Role of exosomal microRNAs in cancer therapy and drug resistance mechanisms: focus on hepatocellular carcinoma

Extracellular vesicles as a promising platform of precision medicine in liver cancer

Extracellular vesicles (EVs) are natural carriers of biological information and play pivotal roles in intercellular communication. EVs are biocompatible, have low immunogenicity, and are capable of traversing biological barriers, making them ideal tools for disease diagnosis and therapy. Despite their promising prospects, the full realization of EVs potential faces several challenges. This article aims to comprehensively review the biological and molecular features of EVs, their applications in liver cancer and possible underlying mechanisms, and the critical challenges affecting the clinical translation of EVs-based therapies in liver cancer.

Role of Circulating microRNAs in Liver Disease and HCC: Focus on miR-122

miR-122 is the most abundant microRNA (miRNA) in the liver; it regulates several genes mainly involved in cell metabolism and inflammation. Host factors, diet, metabolic disorders and viral infection promote the development of liver diseases, including hepatocellular carcinoma (HCC). The downregulation of miR-122 in tissue is a common feature of the progression of liver injury. In addition, the release of miR-122 in the bloodstream seems to be very promising for the early diagnosis of both viral and non-viral liver disease. Although controversial data are available on the role of circulating miR-122 as a single biomarker, high diagnostic accuracy has been observed using miR-122 in combination with other circulating miRNAs and/or proteins. This review is focused on comprehensively summarizing the most recent literature on the potential role of circulating miR-122, and related molecules, as biomarker(s) of metabolic liver diseases, hepatitis and HCC.

Contribution of extracellular vesicles to steatosis-related liver disease and their therapeutic potential

Extracellular vesicles (EVs) are small particles released by many cell types in different tissues, including the liver, and transfer specific cargo molecules from originating cells to receptor cells. This process generally culminates in activation of distant cells and inflammation and progression of certain diseases. The global chronic liver disease (CLD) epidemic is estimated at 1.5 billion patients worldwide. Cirrhosis and liver cancer are the most common risk factors for CLD. However, hepatitis C and B virus infection and obesity are also highly associated with CLD. Nonetheless, the etiology of many CLD pathophysiological, cellular, and molecular events are unclear. Changes in hepatic lipid metabolism can lead to lipotoxicity events that induce EV release. Here, we aimed to present an overview of EV features, from definition to types and biogenesis, with particular focus on the molecules related to steatosis-related liver disease, diagnosis, and therapy.

Exosomal microRNAs in hepatocellular carcinoma, expanding research field

In this editorial we comment on the review by Wang et al published in the recent issue of the World Journal of Gastroenterology in 2023. Small extracellular vesicles (exosomes) play important roles in the tumor microenvironment. In this review, the authors introduce the following points: (1) The composition and function of exosomal microRNAs (miRNAs) of different cell origins in hepatocellular carcinoma (HCC); (2) the crosstalk between exosomal miRNAs from stromal cells and immune cells in the tumor microenvironment and the progression of HCC; and (3) the potential applicability of exosomal miRNAs derived from mesen-chymal stem cells in the treatment of HCC. In addition, the potential applicability of exosomal miRNAs derived from mesenchymal stem cells in the treatment of HCC was introduced. In this review, the authors give us an overview of the exosomal RNA and summarize the function of exosomal RNA in HCC, which provides a deeper understanding of exosomal miRNAs to the readers.

Ropivacaine combined with sorafenib attenuates hepatocellular carcinoma cell proliferation and metastasis by inhibiting the miR-224/HOXD10 axis

OBJECTIVE

The development of drug resistance in hepatocellular carcinoma (HCC) cells limits the effectiveness of sorafenib (Sor). However, the regulatory mechanisms underlying the effects of the combination Sor and ropivacaine (Rop) on HCC cells remain unclear.

METHODS

miR-224 and HOXD10 mRNA expression in HCC cells was analyzed using qRT-PCR. CCK-8, Transwell assays and tumor formation experiments in nude mice were used to assess HCC cell proliferation, migration, and invasion. Migration of HCC cells was also analyzed using a cell scratch assay. Hematoxylin and eosin staining was used to detect tumor area.

RESULTS

miR-224 expression profoundly increased in HepG2 and Huh7 cells. Treatment with Rop and/or Sor blocked miR-244 expression, especially the combination treatment. Transfection of miR-224 mimic increased HCC cell proliferation and tumor size in nude mice, and migration and invasion in vitro in the presence of Rop and Sor compared to the negative control mimic. Dual-luciferase reporter assays showed that HOXD10 was targeted by miR-224. HOXD10 protein expression and was markedly reduced in HepG2 and Huh7 cells. Rop and/or Sor treatment increased HOXD10 protein expression, particularly the combination treatment. miR-224 negatively regulated HOXD10 expression in HCC cells treated with Rop and Sor. Transfection-mediated silencing of HOXD10 increased HCC cell proliferation, migration, and invasion in the presence of Rop and Sor compared with negative control transfection.

CONCLUSION

The combination of Rop and Sor attenuates HCC cell proliferation and metastasis via the miR-224/HOXD10 axis.

Exosomal microRNA profiling revealed enhanced autophagy suppression and anti-tumor effects of a combination of compound Phyllanthus urinaria and lenvatinib in hepatocellular carcinoma

BACKGROUND

Compound Phyllanthus urinaria (CP), a traditional Chinese herbal remedy, possesses strong anti-cancer effects and is extensively employed in the clinical management of hepatocellular carcinoma (HCC). While lenvatinib and other oral tyrosine kinase inhibitors have been authorized as initial treatments for advanced unresectable HCC, the survival of patients is ultimately restricted due to the gradual development of drug resistance. Fortunately, the co-administration of CP and lenvatinib holds promise for anti-cancer applications.

PURPOSE

Our objective was to understand the molecular-level mechanisms of bioactive phytocompounds in CP, in order to explore the anti-HCC effects of combining CP and lenvatinib treatment and reveal the underlying mechanisms. Furthermore, we discovered new miRNAs associated with autophagy that are common to both HepG2-derived exosomes and HepG2 cells. These miRNAs play a role in the advancement of HCC and were identified through the utilization of CP and lenvatinib.

METHODS

To assess the anti-HCC effects of CP in combination with lenvatinib, both an in vitro CCK-8 assay and an in vivo xenograft model assay were performed. TEM, NTA, and nano-flow cytometry were employed for the identification of isolated exosomes. To ascertain the miRNA expression patterns in HepG2 cells and HepG2-derived exosomes, miRNA-sequencing analysis was conducted. Further investigation involved the use of real-time PCR, examination of the fusion protein GFP-mRFP-LC3, TEM analysis, and western blotting.

RESULTS

In vitro and in vivo, the combination of CP and lenvatinib showed a stronger and more powerful impact on HCC compared to either CP or lenvatinib alone. The combination of CP and lenvatinib had a significant impact on autophagy-related miRNAs in HepG2-derived exosomes and HepG2 cells, as demonstrated by cellular and exosomal miRNA sequencing. Additional tests indicated that the increased inhibition of autophagy in HepG2 cells subjected to CP treatment, as well as the combination of CP and lenvatinib, was accomplished through the regulation of Beclin-1, LC3-II, and P62 expression.

CONCLUSION

In conclusion, our results indicate that the combination of CP and lenvatinib can effectively inhibit HCC by promoting the exosome-mediated suppression of autophagy. This novel therapeutic option is highly efficient and durable, making it a promising treatment for HCC. Moreover, the miRNAs that are differentially expressed and associated with exosome-mediated autophagy, which have been discovered in this study, could potentially be targeted for clinical treatment of HCC.

Role of miR50103p in predicting the prognosis of hepatocellular carcinoma

OBJECTIVES

Numerous miRNAs have been found to be abnormally expressed in hepatocellular carcinoma (HCC). However, clinical significance of miR-5010-3p in HCC is not elucidated. This study aims to explore the prognostic value and role of miR-5010-3p in HCC.

METHODS

The differential gene expression analysis of miR-5010-3p in HCC was performed based on the Cancer Genome Atlas (TCGA) database. The receiver operating characteristic (ROC) curve was used to evaluate the predictive value of miR-5010-3p expression level for HCC prognosis. The Kaplan-Meier, Cox univariate, and Cox multivariate analysis were used to predict its role in the prognosis of HCC. The downstream target genes were predicted. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed to predict the potential functional pathways they may participate in. Finally, methyl thiazolyl tetrazolium (MTT) assay and 5-ethyl-2'-deoxyuridine (EDU) incorporation experiment were carried out to prove its effect on proliferation.

RESULTS

The expression of miR-5010-3p was associated with histological grade (P=0.019), vascular invasion degree (P=0.049), TP53 level (P=0.004), and alpha fetoprotein (AFP) level (P=0.012). A moderate ability to distinguish between tumor and paracancerous tissues of miR-5010-3p in HCC was perceived by ROC curve (AUC: 0.712, 95% CI 0.649 to 0.776). High expression of miR-5010-3p was associated with shorter overall survival (OS) (P=0.003). The results of functional enrichment analysis showed that miR-5010-3p was related to the tumorigenesis process. In vitro experiments verified that miR-5010-3p promoted the proliferation of hepatocellular carcinoma cells.

CONCLUSIONS

MiR-5010-3p promotes the proliferation of liver cancer cells, and its high expression is associated with poor prognosis, which may be a potential prognostic marker.

Spotlights on extracellular vesicles in hepatocellular carcinoma diagnosis and treatment: an update review

Hepatocellular carcinoma (HCC), one of the most prevalent cancers, with a high mortality rate worldwide, seriously impairs patient health. The lack of accurate targets impedes the early screening and diagnosis of HCC and is associated with a poor response to routine therapies. Extracellular vesicles (EVs), comprising exosomes, microvesicles, and apoptotic bodies, are lipid bilayer membrane-derived nanometer-sized vesicles. EVs can be secreted from various cancer cells and release diverse biomolecules, such as DNA, RNA, proteins, metabolites, and lipids, making them a potential source of biomarkers and regulators of the tumor microenvironment. Emerging evidence suggests that EVs are involved in intercellular communication by carrying biological information. These EVs elicit physiological functions and are involved in the oncogenesis of HCC, such as proliferation, invasion, metastasis, and chemoresistance of HCC. EVs have also been considered promising biomarkers and nanotherapeutic targets for HCC. Therefore, this review sheds light on the current understanding of the interactions between EVs and HCC to propose potential biomarkers and nanotherapeutic strategies.

Risk factors of primary liver cancer initiation associated with tumour initiating cell emergence: novel targets for promising preventive therapies

Primary liver cancers ranked as the sixth most commonly diagnosed cancers and the third-leading cause of cancer-related death in 2020. Despite encouraging findings on diagnosis and treatments, liver cancer remains a life-threatening disease with a still increasing incidence. Therefore, it is of interest to better characterise and understand the mechanistic process occurring at early steps of carcinogenesis. Inflammatory responses in liver diseases participate in the activation of liver progenitor cells (LPCs) facultative compartment but also to their transformation into cancer stem cells (CSCs) and give rise to primary liver cancer including hepatocellular carcinoma and cholangiocarcinoma. Higher intratumoural heterogeneity has been associated with poorer prognosis and linked to tumour escape from the immune surveillance and to resistance to chemotherapy. A better understanding of the malignant transformation of LPC as tumour initiating cells (ie, CSC) should also provide a potential new therapeutic target for anticancer therapy. In this review, we summarise the recent reports identifying underlying mechanisms by which chronic liver inflammatory responses could trigger the early steps in liver carcinogenesis, notably through the transformation of LPCs into tumour initiating cells.

Immune checkpoint inhibitor resistance in hepatocellular carcinoma

The application of immune checkpoint inhibitors (ICIs) has markedly enhanced the treatment of hepatocellular carcinoma (HCC), and HCC patients who respond to ICIs have shown prolonged survival. However, only a subset of HCC patients benefit from ICIs, and those who initially respond to ICIs may develop resistance. ICI resistance is likely related to various factors, including the immunosuppressive tumor microenvironment (TME), the absence of antigen expression and impaired antigen presentation, tumor heterogeneity, and gut microbiota. Therefore, exploring the possible mechanisms of ICI resistance is crucial to improve the clinical benefit of ICIs further. Various combination therapies for HCC immunotherapy have prevented and reversed ICI resistance to a certain extent. In addition, many new combination therapies that can overcome resistance are being explored. This review seeks to characterize the complex TME in HCC, explore the possible mechanisms of immune resistance to ICIs in different resistance categories, and review the combination therapies currently being applied and those under investigation for immunotherapy.

Advances in Purification, Modification, and Application of Extracellular Vesicles for Novel Clinical Treatments

Extracellular vesicles (EV) are membrane vesicles surrounded by a lipid bilayer membrane and include microvesicles, apoptotic bodies, exosomes, and exomeres. Exosome-encapsulated microRNAs (miRNAs) released from cancer cells are involved in the proliferation and metastasis of tumor cells via angiogenesis. On the other hand, mesenchymal stem cell (MSC) therapy, which is being employed in regenerative medicine owing to the ability of MSCs to differentiate into various cells, is due to humoral factors, including messenger RNA (mRNA), miRNAs, proteins, and lipids, which are encapsulated in exosomes derived from transplanted cells. New treatments that advocate cell-free therapy using MSC-derived exosomes will significantly improve clinical practice. Therefore, using highly purified exosomes that perform their original functions is desirable. In this review, we summarized advances in the purification, modification, and application of EVs as novel strategies to treat some diseases.

Extracellular Vesicle (EVs) Associated Non-Coding RNAs in Lung Cancer and Therapeutics

Lung cancer is one of the most lethal forms of cancer, with a very high mortality rate. The precise pathophysiology of lung cancer is not well understood, and pertinent information regarding the initiation and progression of lung cancer is currently a crucial area of scientific investigation. Enhanced knowledge about the disease will lead to the development of potent therapeutic interventions. Extracellular vesicles (EVs) are membrane-bound heterogeneous populations of cellular entities that are abundantly produced by all cells in the human body, including the tumor cells. A defined class of EVs called small Extracellular Vesicles (sEVs or exosomes) carries key biomolecules such as RNA, DNA, Proteins and Lipids. Exosomes, therefore, mediate physiological activities and intracellular communication between various cells, including constituent cells of the tumor microenvironment, namely stromal cells, immunological cells, and tumor cells. In recent years, a surge in studying tumor-associated non-coding RNAs (ncRNAs) has been observed. Subsequently, studies have also reported that exosomes abundantly carry different species of ncRNAs and these exosomal ncRNAs are functionally involved in cancer initiation and progression. Here, we discuss the function of exosomal ncRNAs, such as miRNAs and long non-coding RNAs, in the pathophysiology of lung tumors. Further, the future application of exosomal-ncRNAs in clinics as biomarkers and therapeutic targets in lung cancer is also discussed due to the multifaceted influence of exosomes on cellular physiology.

Regulation of Extracellular Vesicle-Mediated Immune Responses against Antigen-Specific Presentation

Extracellular vesicles (EVs) produced by various immune cells, including B and T cells, macrophages, dendritic cells (DCs), natural killer (NK) cells, and mast cells, mediate intercellular communication and have attracted much attention owing to the novel delivery system of molecules in vivo. DCs are among the most active exosome-secreting cells of the immune system. EVs produced by cancer cells contain cancer antigens; therefore, the development of vaccine therapy that does not require the identification of cancer antigens using cancer-cell-derived EVs may have significant clinical implications. In this review, we summarise the molecular mechanisms underlying EV-based immune responses and their therapeutic effects on tumour vaccination.