Cancer Stem Cells in Hepatocellular Carcinoma: Intrinsic and Extrinsic Molecular Mechanisms in Stemness Regulation

Diagnostic value of expressions of cancer stem cell markers for adverse outcomes of hepatocellular carcinoma and their associations with prognosis: A Bayesian network meta‑analysis

The expression of cancer stem cell (CSC) markers adversely affect the survival prognosis of patients with hepatocellular carcinoma (HCC), but it is not clear which cancer stem cell marker has the best predictive effect on the survival prognosis and diagnostic value indicators of patients with HCC. Therefore, the present study performed a network meta-analysis to compare the prognostic and diagnostic value of the expressions of several CSC markers for patients with HCC and to identify the most efficient CSC marker. Studies on the associations of positive CSC markers with the overall survival (OS) rate, disease-free survival (DFS) rate, recurrence-free survival (RFS) rate, recurrence rate, differentiation, microvascular invasion and metastasis in patients with HCC were included in the network meta-analysis following searches on the PubMed, Embase, Elsevier and The Cochrane Library databases from January 1, 2013 to November 17, 2023. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess the quality assessment of studies, and R (version 4.3.1), Stata (version 15.0) and Review Manager (version 5.3) were used for analysis. A total of 37 studies involving 3,980 participants were included. For patients with HCC, simultaneous positivity of cytokeratin 19 (CK19) and epithelial cell adhesion molecule (EpCAM) was the strongest predictor of the OS rate [surface under the cumulative ranking curve (SUCRA), 78.65%], positive keratin 19 (K19) was the strongest predictor of the RFS and DFS rates (SUCRA, 98.93 and 84.95%, respectively), and simultaneous positivity of EpCAM and cluster of differentiation (CD)90 was the strongest predictor of the recurrence rate (SUCRA, 5.61%). In addition, positivity of CD56, K19 and CD133 had the best diagnostic efficacy for poor differentiation [superiority index, 7.4498; 95% confidence interval (CI): 0.3333, 13.0000], microvascular invasion (superiority index, 8.4777; 95% CI: 0.2308, 17.0000), and metastasis (superiority index, 5.6097; 95% CI: 0.3333, 11.0000), respectively. In conclusion, no single CSC marker possessed the best predictive effect on all indexes of survival prognosis and diagnosis of patients with HCC. In terms of survival prognosis, simultaneous positivity of CK19 and EpCAM demonstrated the strongest predictive effect on the OS rate, suggesting an association with a low OS rate in patients with HCC; positive K19 revealed the strongest predictive effect on the RFS rate and DFS rate, suggesting an association with low RFS and DFS rates in patients with HCC; and simultaneous positivity of EpCAM and CD90 had the strongest predictive effect on the recurrence rate, suggesting a high recurrence rate in patients with HCC patients. In terms of diagnostic value, CD56, K19 and CD133 were the strongest predictors of poor differentiation, microvascular invasion and metastasis, respectively. In the future, well-designed randomized controlled trials are required to further confirm these findings.

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.

Immunosuppressive tumor microenvironment in the progression, metastasis, and therapy of hepatocellular carcinoma: from bench to bedside

Hepatocellular carcinoma (HCC) is a highly heterogeneous malignancy with high incidence, recurrence, and metastasis rates. The emergence of immunotherapy has improved the treatment of advanced HCC, but problems such as drug resistance and immune-related adverse events still exist in clinical practice. The immunosuppressive tumor microenvironment (TME) of HCC restricts the efficacy of immunotherapy and is essential for HCC progression and metastasis. Therefore, it is necessary to elucidate the mechanisms behind immunosuppressive TME to develop and apply immunotherapy. This review systematically summarizes the pathogenesis of HCC, the formation of the highly heterogeneous TME, and the mechanisms by which the immunosuppressive TME accelerates HCC progression and metastasis. We also review the status of HCC immunotherapy and further discuss the existing challenges and potential therapeutic strategies targeting immunosuppressive TME. We hope to inspire optimizing and innovating immunotherapeutic strategies by comprehensively understanding the structure and function of immunosuppressive TME in HCC.

HGFK1 Enhances the Anti-Tumor Effects of Angiogenesis Inhibitors via Inhibition of CD90+ CSCs in Hepatocellular Carcinoma

The combination of anti-angiogenesis agents with immune-checkpoint inhibitors is a promising treatment for patients with advanced hepatocellular carcinoma (HCC); however, therapeutic resistance caused by cancer stem cells present in tumor microenvironments remains to be overcome. In this study, we report for the first time that the Kringle 1 domain of human hepatocyte growth-factor α chain (HGFK1), a previously described anti-angiogenesis peptide, repressed the sub-population of CD90+ cancer stem cells (CSCs) and promoted their differentiation and chemotherapy sensitivity mainly through downregulation of pre-Met protein expression and inhibition of Wnt/β-catenin and Notch pathways. Furthermore, we showed that the i.p. injection of PH1 (a tumor-targeted and biodegradable co-polymer), medicated plasmids encoding Endostatin (pEndo), HGFK1 genes (pEndo), and a combination of 50% pEndo + 50% pHGFK1 all significantly suppressed tumor growth and prolonged the survival of the HCC-bearing mice. Importantly, the combined treatment produced a potent synergistic effect, with 25% of the mice showing the complete clearance of the tumor via a reduction in the microvessel density (MVD) and the number of CD90+ CSCs in the tumor tissues. These results suggest for the first time that HGFK1 inhibits the CSCs of HCC. Furthermore, the combination of two broad-spectrum anti-angiogenic factors, Endo and HGFK1, is the optimal strategy for the development of effective anti-HCC drugs.

Dualistic Effects of PRKAR1A as a Potential Anticancer Target in Cancer Cells and Cancer-Derived Stem Cells

The integration of innovative medical technologies and interdisciplinary collaboration could improve the treatment of cancer, a globally prevalent and often deadly disease. Despite recent advancements, current cancer therapies fail to specifically address recurrence and target cancer stem cells (CSCs), which contribute to relapse. In this study, we utilized three types of cancer cells, from which three types of CSCs were further derived, to conduct a proteomic analysis. Additionally, shared cell surface biomarkers were identified as potential targets for a comprehensive treatment strategy. The selected biomarkers were evaluated through short hairpin RNA treatment, which revealed contrasting functions in cancer cells and CSCs. Knockdown of the identified proteins revealed that they regulate the epithelial-mesenchymal transition (EMT) and stemness via the ERK signaling pathway. Resistance to anticancer agents was consequently reduced, ultimately enhancing the overall anticancer effects of the treatment. Additionally, the significance of these biomarkers in clinical patient outcomes was confirmed using bioinformatics. Our study suggests a novel cancer treatment strategy that addresses the limitations of current anticancer therapies.

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.

Ubiquitination-specific protease 7 enhances stemness of hepatocellular carcinoma by stabilizing basic transcription factor 3

This study aims to explore the molecular regulation mechanism of ubiquitination-specific protease 7 (USP7) in facilitating the stemness properties of hepatocellular carcinoma (HCC). Gain-of-function and loss-of-function assays were conducted in SK-Hep1 and HepG2 cells transfected with USP7 overexpression/knockdown plasmids and USP7 inhibitor P22077. The proliferation, migration, invasion, and self-renewal capacity of hepatocellular carcinoma cells were detected by CCK-8, colony formation, Transwell, scratch, and tumor sphere formation, respectively. MS was performed to identify the potential substrate of USP7 following P22077 treatment. Co-IP assay was used to verify the interaction between USP7 and basic transcription factor 3 (BTF3) in HCC cells. The overexpression of USP7 could promote the proliferation, migration, invasion, and colony formation capacity of SK-Hep1 and HepG2 cells. Additionally, ectopic UPS7 enhanced the epithelial-mesenchymal transition (EMT) and stem-like characteristics of the HCC cells. In contrast, USP7 depletion by knockdown of USP7 or administrating inhibitor P22077 significantly inhibited these malignant phenotypes of SK-Hep1 and HepG2 cells. Following MS analysis, BTF3 was identified as a potential substrate for USP7. USP7 could interact with BTF3 and upregulate its protein level, while USP7 depletion significantly upregulated the ubiquitination levels. Overexpression of BTF3 partially rescue the inhibitory effects of USP7 depletion on the malignant phenotypes and stemness properties of SK-Hep1 and HepG2 cells. USP7 can promote the stemness and malignant phenotype of HCC by stabilizing BTF3.

Overview of hepatocellular carcinoma: from molecular aspects to future therapeutic options

Hepatocellular carcinoma (HCC) is the seventh most highly prevalent malignant tumor globally and the second most common cause of mortality. HCC develops with complex pathways that occur through multistage biological processes. Non-alcoholic fatty liver disease, metabolic-associated fatty liver disease, alcoholic liver disease, autoimmune hepatitis, hepatitis B, and hepatitis C are the causative etiologies of HCC. HCC develops as a result of epigenetic changes, protein-coding gene mutations, and altered signaling pathways. Biomarkers and potential therapeutic targets for HCC open up new possibilities for treating the disease. Immune checkpoint inhibitors are included in the treatment options in combination with molecular targeted therapy.

Comprehensive Analysis of NKX3.2 in Liver Hepatocellular Carcinoma by Bigdata

Background and Objectives: The gene NKX3.2 plays a role in determining cell fate during development, and mutations of NKX3.2 have been studied in relation to human skeletal diseases. However, due to the lack of studies on the link between NKX3.2 and cancer, we aimed to provide insights into NKX3.2 as a new prognostic biomarker for liver hepatocellular carcinoma (LIHC). Materials and Methods: The clinical significance of LIHC was investigated using open gene expression databases. We comprehensively analyzed NKX3.2 expression in LIHC using Gene Expression Profiling Interactive Analysis 2, Tumor Immune Estimation Resource (TIMER), and Kaplan-Meier plotter databases. Then, we investigated the association between NKX3.2 expression and tumor-infiltrating immune cells (TIICs). Results: NKX3.2 expression was higher in the primary tumor group compared to the normal group, and expression was higher in fibrolamellar carcinoma (FLC) compared to other subtypes. When the prognostic value of NKX3.2 was evaluated, highly expressed NKX3.2 significantly improved the overall survival and had an unfavorable prognosis. In addition, NKX3.2 expression was associated with immune cell infiltration. Patients with low gene expression and high macrophage expression had a poorer survival rate than those with low NKX3.2 and low macrophage expression (p = 0.0309). Conclusions: High NKX3.2 expression may induce poorer prognosis in LIHC. In addition, these findings can be used as basic data due to the lack of available related research. However, further in vivo studies are essential to gain a deeper understanding of the biological role of NKX3.2 in LIHC and its potential implications for cancer development and progression.

Molecular Mechanisms of Tumor Cell Stemness Modulation during Formation of Spheroids

Cancer stem cells (CSCs), their properties and interaction with microenvironment are of interest in modern medicine and biology. There are many studies on the emergence of CSCs and their involvement in tumor pathogenesis. The most important property inherent to CSCs is their stemness. Stemness combines ability of the cell to maintain its pluripotency, give rise to differentiated cells, and interact with environment to maintain a balance between dormancy, proliferation, and regeneration. While adult stem cells exhibit these properties by participating in tissue homeostasis, CSCs behave as their malignant equivalents. High tumor resistance to therapy, ability to differentiate, activate angiogenesis and metastasis arise precisely due to the stemness of CSCs. These cells can be used as a target for therapy of different types of cancer. Laboratory models are needed to study cancer biology and find new therapeutic strategies. A promising direction is three-dimensional tumor models or spheroids. Such models exhibit properties resembling stemness in a natural tumor. By modifying spheroids, it becomes possible to investigate the effect of therapy on CSCs, thus contributing to the development of anti-tumor drug test systems. The review examines the niche of CSCs, the possibility of their study using three-dimensional spheroids, and existing markers for assessing stemness of CSCs.

WDR4/TRIM28 is a novel molecular target linked to lenvatinib resistance that helps retain the stem characteristics in hepatocellular carcinomas

Hepatocellular carcinoma (HCC) is an aggressive malignancy with few effective treatment options. Lenvatinib is the first-line therapy for HCC but has only limited clinical benefit. Here, we explored the role and mechanism of the WD repeat domain 4 (WDR4) in lenvatinib resistance to improve clinical benefit. We found that lenvatinib-resistant HCC tissues/cells exhibited increased the N⁷-methylguanosine (m⁷G) modification and WDR4 expression. By a gain/loss of function experiment, we showed that WDR4 promoted HCC lenvatinib resistance and tumor progress both in vitro and in vivo. By proteomics analysis and RNA immunoprecipitation PCR, we found that tripartite motif protein 28 (trim28) was an important WDR4 target gene. WDR4 promoted TRIM28 expression, further affected target genes expression, and thus increased cell-acquired stemness and lenvatinib resistance. Clinical tissue data showed that TRIM28 expression was correlated with WDR4 levels, and the expression of both was positively correlated with poor prognosis. Our study provides new insight into the role of WDR4, suggesting a potential therapeutic target to enhance the lenvatinib sensitivity of HCC.

Human liver cancer organoids: Biological applications, current challenges, and prospects in hepatoma therapy

Liver cancer and disease are among the most socially challenging global health concerns. Although organ transplantation, surgical resection and anticancer drugs are the main methods for the treatment of liver cancer, there are still no proven cures owing to the lack of donor livers and tumor heterogeneity. Recently, advances in tumor organoid technology have attracted considerable attention as they can simulate the spatial constructs and pathophysiological characteristics of tumorigenesis and metastasis in a more realistic manner. Organoids may further contribute to the development of tailored therapies. Combining organoids with other emerging techniques, such as CRISPR-HOT, organ-on-a-chip, and 3D bioprinting, may further develop organoids and address their bottlenecks to create more practical models that generalize different tissue or organ interactions in tumor progression. In this review, we summarize the various methods in which liver organoids may be generated and describe their biological and clinical applications, present challenges, and prospects for their integration with emerging technologies. These rapidly developing liver organoids may become the focus of in vitro clinical model development and therapeutic research for liver diseases in the near future.

Lenvatinib resistance mechanism and potential ways to conquer

Lenvatinib (LVN) has been appoved to treat advanced renal cell carcinoma, differentiated thyroid carcinoma, hepatocellular carcinoma. Further other cancer types also have been tried in pre-clinic and clinic without approvation by FDA. The extensive use of lenvastinib in clinical practice is sufficient to illustrate its important therapeutic role. Although the drug resistance has not arised largely in clinical, the studies focusing on the resistance of LVN increasingly. In order to keep up with the latest progress of resistance caused by LVN, we summerized the latest studies from identify published reports. In this review, we found the latest report about resistance caused by lenvatinib, which were contained the hotspot mechanism such as the epithelial-mesenchymal transition, ferroptosis, RNA modification and so on. The potential ways to conquer the resistance of LVN were embraced by nanotechnology, CRISPR technology and traditional combined strategy. The latest literature review of LVN caused resistance would bring some ways for further study of LVN. We call for more attention to the pharmacological parameters of LVN in clinic, which was rarely and would supply key elements for drug itself in human beings and help to find the resistance target or idea for further study.