The emerging role of microRNAs and long noncoding RNAs in drug resistance of hepatocellular carcinoma

Single-cell analysis revealed that MTIF2 could promote hepatocellular carcinoma progression through modulating the ROS pathway

Aims

To analyze the expression of mitochondrial translational initiation factor 2 (MTIF2) and the biological functions of the gene in hepatocellular carcinoma (HCC).

Background

The treatment of HCC treatment and its prognostic prediction are limited by a lack of comprehensive understanding of the molecular mechanisms in HCC. OBJECTIVE: To determine the cells expressing MTIF2 in HCC and the function of the MTIF2+ cell subpopulation.

Methods

Gene expression analysis on TIMER 2.0, UALCAN, and GEPIA databases was performed to measure the expression of MTIF2 in HCC tissues. Cell clustering subgroups and annotation were conducted based on the single-cell sequencing data of HCC and paracancerous tissues in the Gene Expression Omnibus (GEO) database. MTIF2 expression in different cell types was analyzed. Further, biological pathways potentially regulated by MTIF2 in each cell type were identified. In addition, protein-protein interaction (PPI) networks of MTIF2 with genes in its regulated biological pathways were developed. The cell function assay was performed to verify the effects of superoxide dismutase-2 (SOD2) and MTIF2 on HCC cells. Finally, we screened virtual drugs targeting MTIF2 and SOD2 employing database screening, molecular docking and molecular dynamics.

Results

MTIF2 showed a remarkably high expression in HCC tissues. We identified a total of 10 cell types between HCC tissues and paracancerous tissues. MTIF2 expression was upregulated in epithelial cells, macrophages, and hepatocytes. More importantly, high-expressed MTIF2 in HCC tissues was mainly derived from epithelial cells and hepatocytes, in which the reactive oxygen species (ROS) pathway was significantly positively correlated with MTIF2. In the PPI network, there was a unique interaction pair between SOD2 and MTIF2 in the ROS pathway. Cell function experiments showed that overexpression of MTIF2 enhanced the proliferative and invasive capacities of HCC, which could synergize with SOD2 to co-promote the development of HCC. Finally, molecular dynamics simulations showed that DB00183 maintained a high structural stability with MTIF2 and SOD2 proteins during the simulation process.

Conclusion

Our study confirmed that the high-expressed MTIF2 in HCC tissues was derived from epithelial cells and hepatocytes. MTIF2 might act on SOD2 to regulate the ROS pathway, thereby affective the progression of HCC.

Long non-coding RNAs; potential contributors in cancer chemoresistance through modulating diverse molecular mechanisms and signaling pathways

One of the mainstays of cancer treatment is chemotherapy. Drug resistance, however, continues to be the primary factor behind clinical treatment failure. Gene expression is regulated by long non-coding RNAs (lncRNAs) in several ways, including chromatin remodeling, translation, epigenetic, and transcriptional levels. Cancer hallmarks such as DNA damage, metastasis, immunological evasion, cell stemness, drug resistance, metabolic reprogramming, and angiogenesis are all influenced by LncRNAs. Numerous studies have been conducted on LncRNA-driven mechanisms of resistance to different antineoplastic drugs. Diverse medication kinds elicit diverse resistance mechanisms, and each mechanism may have multiple contributing factors. As a result, several lncRNAs have been identified as new biomarkers and therapeutic targets for identifying and managing cancers. This compels us to thoroughly outline the crucial roles that lncRNAs play in drug resistance. In this regard, this article provides an in-depth analysis of the recently discovered functions of lncRNAs in the pathogenesis and chemoresistance of cancer. As a result, the current research might offer a substantial foundation for future drug resistance-conquering strategies that target lncRNAs in cancer therapies.

Molecular insights into regulatory RNAs in the cellular machinery

It is apparent that various functional units within the cellular machinery are derived from RNAs. The evolution of sequencing techniques has resulted in significant insights into approaches for transcriptome studies. Organisms utilize RNA to govern cellular systems, and a heterogeneous class of RNAs is involved in regulatory functions. In particular, regulatory RNAs are increasingly recognized to participate in intricately functioning machinery across almost all levels of biological systems. These systems include those mediating chromatin arrangement, transcription, suborganelle stabilization, and posttranscriptional modifications. Any class of RNA exhibiting regulatory activity can be termed a class of regulatory RNA and is typically represented by noncoding RNAs, which constitute a substantial portion of the genome. These RNAs function based on the principle of structural changes through cis and/or trans regulation to facilitate mutual RNA‒RNA, RNA‒DNA, and RNA‒protein interactions. It has not been clearly elucidated whether regulatory RNAs identified through deep sequencing actually function in the anticipated mechanisms. This review addresses the dominant properties of regulatory RNAs at various layers of the cellular machinery and covers regulatory activities, structural dynamics, modifications, associated molecules, and further challenges related to therapeutics and deep learning.

Long Non-coding RNA PCED1B Antisense RNA 1 Promotes Cell Proliferation and Invasion in Hepatocellular Carcinoma by Regulating the MicroRNA-34a/CD44 Axis

OBJECTIVE

This study aimed to examine the role of long non-coding RNA PCED1B antisense RNA 1 (PCED1B-AS1) in the development of hepatocellular carcinoma (HCC).

METHODS

A total of 62 pairs of HCC tissues and adjacent non-tumor tissues were obtained from 62 HCC patients. The interactions of PCED1B-AS1 and microRNA-34a (miR-34a) were detected by dual luciferase activity assay and RNA pull-down assay. The RNA expression levels of PCED1B-AS1, miR-34a and CD44 were detected by RT-qPCR, and the protein expression level of CD44 was determined by Western blotting. The cell proliferation was detected by cell proliferation assay, and the cell invasion and migration by transwell invasion assay. The HCC tumor growth after PCED1B-AS1 was downregulated was determined by in vivo animal study.

RESULTS

PCED1B-AS1 was highly expressed in HCC tissues, which was associated with poor survival of HCC patients. Furthermore, PCED1B-AS1 interacted with miR-34a in HCC cells, but they did not regulate the expression of each other. Additionally, PCED1B-AS1 increased the expression level of CD44, which was targeted by miR-34a. The cell proliferation and invasion assay revealed that miR-34a inhibited the proliferation and invasion of HCC in vitro, while CD44 exhibited the opposite effects. Furthermore, PCED1B-AS1 suppressed the role of miR-34a. Moreover, the knockdown of PCED1B-AS1 repressed the HCC tumor growth in nude mice in vivo.

CONCLUSION

PCED1B-AS1 may play an oncogenic role by regulating the miR-34a/CD44 axis in HCC.

Prolactin receptor potentiates chemotherapy through miRNAs-induced G6PD/TKT inhibition in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies, with a notoriously dismal prognosis. As a competitive inhibitor of DNA synthesis, gemcitabine is the cornerstone drug for treating PDAC at all stages. The therapeutic effect of gemcitabine, however, is often hindered by drug resistance, and the underlying mechanisms remain largely unknown. It is unclear whether their response to chemotherapeutics is regulated by endocrine regulators, despite the association between PDAC risk and endocrine deregulation. Here, we show that prolactin receptor (PRLR) synergizes with gemcitabine in both in vitro and in vivo treatment of PDAC. Interestingly, PRLR promotes the expression of miR-4763-3p and miR-3663-5p, two novel miRNAs whose functions are unknown. Furthermore, the analysis of transcriptome sequencing data of tumors from lactating mouse models enriches the PPP pathway, a multifunctional metabolic pathway. In addition to providing energy, the PPP pathway mainly provides a variety of raw materials for anabolism. We demonstrate that two key enzymes of the pentose phosphate pathway (PPP), G6PD and TKT, are directly targeted by miR-4763-3p and miR-3663-5p. Notably, miR-4763-3p and miR-3663-5p diminish the nucleotide synthesis of the PPP pathway, thereby increasing gemcitabine sensitivity. As a result, PRLR harnesses these two miRNAs to suppress PPP and nucleotide synthesis, subsequently elevating the gemcitabine sensitivity of PDAC cells. Also, PDAC tissues and tumors from LSL-KrasG12D/+, LSL-Trp53R172H/+, and PDX1-cre (KPC) mice exhibit downregulation of PRLR. Bisulfite sequencing of PDAC tissues revealed that PRLR downregulation is due to epigenetic methylation. In this study, we show for the first time that the endocrine receptor PRLR improves the effects of gemcitabine by boosting two new miRNAs that block the PPP pathway and nucleotide synthesis by inhibiting two essential enzymes concurrently. The PRLR-miRNAs-PPP axis may serve as a possible therapeutic target to supplement chemotherapy advantages in PDAC.

Long non-coding RNA RP11-197K6.1 as ceRNA promotes colorectal cancer progression via miR-135a-5p/DLX5 axis

BACKGROUND

Colorectal cancer (CRC) remains a major global health challenge, with high incidence and mortality rates. The role of long noncoding RNAs (lncRNAs) in cancer progression has received considerable attention. The present study aimed to investigate the function and mechanisms underlying the role of lncRNA RP11-197K6.1, microRNA-135a-5p (hsa-miR-135a-5p), and DLX5 in CRC development.

METHODS

We analyzed RNA sequencing data from The Cancer Genome Atlas Colorectal Cancer dataset to identify the association between lncRNA RP11-197K6.1 and CRC progression. The expression levels of lncRNA RP11-197K6.1 and DLX5 in CRC samples and cell lines were determined by real-time quantitative PCR and western blotting assays. Fluorescence in situ hybridization was used to confirm the cellular localization of lncRNA RP11-197K6.1. Cell migration capabilities were assessed by Transwell and wound healing assays, and flow cytometry was performed to analyze apoptosis. The interaction between lncRNA RP11-197K6.1 and miR-135a-5p and its effect on DLX5 expression were investigated by the dual-luciferase reporter assay. Additionally, a xenograft mouse model was used to study the in vivo effects of lncRNA RP11-197K6.1 on tumor growth, and an immunohistochemical assay was performed to assess DLX5 expression in tumor tissues.

RESULTS

lncRNA RP11-197K6.1 was significantly upregulated in CRC tissues and cell lines as compared to that in normal tissues, and its expression was inversely correlated with patient survival. It promoted the migration and metastasis of CRC cells by interacting with miR-135a-5p, alleviated suppression of DLX5 expression, and facilitated tumor growth.

CONCLUSION

This study demonstrated the regulatory network and mechanism of action of the lncRNA RP11-197K6.1/miR-135a-5p/DLX5 axis in CRC development. These findings provided insights into the molecular pathology of CRC and suggested potential therapeutic targets for more effective treatment of patients with CRC.

Exploring non-coding RNA mechanisms in hepatocellular carcinoma: implications for therapy and prognosis

Hepatocellular carcinoma (HCC) is a significant contributor to cancer-related deaths in the world. The development and progression of HCC are closely correlated with the abnormal regulation of non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). Important biological pathways in cancer biology, such as cell proliferation, death, and metastasis, are impacted by these ncRNAs, which modulate gene expression. The abnormal expression of non-coding RNAs in HCC raises the possibility that they could be applied as new biomarkers for diagnosis, prognosis, and treatment targets. Furthermore, by controlling the expression of cancer-related genes, miRNAs can function as either tumor suppressors or oncogenes. On the other hand, lncRNAs play a role in the advancement of cancer by interacting with other molecules within the cell, which, in turn, affects processes such as chromatin remodeling, transcription, and post-transcriptional processes. The importance of ncRNA-driven regulatory systems in HCC is being highlighted by current research, which sheds light on tumor behavior and therapy response. This research highlights the great potential of ncRNAs to improve patient outcomes in this difficult disease landscape by augmenting the present methods of HCC care through the use of precision medicine approaches.

Noncoding RNAs and programmed cell death in hepatocellular carcinoma: Significant role of epigenetic modifications in prognosis, chemoresistance, and tumor recurrence rate

Hepatocellular carcinoma (HCC) is the most common type of liver cancer with a high death rate in the world. The molecular mechanisms related to the pathogenesis of HCC have not been precisely defined so far. Hence, this review aimed to address the potential cross-talk between noncoding RNAs (ncRNAs) and programmed cell death in HCC. All related papers in the English language up to June 2023 were collected and screened. The searched keywords in scientific databases, including Scopus, PubMed, and Google Scholar, were HCC, ncRNAs, Epigenetic, Programmed cell death, Autophagy, Apoptosis, Ferroptosis, Chemoresistance, Tumor recurrence, Prognosis, and Prediction. According to the reports, ncRNAs, comprising long ncRNAs, microRNAs, circular RNAs, and small nucleolar RNAs can affect cell proliferation, migration, invasion, and metastasis, as well as cell death-related processes, such as autophagy, ferroptosis, necroptosis, and apoptosis in HCC by regulating cancer-associated genes and signaling pathways, for example, phosphoinositide 3-kinase/Akt, extracellular signal-regulated kinase/MAPK, and Wnt/β-catenin signaling pathways. It seems that ncRNAs, as epigenetic regulators, can be utilized as biomarkers in diagnosis, prognosis, survival and recurrence rates prediction, chemoresistance, and evaluation of therapeutic response in HCC patients. However, more scientific evidence is suggested to be accomplished to confirm these results.

Dbl family RhoGEFs in cancer: different roles and targeting strategies

Small Ras homologous guanosine triphosphatase (Rho GTPase) family proteins are highly associated with tumorigenesis and development. As intrinsic exchange activity regulators of Rho GTPases, Rho guanine nucleotide exchange factors (RhoGEFs) have been demonstrated to be closely involved in tumor development and received increasing attention. They mainly contain two families: the diffuse B-cell lymphoma (Dbl) family and the dedicator of cytokinesis (Dock) family. More and more emphasis has been paid to the Dbl family members for their abnormally high expression in various cancers and their correlation to poor prognosis. In this review, the common and distinctive structures of Dbl family members are discussed, and their roles in cancer are summarized with a focus on Ect2, Tiam1/2, P-Rex1/2, Vav1/2/3, Trio, KALRN, and LARG. Significantly, the strategies targeting Dbl family RhoGEFs are highlighted as novel therapeutic opportunities for cancer.

Prognostic analysis of hepatocellular carcinoma based on cuproptosis -associated lncRNAs

OBJECTIVES

Cuproptosis represents an innovative type of cell death, distinct from apoptosis, driven by copper dependency, yet the involvement of copper apoptosis-associated long non-coding RNAs (CRLncRNAs) in hepatocellular carcinoma (HCC) remains unclear. This study is dedicated to unveiling the role and significance of these copper apoptosis-related lncRNAs within the context of HCC, focusing on their impact on both the development of the disease and its prognosis.

METHODS

We conducted an analysis of gene transcriptomic and clinical data for HCC cases by sourcing information from The Cancer Genome Atlas database. By incorporating cuproptosis-related genes, we established prognostic features associated with cuproptosis-related lncRNAs. Furthermore, we elucidated the mechanism of cuproptosis-related lncRNAs in the prognosis and treatment of HCC through comprehensive approaches, including Lasso and Cox regression analyses, survival analyses of samples, as well as examinations of tumor mutation burden and immune function.

RESULTS

We developed a prognostic model featuring six cuproptosis-related lncRNAs: AC026412.3, AC125437.1, AL353572.4, MKLN1-AS, TMCC1-AS1, and SLC6A1-AS1. This model demonstrated exceptional prognostic accuracy in both training and validation cohorts for patients with tumors, showing significantly longer survival times for those categorized in the low-risk group compared to the high-risk group. Additionally, our analyses, including tumor mutation burden, immune function, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway enrichment, and drug sensitivity, further elucidated the potential mechanisms through which cuproptosis-associated lncRNAs may influence disease outcome.

CONCLUSIONS

The model developed using cuproptosis-related long non-coding RNAs (lncRNAs) demonstrates promising predictive capabilities for both the prognosis and immunotherapy outcomes of tumor patients. This could play a crucial role in patient management and the optimization of immunotherapeutic strategies, offering valuable insights for future research.

LINC00540 promotes sorafenib resistance and functions as a ceRNA for miR-4677-3p to regulate AKR1C2 in hepatocellular carcinoma

Sorafenib resistance is one of the main causes of poor prognosis in patients with advanced hepatocellular carcinoma (HCC). Long noncoding RNAs (lncRNAs) function as suppressors or oncogenic factors during tumor progression and drug resistance. Here, to identify therapeutic targets for HCC, the biological mechanisms of abnormally expressed lncRNAs were examined in sorafenib-resistant HCC cells. Specifically, we established sorafenib-resistant HCC cell lines (Huh7-S and SMMC7721-S), which displayed an epithelial-mesenchymal transition (EMT) phenotype. Transcriptome sequencing (RNA-Seq) was performed to established differential lncRNA expression profiles for sorafenib-resistant cells. Through this analysis, we identified LINC00540 as significantly up-regulated in sorafenib-resistant cells and a candidate lncRNA for further mechanistic investigation. Functionally, LINC00540 knockdown promoted sorafenib sensitivity and suppressed migration, invasion, EMT and the activation of PI3K/AKT signaling pathway in sorafenib-resistant HCC cells, whereas overexpression of LINC00540 resulted in the opposite effects in parental cells. LINC00540 functions as a competing endogenous RNA (ceRNA) by competitively binding to miR-4677-3p , thereby promoting AKR1C2 expression. This is the first study that demonstrates a role for LINC00540 in enhancing sorafenib resistance, migration and invasion of HCC cells through the LINC00540/miR-4677-3p/AKR1C2 axis, suggesting that LINC00540 may represent a potential therapeutic target and prognosis biomarker for HCC.

circ_HMGCS1 modulates hepatocellular carcinoma chemoresistance via miR-338-5p/IL-7 pathway

Hepatocellular cancer is one of the most serious types of cancer in the world, with high incidence and mortality rates. Most HCC patients with long-term chemotherapy develop chemoresistance, leading to a poor prognosis. However, the underlying mechanism of circRNAs in HCC chemoresistance remains unclear. Our research found that circ_0072391(circ_HMGCS1) expression was significantly upregulated in cisplatin-resistant HCC cells. The silence of circ_HMGCS1 attenuated the cisplatin resistance in HCC. Results showed that circ_HMGCS1 regulated the expression of miR-338-5p via acting as microRNA sponges. Further study confirmed that miR-338-5p regulated the expression of IL-7. IL-7 could remodel the immune system by improving T-cell function and antagonising the immunosuppressive network. IL-7 is an ideal target used to enhance the function of the immune system. circ_HMGCS1 exerts its oncogenic function through the miR-338-5p/IL-7 pathway. Inhibition of circ_HMGCS1/miR-338-5p/IL-7 could effectively attenuate the chemoresistance of HCC. IL-7 might be a promising immunotherapy target for HCC cancer treatment.

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.

miR-557 inhibits hepatocellular carcinoma progression through Wnt/β-catenin signaling pathway by targeting RAB10

Accumulating evidence suggests that aberrant miRNAs participate in carcinogenesis and progression of hepatocellular carcinoma (HCC). Abnormal miR-557 expression is reported to interfere with the progression of several human cancers. However, the potential roles of miR-557 in HCC remain largely unknown. In the current study, we found that miR-557 was down-regulated in HCC tissues and cell lines, and was closely related to recurrence and metastasis of HCC. Notably, overexpression of miR-557 inhibited proliferation, migration, invasion, epithelial-to-mesenchymal transition (EMT) progression, blocked cells in G0/G1 phase of MHCC-97H cells in vitro, and suppressed tumor growth in vivo. However, loss of miR-557 facilitated these parameters in Huh7 cells both in vitro and in vivo. Moreover, RAB10 was identified as a direct downstream target of miR-557 through its 3'-UTR. Furthermore, RAB10 re-expression or knockdown partially abolished the effects of miR-557 on proliferation, migration, invasion, and EMT progression of HCC cells. Mechanistically, overexpression of miR-557 suppressed Wnt/β-catenin signaling by inhibiting GSK-3β phosphorylation, increasing β-catenin phosphorylation, and decreasing β-catenin transport to the nucleus, while knockdown of miR-557 activated Wnt/β-catenin signaling. Moreover, the TOP/FOP-Flash reporter assays showed that miR-557 overexpression or knockdown significantly suppressed or activated Wnt signaling activity, respectively. Additionally, low expression of miR-557 and high expression of RAB10 in HCC tissues was closely associated with tumor size, degree of differentiation, TNM stage and poor prognosis in HCC patients. Taken together, these results demonstrate that miR-557 blocks the progression of HCC via the Wnt/β-catenin pathway by targeting RAB10.

Noncoding RNAs in Hepatocellular Carcinoma: Potential Applications in Combined Therapeutic Strategies and Promising Candidates of Treatment Response

The incidence of hepatocellular carcinoma (HCC) is increasing, and 40% of patients are diagnosed at advanced stages. Over the past 5 years, the number of clinically available treatments has dramatically increased for HCC, making patient management particularly complex. Immune checkpoint inhibitors (ICIs) have improved the overall survival of patients, showing a durable treatment benefit over time and a different response pattern with respect to tyrosine kinase inhibitors (TKIs). Although there is improved survival in responder cases, a sizeable group of patients are primary progressors or are ineligible for immunotherapy. Indeed, patients with nonviral etiologies, such as nonalcoholic steatohepatitis (NASH), and alterations in specific driver genes might be less responsive to immunotherapy. Therefore, improving the comprehension of mechanisms of drug resistance and identifying biomarkers that are informative of the best treatment approach are required actions to improve patient survival. Abundant evidence indicates that noncoding RNAs (ncRNAs) are pivotal players in cancer. Molecular mechanisms through which ncRNAs exert their effects in cancer progression and drug resistance have been widely investigated. Nevertheless, there are no studies summarizing the synergistic effect between ncRNA-based strategies and TKIs or ICIs in the preclinical setting. This review aims to provide up-to-date information regarding the possible use of ncRNAs as therapeutic targets in association with molecular-targeted agents and immunotherapies and as predictive tools for the selection of optimized treatment options in advanced HCCs.

Development of a novel lncRNA-derived immune gene score using machine learning-based ensembles for predicting the survival of HCC

BACKGROUND

Long noncoding RNAs (lncRNAs) are implicated in the tumor immunology of hepatocellular carcinoma (HCC).

METHODS

HCC mRNA and lncRNA expression profiles were used to extract immune-related genes with the ImmPort database, and immune-related lncRNAs with the ImmLnc algorithm. The MOVICS package was used to cluster immune-related mRNA, immune-related lncRNA, gene mutation and methylation data on HCC from the TCGA. GEO and ICGC datasets were used to validate the model. Data from single-cell sequencing was used to determine the expression of genes from the model in various immune cell types.

RESULTS

With this model, the area under the curve (AUC) for 1-, 3- and 5-year survival of HCC patients was 0.862, 0.869 and 0.912, respectively. Single-cell sequencing showed EREG was significantly expressed in a variety of immune cell types. Knockdown of the EREG target gene resulted in significant anti-apoptosis, pro-proliferation and pro-migration effects in HepG2 and HUH7 cells. Moreover, serum and liver tissue EREG levels in HCC patients were significantly higher than those of healthy control patients.

CONCLUSION

We built a prognostic model with good accuracy for predicting HCC patient survival. EREG is a potential immunotherapeutic target and a promising prognostic biomarker.

Exploring the mechanism of LncRNA CASC15 affecting hepatocellular carcinoma through miRNA

This study aimed to determine the potential mechanisms through which long noncoding (Lnc) RNA cancer susceptibility candidate 15 (CASC15) affects hepatocellular carcinoma (HCC). We retrieved HCC RNA-seq and clinical information from the UCSC Xena database. The differential expression (DE) of CASC15 was detected. Overall survival was analyzed using Kaplan-Meier (K-M) curves. Molecular function and signaling pathways affected by CASC15 were determined using Gene Set Enrichment Analysis. Associations between CASC15 and the HCC microenvironment were investigated using immuno-infiltration assays. A differential CASC15-miRNA-mRNA network and HCC-specific CASC15-miRNA-mRNA ceRNA network were constructed. The overexpression of CASC15 in HCC tissues was associated with histological grade, clinical stage, pathological T stage, poor survival, more complex immune cell components, and 12 immune checkpoints. We identified 27 DE miRNAs and 270 DE mRNAs in the differential CASC15-miRNA-mRNA network, and 10 key genes that were enriched in 12 cancer-related signaling pathways. Extraction of the HCC-specific CASC15-miRNA-mRNA network revealed that IGF1R, MET, and KRAS were associated with HCC progression and occurrence. Our bioinformatic findings confirmed that CASC15 is a promising prognostic biomarker for HCC, and elevated levels in HCC are associated with the tumor microenvironment. We also constructed a disease-specific CASC15-miRNA-mRNA regulatory ceRNA network that provides a new perspective for the precise indexing of patients with elevated levels of CASC15.

MIR222HG/LIN28B/ATG5 Axis Drives M2 Macrophage Polarization and Proliferation of Hepatocellular Carcinoma Cells

Long non-coding RNAs (lncRNAs) are involved in the pathogenesis of hepatocellular carcinoma (HCC). This study aimed to investigate the potential of MIR222HG in HCC. HCC cells were co-cultured with U937 cells. Gene expression was determined using reverse transcription-quantitative (RT-q) PCR and western blot. Functional analysis was performed using Cell Counting Kit 8 (CCK-8), colony formation, and flow cytometry assays. We found that MIR222HG was overexpressed in HCC patients as well as HepG2 and Huh7 cells. MIR222HG-mediated upregulation of autophagy related 5 (ATG5) promoted tumor cell autophagy and the activation of M2-like tumor-associated macrophages (TAM2). Moreover, MIR222HG-mediated the activation of TAM2 drove the proliferation of HCC cells. Additionally, MIR222HG increased the mRNA expression as well as promoted the mRNA stability of ATG5 via binding to lin-28 homolog B (LIN28B). In conclusion, MIR222HG-mediated autophagy and the activation of TAM2 promote the aggressiveness of HCC cells via regulating LIN28B/ATG5 signaling.

Interaction between miR‑206 and lncRNA MALAT1 in regulating viability and invasion in hepatocellular carcinoma

MicroRNAs (miRNAs) are strongly associated to the progression of hepatocellular carcinoma (HCC), which presents a high potential for diagnosis and treatment; however, the role of miRNAs is still largely unknown. The aim of the present study was to examine the expression and the biological role of miRNA (miR)-206 in the development of HCC, and to identify the underlying molecular mechanism. Results from this study show that miR-206 was significantly downregulated in HCC tissues and cell lines. It was observed that low expression of miR-206 was linked to advanced TNM stage, tumor nodularity and venous infiltration in patients with HCC; low miR-206 expression was associated with shorter survival times. miR-206 overexpression using miR-206 mimics notably decreased the proliferative ability and increased apoptosis of MHCC97-H and HCCLM3 HCC cell lines. Overexpression of miR-206 suppressed invasiveness associated with reduced epithelial-mesenchymal transition. Moreover, the c-Met oncogene, which is upregulated in HCC tissues, was negatively associated with the expression of miR-206. Notably, it was shown that miR-206 may exert its antitumor effect through suppressing c-Met/Akt/mTOR signaling. Low expression of miR-206 was shown to be regulated by lncRNA MALAT1 in HCC. Collectively, this study presented evidence that miR-206 was controlled by lncRNA MALAT1 and partially suppressed the proliferation and invasion of HCC through the c-Met/Akt/mTOR signaling pathway. According to these results, understanding MALAT1/miR-206-dependent regulation may lead to potential approaches for diagnosis and prospective treatment of HCC.

let-7g sensitized liver cancer cells to 5-fluorouracil by downregulating ABCC10 expression

Patients with advanced liver cancer may benefit from 5-fluorouracil (5-FU) therapy. However, most of them eventually faced drug resistance, resulting in a poor prognosis. The present study aims to explore the potential mechanism of let-7g/ABCC10 axis in the regulation of 5-FU resistance in liver cancer cells. Huh-7 cells were used to construct 5-FU resistant Huh-7/4X cells. CCK8, flow cytometry, and TUNEL staining were used to detect the characterization of Huh-7 cells and Huh-7/4X cells. Double luciferase report, PCR, and western blot analyses were used to detect the regulatory effects between let-7g and ABCC10. The levels of biomarkers related to cell cycle progression and apoptosis were detected by western blot assays. The role of let-7g in 5-FU sensitivity of liver cancer cells was evaluated in nude mice. Compared with LX-2 cells, the expression of let-7g was decreased in Hep3B, HepG2, Huh-7, and SK-Hep1 cells, with the lowest expression in Huh-7 cells. The sensitivity of Huh-7 cell to 5-FU was positively correlated with let-7g expression. Transfection of let-7g mimics inhibited the viability of Huh-7/4X cells by prolonging the G1 phase, with the downregulation of ABCC10, PCNA, Cyclin D1, and CDK4. Meanwhile, let-7g promoted apoptosis to increase 5-FU sensitivity of Huh-7/4X by downregulating ABCC10, Bcl-XL as well as upregulating Bax, C-caspase 3, and C-PARP. Dual-luciferase assay further confirmed that let-7g inhibited ABCC10 expression by binding to the ABCC10 3'-UTR region. Furthermore, let-7g increased the sensitivity of Huh-7/4X to 5-FU in vitro and in vivo, which can be reversed by ABCC10 overexpression. In conclusion, let-7g sensitized liver cancer cells to 5-FU by downregulating ABCC10 expression.

Exploring Novel Genome Instability-associated lncRNAs and their Potential Function in Pan-Renal Cell Carcinoma

OBJECTIVE

Genomic instability can drive clonal evolution, continuous modification of tumor genomes, and tumor genomic heterogeneity. The molecular mechanism of genomic instability still needs further investigation. This study aims to identify novel genome instabilityassociated lncRNAs (GI-lncRNAs) and investigate the role of genome instability in pan-Renal cell carcinoma (RCC).

MATERIALS AND METHODS

A mutator hypothesis was employed, combining the TCGA database of somatic mutation (SM) information, to identify GI-lncRNAs. Subsequently, a training cohort (n = 442) and a testing cohort (n = 439) were formed by randomly dividing all RCC patients. Based on the training cohort dataset, a multivariate Cox regression analysis lncRNAs risk model was created. Further validations were performed in the testing cohort, TCGA cohort, and different RCC subtypes. To confirm the relative expression levels of lncRNAs in HK-2, 786-O, and 769-P cells, qPCR was carried out. Functional pathway enrichment analyses were performed for further investigation.

RESULTS

A total of 170 novel GI-lncRNAs were identified. The lncRNA prognostic risk model was constructed based on LINC00460, AC073218.1, AC010789.1, and COLCA1. This risk model successfully differentiated patients into distinct risk groups with significantly different clinical outcomes. The model was further validated in multiple independent patient cohorts. Additionally, functional and pathway enrichment analyses revealed that GI-lncRNAs play a crucial role in GI. Furthermore, the assessments of immune response, drug sensitivity, and cancer stemness revealed a significant relationship between GI-lncRNAs and tumor microenvironment infiltration, mutational burden, microsatellite instability, and drug resistance.

CONCLUSIONS

In this study, we discovered four novel GI-lncRNAs and developed a novel signature that effectively predicted clinical outcomes in pan-RCC. The findings provide valuable insights for pan-RCC immunotherapy and shed light on potential underlying mechanisms.

Moving beyond cisplatin resistance: mechanisms, challenges, and prospects for overcoming recurrence in clinical cancer therapy

Cisplatin, a classical platinum-based chemotherapy agent, has been a frontline treatment for various cancers for decades. However, its effectiveness has been hindered by the development of resistance, leading to cancer relapse. Addressing this challenge is crucial for both clinical practice and research. Hence, the imperative to unravel the intricate mechanisms underpinning cisplatin resistance and to uncover novel strategies to overcome this barrier holds immense significance. Within this review, we summarized the classification of platinum agents, highlighting their roles in therapeutic landscapes. We discussed the diverse mechanisms behind cisplatin resistance, including diminished intracellular cisplatin accumulation, intracellular detoxification, DNA repair, autophagy responses, heat shock proteins, tumor microenvironment, cancer stem cells, epigenetic regulation, ferroptosis resistance, and metabolic reprogramming. Drawing from this comprehensive understanding, we offered a series of prospective solutions to surmount cisplatin resistance and consequently mitigate the specter of disease recurrence within the realm of clinical cancer therapy.

[Circular RNA hsa_circ_0006834 is a potential prognostic biomarker for hepatocellular carcinoma]

OBJECTIVE

To explore the differentially expressed circular RNAs (circRNAs) in hepatocellular carcinoma (HCC) and their association with clinical features and prognosis of HCC patients.

METHODS

RNA sequencing was performed on 56 pairs of HCC and adjacent tissues to identify the differentially expressed circRNAs in HCC, whose expressions were validated by RT-qPCR in another 15 pairs of HCC and adjacent tissues. The correlation of the selected circRNAs with the clinical features and prognosis of the patients was analyzed using Chi-square test, Cox proportional hazards regression model and Kaplan-Meier analysis. The predictive value of the identified circRNA for recurrence-free survival and overall survival of HCC patients was assessed using ROC curves.

RESULTS

We identified 17 significantly up-regulated and 45 down-regulated circRNAs in HCC tissues using RNA sequencing (P < 0.05). Among these circRNAs, hsa_circ_0006834 was found to be significantly down-regulated in HCC tissues, and its expression level was negatively correlated with vascular invasion and Barcelona Clinic Liver Cancer (BCLC) stage and positively with recurrence-free survival and overall survival of the patients (P < 0.05). As an independent prognostic factor for HCC, hsa_circ_0006834 had an AUC of 0.750 and 0.7601 for predicting 2-year recurrence-free survival and overall survival of HCC patients, respectively.

CONCLUSION

hsa_circ_0006834 is a new potential biomarker for evaluating the prognosis of HCC patients.

Identification of a bile acid and bile salt metabolism-related lncRNA signature for predicting prognosis and treatment response in hepatocellular carcinoma

Bile acids and salts have been shown to play a role in liver carcinogenesis through DNA damage, inflammation, and tumor proliferation. However, the correlation between bile acid metabolism and hepatocellular carcinoma (HCC) prognosis remains unclear. This study aimed to identify a predictive signature of bile acid and bile salt metabolism-related long non-coding RNAs (lncRNAs) for HCC prognosis and treatment response. The study used HCC RNA-sequencing data and corresponding clinical and prognostic data from The Cancer Genome Atlas. A prognostic model consisting of five bile acid and bile salt metabolism-related lncRNAs was developed and evaluated in a training set, a validation set and an external set. The model demonstrated good performance in predicting HCC prognosis and was shown to be an independent biomarker for prognosis. Additionally, our study revealed a significant association between the signature and immune cell infiltration, as well as its predictive value for therapeutic responses to both immunotherapy and chemotherapy. Furthermore, three LncRNAs (LUCAT1, AL031985.3 and AC015908.3) expression levels in our signature were validated through qRT-PCR in a cohort of 50 pairs of HCC patient tumor samples and corresponding adjacent non-tumor samples, along with 10 samples of normal liver tissue adjacent to benign lesions. These findings suggest that this novel bile acid and bile salt metabolism-related lncRNA signature can independently predict the prognosis of patients with HCC and may be utilized as a potential predictor of response to treatment in this setting.

A review on the role of gamma-butyrobetaine hydroxylase 1 antisense RNA 1 in the carcinogenesis and tumor progression

Gamma-butyrobetaine hydroxylase 1 antisense RNA 1 (BBOX1-AS1), located on human chromosome 11 p14, emerges as a critical player in tumorigenesis with diverse oncogenic effects. Aberrant expression of BBOX1-AS1 intricately regulates various cellular processes, including cell growth, epithelial-mesenchymal transition, migration, invasion, metastasis, cell death, and stemness. Notably, the expression of BBOX1-AS1 was significantly correlated with clinical-pathological characteristics and tumor prognoses, and it could also be used for the diagnosis of lung and esophageal cancers. Through its involvement in the ceRNA network, BBOX1-AS1 competitively binds to eight miRNAs in ten different cancer types. Additionally, BBOX1-AS1 can directly modulate downstream protein-coding genes or act as an mRNA stabilizer. The implications of BBOX1-AS1 extend to critical signaling pathways, including Hedgehog, Wnt/β-catenin, and MELK/FAK pathways. Moreover, it influences drug resistance in hepatocellular carcinoma. The present study provides a systematic review of the clinical significance of BBOX1-AS1's aberrant expression in diverse tumor types. It sheds light on the intricate molecular mechanisms through which BBOX1-AS1 influences cancer initiation and progression and outlines potential avenues for future research in this field.

Monocytes subsets altered distribution and dysregulated plasma hsa-miR-21-5p and hsa-miR-155-5p in HCV-linked liver cirrhosis progression to hepatocellular carcinoma

PURPOSE

The authors aim to investigate the altered monocytes subsets distribution in liver cirrhosis (LC) and subsequent hepatocellular carcinoma (HCC) in association with the expression level of plasma Homo sapiens (has)-miR-21-5p and hsa-miR-155-5p. A step toward non-protein coding (nc) RNA precision medicine based on the immune perturbation manifested as altered monocytes distribution, on top of LC and HCC.

METHODS

Seventy-nine patients diagnosed with chronic hepatitis C virus (CHCV) infection with LC were enrolled in the current study. Patients were sub-classified into LC group without HCC (n = 40), LC with HCC (n = 39), and 15 apparently healthy controls. Monocyte subsets frequencies were assessed by flow cytometry. Real-time quantitative PCR was used to measure plasma hsa-miR-21-5p and hsa-miR-155-5p expression.

RESULTS

Hsa-miR-21-5p correlated with intermediate monocytes (r = 0.30, p = 0.007), while hsa-miR-155-5p negatively correlated with non-classical monocytes (r = - 0.316, p = 0.005). ROC curve analysis revealed that combining intermediate monocytes frequency and hsa-miR-21 yielded sensitivity = 79.5%, specificity = 75%, and AUC = 0.84. In comparison, AFP yielded a lower sensitivity = 69% and 100% specificity with AUC = 0.85. Logistic regression analysis proved that up-regulation of intermediate monocytes frequency and hsa-miR-21-5p were independent risk factors for LC progression to HCC, after adjustment for co-founders.

CONCLUSION

Monocyte subsets differentiation in HCC was linked to hsa-miR-21-5p and hsa-miR-155-5p. Combined up-regulation of intermediate monocytes frequency and hsa-miR-21-5p expression could be considered a sensitive indicator of LC progression to HCC. Circulating intermediate monocytes and hsa-miR-21-5p were independent risk factors for HCC evolution, clinically and in silico proved.

CRISPR/Cas9 screens unravel miR-3689a-3p regulating sorafenib resistance in hepatocellular carcinoma via suppressing CCS/SOD1-dependent mitochondrial oxidative stress

AIMS

Therapeutic outcome of sorafenib in hepatocellular carcinoma (HCC) is undermined by the development of drug resistance. This study aimed to identify the critical microRNA (miRNA) which is responsible for sorafenib resistance at the genomic level.

METHODS

CRISPR/Cas9 screen followed by gain- and loss-of-function assays both in vitro and in vivo were applied to identify the role of miR-3689a-3p in mediating sorafenib response in HCC. The upstream and downstream molecules of miR-3689a-3p and their mechanism of action were investigated.

RESULTS

CRISPR/Cas9 screening identified miR-3689a-3p was the most up-regulated miRNA in sorafenib sensitive HCC. Knockdown of miR-3689a-3p significantly increased sorafenib resistance, while its overexpression sensitized HCC response to sorafenib treatment. Proteomic analysis revealed that the effect of miR-3689a-3p was related to the copper-dependent mitochondrial superoxide dismutase type 1 (SOD1) activity. Mechanistically, miR-3689a-3p targeted the 3'UTR of the intracellular copper chaperone for superoxide dismutase (CCS) and suppressed its expression. As a result, miR-3689a-3p disrupted the intracellular copper trafficking and reduced SOD1-mediated scavenge of mitochondrial oxidative stress that eventually caused HCC cell death in response to sorafenib treatment. CCS overexpression blunted sorafenib response in HCC. Clinically, miR-3689a-3p was down-regulated in HCC and predicted favorable prognosis for HCC patients.

CONCLUSION

Our findings provide comprehensive evidence for miR-3689a-3p as a positive regulator and potential druggable target for improving sorafenib treatment in HCC.

Targeting LINC01607 sensitizes hepatocellular carcinoma to Lenvatinib via suppressing mitophagy

Lenvatinib is a standard therapy option for advanced hepatocellular carcinoma (HCC), but resistance limits clinical benefits. In this study, we identified inhibition of ROS levels and reduced redox status in Lenvatinib-resistant HCC. Integrating RNA-seq with unbiased whole-genome CRISPR-Cas9 screen analysis indicated LINC01607 regulated the P62 to enhance drug resistance by affecting mitophagy and antioxidant pathways. Underlying mechanisms were investigated both in vitro and in vivo. We initially confirmed that LINC01607, as a competing endogenous RNA (ceRNA) competing with mirRNA-892b, triggered protective mitophagy by upregulating P62, which reduced ROS levels and promoted drug resistance. Furthermore, LINC01607 was proved to resist oxidative stress by regulating the P62-Nrf2 axis, which transcriptionally regulated the expression of LINC01607 to form a positive feedback loop. Finally, silencing LINC01607 combined with Lenvatinib reversed resistance in animal and patient-derived organoid models. In conclusion, we proposed a novel mechanism of Lenvatinib resistance involving ROS homeostasis. This work contributed to understanding redox homeostasis-related drug resistance and provided new therapeutic targets and strategies for HCC patients.

YY1-regulated lncRNA SOCS2-AS1 suppresses HCC cell stemness and progression via miR-454-3p/CPEB1

BACKGROUND

Cancer stem cells are one fundamental reason for the high recurrence rate of hepatocellular carcinoma (HCC) and its resistance to treatment. This study explored the mechanism by which SOCS2-AS1 affects HCC cell stemness.

METHODS

Stem cells of HCC cell lines Huh7 and SNU-398 were sorted as NANOG-positive by flow cytometry. Stem cell sphere formation ability was detected. Stem cell viability, migration, invasion, and apoptosis were assessed by colony formation assays, Transwell assays, wound-healing assays, and TUNEL assays, respectively. The binding sites for SOCS2-AS1, miR-454-3p, miR-454-3p, and CPEB1 mRNA were assessed by dual-luciferase reporter assays. Quantitative real-time PCR (qPCR) and Western blot studies were performed to evaluate gene expression levels. ChIP and EMSA assays were conducted to confirm that YY1 binds with the SOCS2-AS1 promoter. A subcutaneous xenograft model was used to verify results in vivo. Tumor tissues were analyzed by H&E and TUNEL staining.

RESULTS

SOCS2-AS1 was expressed at low levels in NANOG+ HCC stem cells, and HCC patients with a high level of SOCS2-AS1 expression had a higher survival rate. SOCS2-AS1 inhibited HCC cell stemness, migration, and invasion, and increased the cisplatin sensitivity of HCC cells by regulating miR-454-3p/CPEB1. YY1 was confirmed as a transcription factor of SOCS2-AS1, and served to inhibit SOCS2-AS1 transcription. YY1 knockdown suppressed HCC stemness via SOCS2-AS1. The role of SOCS2-AS1 was confirmed in a subcutaneous xenograft model, and SOCS2-AS1 overexpression enhanced the inhibitory effect of cisplatin on HCC in vivo.

CONCLUSIONS

YY1-regulated lncRNA SOCS2-AS1 suppresses HCC cell stemness and progression via miR-454-3p/CPEB1.

Exosome-transported circHDAC1_004 Promotes Proliferation, Migration, and Angiogenesis of Hepatocellular Carcinoma by the miR-361-3p/NACC1 Axis

Background and Aims

Hepatocellular carcinoma (HCC) is among the most common malignant tumors globally. Circular RNAs (circRNAs), as a type of noncoding RNAs, reportedly participate in various tumor biological processes. However, the role of circHDAC1_004 in HCC remains unclear. Thus, we aimed to explore the role and the underlying mechanisms of circHDAC1_004 in the development and progression of HCC.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect circHDAC1_004 expression (circ_0005339) in HCC. Sanger sequencing and agarose gel electrophoresis were used to determine the structure of circHDAC1_004. In vitro and in vivo experiments were used to determine the biological function of circHDAC1_004 in HCC. Herein, qRT-PCR, RNA immunoprecipitation, western blotting, and a luciferase reporter assay were used to explore the relationships among circHDAC1_004, miR-361-3p, and NACC1.

Results

circHDAC1_004 was upregulated in HCC and significantly associated with poor overall survival. circHDAC1_004 promoted HCC cell proliferation, stemness, migration, and invasion. In addition, circHDAC1_004 upregulated human umbilical vein endothelial cells (HUVECs) and promoted angiogenesis through exosomes. circHDAC1_004 promoted NACC1 expression and stimulated the epithelial-mesenchymal transition pathway by sponging miR-361-3p.

Conclusions

We found that circHDAC1_004 overexpression enhanced the proliferation, stemness, and metastasis of HCC via the miR-361-3p/NACC1 axis and promoted HCC angiogenesis through exosomes. Our findings may help develop a possible therapeutic strategy for HCC.

Role of Non-Coding RNAs in Hepatocellular Carcinoma Progression: From Classic to Novel Clinicopathogenetic Implications

Hepatocellular carcinoma (HCC) is a predominant malignancy with increasing incidences and mortalities worldwide. In Western countries, the progressive affirmation of Non-alcoholic Fatty Liver Disease (NAFLD) as the main chronic liver disorder in which HCC occurrence is appreciable even in non-cirrhotic stages, constitutes a real health emergency. In light of this, a further comprehension of molecular pathways supporting HCC onset and progression represents a current research challenge to achieve more tailored prognostic models and appropriate therapeutic approaches. RNA non-coding transcripts (ncRNAs) are involved in the regulation of several cancer-related processes, including HCC. When dysregulated, these molecules, conventionally classified as "small ncRNAs" (sncRNAs) and "long ncRNAs" (lncRNAs) have been reported to markedly influence HCC-related progression mechanisms. In this review, we describe the main dysregulated ncRNAs and the relative molecular pathways involved in HCC progression, analyzing their implications in certain etiologically related contexts, and their applicability in clinical practice as novel diagnostic, prognostic, and therapeutic tools. Finally, given the growing evidence supporting the immune system response, the oxidative stress-regulated mechanisms, and the gut microbiota composition as relevant emerging elements mutually influencing liver-cancerogenesis processes, we investigate the relationship of ncRNAs with this triad, shedding light on novel pathogenetic frontiers of HCC progression.

Progress on traditional Chinese medicine in improving hepatic fibrosis through inhibiting oxidative stress

Hepatic fibrosis is a common pathological process that occurs in the development of various chronic liver diseases into cirrhosis and liver cancer, characterized by excessive deposition of the extracellular matrix. In the past, hepatic fibrosis was thought to be a static and irreversible pathological process. In recent years, with the rapid development of molecular biology and the continuous in-depth study of the liver at the microscopic level, more and more evidence has shown that hepatic fibrosis is a dynamic and reversible process. Therefore, it is particularly important to find an effective, simple, and inexpensive method for its prevention and treatment. Traditional Chinese medicine (TCM) occupies an important position in the treatment of hepatic fibrosis due to its advantages of low adverse reactions, low cost, and multi-target effectiveness. A large number of research results have shown that TCM monomers, single herbal extracts, and TCM formulas play important roles in the prevention and treatment of hepatic fibrosis. Oxidative stress (OS) is one of the key factors in the occurrence and development of hepatic fibrosis. Therefore, this article reviews the progress in the understanding of the mechanisms of TCM monomers, single herbal extracts, and TCM formulas in preventing and treating hepatic fibrosis by inhibiting OS in recent years, in order to provide a reference and basis for drug therapy of hepatic fibrosis.

Development and validation a radiomics nomogram for predicting thymidylate synthase status in hepatocellular carcinoma based on Gd-DTPA contrast enhanced MRI

OBJECTIVES

The purpose of this study was to develop and validate a radiomics nomogram for predicting thymidylate synthase (TYMS) status in hepatocellular carcinoma (HCC) by using Gd-DTPA contrast enhanced MRI.

METHODS

We retrospectively enrolled 147 consecutive patients with surgically confirmed HCC and randomly allocated to training and validation set (7:3). The TYMS status was immunohistochemical determined and classified into low TYMS (positive cells ≤ 25%) and high TYMS (positive cells > 25%) groups. Radiomics features were extracted from the arterial phases and portal venous phase of Gd-DTPA contrast enhanced MRI. Least absolute shrinkage and selection operator (LASSO) were applied for generating the Rad score. Clinical data and MRI findings were assessed to build a clinical model. Rad score combined with clinical features was used to construct radiomics nomogram.

RESULTS

A total of 2260 features were extracted and reduced to 7 features as the most important discriminators to build the Rad score. InAFP was identified as the only independent clinical factors for TYMS status. The radiomics nomogram showed good discrimination in training (AUC, 0.759; 95% CI 0.665-0.838) and validation set (AUC, 0.739; 95% CI 0.585-0.860), and showed better discrimination capability (P < 0.05) compared with clinical model in training (AUC, 0.656; 95% CI 0.555-0.746) and validation set (AUC, 0.622; 95% CI 0.463-0.764).

CONCLUSIONS

The radiomics nomogram shows favorable predictive efficacy for TYMS status in HCC, which might be helpful for the personalized treatment of HCC.

LncRNA RP11-58O9.2 predicts poor prognosis and promotes progression of non-small cell lung cancer

OBJECTIVE

Long non-coding RNAs (lncRNAs) play a crucial role in non-small cell lung cancer (NSCLC). This study aimed to investigate the novel biomarker, lncRNA RP11-58O9.2, in patients with NSCLC.

METHODS

RP11-58O9.2 expression in NSCLC cells and tissues was detected by reverse transcription-quantitative polymerase chain reaction. Patient survival was analyzed in relation to RP11-58O9.2 expression levels. RP11-58O9.2 expression was knocked down and endogenous expression was verified in two NSCLC cell lines. Cell proliferation was then assessed by Cell Counting Kit-8 and colony-formation assays, and cell invasion and migration were assessed by Transwell and wound-healing assays, respectively. In vivo experiments were performed in mice, and the combination of RP11-58O9.2 and miR-6749-3p was predicted by miRanda.

RESULTS

RP11-58O9.2 was highly expressed in NSCLC cell lines and tissues, and was associated with advanced stage, lymphatic metastasis, and differentiation group. High RP11-58O9.2 levels were also associated with shorter survival. RP11-58O9.2 knockdown inhibited the proliferation, invasion, and migration of lung cancer cells, and tumor growth in mouse xenografts in vivo. RP11-58O9.2 may target and regulate miR-6749-3p.

CONCLUSIONS

LncRNA RP11-58O9.2 is associated with NSCLC prognosis and promotes lung cancer progression. Further studies are needed to investigate the mechanisms and the regulatory association between RP11-58O9.2 and miR-6749-3p.

Deciphering the Enigmatic Influence: Non-Coding RNAs Orchestrating Wnt/β-Catenin Signaling Pathway in Tumor Progression

Dysregulated expression of specific non-coding RNAs (ncRNAs) has been strongly linked to tumorigenesis, cancer progression, and therapeutic resistance. These ncRNAs can act as either oncogenes or tumor suppressors, thereby serving as valuable diagnostic and prognostic markers. Numerous studies have implicated the participation of ncRNAs in the regulation of diverse signaling pathways, including the pivotal Wnt/β-catenin signaling pathway that is widely acknowledged for its pivotal role in embryogenesis, cellular proliferation, and tumor biology control. Recent emerging evidence has shed light on the capacity of ncRNAs to interact with key components of the Wnt/β-catenin signaling pathway, thereby modulating the expression of Wnt target genes in cancer cells. Notably, the activity of this pathway can reciprocally influence the expression levels of ncRNAs. However, comprehensive analysis investigating the specific ncRNAs associated with the Wnt/β-catenin signaling pathway and their intricate interactions in cancer remains elusive. Based on these noteworthy findings, this review aims to unravel the intricate associations between ncRNAs and the Wnt/β-catenin signaling pathway during cancer initiation, progression, and their potential implications for therapeutic interventions. Additionally, we provide a comprehensive overview of the characteristics of ncRNAs and the Wnt/β-catenin signaling pathway, accompanied by a thorough discussion of their functional roles in tumor biology. Targeting ncRNAs and molecules associated with the Wnt/β-catenin signaling pathway may emerge as a promising and effective therapeutic strategy in future cancer treatments.

cDCBLD2 mediates sorafenib resistance in hepatocellular carcinoma by sponging miR-345-5p binding to the TOP2A coding sequence

Sorafenib is a first-line chemotherapy drug for treating advanced hepatocellular carcinoma (HCC). However, its therapeutic effect has been seriously affected by the emergence of sorafenib resistance in HCC patients. The underlying mechanism of sorafenib resistance is unclear. Here, we report a circular RNA, cDCBLD2, which plays an important role in sorafenib resistance in HCC. We found that cDCBLD2 was upregulated in sorafenib-resistant (SR) HCC cells, and knocking down cDCBLD2 expression could significantly increase sorafenib-related cytotoxicity. Further evidence showed that cDCBLD2 can bind to microRNA (miR)-345-5p through a competing endogenous RNA mechanism, increase type IIA topoisomerase (TOP2A) mRNA stability through a miRNA sponge mechanism, and reduce the effects of sorafenib treatment on HCC by inhibiting apoptosis. Our findings also suggest that miR-345-5p can negatively regulate TOP2A levels by binding to the coding sequence region of its mRNA. Additionally, targeting cDCBLD2 by injecting a specific small interfering RNA (siRNA) could significantly overcome sorafenib resistance in a patient-derived xenograft (PDX) mouse model of HCC. Taken together, our study provides a proof-of-concept for a potential strategy to overcome sorafenib resistance in HCC patients by targeting cDCBLD2 or TOP2A.

Advances of Long Non-Coding RNAs as Potential Biomarkers for Tuberculosis: New Hope for Diagnosis?

Tuberculosis (TB), one of the top ten causes of death globally induced by the infection of Mycobacterium tuberculosis (Mtb), remains a grave public health issue worldwide. With almost one-third of the world's population getting infected by Mtb, between 5% and 10% of these infected individuals are predicted to develop active TB disease, which would not only result in severe tissue damage and necrosis, but also pose serious threats to human life. However, the exact molecular mechanisms underlying the pathogenesis and immunology of TB remain unclear, which significantly restricts the effective control of TB epidemics. Despite significant advances in current detection technologies and treatments for TB, there are still no appropriate solutions that are suitable for simultaneous, early, rapid, and accurate screening of TB. Various cellular events can perturb the development and progression of TB, which are always associated with several specific molecular signaling events controlled by dysregulated gene expression patterns. Long non-coding RNAs (lncRNAs), a kind of non-coding RNA (ncRNA) with a transcript of more than 200 nucleotides in length in eukaryotic cells, have been found to regulate the expression of protein-coding genes that are involved in some critical signaling events, such as inflammatory, pathological, and immunological responses. Increasing evidence has claimed that lncRNAs might directly influence the susceptibility to TB, as well as the development and progression of TB. Therefore, lncRNAs have been widely expected to serve as promising molecular biomarkers and therapeutic targets for TB. In this review, we summarized the functions of lncRNAs and their regulatory roles in the development and progression of TB. More importantly, we widely discussed the potential of lncRNAs to act as TB biomarkers, which would offer new possibilities in novel diagnostic strategy exploration and benefit the control of the TB epidemic.

DNAJ heat shock protein family member C1 can regulate proliferation and migration in hepatocellular carcinoma

Background

DNAJ heat shock protein family (Hsp40) member C1(DNAJC1) is a member of the DNAJ family. Some members of the DNAJ gene family had oncogenic properties in many cancers. However, the role of DNAJC1 in hepatocellular carcinoma (HCC) was unclear.

Methods

In this study, expression and prognostic value of DNAJC1 in HCC were analyzed by bioinformatics. Quantitative real-time PCR and Western blotting were used to verify DNAJC1 expression in liver cancer cell lines. Furthermore, immunohistochemical (IHC) was used to detect DNAJC1 expression in liver cancer tissues. Subsequently, the effect of DNAJC1 on the proliferation, migration, invasion and apoptosis of HCC cells was detected by knocking down DNAJC1. Finally, gene set enrichment analysis (GSEA) was used to investigate the potential mechanism of DNAJC1 and was verified by Western blotting.

Results

DNAJC1 was highly expressed in HCC and was significantly associated with the prognosis of patients with HCC. Importantly, the proliferation, migration and invasion of Huh7 and MHCC97H cells were inhibited by the knockdown of DNAJC1 and the knockdown of DNAJC1 promoted Huh7 and MHCC97H cell apoptosis. Furthermore, compared to the negative control group, DNAJC1 knockdown in Huh7 and MHCC97H cells promoted the expression of p21, p53, p-p53(Ser20), Bax and E-cadherin proteins, while inhibiting the expression of PARP, MMP9, Vimentin, Snai1, Bcl-2 and N-cadherin proteins.

Conclusions

DNAJC1 had a predictive value for the prognosis of HCC. Knockdown of DNAJC1 may inhibit HCC cell proliferation, migration and invasion and promote the HCC cell apoptosis through p53 and EMT signaling pathways.

Combining WGCNA and machine learning to construct immune-related EMT patterns to predict HCC prognosis and immune microenvironment

Hepatocellular carcinoma (HCC) is a malignancy with a very high mortality rate. Because of its high heterogeneity, there is an urgent need to find biomarkers that accurately predict prognosis. Epithelial-mesenchymal transition (EMT) is closely associated with frequent recurrence and high mortality of HCC. Therefore, it is necessary to comprehensively analyze the prognostic value and immunological properties of EMT gene in HCC. In our study, we performed bioinformatics analysis of the TCGA and ICGC liver cancer cohorts and identified the module genes of immune-associated EMTs (iEMT) by Weighted Gene Co-Expression Network Analysis (WGCNA). Further we used machine learning (support vector machines-recursive feature elimination and Lasso) to identify three central iEMT genes (ARMC9, ADAM15 and STC2) and construct iEMT_score. Subsequently, in the training and validation cohorts, it was demonstrated that the overall survival (OS) of patients in the high iEMT_score group was worse than that of patients in the low iEMT_score group. Based on this, we have constructed a nomogram that is easy for clinicians to use. In addition, our study explored differences in pathway enrichment, immunological properties, and sensitivity to common chemotherapy and targeted drugs in different subgroups of iEMT_score. Finally, we showed through in vitro experiments that knockdown of ARMC9 could significantly inhibit the proliferation, migration and invasion of HCC cells BEL7402. Taken together, our findings suggest that iEMT_score is an excellent biomarker for predicting prognosis and provide some new insights for personalized treatment of HCC patients.

ZNF765 is a prognostic biomarker of hepatocellular carcinoma associated with cell cycle, immune infiltration, m6A modification, and drug susceptibility

Hepatocellular carcinoma (HCC) is an ongoing challenge worldwide. Zinc finger protein 765 (ZNF765) is an important zinc finger protein that is related to the permeability of the blood-tumor barrier. However, the role of ZNF765 in HCC is unclear. This study evaluated the expression of ZNF765 in hepatocellular carcinoma and the impact of its expression on patient prognosis based on The Cancer Genome Atlas (TCGA). Immunohistochemical assays (IHC) were used to examine protein expression. Besides, a colony formation assay was used to examine cell viability. We also explored the relationship between ZNF765 and chemokines in the HCCLM3 cells by qRT-PCR. Moreover, we examined the effect of ZNF765 on cell resistance by measurement of the maximum half-inhibitory concentration. Our research revealed that ZNF765 expression in HCC samples was higher than that in normal samples, whose upregulation was not conducive to the prognosis. The results of GO, KEGG, and GSEA showed that ZNF765 was associated with the cell cycle and immune infiltration. Furthermore, we confirmed that the expression of ZNF765 had a strong connection with the infiltration level of various immune cells, such as B cells, CD4+ T cells, macrophages, and neutrophils. In addition, we found that ZNF765 was associated with m6A modification, which may affect the progression of HCC. Finally, drug sensitivity testing found that patients with HCC were sensitive to 20 drugs when they expressed high levels of ZNF765. In conclusion, ZNF765 may be a prognostic biomarker related to cell cycle, immune infiltration, m6A modification, and drug sensitivity for hepatocellular carcinoma.

Glycoproteomic contributions to hepatocellular carcinoma research: a 2023 update

INTRODUCTION

Hepatocellular carcinoma (HCC) represents a significant burden globally, which ranks sixth among the most frequently diagnosed cancers and stands as the third leading cause of cancer-related mortality. Glycoproteomics, as an important branch of proteomics, has already made significant achievements in the field of HCC research. Aberrant protein glycosylation has shown to promote the malignant transformation of hepatocytes by modulating a wide range of tumor-promoting signaling pathways. The glycoproteome provides valuable information for understanding cancer progression, tumor immunity, and clinical outcome, which could serve as potential diagnostic, prognostic, and therapeutic tools in HCC.

AREAS COVERED

In this review, recent advances of glycoproteomics contribute to clinical applications (diagnosis and prognosis) and molecular mechanisms (hepatocarcinogenesis, progression, stemness and recurrence, and drug resistance) of HCC are summarized.

EXPERT OPINION

Glycoproteomics shows promise in HCC, enhancing early detection, risk stratification, and personalized treatments. Challenges include sample heterogeneity, diverse glycans structures, sensitivity issues, complex workflows, limited databases, and incomplete understanding of immune cell glycosylation. Addressing these limitations requires collaborative efforts, technological advancements, standardization, and validation studies. Future research should focus on targeting abnormal protein glycosylation therapeutically. Advancements in glycobiomarkers and glycosylation-targeted therapies will greatly impact HCC diagnosis, prognosis, and treatment.

Understanding HAT1: A Comprehensive Review of Noncanonical Roles and Connection with Disease

Histone acetylation plays a vital role in organizing chromatin, regulating gene expression and controlling the cell cycle. The first histone acetyltransferase to be identified was histone acetyltransferase 1 (HAT1), but it remains one of the least understood acetyltransferases. HAT1 catalyzes the acetylation of newly synthesized H4 and, to a lesser extent, H2A in the cytoplasm. However, 20 min after assembly, histones lose acetylation marks. Moreover, new noncanonical functions have been described for HAT1, revealing its complexity and complicating the understanding of its functions. Recently discovered roles include facilitating the translocation of the H3H4 dimer into the nucleus, increasing the stability of the DNA replication fork, replication-coupled chromatin assembly, coordination of histone production, DNA damage repair, telomeric silencing, epigenetic regulation of nuclear lamina-associated heterochromatin, regulation of the NF-κB response, succinyl transferase activity and mitochondrial protein acetylation. In addition, the functions and expression levels of HAT1 have been linked to many diseases, such as many types of cancer, viral infections (hepatitis B virus, human immunodeficiency virus and viperin synthesis) and inflammatory diseases (chronic obstructive pulmonary disease, atherosclerosis and ischemic stroke). The collective data reveal that HAT1 is a promising therapeutic target, and novel therapeutic approaches, such as RNA interference and the use of aptamers, bisubstrate inhibitors and small-molecule inhibitors, are being evaluated at the preclinical level.

Pathogenesis of Hepatocellular Carcinoma: The Interplay of Apoptosis and Autophagy

The pathogenesis of hepatocellular carcinoma (HCC) is a multifactorial process that has not yet been fully investigated. Autophagy and apoptosis are two important cellular pathways that are critical for cell survival or death. The balance between apoptosis and autophagy regulates liver cell turnover and maintains intracellular homeostasis. However, the balance is often dysregulated in many cancers, including HCC. Autophagy and apoptosis pathways may be either independent or parallel or one may influence the other. Autophagy may either inhibit or promote apoptosis, thus regulating the fate of the liver cancer cells. In this review, a concise overview of the pathogenesis of HCC is presented, with emphasis on new developments, including the role of endoplasmic reticulum stress, the implication of microRNAs and the role of gut microbiota. The characteristics of HCC associated with a specific liver disease are also described and a brief description of autophagy and apoptosis is provided. The role of autophagy and apoptosis in the initiation, progress and metastatic potential is reviewed and the experimental evidence indicating an interplay between the two is extensively analyzed. The role of ferroptosis, a recently described specific pathway of regulated cell death, is presented. Finally, the potential therapeutic implications of autophagy and apoptosis in drug resistance are examined.

An Insight into the Arising Role of MicroRNAs in Hepatocellular Carcinoma: Future Diagnostic and Therapeutic Approaches

Hepatocellular carcinoma (HCC) constitutes a frequent highly malignant form of primary liver cancer and is the third cause of death attributable to malignancy. Despite the improvement in the therapeutic strategies with the exploration of novel pharmacological agents, the survival rate for HCC is still low. Shedding light on the multiplex genetic and epigenetic background of HCC, such as on the emerging role of microRNAs, is considered quite promising for the diagnosis and the prediction of this malignancy, as well as for combatting drug resistance. MicroRNAs (miRNAs) constitute small noncoding RNA sequences, which play a key role in the regulation of several signaling and metabolic pathways, as well as of pivotal cellular functions such as autophagy, apoptosis, and cell proliferation. It is also demonstrated that miRNAs are significantly implicated in carcinogenesis, either acting as tumor suppressors or oncomiRs, while aberrations in their expression levels are closely associated with tumor growth and progression, as well as with local invasion and metastatic dissemination. The arising role of miRNAs in HCC is in the spotlight of the current scientific research, aiming at the development of novel therapeutic perspectives. In this review, we will shed light on the emerging role of miRNAs in HCC.

Non-Coding RNAs Derived from Extracellular Vesicles Promote Pre-Metastatic Niche Formation and Tumor Distant Metastasis

Metastasis is a critical stage of tumor progression, a crucial challenge of clinical therapy, and a major cause of tumor patient death. Numerous studies have confirmed that distant tumor metastasis is dependent on the formation of pre-metastatic niche (PMN). Recent studies have shown that extracellular vesicles (EVs) play an important role in PMN formation. The non-coding RNAs (ncRNAs) derived from EVs mediate PMN formation and tumor-distant metastasis by promoting an inflammatory environment, inhibiting anti-tumor immune response, inducing angiogenesis and permeability, and by microenvironmental reprogramming. Given the stability and high abundance of ncRNAs carried by EVs in body fluids, they have great potential for application in tumor diagnosis as well as targeted interventions. This review focuses on the mechanism of ncRNAs derived from EVs promoting tumor PMN formation and distant metastasis to provide a theoretical reference for strategies to control tumor metastasis.

Circ_RBM23 knockdown suppresses chemoresistance, proliferation, migration and invasion of sorafenib-resistant HCC cells through miR-338-3p/RAB1B axis

BACKGROUND

Circular RNA RNA-binding motif protein 23 (circ_RBM23; ID: hsa_circ_0000524) is a novel regulator in hepatocellular carcinoma (HCC). Herein, we planned to investigate its role in sorafenib resistance in HCC.

METHOD

Levels of circ_RBM23, microRNA (miR)-338-3p, Ras-related GTPase-trafficking protein (RAB1B), Snail and E-cadherin were detected by real-time quantitative PCR and western blotting. Sorafenib resistant (SR) HCC cells (Huh7/SR and SK-HEP-1/SR) were established by acquisition of sorafenib resistance, and cell functions were measured by MTT assay, Edu assay, colony formation assay, apoptosis assay, transwell assay, and in vivo xenograft formation assay. Crosslink between miR-338-3p and circ_RBM23 or RAB1B was confirmed by bioinformatics analysis and dual-luciferase reporter assay.

RESULTS

Circ_RBM23 upregulation was discovered in the tissues of SR patients and SR cells, which was accompanied with miR-338-3p downregulation and RAB1B upregulation. The 50% inhibitory concentration (IC₅₀) of sorafenib in SR cells was greatly suppressed by interfering circ_RBM23 or reinforcing miR-338-3p, allied with this was the inhibition of EdU-positive cell rate, colony formation and migration/invasion abilities under sorafenib treatment, as well as the enhancement of apoptotic rate. Moreover, circ_RBM23 inhibition delayed tumor growth of Huh7/SR cells under sorfanib treatment in vivo.

CONCLUSION

Circ_RBM23 promoted chemoresistance, malignant proliferation, migration and invasion of SR HCC cells by modulating miR-338-3p/RAB1B axis.

Hypoxia-induced lncRNA MRVI1-AS1 accelerates hepatocellular carcinoma progression by recruiting RNA-binding protein CELF2 to stabilize SKA1 mRNA

BACKGROUND

Long non-coding RNAs (lncRNAs) perform a vital role during the progression of hepatocellular carcinoma (HCC). Here, we aimed to identify a novel lncRNA involved in HCC development and elucidate the underlying molecular mechanism.

METHODS

The RT-qPCR and TCGA dataset analysis were applied to explore the expressions of MRVI1-AS1 in HCC tissues and cell lines. Statistical analysis was applied to analyze the clinical significance of MRVI1-AS1 in HCC. The functions of MRVI1-AS1 in HCC cells metastasis and growth were explored by transwell assays, wound healing assay, MTT assay, EdU assay, the intravenous transplantation tumor model, and the subcutaneous xenograft tumor model. Microarray mRNA expression analysis, dual luciferase assays, and actinomycin D treatment were used to explore the downstream target of MRVI1-AS1 in HCC cells. RIP assay was applied to assess the direct interactions between CELF2 and MRVI1-AS1 or SKA1 mRNA. Rescue experiments were employed to validate the functional effects of MRVI1-AS1, CELF2, and SKA1 on HCC cells.

RESULTS

MRVI1-AS1 was found to be dramatically upregulated in HCC and the expression was strongly linked to tumor size, venous infiltration, TNM stage, as well as HCC patients' outcome. Cytological experiments and animal experiments showed that MRVI1-AS1 promoted HCC cells metastasis and growth. Furthermore, SKA1 was identified as the downstream targeted mRNA of MRVI1-AS1 in HCC cells, and MRVI1-AS1 increased SKA1 expression by recruiting CELF2 protein to stabilize SKA1 mRNA. In addition, we found that MRVI1-AS1 expression was stimulated by hypoxia through a HIF-1-dependent manner, which meant that MRVI1-AS was a direct downstream target gene of HIF-1 in HCC.

CONCLUSION

In a word, our findings elucidated that hypoxia-induced MRVI1-AS1 promotes metastasis and growth of HCC cells via recruiting CELF2 protein to stabilize SKA1 mRNA, pointing to MRVI1-AS1 as a promising clinical application target for HCC therapy.

Identification of biomarkers of hepatocellular carcinoma gene prognosis based on the immune-related lncRNA signature of transcriptome data

BACKGROUND

Long non-coding RNAs (lncRNAs) are well established to have an important role in cancer. The goal of this research was to investigate the prognostic usefulness of putative immune-related lncRNAs in hepatocellular carcinoma (HCC).

METHODS

The developed lncRNA signature was validated using 343 HCC patients from The Cancer Genome Atlas (TCGA) and 81 samples from Gene Expression Omnibus (GEO). Cox regression and Least Absolute Shrinkage and Selection Operator (LASSO) analysis were used to analyze immune-related lncRNAs for HCC prognosis. Patients in the low-risk group survived substantially longer than those in the high-risk group (P < 0.05). The discovered signal might be a useful prognostic factor for predicting patient survival. Overall survival predicted some clinical net improvements, according to the nomogram. Numerous enrichment approaches (including gene set enrichment analysis) were utilized to investigate the underlying mechanisms.

RESULTS

Drug metabolism, mTOR, and p53 signaling pathways were associated with high-risk groups. When the expression of lncRNA PRRT3-AS1 was silenced in HepG2 cells, the proliferation, migration, and invasion abilities of HepG2 cells were decreased, and apoptosis was enhanced. In the supernatant from HepG2 cells with PRRT3-AS1 knockdown, the anti-inflammatory factors IL-10 and TGF-1 were induced, whereas the pro-inflammatory factors IL-1β, TNF-α, and IL-6 were reduced (P < 0.05). After PRRT3-AS1 knockdown, the protein expression of CD24, THY1, LYN, CD47, and TRAF2 in HepG2 cells was attenuated (P < 0.05).

CONCLUSION

The discovery of five immune-related lncRNA signatures has significant therapeutic significance for predicting patient prognosis and directing personalized treatment for patients with HCC, which requires additional prospective confirmation.

Exosome-derived circCCAR1 promotes CD8 + T-cell dysfunction and anti-PD1 resistance in hepatocellular carcinoma

BACKGROUND

Circular RNAs (circRNAs) can be encapsulated into exosomes to participate in intercellular communication, affecting the malignant progression of a variety of tumors. Dysfunction of CD8 + T cells is the main factor in immune escape from hepatocellular carcinoma (HCC). Nevertheless, the effect of exosome-derived circRNAs on CD8 + T-cell dysfunction needs further exploration.

METHODS

The effect of circCCAR1 on the tumorigenesis and metastasis of HCC was assessed by in vitro and in vivo functional experiments. The function of circCCAR1 in CD8 + T-cell dysfunction was measured by enzyme-linked immunosorbent assay (ELISA), western blotting and flow cytometry. Chromatin immunoprecipitation, biotinylated RNA pull-down, RNA immunoprecipitation, and MS2 pull-down assays were used to the exploration of mechanism. A mouse model with reconstituted human immune system components (huNSG mice) was constructed to explore the role of exosomal circCCAR1 in the resistance to anti-PD1 therapy in HCC.

RESULTS

Increased circCCAR1 levels existed in tumor tissues and exosomes in the plasma of HCC patients, in the culture supernatant and HCC cells. CircCCAR1 accelerated the growth and metastasis of HCC in vitro and in vivo. E1A binding protein p300 (EP300) and eukaryotic translation initiation factor 4A3 (EIF4A3) promoted the biogenesis of circCCAR1, and Wilms tumor 1-associated protein (WTAP)-mediated m6A modification enhanced circCCAR1 stability by binding insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3). CircCCAR1 acted as a sponge for miR-127-5p to upregulate its target WTAP and a feedback loop comprising circCCAR1/miR-127-5p/WTAP axis was formed. CircCCAR1 is secreted by HCC cells in a heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2B1)-dependent manner. Exosomal circCCAR1 was taken in by CD8 + T cells and caused dysfunction of CD8 + T cells by stabilizing the PD-1 protein. CircCCAR1 promoted resistance to anti-PD1 immunotherapy. Furthermore, increased cell division cycle and apoptosis regulator 1 (CCAR1) induced by EP300 promoted the binding of CCAR1 and β-catenin protein, which further enhanced the transcription of PD-L1.

CONCLUSIONS

The circCCAR1/miR-127-5p/WTAP feedback loop enhances the growth and metastasis of HCC. Exosomal circCCAR1 released by HCC cells contributes to immunosuppression by facilitating CD8 + T-cell dysfunction in HCC. CircCCAR1 induces resistance to anti-PD1 immunotherapy, providing a potential therapeutic strategy for HCC patients.

CircFOXK2 promotes hepatocellular carcinoma progression and leads to a poor clinical prognosis via regulating the Warburg effect

BACKGROUND

The Warburg effect is well-established to be essential for tumor progression and accounts for the poor clinical outcomes of hepatocellular carcinoma (HCC) patients. An increasing body of literature suggests that circular RNAs (circRNAs) are important regulators for HCC. However, few circRNAs involved in the Warburg effect of HCC have hitherto been investigated. Herein, we aimed to explore the contribution of circFOXK2 to glucose metabolism reprogramming in HCC.

METHODS

In the present study, different primers were designed to identify 14 circRNAs originating from the FOXK2 gene, and their differential expression between HCC and adjacent liver tissues was screened. Ultimately, circFOXK2 (hsa_circ_0000817) was selected for further research. Next, the clinical significance of circFOXK2 was evaluated. We then assessed the pro-oncogenic activity of circFOXK2 and its impact on the Warburg effect in both HCC cell lines and animal xenografts. Finally, the molecular mechanisms of how circFOXK2 regulates the Warburg effect of HCC were explored.

RESULTS

CircFOXK2 was aberrantly upregulated in HCC tissues and positively correlated with poor clinical outcomes in patients that underwent radical hepatectomy. Silencing of circFOXK2 significantly suppressed HCC progression both in vitro and in vivo. Mechanistically, circFOXK2 upregulated the expression of protein FOXK2-142aa to promote LDHA phosphorylation and led to mitochondrial fission by regulating the miR-484/Fis1 pathway, ultimately activating the Warburg effect in HCC.

CONCLUSIONS

CircFOXK2 is a prognostic biomarker of HCC that promotes the Warburg effect by promoting the expression of proteins and miRNA sponges that lead to tumor progression. Overall, circFOXK2 has huge prospects as a potential therapeutic target for patients with HCC.