IRF2 regulates cellular survival and Lenvatinib-sensitivity of hepatocellular carcinoma (HCC) through regulating β-catenin

Lenvatinib in hepatocellular carcinoma: Resistance mechanisms and strategies for improved efficacy

Hepatocellular carcinoma (HCC), one of the most prevalent and destructive causes of cancer-related deaths worldwide, approximately 70% of patients with HCC exhibit advanced disease at diagnosis, limiting the potential for radical treatment. For such patients, lenvatinib, a long-awaited alternative to sorafenib for first-line targeted therapy, has become a key treatment. Unfortunately, despite some progress, the prognosis for advanced HCC remains poor because of drug resistance development. However, the molecular mechanisms underlying lenvatinib resistance and ways to relief drug resistance in HCC are largely unknown and lack of systematic summary; thus, this review not only aims to explore factors contributing to lenvatinib resistance in HCC, but more importantly, summary potential methods to conquer or mitigate the resistance. The results suggest that abnormal activation of pathways, drug transport, epigenetics, tumour microenvironment, cancer stem cells, regulated cell death, epithelial-mesenchymal transition, and other mechanisms are involved in the development of lenvatinib resistance in HCC and subsequent HCC progression. To improve the therapeutic outcomes of lenvatinib, inhibiting acquired resistance, combined therapies, and nano-delivery carriers may be possible approaches.

Mechanisms of drug resistance in HCC

HCC comprises ∼80% of primary liver cancer. HCC is the only major cancer for which death rates have not improved over the last 10 years. Most patients are diagnosed with advanced disease when surgical and locoregional treatments are not feasible or effective. Sorafenib, a multikinase inhibitor targeting cell growth and angiogenesis, was approved for advanced unresectable HCC in 2007. Since then, other multikinase inhibitors have been approved. Lenvatinib was found to be noninferior to sorafenib as a first-line agent. Regorafenib, cabozantinib, and ramucirumab were shown to prolong survival as second-line agents. Advances in immunotherapy for HCC have also added hope for patients, but their efficacy remains limited. A large proportion of patients with advanced HCC gain no long-term benefit from systemic therapy due to primary and acquired drug resistance, which, combined with its rising incidence, keeps HCC a highly fatal disease. This review summarizes mechanisms of primary and acquired resistance to therapy and includes methods for bypassing resistance. It addresses recent advancements in immunotherapy, provides new perspectives on the linkage between drug resistance and molecular etiology of HCC, and evaluates the role of the microbiome in drug resistance. It also discusses alterations in signaling pathways, dysregulation of apoptosis, modulations in the tumor microenvironment, involvement of cancer stem cells, changes in drug metabolism/transport, tumor hypoxia, DNA repair, and the role of microRNAs in drug resistance. Understanding the interplay among these factors will provide guidance on the development of new therapeutic strategies capable of improving patient outcomes.

Insights into lenvatinib resistance: mechanisms, potential biomarkers, and strategies to enhance sensitivity

Lenvatinib is a multitargeted tyrosine kinase inhibitor capable of promoting apoptosis, suppressing angiogenesis, inhibiting tumor cell proliferation, and modulating the immune response. In multiple cancer types, lenvatinib has presented manageable safety and is currently approved as an effective first-line therapy. However, with the gradual increase in lenvatinib application, the inevitable progression of resistance to lenvatinib is becoming more prevalent. A series of recent researches have reported the mechanisms underlying the development of lenvatinib resistance in tumor therapy, which are related to the regulation of cell death or proliferation, histological transformation, metabolism, transport processes, and epigenetics. In this review, we aim to outline recent discoveries achieved in terms of the mechanisms and potential predictive biomarkers of lenvatinib resistance as well as to summarize untapped approaches available for improving the therapeutic efficacy of lenvatinib in patients with various types of cancers.

Pan-cancer analysis identifies the IRF family as a biomarker for survival prognosis and immunotherapy

IRF family genes have been shown to be crucial in tumorigenesis and tumour immunity. However, information about the role of IRF in the systematic assessment of pan-cancer and in predicting the efficacy of tumour therapy is still unknown. In this work, we performed a systematic analysis of IRF family genes in 33 tumour samples, including expression profiles, genomics and clinical characteristics. We then applied Single-Sample Gene-Set Enrichment Analysis (ssGSEA) to calculate IRF-scores and analysed the impact of IRF-scores on tumour progression, immune infiltration and treatment efficacy. Our results showed that genomic alterations, including SNPs, CNVs and DNA methylation, can lead to dysregulation of IRFs expression in tumours and participate in regulating multiple tumorigenesis. IRF-score expression differed significantly between 12 normal and tumour samples and the impact on tumour prognosis and immune infiltration depended on tumour type. IRF expression was correlated to drug sensitivity and to the expression of immune checkpoints and immune cell infiltration, suggesting that dysregulation of IRF family expression may be a critical factor affecting tumour drug response. Our study comprehensively characterizes the genomic and clinical profile of IRFs in pan-cancer and highlights their reliability and potential value as predictive markers of oncology drug efficacy. This may provide new ideas for future personalized oncology treatment.

A single-nucleus transcriptomic atlas of primate liver aging uncovers the pro-senescence role of SREBP2 in hepatocytes

Aging increases the risk of liver diseases and systemic susceptibility to aging-related diseases. However, cell type-specific changes and the underlying mechanism of liver aging in higher vertebrates remain incompletely characterized. Here, we constructed the first single-nucleus transcriptomic landscape of primate liver aging, in which we resolved cell type-specific gene expression fluctuation in hepatocytes across three liver zonations and detected aberrant cell-cell interactions between hepatocytes and niche cells. Upon in-depth dissection of this rich dataset, we identified impaired lipid metabolism and upregulation of chronic inflammation-related genes prominently associated with declined liver functions during aging. In particular, hyperactivated sterol regulatory element-binding protein (SREBP) signaling was a hallmark of the aged liver, and consequently, forced activation of SREBP2 in human primary hepatocytes recapitulated in vivo aging phenotypes, manifesting as impaired detoxification and accelerated cellular senescence. This study expands our knowledge of primate liver aging and informs the development of diagnostics and therapeutic interventions for liver aging and associated diseases.

Advances in Targeted Drug Resistance Associated with Dysregulation of Lipid Metabolism in Hepatocellular Carcinoma

Hepatocellular carcinoma is the prevailing malignant neoplasm affecting the liver, often diagnosed at an advanced stage and associated with an unfavorable overall prognosis. Sorafenib and Lenvatinib have emerged as first-line therapeutic drugs for advanced hepatocellular carcinoma, improving the prognosis for these patients. Nevertheless, the issue of tyrosine kinase inhibitor (TKI) resistance poses a substantial obstacle in the management of advanced hepatocellular carcinoma. The pathogenesis and advancement of hepatocellular carcinoma exhibit a close association with metabolic reprogramming, yet the attention given to lipid metabolism dysregulation in hepatocellular carcinoma development remains relatively restricted. This review summarizes the potential significance and research progress of lipid metabolism dysfunction in Sorafenib and Lenvatinib resistance in hepatocellular carcinoma. Targeting hepatocellular carcinoma lipid metabolism holds promising potential as an effective strategy to overcome hepatocellular carcinoma drug resistance in the future.

The action and resistance mechanisms of Lenvatinib in liver cancer

Lenvatinib is a tyrosine kinase inhibitor that prevents the formation of new blood vessels namely by inhibiting tyrosine kinase enzymes as the name suggests. Specifically, Lenvatinib acts on vascular endothelial growth factor receptors 1-3 (VEGFR1-3), fibroblast growth factor receptors 1-4 (FGFR1-4), platelet-derived growth factor receptor-alpha (PDGFRα), tyrosine-kinase receptor (KIT), and rearranged during transfection receptor (RET). Inhibition of these receptors works to inhibit tumor proliferation. It is through these inhibition mechanisms that Lenvatinib was tested to be noninferior to Sorafenib. However, resistance to Lenvatinib is common, making the positive effects of Lenvatinib on a patient's survival null after resistance is acquired. Therefore, it is crucial to understand mechanisms related to Lenvatinib resistance. This review aims to piece together various mechanisms involved in Lenvatinib resistance and summarizes the research done so far investigating it.

Macrophage metabolism, phenotype, function, and therapy in hepatocellular carcinoma (HCC)

The pivotal role of the tumor microenvironment (TME) in the initiation and advancement of hepatocellular carcinoma (HCC) is widely acknowledged, as it fosters the proliferation and metastasis of HCC cells. Within the intricate TME of HCC, tumor-associated macrophages (TAMs) represent a significant constituent of non-malignant cells. TAMs engage in direct communication with cancer cells in HCC, while also exerting influence on other immune cells to adopt a tumor-supportive phenotype that facilitates tumor progression. Among the multifaceted mechanisms at play, the metabolic reprogramming of both tumor cells and macrophages leads to phenotypic alterations and functional modifications in macrophages. This comprehensive review elucidates the intricate interplay between cellular metabolism and macrophage phenotype/polarization, while also providing an overview of the associated signaling molecules and potential therapeutic strategies for HCC.

Mesenchymal Stem Cell-Derived Exosomal miRNA-222-3p Increases Th1/Th2 Ratio and Promotes Apoptosis of Acute Myeloid Leukemia Cells

Interferon regulatory factor 2 (IRF2) participates in the differentiation of immune T cells. Bone marrow mesenchymal stem cell (BM-MSC)-derived exosomes can secret mRNA, miRNAs, and proteins to regulate tumor microenvironment. The present study focused on the miRNA/IRF2 axis in regulating Th1/Th2 ratio and cell apoptosis in acute myeloid leukemia (AML). The flow cytometry analysis was performed to examine the Th1/Th2 ratio and AML apoptosis in vivo and in vitro. The contents of Interferon γ (IFN-γ) and Interleukin-4 (IL-4) were measured using enzyme-linked immunosorbent assay. StarBase was used to predict the potential binding site between miR-222-3p and the 3' untranslated region of IRF2. Luciferase reporter assay was applied for validating the combination of miR-222-3p and IRF2. BM-MSC exosomes were successfully isolated. BM-MSC exosomes increased Th1/Th2 ratio and promoted apoptosis of AML cells. Further analysis showed that IRF2 was targeted by miR-222-3p. Overexpression of miR-222-3p promoted Th1/Th2 ratio and AML cell apoptosis. IRF2 partially reversed the effect that is exerted by miR-222-3p on Th1/Th2 ratio and AML cell apoptosis. Overexpression of miR-222-3p promoted Th1/Th2 ratio and caspase 3 expression in vivo. To sum up, miR-222-3p promotes Th1/Th2 ratio and AML cell apoptosis by regulating IRF2 expression, which provided crucial targets for the treatment of AML.

Evaluation and Application of Drug Resistance by Biomarkers in the Clinical Treatment of Liver Cancer

Liver cancer is one of the most lethal cancers in the world, mainly owing to the lack of effective means for early monitoring and treatment. Accordingly, there is considerable research interest in various clinically applicable methods for addressing these unmet needs. At present, the most commonly used biomarker for the early diagnosis of liver cancer is alpha-fetoprotein (AFP), but AFP is sensitive to interference from other factors and cannot really be used as the basis for determining liver cancer. Treatment options in addition to liver surgery (resection, transplantation) include radiation therapy, chemotherapy, and targeted therapy. However, even more expensive targeted drug therapies have a limited impact on the clinical outcome of liver cancer. One of the big reasons is the rapid emergence of drug resistance. Therefore, in addition to finding effective biomarkers for early diagnosis, an important focus of current discussions is on how to effectively adjust and select drug strategies and guidelines for the treatment of liver cancer patients. In this review, we bring this thought process to the drug resistance problem faced by different treatment strategies, approaching it from the perspective of gene expression and molecular biology and the possibility of finding effective solutions.

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.

Comparison between articular chondrocytes and mesenchymal stromal cells for the production of articular cartilage implants

Focal lesions of articular cartilage give rise to pain and reduced joint function and may, if left untreated, lead to osteoarthritis. Implantation of in vitro generated, scaffold-free autologous cartilage discs may represent the best treatment option. Here we compare articular chondrocytes (ACs) and bone marrow-derived mesenchymal stromal cells (MSCs) for their ability to make scaffold-free cartilage discs. Articular chondrocytes produced more extracellular matrix per seeded cell than mesenchymal stromal cells. Quantitative proteomics analysis showed that articular chondrocyte discs contained more articular cartilage proteins, while mesenchymal stromal cell discs had more proteins associated with cartilage hypertrophy and bone formation. Sequencing analysis revealed more microRNAs associated with normal cartilage in articular chondrocyte discs, and large-scale target predictions, performed for the first time for in vitro chondrogenesis, suggested that differential expression of microRNAs in the two disc types were important mechanisms behind differential synthesis of proteins. We conclude that articular chondrocytes should be preferred over mesenchymal stromal cells for tissue engineering of articular cartilage.

Five years of lenvatinib in hepatocellular carcinoma: are there any predictive and/or prognostic factors?

INTRODUCTION

Lenvatinib was the first drug approved in 2017 for first-line treatment of hepatocarcinoma (HCC) after 10 years of Sorafenib as exclusive standard of care. The therapeutic armamentarium has recently expanded following the approval of atezolizumab plus bevacizumab.

AREAS COVERED

Numerous studies have been conducted during the past 5 years on Lenvatinib use in real-world settings in an effort to determine prognostic and predictive factors of Lenvatinib efficacy. In order to choose the most effective therapeutic approach, it may be helpful to summarize these results in this review.

EXPERT OPINION

A subgroup that appears to benefit most from Lenvatinib therapy are patients with non-viral cirrhosis. This aspect is of great importance today considering the increase in NASH prevalence. Also, a significant proportion of BCLC B patients appear to respond well to Lenvatinib therapy. The biological heterogeneity highlighted in HCC patients, along with the growing number of therapeutic options, makes the identification of stratification tools able to define which patients are more likely to respond to a treatment rather than another one of crucial interest. Further investigation deepening the biological pathways underlying HCC carcinogenesis are of particular interest in order to pave the way for precision medicine even for HCC patients.

IRF2-ferroptosis related gene is associated with prognosis and EMT in gliomas

Ferroptosis is a new type of programmed cell death that has excellent anti-tumor potential in different tumors. However, the research on ferroptosis in glioma is still incomplete. In this study, we aimed to revealed the relationship between ferroptosis-related genes (FRGs) and glioma. We collected gene expression profiles of glioma patients from the TCGA and CGGA databases. All glioma samples were classified into five subtypes using the R software ConsensusClusterPlus. Subsequently, we performed single sample gene set enrichment analysis (ssGSEA) to explore the correlation between different subtypes and immune status and ferroptosis. Then co-expression modules were constructed via weighted gene co-expression network analysis (WGCNA). A Gene Ontology (GO) analysis was conducted to analyze the potential biological functions of the genes in the modules. Finally, we identified 10 hub genes using the PPI network. The in vitro experiments were used to validate our predictions. We found that the expression level of IRF2 is positively correlated with the grade of glioma. The overexpression of IRF2 could protect glioma cells from ferroptosis and enhance the invasive and migratory abilities. Silence of IRF2 had the opposite effect. In conclusion, we demonstrated a novel ferroptosis-related signature for predicting prognosis, and IRF2 could be a potential biomarker for diagnosis and treatment in glioma.

Wnt/β-Catenin Signaling as a Driver of Stemness and Metabolic Reprogramming in Hepatocellular Carcinoma

Simple Summary

Aberrant Wnt/β-catenin signaling has been reported to play crucial role in pathogenesis of hepatocellular carcinoma (HCC). In this review, we focus on the regulatory role of Wnt/β-catenin signaling in cancer stemness and metabolic reprogramming, which are two emerging hallmarks of cancer. Understanding the role of Wnt/β-catenin signaling in regulation of the above processes reveals novel therapeutic strategy against this deadly disease.

Abstract

Hepatocellular carcinoma (HCC) is a major cause of cancer death worldwide due to its high rates of tumor recurrence and metastasis. Aberrant Wnt/β-catenin signaling has been shown to play a significant role in HCC development, progression and clinical impact on tumor behavior. Accumulating evidence has revealed the critical involvement of Wnt/β-catenin signaling in driving cancer stemness and metabolic reprogramming, which are regarded as emerging cancer hallmarks. In this review, we summarize the regulatory mechanism of Wnt/β-catenin signaling and its role in HCC. Furthermore, we provide an update on the regulatory roles of Wnt/β-catenin signaling in metabolic reprogramming, cancer stemness and drug resistance in HCC. We also provide an update on preclinical and clinical studies targeting Wnt/β-catenin signaling alone or in combination with current therapies for effective cancer therapy. This review provides insights into the current opportunities and challenges of targeting this signaling pathway in HCC.

A CD8+ T cell-associated immune gene panel for prediction of the prognosis and immunotherapeutic effect of melanoma

Background

Skin cutaneous melanoma (SKCM) is the most frequently encountered tumor of the skin. Immunotherapy has opened a new horizon in melanoma treatment. We aimed to construct a CD8⁺ T cell-associated immune gene prognostic model (CDIGPM) for SKCM and unravel the immunologic features and the benefits of immunotherapy in CDIGPM-defined SKCM groups.

Method

Single-cell SKCM transcriptomes were utilized in conjunction with immune genes for the screening of CD8⁺ T cell-associated immune genes (CDIGs) for succeeding assessment. Thereafter, through protein-protein interaction (PPI) networks analysis, univariate COX analysis, and multivariate Cox analysis, six genes (MX1, RSAD2, IRF2, GBP2, IFITM1, and OAS2) were identified to construct a CDIGPM. We detected cell proliferation of SKCM cells transfected with IRF2 siRNA. Then, we analyzed the immunologic features and the benefits of immunotherapy in CDIGPM-defined groups.

Results

The overall survival (OS) was much better in low-CDIGPM group versus high CDIGPM group in TCGA dataset and GSE65904 dataset. On the whole, the results unfolded that a low CDIGPM showed relevance to immune response-correlated pathways, high expressions of CTLA4 and PD-L1, a high infiltration rate of CD8⁺ T cells, and more benefits from immunotherapy.

Conclusion

CDIGPM is an good model to predict the prognosis, the potential immune escape from immunotherapy for SKCM, and define immunologic and molecular features.

Co-administration of MDR1 and BCRP or EGFR/PI3K inhibitors overcomes lenvatinib resistance in hepatocellular carcinoma

Lenvatinib is the first-line treatment for hepatocellular carcinoma (HCC), the most common type of primary liver cancer; however, some patients become refractory to lenvatinib. The underlying mechanism of lenvatinib resistance (LR) in patients with advanced HCC remains unclear. We focused on exploring the potential mechanism of LR and novel treatments of lenvatinib-resistant HCC. In particular, we established a Huh7 LR cell line and performed in vitro, bioinformatic, and biochemical assays. Additionally, we used a Huh7-LR cell-derived xenograft mouse model to confirm the results in vivo. Following LR induction, multidrug resistance protein 1 (MDR1) and breast cancer resistance protein (BCRP) transporters were markedly upregulated, and the epidermal growth factor receptor (EGFR), MEK/ERK, and PI3K/AKT pathways were activated. In vitro, the co-administration of elacridar, a dual MDR1 and BCRP inhibitor, with lenvatinib inhibited proliferation and induced apoptosis of LR cells. These effects might be due to inhibiting cancer stem-like cells (CSCs) properties, by decreasing colony formation and downregulating CD133, EpCAM, SOX-9, and c-Myc expression. Moreover, the co-administration of gefitinib, an EGFR inhibitor, with lenvatinib retarded proliferation and induced apoptosis of LR cells. These similar effects might be caused by the inhibition of EGFR-mediated MEK/ERK and PI3K/AKT pathway activation. In vivo, co-administration of lenvatinib with elacridar or gefitinib suppressed tumour growth and angiogenesis. Therefore, inhibiting MDR1 and BCRP transporters or targeting the EGFR/PI3K pathway might overcome LR in HCC. Notably, lenvatinib should be used to treat HCC after LR induction owing to its role in inhibiting tumour proliferation and angiogenesis. Our findings could help develop novel and effective treatment strategies for HCC.

Mecheliolide elicits ROS-mediated ERS driven immunogenic cell death in hepatocellular carcinoma

The nonnegligible reason for the poor prognosis of hepatocellular carcinoma (HCC) is resistance to conventional chemotherapy. Immunogenic cell death (ICD) is a rare immunostimulatory form of cell death that can reengage the tumor-specific immune system. ICD can improve the clinical outcomes of chemotherapeutics by promoting a long-term cancer immunity. The discovery of potential ICD inducers is emerging as a promising direction. In the present study, micheliolide (MCL), a natural guaianolide sesquiterpene lactone, was screened out by the virtual screening strategies, identified as an inhibitor of thioredoxin reductase (TrxR) and was evaluated to have high potential to induce ICD. Here, we showed that MCL induced ICD-associated DAMPs (damage-associated molecular patterns, such as CRT exposure, ATP secretion and HMGB1 release). MCL significantly triggered the regression of established tumors in an immunocompetent mouse vaccine model, and induced ICD (DCs maturation, the stimulation of CD4⁺, and CD8⁺ T-cells responses) in vivo. Mechanistically, we found that the magnitude of ICD-associated effects induced upon exposure of HCC cells to MCL was dependent on the generation of reactive oxygen species (ROS)-mediated endoplasmic reticulum stress (ERS). In addition, the suppression of ROS normalized MCL-induced ERS, in contrast, the downregulation of TrxR synergized with the ERS driven by MCL. We also systematically detected the H₂O₂ generation using Hyper7 sensors in HCC cells exposed to MCL. Notably, MCL inhibited the development of HCC organoids. Collectively, our results reveal a potential association between the TrxR inhibitors and ICD, presenting valuable insights into the MCL-activated ICD in HCC cells.

Glycosylation-related molecular subtypes and risk score of hepatocellular carcinoma: Novel insights to clinical decision-making

BACKGROUND

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer deaths worldwide, seriously affecting human community health and care. Emerging evidence has shown that aberrant glycosylation is associated with tumor progression and metastasis. However, the role of glycosylation-related genes in HCC has notbeen reported.

METHODS

Weighted gene coexpression network analysis and non-negative matrix factorization analysis were applied to identify functional modules and molecularm subtypes in HCC. The least absolute shrinkage and selection operator Cox regression was used to construct the glycosylation-related signature. The independent prognostic value of the risk model was confirmed and validated by systematic techniques, including principal component analysis, T-distributed random neighbor embedding analysis, Kaplan-Meier survival analysis, the ROC curve, multivariate Cox regression, the nomogram, and the calibration curve. The single-sample gene set enrichment analysis, gene set variation analysis, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes analyses were evaluated by the immune microenvironment and potential biological processes. The quantitative real-time polymerase chain reaction and immunohistochemistry analysis were used to verify the expression of five genes.

RESULTS

We identified the glycosylation-related genes with bioinformatics analysis to construct and validate a five-gene signature for the prognosis of HCC patients. Patients with HCC in the high-risk group had a worse prognosis. The risk score could be an independent factor and was associated with clinical features, such as the grade and stage. The nomogram exhibited an accurate score that included the risk score and clinical parameters. The infiltration levels of antitumor cells were upregulated in the low-risk group, including B_cells, Mast_cells, neutrophils, NK_cells, and T_helper_cells. Moreover, glycosylation was more sensitive to immunotherapy, and may play a critical role in the metabolic processes of HCC, such as bile acid metabolism and fatty acid metabolism. In addition, the five-gene messenger RNA (mRNA) and protein expression were overexpressed in HCC cells and tissues.

CONCLUSIONS

The glycosylation-related signature is effective for prognostic recognition, immune efficacy evaluation, and substance metabolism in HCC, providing a novel insight for therapeutic target prediction and clinical decision-making.

The role of ceRNA-mediated diagnosis and therapy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide due to its high degree of malignancy, high incidence, and low survival rate. However, the underlying mechanisms of hepatocarcinogenesis remain unclear. Long non coding RNA (lncRNA) has been shown as a novel type of RNA. lncRNA by acting as ceRNA can participate in various biological processes of HCC cells, such as tumor cell proliferation, migration, invasion, apoptosis and drug resistance by regulating downstream target gene expression and cancer-related signaling pathways. Meanwhile, lncRNA can predict the efficacy of treatment strategies for HCC and serve as a potential target for the diagnosis and treatment of HCC. Therefore, lncRNA serving as ceRNA may become a vital candidate biomarker for clinical diagnosis and treatment. In this review, the epidemiology of HCC, including morbidity, mortality, regional distribution, risk factors, and current treatment advances, was briefly discussed, and some biological functions of lncRNA in HCC were summarized with emphasis on the molecular mechanism and clinical application of lncRNA-mediated ceRNA regulatory network in HCC. This paper can contribute to the better understanding of the mechanism of the influence of lncRNA-mediated ceRNA networks (ceRNETs) on HCC and provide directions and strategies for future studies.

N6-Methyladenosine-regulated LINC00675 Suppress the Proliferation, Migration and Invasion of Breast Cancer cells via Inhibiting miR-513b-5p

Breast cancer (BC) is the most common cancer among women. LINC00675 and miR-513b-5p has been reported to be abnormally expressed in multiple types of cancers and modulate malignant phenotypes of cancer cells. However, to date, the functional role and underlying regulatory mechanism of LINC00675 and miR-513b-5p in BC remains largely unknown. Here, we found that LINC00675 was significantly downregulated in BC tissues and cell lines. Decrease of LINC00675 expression associated with higher tumor grade, lymphovascular invasion and shorter survival in BC patients. Functional experiments demonstrated that overexpression of LINC00675 suppressed BC cell proliferation, migration and invasion, whereas depletion of LINC00675 exerted opposite effects. Mechanistically, LINC00675 functioned as a competing endogenous RNA (ceRNA) to interact with miR-513b-5p and suppress its expression. Moreover, METTL3 increased the m⁶A methylation of LINC00675, which enhanced the association between LINC00675 and miR-513b-5p. Collectively, the central findings of our study suggest that LINC00675 represses BC progression through the inhibition of miR-513b-5p in a m⁶A-dependent manner.

YRDC Mediates the Resistance of Lenvatinib in Hepatocarcinoma Cells via Modulating the Translation of KRAS

Lenvatinib is the latest and promising agent that has demonstrated a significant improvement of progression-free survival in advanced hepatocellular carcinoma (HCC). However, resistance emerges soon after initial treatment, limiting the clinical benefits of lenvatinib. Therefore, understanding the mechanism of resistance is necessary for improving lenvatinib efficacy. YRDC promotes the proliferation of hepatocarcinoma cells via regulating the activity of the RAS/RAF/MEK/ERK pathway, which was the primary pathway of the anticancer effect of lenvatinib. The purpose of this study is to investigate whether YRDC modulates the sensitivity of lenvatinib in hepatocarcinoma cells. Using the CCK-8 cell viability assay, wound-healing assay and clone formation assay in cell models, and xenograft assay in null mouse, we demonstrated that Huh7 cells with YRDC knockdown showed decreased susceptibility to lenvatinib than their control cells. Furthermore, we found that lenvatinib inhibited the expression of YRDC in a time-dependent manner. This effect may aggravate resistance to lenvatinib in hepatocarcinoma cells and may be an underlying cause of resistance, which emerges soon after lenvatinib initial treatment. To investigate how YRDC modulates the sensitivity of lenvatinib, we assessed the effect of tRNA with different t⁶A levels on the translation of the KRAS gene by in vitro rabbit reticulocyte translation system and measured the expression levels of the KRAS gene by western blot together with qPCR. We found that YRDC regulates the protein translation of KRAS in cell models, and the tRNA with low t⁶A modification level reduces the translation of the KRAS in the in vitro translation system. These results suggested that YRDC mediates the resistance of lenvatinib in hepatocarcinoma cells via modulating the translation of the KRAS. In this study, YRDC was confirmed to be a potential novel predictive biomarker of lenvatinib sensitivity in HCC.