding whether various HCC etiologies may be associated to the appearance of CSC biomarkers. It also described the genetic variations of tumoral tissues obtained from Western and Eastern populations, in particular to the oncogenic effect of HBV in the human genome.

Tumor Microenvironment Composition and Related Therapy in Hepatocellular Carcinoma

Globally, primary liver cancer is the third leading cause of cancer death, and hepatocellular carcinoma (HCC) accounts for 75%-95%. The tumor microenvironment (TME), composed of the extracellular matrix, helper cells, immune cells, cytokines, chemokines, and growth factors, promotes the immune escape, invasion, and metastasis of HCC. Tumor metastasis and postoperative recurrence are the main threats to the long-term prognosis of HCC. TME-related therapies are increasingly recognized as effective treatments. Molecular-targeted therapy, immunotherapy, and their combined therapy are the main approaches. Immunotherapy, represented by immune checkpoint inhibitors (ICIs), and targeted therapy, highlighted by tyrosine kinase inhibitors (TKIs), have greatly improved the prognosis of HCC. This review focuses on the TME compositions and emerging therapeutic approaches to TME in HCC.

Histone chaperone SSRP1 is required for apoptosis inhibition and mitochondrial function in HCC via transcriptional promotion of TRAP1

Epigenetic regulation contributes to human health and disease, especially cancer, but the mechanisms of many epigenetic regulators remain obscure. Most research is focused on gene regulatory processes, such as mRNA translation and DNA damage repair, rather than the effects on biological functions like mitochondrial activity and oxidative phosphorylation. Here, we identified an essential role for the histone chaperone structure-specific recognition protein 1 (SSRP1) in mitochondrial oxidative respiration in hepatocellular carcinoma, and found that SSRP1 suppression led to mitochondrial damage and decreased oxidative respiration. Further, we focused on TNF receptor-associated protein 1 (TRAP1), the only member of the heat shock protein 90 (HSP90) family, which directly interacts with selected respiratory complexes and affects their stability and activity. We confirmed that SSRP1 downregulation caused a decrease in TRAP1 expression at both the mRNA and protein levels. A chromatin immunoprecipitation assay also showed that SSRP1 could deposit in the TRAP1 promoter region, indicating that SSRP1 maintains mitochondrial function and reactive oxygen species levels through TRAP1. Additionally, rescue experiments and animal experiments confirmed the mechanism of SSRP1 and TRAP1 interaction. In summary, we identified a new mechanism that connects mitochondrial respiration and apoptosis, via SSRP1.

Targeting Lin28 axis enhances glypican-3-CAR T cell efficacy against hepatic tumor initiating cell population

Overexpression of Lin28 is detected in various cancers with involvement in the self-renewal process and cancer stem cell generation. In the present study, we evaluated how the Lin28 axis plays an immune-protective role for tumor-initiating cancer cells in hepatocellular carcinoma (HCC). Our result using HCC patient samples showed a positive correlation between indoleamine 2,3-dioxygenase-1 (IDO1), a kynurenine-producing enzyme with effects on tumor immune escape, and Lin28B. Using in silico prediction, we identified a Sox2/Oct4 transcriptional motif acting as an enhancer for IDO1. Knockdown of Lin28B reduced Sox2/Oct4 and downregulated IDO1 in tumor-initiating hepatic cancer cells. We further observed that inhibition of Lin28 by a small-molecule inhibitor (C1632) suppressed IDO1 expression. Suppression of IDO1 resulted in a decline in kynurenine production from tumor-initiating cells. Inhibition of the Lin28 axis also impaired PD-L1 expression in HCC cells. Consequently, modulating Lin28B enhanced in vitro cytotoxicity of glypican-3 (GPC3)-chimeric antigen receptor (CAR) T and NK cells. Next, we observed that GPC3-CAR T cell treatment together with C1632 in a HCC xenograft mouse model led to enhanced anti-tumor activity. In conclusion, our results suggest that inhibition of Lin28B reduces IDO1 and PD-L1 expression and enhances immunotherapeutic potential of GPC3-CART cells against HCC.

Circulating liver cancer stem cells and their stemness-associated MicroRNAs as diagnostic and prognostic biomarkers for viral hepatitis-induced liver cirrhosis and hepatocellular carcinoma

Background

Liver cancer stem cells (LCSCs) are a subpopulation of tumor cells that can drive cancer initiation and relapses. Because of their significance, researchers are looking for biomarkers that characterize or regulate LCSCs so that they can be used as targets for the diagnosis and treatment of chronic liver diseases and hepatocellular carcinoma (HCC).

Methodology

Six groups of patients having hepatitis C virus (HCV), HCV + cirrhosis, HCV + HCC, hepatitis B virus (HBV), HBV + cirrhosis, or HBV + HCC, in addition to a control group, were subjected to the measurement of LCSCs levels and analysis of miR-1290 and miR-1825 expression.

Results

The percentages of the CD133/EpCAM-expressing LCSCs were increased in viral hepatitis and cirrhosis groups, compared to the control group. HCC patients had the highest percentages of LCSCs. CD133/EpCAM-expressing cells showed significant correlations with stemness-associated miRNAs; miR-1290 and miR-1825. Also, the miR-1290 and miR-1825 were significantly up-regulated in viral hepatitis-associated cirrhosis and HCC groups. Moreover, in HCV + HCC, miR-1290 and miR-1825 expression was significantly positively correlated with tumor size and number. However, only miR-1825 could distinguish between HCV- and HBV-associated HCC groups. MiR-1290 exhibited the highest sensitivity and specificity for detecting HCC, followed by miR-1825 and CD133/EpCAM-expressing LCSCs.

Conclusions

These findings indicate the relevance of CD133/EpCAM-expressing cells in the pathogenesis of liver cirrhosis and HCC developed as a consequence of either chronic HCV or HBV infection. Accordingly, CD133/EpCAM-expressing cells, miR-1290, and miR-1825, could serve as promising diagnostic and prognostic biomarkers as well as therapeutic targets in patients suffering from liver cirrhosis or HCC.

Clinical applications of circulating tumor cells in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly malignant tumor and ranked as the fourth cause of cancer-related mortality. The poor clinical prognosis is due to an advanced stage and resistance to systemic treatment. There are no obvious clinical symptoms in the early stage and the early diagnosis rate remains low. Novel effective biomarkers are important for early diagnosis and tumor surveillance to improve the survival of HCC patients. Circulating tumor cells (CTCs) are cancer cells shed from primary or metastatic tumor and extravasate into the blood system. The number of CTCs is closely related to the metastasis of various solid tumors. CTCs escape from blood vessels and settle in target organs, then form micro-metastasis. Epithelial-mesenchymal transformation (EMT) plays a crucial role in distant metastasis, which confers strong invasiveness to CTCs. The fact that CTCs can provide complete cellular biological information, which allows CTCs to be one of the most promising liquid biopsy targets. Recent studies have shown that CTCs are good candidates for early diagnosis, prognosis evaluation of metastasis or recurrence, and even a potential therapeutic target in patients with HCC. It is a new indicator for clinical application in the future. In this review, we introduce the enrichment methods and mechanisms of CTCs, and focus on clinical application in patients with HCC.

KCNN4 Promotes the Stemness Potentials of Liver Cancer Stem Cells by Enhancing Glucose Metabolism

The presence of liver cancer stem cells (LCSCs) is one of the reasons for the treatment failure of hepatocellular carcinoma (HCC). For LCSCs, one of their prominent features is metabolism plasticity, which depends on transporters and ion channels to exchange metabolites and ions. The K⁺ channel protein KCNN4 (Potassium Calcium-Activated Channel Subfamily N Member 4) has been reported to promote cell metabolism and malignant progression of HCCs, but its influence on LCSC stemness has remained unclear. Here, we demonstrated that KCNN4 was highly expressed in L-CSCs by RT-PCR and Western blot. Then, we illustrated that KCNN4 promoted the stemness of HC-C cells by CD133⁺CD44⁺ LCSC subpopulation ratio analysis, in vitro stemness transcription factor detection, and sphere formation assay, as well as in vivo orthotopic liver tumor formation and limiting dilution tumorigenesis assays. We also showed that KCNN4 enhanced the glucose metabolism in LCSCs by metabolic enzyme detections and seahorse analysis, and the KCNN4-promoted increase in LCSC ratios was abolished by glycolysis inhibitor 2-DG or OXPHOS inhibitor oligomycin. Collectively, our results suggested that KCNN4 promoted LCSC stemness via enhancing glucose metabolism, and that KCNN4 would be a potential molecular target for eliminating LCSCs in HCC.

CHRNA5 Contributes to Hepatocellular Carcinoma Progression by Regulating YAP Activity

Hepatocellular carcinoma (HCC) is a major health concern worldwide. A better understanding of the mechanisms underlying the malignant phenotype is necessary for developing novel therapeutic strategies for HCC. Signaling pathways initiated by neurotransmitter receptors, such as α5-nicotinic acetylcholine receptor (CHRNA5), have been reported to be implicated in tumor progression. However, the functional mechanism of CHRNA5 in HCC remains unclear. In this study, we explored the role of CHRNA5 in HCC and found that CHRNA5 expression was increased in human HCC tissues and positively correlated with the T stage (p < 0.05) and AJCC phase (p < 0.05). The KM plotter database showed that the high expression level of CHRNA5 was strongly associated with worse survival in HCC patients. Both in vitro and in vivo assays showed that CHRNA5 regulates the proliferation ability of HCC by regulating YAP activity. In addition, CHRNA5 promotes the stemness of HCC by regulating stemness-associated genes, such as Nanog, Sox2 and OCT4. Cell migration and invasion assays demonstrated that CHRNA5 significantly enhanced the metastasis of HCC by regulating epithelial–mesenchymal transition (EMT)-associated genes. Furthermore, we found that CHRNA5 regulates the sensitivity of sorafenib in HCC. Our findings suggest that CHRNA5 plays a key role in the progression and drug resistance of HCC, and targeting CHRNA5 may be a strategy for the treatment of HCC.