Hepatic Stellate Cell Modulates the Immune Microenvironment in the Progression of Hepatocellular Carcinoma

Reconstructing the hepatocellular carcinoma microenvironment: the current status and challenges of 3D culture technology

Hepatocellular carcinoma (HCC), with high incidence and mortality rates among digestive system diseases, has become a focal point for researchers. However, the more we learn about HCC, the more apparent it becomes that our understanding is still superficial. The successes and failures of numerous studies underscore the urgent need for precision medicine in cancer treatment. A crucial aspect of preclinical research in precision medicine is the experimental model, particularly cell culture models. Among these, 3D cell culture models can effectively integrate and simulate the tumor microenvironment, closely reflecting the in vivo conditions of patients. This capability provides a solid theoretical foundation for personalized treatment approaches. In this review, we first outline the common in vitro 3D cell culture models and examine the essential elements within the tumor microenvironment, followed by insights into the current state and future developments of 3D in vitro cell models for HCC.

Depletion of tumor-reactive HSCs reveals their significance during different stages of liver metastasis

BACKGROUND

Activated HSCs play a major role in tissue repair, extracellular matrix regulation, immune response, and inflammation. However, their contributions to the hepatic tumor microenvironment are underexplored and need to be clarified.

METHODS

In vitro, we analyzed the responses of freshly isolated LSECs and HSCs to tumor cell supernatants and secretome-driven activation of both primary cell types. For in vivo HSC depletion, transgenic mice expressing the herpes simplex virus-thymidine kinase (HSV-Tk) gene driven by the mouse glial fibrillary acidic protein promoter were used. MC38 colon carcinoma or B16 melanoma was intrasplenically injected to generate liver metastasis to further analyze metastatic growth, collagen accumulation, angiogenesis, and immunosuppression.

RESULTS

Metastatic tumor cells arrest and adhere in the liver 48 hours after intrasplenic injection. The 65% of arrested tumor cells were surrounded by α-smooth muscle actin-expressing cells. In vitro, tumor-activated LSEC-derived secretomes stimulated α-smooth muscle actin expression, migration, VEGF, and LSEC promigratory factor release by HSCs. Tumor cell secretomes stimulated HSC proliferation and the secretion of proangiogenic and protumoral mediators. HSC depletion reduced the foci number and metastatic area in colorectal cancer and melanoma models. Moreover, livers from transgenic mice showed reduced key tumor microenvironment parameters, including intratumoral collagen accumulation, neoangiogenesis, and recruitment of myeloid-derived suppressor cells.

CONCLUSIONS

Depletion of tumor-reactive proliferating HSCs implicates these cells as the required spark for the initiation and progression of liver metastasis, making them a good candidate for new therapies targeting the tumor microenvironment to treat liver metastasis of different primary origins.

Cross-Talk Between Tumor Cells and Stellate Cells Promotes Oncolytic VSV Activity in Intrahepatic Cholangiocarcinoma

As the mechanisms underlying tumorigenesis become better understood, the dynamic roles of cellular components of the tumor microenvironment, and their cross-talk with tumor cells, have come to light as key drivers of disease progression and have emerged as important targets of new cancer therapies. In the field of oncolytic virus (OV) therapy, stromal cells have been considered as potential barriers to viral spread, thus limiting virus replication and therapeutic outcome. However, new evidence indicates that intratumoral fibroblasts could support virus replication. We have demonstrated in a rat model of stromal-rich intrahepatic cholangiocarcinoma (CCA) that vesicular stomatitis virus (VSV) can be localized within intratumoral hepatic stellate cells (HSCs), in addition to tumor cells, when the virus was applied via hepatic arterial infusion. Furthermore, VSV was shown to efficiently kill CCA cells and activated HSCs, and co-culture of CCA and HSCs increased viral titers. Interestingly, this effect is also observed when each cell type is cultured alone in a conditioned medium of the other cell type, indicating that secreted cell factors are at least partially responsible for this phenomenon. Partial reduction in sensitivity to type I interferons was observed in co-culture systems, providing a possible mechanism for the increased viral titers. Together, the results indicate that targeting activated HSCs with VSV could provide an additional mechanism of OV therapy, which, until now has not been considered. Furthermore, these findings suggest that VSV is a potentially powerful therapeutic agent for stromal-rich tumors, such as CCA and pancreatic cancer, both of which are very difficult to treat with conventional therapy and have a very poor prognosis.

Lipid Nanoparticle (LNP) -A Vector Suitable for Evolving Therapies for Advanced Hepatocellular Carcinoma (HCC)

Hepatocellular carcinoma (HCC) stands as the predominant form of primary liver cancer, characterized by a dismal prognosis. Therapeutic options for advanced HCC remain sparse, with efficacy significantly hampered by the emergence of drug resistance. In parallel with research into novel pharmacological agents, advances in drug delivery systems represent a promising avenue for overcoming resistance. Lipid nanoparticles (LNPs) have demonstrated considerable efficacy in the delivery of nucleic acid-based therapeutics and hold potential for broader applications in drug delivery. This review describes the development of LNPs tailored for HCC treatment and consolidates recent investigations using LNPs to target HCC.

Hepatic stellate cells promote hepatocellular carcinoma development by regulating histone lactylation: Novel insights from single-cell RNA sequencing and spatial transcriptomics analyses

This study evaluated the cellular heterogeneity and molecular mechanisms of hepatocellular carcinoma (HCC). Single cell RNA sequencing (scRNA-seq), transcriptomic data, histone lactylation-related genes were collected from public databases. Cell-cell interaction, trajectory, pathway, and spatial transcriptome analyses were executed. Differential expression and survival analyses were conducted. Western blot, Real-time reverse transcription PCR (qRT-PCR), and Cell Counting Kit 8 (CCK8) assay were used to detect the expression of αSMA, AKR1B10 and its target genes, and verify the roles of AKR1B10 in HCC cells. Hepatic stellate cell (HSC) subgroups strongly interacted with tumor cell subgroups, and their spatial distribution was heterogeneous. Two candidate prognostic genes (AKR1B10 and RMRP) were obtained. LONP1, NPIPB3, and ZSWIM6 were determined as AKR1B10 targets. Besides, the expression levels of AKR1B10 and αSMA were significantly increased in LX-2 + HepG2 and LX-2 + HuH7 groups compared to those in LX-2 group, respectively. sh-AKR1B10 significantly inhibited the HCC cell proliferation and change the expression of AKR1B10 target genes, Bcl-2, Bax, Pan Kla, and H3K18la at protein levels. Our findings unveil the pivotal role of HSCs in HCC pathogenesis through regulating histone lactylation.

Activin A levels in metabolic dysfunction-associated steatotic liver disease associates with fibrosis and the PNPLA3 I148M variant

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver condition worldwide. There is an urgent need to develop new biomarkers to assess disease severity and to define patients with a progressive phenotype. Activin A is a new promising biomarker with conflicting results about liver fibrosis. In this study we investigate levels of Activin A in patients with biopsy proven MASLD. We assess levels of Activin A in regard to fibrosis stage and genetic variant I148M in the patatin-like phospholipase domain-containing protein 3 (PNPLA3).

METHODS

Activin A levels were assessed in plasma samples from patients with biopsy-proven MASLD in a cross-sectional study. All patients were clinically evaluated and the PNPLA3 I148M genotype of the cohort was assessed.

FINDINGS

41 patients were included and 27% of these had advanced fibrosis. In MASLD patients with advanced fibrosis, Activin A levels was higher (p < 0.001) and could classify advanced fibrosis with an AUROC for activin A of 0.836 (p < 0.001). Patients homozygous for PNPLA3 I148M G/G had higher levels of activin A than non-homozygotes (p = 0.027).

CONCLUSIONS

Circulating activin A levels were associated with advanced fibrosis and could be a potential blood biomarker for identifying advanced fibrosis in MASLD. Patients with the risk genotype PNPLA3 I148M G/G had higher levels of activin A proposing activin A as a contributor of the transition from simple steatosis to a fibrotic phenotype.

Abnormal metabolism in hepatic stellate cells: Pandora's box of MAFLD related hepatocellular carcinoma

Metabolic associated fatty liver disease (MAFLD) is a significant risk factor for the development of hepatocellular carcinoma (HCC). Hepatic stellate cells (HSCs), as key mediators in liver injury response, are believed to play a crucial role in the repair process of liver injury. However, in MAFLD patients, the normal metabolic and immunoregulatory mechanisms of HSCs become disrupted, leading to disturbances in the local microenvironment. Abnormally activated HSCs are heavily involved in the initiation and progression of HCC. The metabolic disorders and abnormal activation of HSCs not only initiate liver fibrosis but also contribute to carcinogenesis. In this review, we provide an overview of recent research progress on the relationship between the abnormal metabolism of HSCs and the local immune system in the liver, elucidating the mechanisms of immune imbalance caused by abnormally activated HSCs in MAFLD patients. Based on this understanding, we discuss the potential and challenges of metabolic-based and immunology-based mechanisms in the treatment of MAFLD-related HCC, with a specific focus on the role of HSCs in HCC progression and their potential as targets for anti-cancer therapy. This review aims to enhance researchers' understanding of the importance of HSCs in maintaining normal liver function and highlights the significance of HSCs in the progression of MAFLD-related HCC.

Unraveling the underlying pathogenic factors driving nonalcoholic steatohepatitis and hepatocellular carcinoma: an in-depth analysis of prognostically relevant gene signatures in hepatocellular carcinoma

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is a progressive manifestation of nonalcoholic fatty liver disease (NAFLD) that can lead to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Despite the growing knowledge of NASH and HCC, the association between the two conditions remains to be fully explored. Bioinformatics has emerged as a valuable approach for identifying disease-specific feature genes, enabling advancements in disease prediction, prevention, and personalized treatment strategies.

MATERIALS AND METHODS

In this study, we utilized CellChat, copy number karyotyping of aneuploid tumors (CopyKAT), consensus Non-negative Matrix factorization (cNMF), Gene set enrichment analysis (GSEA), Gene set variation analysis (GSVA), Monocle, spatial co-localization, single sample gene set enrichment analysis (ssGSEA), Slingshot, and the Scissor algorithm to analyze the cellular and immune landscape of NASH and HCC. Through the Scissor algorithm, we identified three cell types correlating with disease phenotypic features and subsequently developed a novel clinical prediction model using univariate, LASSO, and multifactor Cox regression.

RESULTS

Our results revealed that macrophages are a significant pathological factor in the development of NASH and HCC and that the macrophage migration inhibitory factor (MIF) signaling pathway plays a crucial role in cellular crosstalk at the molecular level. We deduced three prognostic genes (YBX1, MED8, and KPNA2), demonstrating a strong diagnostic capability in both NASH and HCC.

CONCLUSION

These findings shed light on the pathological mechanisms shared between NASH and HCC, providing valuable insights for the development of novel clinical strategies.

Liver Fibrosis in Non-Alcoholic Fatty Liver Disease and Progression to Hepatocellular Carcinoma in Patients with Inflammatory Bowel Disease: A Systematic Review

The aim of the systematic review is to assess the prevalence and risk factors of liver fibrosis in patients with Inflammatory Bowel Disease (IBD) and Non-Alcoholic Fatty Liver Disease (NAFLD) and to discuss the role of liver fibrosis in the progression to hepatocellular carcinoma (HCC). We performed a structured search in PubMed, Web of Science, Embase, and Scopus up to 3 March 2023 to identify observational studies reporting liver fibrosis in patients with NAFLD and IBD. Quality of studies was assessed using the Newcastle-Ottawa Scale (NOS) score. A total of 23 studies met our inclusion criteria, including 629,781 patients. A total of 10 cross-sectional, 3 case-control, and 10 cohort studies were included. Fourteen studies had a NOS score ≥ 7 points. NAFLD was diagnosed in 2162/6332 (34.1%) IBD participants. However, NAFLD diagnosis was established in 924/2962 (31.2%) healthy individuals without IBD. Advanced liver fibrosis was found in 116 (11.6%) of 992 IBD patients with NAFLD. Most studies found an association between NAFLD and classic cardiovascular risk factors such as older age, male sex, higher BMI, diabetes, hypertension and dyslipidemia. In addition, metabolic syndrome features were also associated with an increased risk of significant and advanced liver fibrosis. Although no strong association between NAFLD and IBD therapy was reported, some studies associated NAFLD with IBD diagnosis, Crohn's Disease, a complicated course of IBD, disease activity, and IBD duration. Advanced liver fibrosis was also associated with Crohn's disease in several studies. In conclusion, NAFLD and advanced liver fibrosis are prevalent and clinically relevant extraintestinal manifestations, so its diagnosis and potential progression to HCC should be carefully considered in daily clinical practice.

A hepatoprotective role of peritumoral non-parenchymal cells in early liver tumorigenesis

Various 3D models of hepatocytes (HCs) have been established to assess liver functions in vitro. The contribution of the hepatic non-parenchymal cells (NPCs), however, is largely neglected in these models. Here, we report a comparative study of hepatic spheroids generated from freshly isolated mouse whole liver cells (WLCs) and HCs (referred to as SphWLC and SphHC, respectively). We found that HC differentiation was preserved better in SphWLC than in SphHC, and, when co-cultured with liver tumor spheroids (SphT), SphWLC showed more potent suppression of SphT growth compared to SphHC. Histological characterization revealed marked activation and accumulation of hepatic stellate cells (HSCs) at the SphWLC:SphT interface. We found that mixing HSCs in both 3D and 2D HC:tumor co-cultures provided potent protection to HCs against tumor-induced cell death. Activation of HSCs at the tumor border was similarly found in liver tumors from both mice and patients. Overall, our study suggests a hepatoprotective role of peritumoral HSCs in liver tumorigenesis and the potential application of SphWLC as a useful 3D model for dissecting the liver's response to tumorigenesis in vitro.

Ongoing involvers and promising therapeutic targets of hepatic fibrosis: The hepatic immune microenvironment

Hepatic fibrosis is often secondary to chronic inflammatory liver injury. During the development of hepatic fibrosis, the damaged hepatocytes and activated hepatic stellate cells (HSCs) caused by the pathogenic injury could secrete a variety of cytokines and chemokines, which will chemotactic innate and adaptive immune cells of liver tissue and peripheral circulation infiltrating into the injury site, mediating the immune response against injury and promoting tissue reparation. However, the continuous release of persistent injurious stimulus-induced inflammatory cytokines will promote HSCs-mediated fibrous tissue hyperproliferation and excessive repair, which will cause hepatic fibrosis development and progression to cirrhosis even liver cancer. And the activated HSCs can secrete various cytokines and chemokines, which directly interact with immune cells and actively participate in liver disease progression. Therefore, analyzing the changes in local immune homeostasis caused by immune response under different pathological states will greatly enrich our understanding of liver diseases' reversal, chronicity, progression, and even deterioration of liver cancer. In this review, we summarized the critical components of the hepatic immune microenvironment (HIME), different sub-type immune cells, and their released cytokines, according to their effect on the development of progression of hepatic fibrosis. And we also reviewed and analyzed the specific changes and the related mechanisms of the immune microenvironment in different chronic liver diseases.Moreover, we retrospectively analyzed whether the progression of hepatic fibrosis could be alleviated by modulating the HIME.We aimed to elucidate the pathogenesis of hepatic fibrosis and provide the possibility for exploring the therapeutic targets for hepatic fibrosis.