HDAC6 Suppresses Let-7i-5p to Elicit TSP1/CD47-Mediated Anti-Tumorigenesis and Phagocytosis of Hepatocellular Carcinoma

Potential targets and therapeutics for cancer stem cell-based therapy against drug resistance in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common digestive malignancyin the world, which is frequently diagnosed at late stage with a poor prognosis. For most patients with advanced HCC, the therapeutic options arelimiteddue to cancer occurrence of drug resistance. Hepatic cancer stem cells (CSCs) account for a small subset of tumor cells with the ability of self-renewal and differentiationin HCC. It is widely recognized that the presence of CSCs contributes to primary and acquired drug resistance. Therefore, hepatic CSCs-targeted therapy is considered as a promising strategy to overcome drug resistance and improve therapeutic outcome in HCC. In this article, we review drug resistance in HCC and provide a summary of potential targets for CSCs-based therapy. In addition, the development of CSCs-targeted therapeuticsagainst drug resistance in HCC is summarized in both preclinical and clinical trials. The in-depth understanding of CSCs-related drug resistance in HCC will favor optimization of the current therapeutic strategies and gain encouraging therapeutic outcomes.

THBS1 promotes angiogenesis and accelerates ESCC malignant progression by the HIF-1/VEGF signaling pathway

Previously, we demonstrated that the expression of THBS1 is increased in esophageal squamous cell carcinoma (ESCC) tissues and is correlated with lymph node metastasis and poor prognosis, indicating that THBS1 might be a candidate oncogene in ESCC. In this study, we future studied the specific role of THBS1 in ESCC and its molecular mechanism. Silencing THBS1 expression resulted in inhibition of cell migration and cell invasion of ESCC cells, the decrease of colony formation and proliferation. Tube formation of human umbilical vein endothelial cells (HUVECs) in vitro was decreased when cultured with conditioned medium from THBS1-silenced cells. The expression of CD31, a marker for blood vessel endothelial cells, was decreased in tumor tissues derived from THBS1-silenced tumors in vivo. Silencing THBS1 leaded the decreased of hypoxia-inducible factor-1α (HIF-1α), HIF-1β, and VEGFA protein. The expression of p-ERK and p-AKT were declined in HUVECs following incubation with conditioned medium from THBS1-silenced ESCC cells compared conditioned medium from control cells. Furthermore, the treatment with bevacizumab boosted the decrease of the p-ERK and p-AKT levels in HUVECs incubated with the conditioned medium from THBS1-silenced ESCC cells. THBS1 silencing combined with bevacizumab blocked VEGF, inhibited to the tube formation, colony formation and migration of HUVECs, which were superior to that of bevacizumab alone. We presumed that THBS1 can enhance HIF-1/VEGF signaling and subsequently induce angiogenesis by activating the AKT and ERK pathways in HUVECs, resulting in bevacizumab resistance. THBS1 would be a potential target in tumor antiangiogenesis therapies.

Serum microRNA Profiles and Pathways in Hepatitis B-Associated Hepatocellular Carcinoma: A South African Study

The incidence and mortality of hepatocellular carcinoma (HCC) in Sub-Saharan Africa is projected to increase sharply by 2040 against a backdrop of limited diagnostic and therapeutic options. Two large South African-based case control studies have developed a serum-based miRNome for Hepatitis B-associated hepatocellular carcinoma (HBV-HCC), as well as identifying their gene targets and pathways. Using a combination of RNA sequencing, differential analysis and filters including a unique molecular index count (UMI) ≥ 10 and log fold change (LFC) range > 2: <-0.5 (p < 0.05), 91 dysregulated miRNAs were characterized including 30 that were upregulated and 61 were downregulated. KEGG analysis, a literature review and other bioinformatic tools identified the targeted genes and HBV-HCC pathways of the top 10 most dysregulated miRNAs. The results, which are based on differentiating miRNA expression of cases versus controls, also develop a serum-based miRNA diagnostic panel that indicates 95.9% sensitivity, 91.0% specificity and a Youden Index of 0.869. In conclusion, the results develop a comprehensive African HBV-HCC miRNome that potentially can contribute to RNA-based diagnostic and therapeutic options.

Tumour-associated macrophages: versatile players in the tumour microenvironment

Tumour-Associated Macrophages (TAMs) are one of the pivotal components of the tumour microenvironment. Their roles in the cancer immunity are complicated, both pro-tumour and anti-cancer activities are reported, including not only angiogenesis, extracellular matrix remodeling, immunosuppression, drug resistance but also phagocytosis and tumour regression. Interestingly, TAMs are highly dynamic and versatile in solid tumours. They show anti-cancer or pro-tumour activities, and interplay between the tumour microenvironment and cancer stem cells and under specific conditions. In addition to the classic M1/M2 phenotypes, a number of novel dedifferentiation phenomena of TAMs are discovered due to the advanced single-cell technology, e.g., macrophage-myofibroblast transition (MMT) and macrophage-neuron transition (MNT). More importantly, emerging information demonstrated the potential of TAMs on cancer immunotherapy, suggesting by the therapeutic efficiency of the checkpoint inhibitors and chimeric antigen receptor engineered cells based on macrophages. Here, we summarized the latest discoveries of TAMs from basic and translational research and discussed their clinical relevance and therapeutic potential for solid cancers.

Dual mechanism of Let-7i in tumor progression

Let-7i regulates tumors primarily by binding to the 3' untranslated region (3' UTR) of mRNA, which indirectly regulates post-transcriptional gene expression. Let-7i also has an epigenetic function via modulating DNA methylation to directly regulate gene expression. Let-7i performs a dual role by inducing both the promotion and inhibition of various malignancies, depending on its target. The mechanism of Let-7i action involves cancer cell proliferation, migration, invasion, apoptosis, epithelial-mesenchymal transition, EV transmission, angiogenesis, autophagy, and drug resistance sensitization. Let-7i is closely related to cancer, and hence, is a potential biomarker for the diagnosis and prognosis of various cancers. Therapeutically, it can be used to promote an anti-cancer immune response by modifying exosomes, thus exerting a tumor-suppressive effect.

Involvement of Ataxin-3 (ATXN3) in the malignant progression of pancreatic cancer via deubiquitinating HDAC6

BACKGROUND

Pancreatic cancer is a common digestive system cancer and one of the most lethal malignancies worldwide. Ataxin-3 (ATXN3) protein is a deubiquitinating enzyme implicated in the occurrence of diverse human cancers. The potential role of ATXN3 in pancreatic cancer still remains unclear.

METHODS

ATXN3 was screened from differentially-upregulated genes of GSE71989, GSE27890 and GSE40098 datasets. The mRNA and protein levels of ATXN3 was evaluated in pancreatic cancer samples and cell lines. Through the gain- and loss-of-function experiments, the effects of ATXN3 on cell proliferation, migration and invasion were evaluated using cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) staining, wound healing and Transwell assays. Subsequently, the interaction between ATXN3 and HDAC6 was confirmed using double immunofluorescence staining, co-immunoprecipitation (co-IP) and proximity ligation assay (PLA). The underlying mechanism of ATXN3 was determined by knockdown of HDAC6 in ATXN3-upregulated pancreatic cancer cells. The function of ATXN3 in vivo was verified through xenograft assay.

RESULTS

High expression of ATXN3 was found in pancreatic cancer tissues. Increased ATXN3 expression dramatically promoted cell proliferation, migration, and invasion. The malignant phenotypes were suppressed in ATXN3-silenced pancreatic cancer cells. ATXN3 was proved to interact with HDAC6 and regulate its degradation through deubiquitination. Downregulation of HDAC6 inhibited ATXN3-induced development of pancreatic cancer cells through regulating the expression of PCNA, vimentin and E-cadherin. ATXN3 facilitated tumor growth of pancreatic cancer and increased HDAC6 expression in vivo.

CONCLUSIONS

This study confirmed that ATXN3 facilitated malignant phenotypes of pancreatic cancer via reducing the ubiquitination of HDAC6.

The prognosis and clinicopathological significance of histone deacetylase in hepatocellular carcinoma: a meta-analysis

The value of the different types of HDACs (histone deacetylases) for HCC (hepatocellular carcinoma) prognosis and clinicopathological features is still controversial. Here, we performed a meta-analysis to investigate the possible role of different types of HDACs in HCC. Until October 28, 2021, we have searched the Embase, Cochrane, PubMed, Scopus, Web of Science (WOS), SinoMed, Chinese China National Knowledge Infrastructure (CNKI), Chinese WanFang, and Chinese Weipu databases and evaluated eligible studies according to the criteria. We used hazard ratio (HR) and 95% confidence interval (95% CI) to evaluate the prognostic effects of different types of HDACs on overall survival (OS), disease-free survival (DFS)/recurrence-free survival (RFS) and used odds ratio (OR) and corresponding 95% CI to evaluate the significance of HDACs on clinicopathological characteristics. The I2 statistic and chi-square-based Q test were used to assess the heterogeneity. When the heterogeneity was significant, we conducted a subgroup analysis. In addition, Egger's test and funnel chart were used to assess publication bias. The high expression of class I HDACs was associated with poorer OS, DFS/RFS and differentiation, intrahepatic metastasis, tumor-node-metastasis (TNM), tumor number, tumor size, vascular invasion, and other poor clinicopathological characteristics. The high expression of class II HDACs was related to poor OS and multiple and larger tumors. After subgroup analysis, class II HDACs may also be related to worse TNM and Edmondson grading. The high expression of class III HDACs was related to poor OS, hepatitis B, liver cirrhosis, serum AFP, and vascular invasion. But it was more common in women and was related to single, smaller tumors. Type I, II, and III HDACs are associated with poor prognosis, and there are also correlations with some clinicopathological features, suggesting that different types of HDACs may be valuable biomarkers for HCC.

Immune System and Hepatocellular Carcinoma (HCC): New Insights into HCC Progression

According to the WHO's recently released worldwide cancer data for 2020, liver cancer ranks sixth in morbidity and third in mortality among all malignancies. Hepatocellular carcinoma (HCC), the most common kind of liver cancer, accounts approximately for 80% of all primary liver malignancies and is one of the leading causes of death globally. The intractable tumor microenvironment plays an important role in the development and progression of HCC and is one of three major unresolved issues in clinical practice (cancer recurrence, fatal metastasis, and the refractory tumor microenvironment). Despite significant advances, improved molecular and cellular characterization of the tumor microenvironment is still required since it plays an important role in the genesis and progression of HCC. The purpose of this review is to present an overview of the HCC immune microenvironment, distinct cellular constituents, current therapies, and potential immunotherapy methods.

Crosstalk between Noncoding RNAs and the Epigenetics Machinery in Pediatric Tumors and Their Microenvironment

According to the World Health Organization, every year, an estimated 400,000+ new cancer cases affect children under the age of 20 worldwide. Unlike adult cancers, pediatric cancers develop very early in life due to alterations in signaling pathways that regulate embryonic development, and environmental factors do not contribute much to cancer development. The highly organized complex microenvironment controlled by synchronized gene expression patterns plays an essential role in the embryonic stages of development. Dysregulated development can lead to tumor initiation and growth. The low mutational burden in pediatric tumors suggests the predominant role of epigenetic changes in driving the cancer phenotype. However, one more upstream layer of regulation driven by ncRNAs regulates gene expression and signaling pathways involved in the development. Deregulation of ncRNAs can alter the epigenetic machinery of a cell, affecting the transcription and translation profiles of gene regulatory networks required for cellular proliferation and differentiation during embryonic development. Therefore, it is essential to understand the role of ncRNAs in pediatric tumor development to accelerate translational research to discover new treatments for childhood cancers. This review focuses on the role of ncRNA in regulating the epigenetics of pediatric tumors and their tumor microenvironment, the impact of their deregulation on driving pediatric tumor progress, and their potential as effective therapeutic targets.

Extracellular vesicle RNA signaling in the liver tumor microenvironment

The tumor microenvironment (TME) in liver cancers such as hepatocellular cancer (HCC) consists of a complex milieu of liver tissue-resident cells, infiltrated immune cells, and secreted factors that collectively serve to promote tumor growth and progression. Intercellular crosstalk contributes to tissue homeostasis, and perturbations during injury, inflammation and tumorigenesis that are important for tumor progression. Extracellular vesicle (EV)-mediated transfer of a payload of RNA molecules that serve as an intercellular signaling is an important contributor to tissue homeostasis within the TME. Several types of RNA have been implicated in EV-mediated signaling. Biological processes that can be modulated by EV RNA signaling within the liver include tumor growth, invasion, metastasis, angiogenesis, and modulation of the immune cell activities. This mini-review describes the liver TME, and the biological effects of EV RNA-mediated signaling within the liver to highlight the role of EV RNA in intercellular communication.

lnc001776 Affects CPB2 Toxin-Induced Excessive Injury of Porcine Intestinal Epithelial Cells via Activating JNK/NF-kB Pathway through ssc-let-7i-5p/IL-6 Axis

Piglet diarrhea caused by Clostridium perfringens (C. perfringens) type C (CpC) seriously endangers the development of the pig production industry. C. perfringens beta2 (CPB2) toxin is a virulent toxin produced by CpC. Long non-coding RNAs (lncRNAs) are key regulators in the immune inflammatory response to bacterial infection. Nevertheless, the functional mechanism of lncRNAs in bacterial piglet diarrhea is unclear. Herein, a novel lncRNA lnc001776 expression was confirmed to be substantially elevated in the ileum tissue of CpC-infected diarrhea piglets and in CPB2 toxin-treated porcine small intestinal epithelial cells (IPEC-J2). lnc001776 knockdown restrained CPB2 toxin-induced apoptosis, inflammatory injury, barrier dysfunction and activation of JNK/NF-kB pathway in IPEC-J2 cells. Additionally, ssc-let-7i-5p was identified as sponge for lnc001776. Overexpression of ssc-let-7i-5p repressed CPB2-induced injury in IPEC-J2 cells. Interleukin 6 (IL-6), a target gene of ssc-let-7i-5p, was enhanced in CPB2 toxin-treated IPEC-J2 cells. Rescue experiments demonstrated that a ssc-let-7i-5p mimic reversed the effect of lnc001776 overexpression on CPB2 toxin-induced IPEC-J2 cell injury and JNK/NF-kB pathway, whereas IL-6 overexpression partially restored the impact of lnc001776. Overall, lnc001776 overexpression exacerbated CPB2 toxin-induced IPEC-J2 cell damage by sponging ssc-let-7i-5p to regulate IL-6 to activate JNK/NF-kB pathway, indicating that lnc001776 could be a key target for piglet resistance to CpC-induced diarrhea.

HELLPAR/RRM2 axis related to HMMR as novel prognostic biomarker in gliomas

BACKGROUND

Gliomas are the most frequent type of central nervous system tumor, accounting for more than 70% of all malignant CNS tumors. Recent research suggests that the hyaluronan-mediated motility receptor (HMMR) could be a novel potential tumor prognostic marker. Furthermore, mounting data has highlighted the important role of ceRNA regulatory networks in a variety of human malignancies. The complexity and behavioural characteristics of HMMR and the ceRNA network in gliomas, on the other hand, remained unknown.

METHODS

Transcriptomic expression data were collected from TCGA, GTEx, GEO, and CGGA database.The relationship between clinical variables and HMMR was analyzed with the univariate and multivariate Cox regression. Kaplan-Meier method was used to assess OS. TCGA data are analyzed and processed, and the correlation results obtained were used to perform GO, GSEA, and ssGSEA. Potentially interacting miRNAs and lncRNAs were predicted by miRWalk and StarBase.

RESULTS

HMMR was substantially expressed in gliomas tissues compared to normal tissues. Multivariate analysis revealed that high HMMR expression was an independent predictive predictor of OS in TCGA and CGGA. Functional enrichment analysis found that HMMR expression was associated with nuclear division and cell cycle. Base on ssGSEA analysis, The levels of HMMR expression in various types of immune cells differed significantly. Bioinformatics investigation revealed the HEELPAR-hsa-let-7i-5p-RRM2 ceRNA network, which was linked to gliomas prognosis. And through multiple analysis, the good predictive performance of HELLPAR/RRM2 axis for gliomas patients was confirmed.

CONCLUSION

This study provides multi-layered and multifaceted evidence for the importance of HMMR and establishes a HMMR-related ceRNA (HEELPAR-hsa-let-7i-5p-RRM2) overexpressed network related to the prognosis of gliomas.

Transcriptome analysis preliminary reveals the immune response mechanism of golden cuttlefish (Sepia esculenta) larvae exposed to Cd

As a well-known marine metal element, Cd can significantly affect bivalve mollusk life processes such as growth and development. However, the effects of Cd on the molecular mechanisms of the economically important cephalopod species Sepia esculenta remain unclear. In this study, S. esculenta larval immunity exposed to Cd is explored based on RNA-Seq. The analyses of GO, KEGG, and protein-protein interaction (PPI) network of 1,471 differentially expressed genes (DEGs) reveal that multiple immune processes are affected by exposure such as inflammatory reaction and cell adhesion. Comprehensive analyses of KEGG signaling pathways and the PPI network are first used to explore Cd-exposed S. esculenta larval immunity, revealing the presence of 16 immune-related key and hub genes involved in exposure response. Results of gene and pathway functional analyses increase our understanding of Cd-exposed S. esculenta larval immunity and improve our overall understanding of mollusk immune functions.

Inferring causal gene regulatory network via GreyNet: From dynamic grey association to causation

Gene regulatory network (GRN) provides abundant information on gene interactions, which contributes to demonstrating pathology, predicting clinical outcomes, and identifying drug targets. Existing high-throughput experiments provide rich time-series gene expression data to reconstruct the GRN to further gain insights into the mechanism of organisms responding to external stimuli. Numerous machine-learning methods have been proposed to infer gene regulatory networks. Nevertheless, machine learning, especially deep learning, is generally a “black box,” which lacks interpretability. The causality has not been well recognized in GRN inference procedures. In this article, we introduce grey theory integrated with the adaptive sliding window technique to flexibly capture instant gene–gene interactions in the uncertain regulatory system. Then, we incorporate generalized multivariate Granger causality regression methods to transform the dynamic grey association into causation to generate directional regulatory links. We evaluate our model on the DREAM4 in silico benchmark dataset and real-world hepatocellular carcinoma (HCC) time-series data. We achieved competitive results on the DREAM4 compared with other state-of-the-art algorithms and gained meaningful GRN structure on HCC data respectively.

Tumor-associated macrophages in liver cancer: From mechanisms to therapy

Multidimensional analyses have demonstrated the presence of a unique tumor microenvironment (TME) in liver cancer. Tumor-associated macrophages (TAMs) are among the most abundant immune cells infiltrating the TME and are present at all stages of liver cancer progression, and targeting TAMs has become one of the most favored immunotherapy strategies. In addition, macrophages and liver cancer cells have distinct origins. At the early stage of liver cancer, macrophages can provide a niche for the maintenance of liver cancer stem cells. In contrast, cancer stem cells (CSCs) or poorly differentiated tumor cells are key factors modulating macrophage activation. In the present review, we first propose the origin connection between precursor macrophages and liver cancer cells. Macrophages undergo dynamic phenotypic transition during carcinogenesis. In this course of such transition, it is critical to determine the appropriate timing for therapy and block specific markers to suppress pro-tumoral TAMs. The present review provides a more detailed discussion of transition trends of such surface markers than previous reviews. Complex crosstalk occurs between TAMs and liver cancer cells. TAMs play indispensable roles in tumor progression, angiogenesis, and autophagy due to their heterogeneity and robust plasticity. In addition, macrophages in the TME interact with other immune cells by directing cell-to-cell contact or secreting various effector molecules. Similarly, tumor cells combined with other immune cells can drive macrophage recruitment and polarization. Despite the latest achievements and the advancements in treatment strategies following TAMs studies, comprehensive discussions on the communication between macrophages and cancer cells or immune cells in liver cancer are currently lacking. In this review, we discussed the interactions between TAMs and liver cancer cells (from cell origin to maturation), the latest therapeutic strategies (including chimeric antigen receptor macrophages), and critical clinical trials for hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA) to provide a rationale for further clinical investigation of TAMs as a potential target for treating patients with liver cancer.

Intercellular communication in the tumour microecosystem: Mediators and therapeutic approaches for hepatocellular carcinoma

Hepatocellular carcinoma (HCC), one of the most common tumours worldwide, is one of the main causes of mortality in cancer patients. There are still numerous problems hindering its early diagnosis, which lead to late patients receiving treatment, and these problems need to be solved urgently. The tumour microecosystem is a complex network system comprising seven parts: the hypoxia niche, immune microenvironment, metabolic microenvironment, acidic niche, innervated niche, mechanical microenvironment, and microbial microenvironment. Intercellular communication is divided into direct contact and indirect communication. Direct contact communication includes gap junctions, tunneling nanotubes, and receptor-ligand interactions, whereas indirect communication includes exosomes, apoptotic vesicles, and soluble factors. Mechanical communication and cytoplasmic exchange are further means of intercellular communication. Intercellular communication mediates the crosstalk between the tumour microecosystem and the host as well as that between cells and cell-free components in the tumour microecosystem, causing changes in the tumour hallmarks of the HCC microecosystem such as changes in tumour proliferation, invasion, apoptosis, angiogenesis, metastasis, inflammatory response, gene mutation, immune escape, metabolic reprogramming, and therapeutic resistance. Here, we review the role of the above-mentioned intercellular communication in the HCC microecosystem and discuss the advantages of targeted intercellular communication in the clinical diagnosis and treatment of HCC. Finally, the current problems and prospects are discussed.

Noncoding RNA-mediated macrophage and cancer cell crosstalk in hepatocellular carcinoma

The tumor microenvironment (TME) is a well-recognized system that plays an essential role in tumor initiation, development, and progression. Intense intercellular communication between tumor cells and other cells (especially macrophages) occurs in the TME and is mediated by cell-to-cell contact and/or soluble messengers. Emerging evidence indicates that noncoding RNAs (ncRNAs) are critical regulators of the relationship between cells within the TME. In this review, we provide an update on the regulation of ncRNAs (primarily micro RNAs [miRNAs], long ncRNAs [lncRNAs], and circular RNAs [circRNAs]) in the crosstalk between macrophages and tumor cells in hepatocellular carcinoma (HCC). These ncRNAs are derived from macrophages or tumor cells and act as oncogenes or tumor suppressors, contributing to tumor progression not only by regulating the physiological and pathological processes of tumor cells but also by controlling macrophage infiltration, activation, polarization, and function. Herein, we also explore the options available for clinical therapeutic strategies targeting crosstalk-related ncRNAs to treat HCC. A better understanding of the relationship between macrophages and tumor cells mediated by ncRNAs will uncover new diagnostic biomarkers and pharmacological targets in cancer.

HDAC6-specific inhibitor alleviates hashimoto's thyroiditis through inhibition of Th17 cell differentiation

OBJECTIVE

Hashimoto's thyroiditis (HT) is one of the commonest autoimmune disorders. This study was performed to investigate the potential effect of histone deacetylase 6-specific inhibitor (HDAC6i) on Th17 cell differentiation in animal model and the underlying mechanism.

METHODS

Experimental autoimmune thyroiditis (EAT) mouse model was established by subcutaneously immunization of porcine thyroglobulin (pTg) and adjuvant, and the HDACi Tubastatin A (TSA) or HDAC6i (ACY-1215) was intraperitoneally injected into mice in the following. The histological examination and immune analysis in EAT mice were carried out. Next, the CD4+ T cells were isolated from peripheral blood mononuclear cells (PBMCs) of EAT mice followed by Th17 cell differentiation assay. The associated factor levels, and the protein interaction between HDAC6 and PKM2 were examined. Subsequently, the effect of STAT3 activation on Th17 cell differentiation was explored.

RESULTS

ACY-1215 or TSA treatment reduced lymphocytic infiltration and alleviated thyroid tissue injury in EAT mice. Correspondingly, either ACY-1215 or TSA treatment reduced the levels of anti-thyroglobulin (Tg), anti-thyroid peroxidase (TPO), IL-17A, and IFN-γ in the serum, decreased Th17 cell differentiation, but enhanced TGF-β level and promoted Treg cell differentiation. In vitro, after induction of Th17 cell differentiation from CD4+ T cells, HDAC6 activity and Th17 cell differentiation were significantly decreased when treated with ACY-1215 or TSA. HDAC6 could interact with PKM2, and HDAC6 overexpression promoted the phosphorylation of STAT3 and PKM2 nuclear translocation. Furthermore, the STAT3 activator treatment reversed the effects of ACY-1215 or TSA treatment.

CONCLUSION

HDAC6i suppresses Th17 cell differentiation and attenuates HT via PKM2/STAT3 axis.

Opposing roles of HDAC6 in liver regeneration and hepatocarcinogenesis

Histone deacetylase 6 (HDAC6), a deacetylase of p53, has emerged as a privileged inhibitory target for cancer therapy because of its deacetylating activity for p53 at K120 and K373/382. However, intricate roles of HDAC6 in hepatocellular carcinogenesis have been suggested by recent evidence, namely that HDAC6 ablation suppresses innate immunity, which plays critical roles in tumor immunosurveillance and antitumor immune responses. Therefore, it is valuable to determine whether HDAC6 ablation inhibits hepatocellular carcinogenesis using in vivo animal models. Here, we firstly showed that HDAC6 ablation increased K320 acetylation of p53, known as pro‐survival acetylation, in all tested animal models but did not always increase K120 and K373/382 acetylation of p53, known as pro‐apoptotic acetylation. HDAC6 ablation induced cellular senescence in primary MEFs and inhibited cell proliferation in HepG2 cells and liver regeneration after two‐thirds partial hepatectomy. However, the genetic ablation of HDAC6 did not inhibit hepatocarcinogenesis, but instead slightly enhanced it in two independent mouse models (DEN + HFD and DEN + TAA). Notably, HDAC6 ablation significantly promoted hepatocarcinogenesis in a multiple DEN treatment hepatocellular carcinoma (HCC) mouse model, mimicking chronic DNA damage in the liver, which correlated with hyperacetylation at K320 of p53 and a decrease in inflammatory cytokines and chemokines. Our data from three independent in vivo animal HCC models emphasize the importance of the complex roles of HDAC6 ablation in hepatocellular carcinogenesis, highlighting its immunosuppressive effects.

We provide the first evidence that HDAC6 is a p53 deacetylase at K320, which is especially important for cancer cell survival in chronic DNA damage conditions. Contrary to the general assumption that HDAC6 inhibition leads to hyperacetylation of p53 at K120, resulting in tumor suppression, our findings from in vivo animal HCC modelsemphasize the importance of the opposing roles of HDAC6 ablation in hepatocellular carcinogenesis by highlighting the K320 acetylation of p53 and immunosuppressive effects.

METTL14 promotes prostate tumorigenesis by inhibiting THBS1 via an m6A-YTHDF2-dependent mechanism

N6-methyladenine (m6A) is the most predominant RNA modification, which has been shown to be related to many types of cancers. However, understanding of its role in prostate cancer (PCa) is largely unknown. Here, we report an upregulation of METTL14 that was correlated with poor prognosis in PCa patients. Functionally, knocking down METTL14 inhibited tumor proliferation both in vitro and in vivo. Mechanically, RNA-seq and MeRIP-seq analyses identified THBS1 as the downstream target of METTL14 in PCa. METTL14 downregulated THBS1 expression in an m6A-dependent manner, which resulted in the recruitment of YTHDF2 to recognize and degrade Thrombospondin 1 (THBS1) mRNA. Thus, our findings revealed that METTL14 acted as an oncogene by inhibiting THBS1 expression via an m6A-YTHDF2-dependent manner. METTL14 could be a potential prognosis marker and a therapeutic target.

The Prognostic Value of Lysine Acetylation Regulators in Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is a tumor with high morbidity and mortality worldwide. lysine acetylation regulators (LARs) dynamically regulate Lysine acetylation modification which plays an important regulatory role in cancer. Therefore, we aimed to explore the potential clinical prognostic value of LARs in HCC.

Methods: Differentially expressed LARs in normal liver and HCC tissues were obtained from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) datasets. To identify genes with prognostic value and establish the risk characteristics of LARs, consensus clustering was employed. We used univariate Cox regression survival analysis and LASSO Cox regression based on LARs to determine the independent prognostic signature of HCC. CIBERSORT and Gene Set Enrichment Analysis (GSEA) were used to estimate immune infiltration and functional enrichment analysis respectively. The expression of LAR was detected by Real-time quantitative polymerase chain reaction (RT-qPCR). statistical analyses were conducted using SPSS and R software.

Results: In this study, the 33 LARs expression data and corresponding clinical information of HCC were obtained using TCGA and ICGC datasets. We found majority of the LARs were differentially expressed. Consensus cluster analysis was carried out based on the TCGA cohort, and three HCC subtypes (cluster 1, 2, and 3) were obtained. The LA3 subgroup had the worst clinical outcomes. Nine key LARs were identified to affect prognosis. The results showed that LARs signature has a strong independent prognostic value in HCC patients, whether in the training datasets or in the testing datasets. GSEA results showed that various tumor-related processes and pathways were abundant in the high-risk groups. RT-qPCR results showed that HAT1, HDAC1, HDAC2, HDAC4, and HDAC11 were highly expressed in HCC cells.

Conclusion: Our results suggest that LARs play critical roles in HCC and are helpful for individual prognosis monitoring and clinical decision-making of HCC.

Update on genetics and epigenetics in metabolic associated fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is becoming the most frequent chronic liver disease worldwide. Metabolic (dysfunction) associated fatty liver disease (MAFLD) is suggested to replace the nomenclature of NAFLD. For individuals with metabolic dysfunction, multiple NAFLD-related factors also contribute to the development and progression of MAFLD including genetics and epigenetics. The application of genome-wide association study (GWAS) and exome-wide association study (EWAS) uncovers single-nucleotide polymorphisms (SNPs) in MAFLD. In addition to the classic SNPs in PNPLA3, TM6SF2, and GCKR, some new SNPs have been found recently to contribute to the pathogenesis of liver steatosis. Epigenetic factors involving DNA methylation, histone modifications, non-coding RNAs regulations, and RNA methylation also play a critical role in MAFLD. DNA methylation is the most reported epigenetic modification. Developing a non-invasion biomarker to distinguish metabolic steatohepatitis (MASH) or liver fibrosis is ongoing. In this review, we summarized and discussed the latest progress in genetic and epigenetic factors of NAFLD/MAFLD, in order to provide potential clues for MAFLD treatment.

Fine Particulate Matter Induces Childhood Asthma Attacks via Extracellular Vesicle-Packaged Let-7i-5p-Mediated Modulation of the MAPK Signaling Pathway

Fine particulate matter less than 2.5 µm in diameter (PM_2.5 ) is a major risk factor for acute asthma attacks in children. However, the biological mechanism underlying this association remains unclear. In the present study, PM_2.5 -treated HBE cells-secreted extracellular vesicles (PM_2.5 -EVs) caused cytotoxicity in "horizontal" HBE cells and increased the contractility of "longitudinal" sensitive human bronchial smooth muscle cells (HBSMCs). RNA sequencing showed that let-7i-5p is significantly overexpressed in PM_2.5 -EVs and asthmatic plasma; additionally, its level is correlated with PM_2.5 exposure in children with asthma. The combination of EV-packaged let-7i-5p and the traditional clinical biomarker IgE exhibits the best diagnostic performance (area under the curve [AUC] = 0.855, 95% CI = 0.786-0.923). Mechanistically, let-7i-5p is packaged into PM_2.5 -EVs by interacting with ELAVL1 and internalized by both "horizontal" recipient HBE cells and "longitudinal" recipient-sensitive HBSMCs, with subsequent activation of the MAPK signaling pathway via suppression of its target DUSP1. Furthermore, an injection of EV-packaged let-7i-5p into PM_2.5 -treated juvenile mice aggravated asthma symptoms. This comprehensive study deciphered the remodeling of the extracellular environment mediated by the secretion of let-7i-5p-enriched EVs during PM_2.5 -induced asthma attacks and identified plasma EV-packaged let-7i-5p as a novel predictor of childhood asthma.

Cancer stem cells in hepatocellular carcinoma - from origin to clinical implications

Hepatocellular carcinoma (HCC) is an aggressive disease with a poor clinical outcome. The cancer stem cell (CSC) model states that tumour growth is powered by a subset of tumour stem cells within cancers. This model explains several clinical observations in HCC (as well as in other cancers), including the almost inevitable recurrence of tumours after initial successful chemotherapy and/or radiotherapy, as well as the phenomena of tumour dormancy and treatment resistance. The past two decades have seen a marked increase in research on the identification and characterization of liver CSCs, which has encouraged the design of novel diagnostic and treatment strategies for HCC. These studies revealed novel aspects of liver CSCs, including their heterogeneity and unique immunobiology, which are suggestive of opportunities for new research directions and potential therapies. In this Review, we summarize the present knowledge of liver CSC markers and the regulators of stemness in HCC. We also comprehensively describe developments in the liver CSC field with emphasis on experiments utilizing single-cell transcriptomics to understand liver CSC heterogeneity, lineage-tracing and cell-ablation studies of liver CSCs, and the influence of the CSC niche and tumour microenvironment on liver cancer stemness, including interactions between CSCs and the immune system. We also discuss the potential application of liver CSC-based therapies for treatment of HCC.

Identification of an Autophagy-Related Gene Signature for the Prediction of Prognosis in Early-Stage Colorectal Cancer

Purpose: A certain number of early-stage colorectal cancer (CRC) patients suffer tumor recurrence after initial curative resection. In this context, an effective prognostic biomarker model is constantly in need. Autophagy exhibits a dual role in tumorigenesis. Our study aims to develop an autophagy-related gene (ATG) signature-based on high-throughput data analysis for disease-free survival (DFS) prognosis of patients with stage I/II CRC.

Methods: Gene expression profiles and clinical information of CRC patients extracted from four public datasets were distributed to discovery and training cohort (GSE39582), validation cohort (TCGA CRC, n = 624), and meta-validation cohort (GSE37892 and GSE14333, n = 420). Autophagy genes significantly associated with prognosis were identified.

Results: Among 655 autophagy-related genes, a 10-gene ATG signature, which was significantly associated with DFS in the training cohort (HR, 2.76[1.56–4.82]; p = 2.06 × 10–4), was constructed. The ATG signature, stratifying patients into high and low autophagy risk groups, was validated in the validation (HR, 2.29[1.15–4.55]; p = 1.5 × 10–2) and meta-validation cohorts (HR, 2.5[1.03–6.06]; p = 3.63 × 10–2) and proved to be prognostic in a multivariate analysis. Functional analysis revealed enrichment of several immune/inflammatory pathways in the high autophagy risk group, where increased infiltration of T regulatory cells (Tregs) and decreased infiltration of M1 macrophages were observed.

Conclusion: Our study established a prognostic ATG signature that effectively predicted DFS for early-stage CRC patients. Meanwhile, the study also revealed the possible relationship among autophagy process, immune/inflammatory response, and tumorigenesis.

Upregulation of OATP1A2 in human oesophageal squamous cell carcinoma cells via the HDAC6-GCN5/PCAF-H3K9Ac axis

1. OATP1A2 overexpressed is involved in chemotherapy disposition, indicating its role in tumour development and progression.2. CHIP and siRNA were used to evaluate the status of histone acetylation at the OATP1A2 promoter. The role of OATP1A2 was analysed by gene-set enrichment and overall survival analysis.3. OATP1A2 expression levels in ESCC was notably higher than that in para-cancer tissues. OATP1A2 high expression are associated with bile salt metabolic pathway and poor prognosis. Furthermore, HDAC6 was repressed in ESCC, increasing the levels of H3K9Ac catalysed by GCN5/PCAF at the OATP1A2 promoter region.4. Abnormal histone hyperacetylation mediated by the HDAC6-GCN5/PCAF-H3K9Ac axis resulted in increased OATP1A2 expression in ESCC, and OATP1A2 may serve as a promising prognostic biomarker for ESCC.5. In conclusion, this study indicated that suppression of OATP1A2 would inhibit the progression and prognosis in ESCC.

HDAC6 Negatively Regulates miR-155-5p Expression to Elicit Proliferation by Targeting RHEB in Microvascular Endothelial Cells under Mechanical Unloading

Mechanical unloading contributes to significant cardiovascular deconditioning. Endothelial dysfunction in the sites of microcirculation may be one of the causes of the cardiovascular degeneration induced by unloading, but the detailed mechanism is still unclear. Here, we first demonstrated that mechanical unloading inhibited brain microvascular endothelial cell proliferation and downregulated histone deacetylase 6 (HDAC6) expression. Furthermore, HDAC6 promoted microvascular endothelial cell proliferation and attenuated the inhibition of proliferation caused by clinorotation unloading. To comprehensively identify microRNAs (miRNAs) that are regulated by HDAC6, we analyzed differential miRNA expression in microvascular endothelial cells after transfection with HDAC6 siRNA and selected miR-155-5p, which was the miRNA with the most significantly increased expression. The ectopic expression of miR-155-5p inhibited microvascular endothelial cell proliferation and directly downregulated Ras homolog enriched in brain (RHEB) expression. Moreover, RHEB expression was downregulated under mechanical unloading and was essential for the miR-155-5p-mediated promotion of microvascular endothelial cell proliferation. Taken together, these results are the first to elucidate the role of HDAC6 in unloading-induced cell growth inhibition through the miR-155-5p/RHEB axis, suggesting that the HDAC6/miR-155-5p/RHEB pathway is a specific target for the preventative treatment of cardiovascular deconditioning.

Construction of a microRNA-mRNA Regulatory Network in De Novo Cytogenetically Normal Acute Myeloid Leukemia Patients

Background: The association between dysregulated microRNAs (miRNAs) and acute myeloid leukemia (AML) is well known. However, our understanding of the regulatory role of miRNAs in the cytogenetically normal AML (CN-AML) subtype pathway is still poor. The current study integrated miRNA and mRNA profiles to explore novel miRNA-mRNA interactions that affect the regulatory patterns of de novo CN-AML. Methods: We utilized a multiplexed nanoString nCounter platform to profile both miRNAs and mRNAs using similar sets of patient samples (n = 24). Correlations were assessed, and an miRNA-mRNA network was constructed. The underlying biological functions of the mRNAs were predicted by gene enrichment. Finally, the interacting pairs were assessed using TargetScan and microT-CDS. We identified 637 significant negative correlations (false discovery rate <0.05). Results: Network analysis revealed a cluster of 12 miRNAs representing the majority of mRNA targets. Within the cluster, five miRNAs (miR-495-3p, miR-185-5p, let-7i-5p, miR-409-3p, and miR-127-3p) were posited to play a pivotal role in the regulation of CN-AML, as they are associated with the negative regulation of myeloid leukocyte differentiation, negative regulation of myeloid cell differentiation, and positive regulation of hematopoiesis. Conclusion: Three novel interactions in CN-AML were predicted as let-7i-5p:HOXA9, miR-495-3p:PIK3R1, and miR-495-3p:CDK6 may be responsible for regulating myeloid cell differentiation in CN-AML.

Circ_FBLN1 promotes the proliferation and osteogenic differentiation of human bone marrow-derived mesenchymal stem cells by regulating let-7i-5p/FZD4 axis and Wnt/β-catenin pathway

BACKGROUND

Recently, more and more circular RNAs (circRNAs) have been identified in osteogenesis. In this study, we aimed to explore the effect of circ_FBLN1 on the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs).

METHODS

The protein levels of osteogenesis-related genes, let-7i-5p, frizzled class receptor 4 (FZD4), Ki67, Wnt6 and β-catenin were measured by western blot assay. The levels of circ_FBLN1, FBLN1 mRNA and FZD4 mRNA were determined by quantitative real-time polymerase chain reaction (qRT-PCR) assay. The feature of circ_FBLN1 was investigated by RNase R and Actinomycin D assays. Cell proliferation ability was evaluated by colony formation assay and 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The targeting relationship between let-7i-5p and circ_FBLN1 or FZD4 was verified by dual-luciferase reporter assay.

RESULTS

Circ_FBLN1 level was enhanced during the osteogenic differentiation of hBMSCs. Silencing of circ_FBLN1 repressed cell proliferation and osteogenic differentiation in hBMSCs. For mechanism analysis, circ_FBLN1 was found to act as a sponge for let-7i-5p and FZD4 served as a direct target gene of let-7i-5p. Let-7i-5p was downregulated during the osteogenic differentiation of hBMSCs and let-7i-5p inhibition restored the effects of circ_FBLN1 knockdown on the proliferation and osteogenesis of hBMSCs. Moreover, let-7i-5p overexpression suppressed cell proliferation and osteogenesis in hBMSCs through targeting FZD4. In addition, circ_FBLN1 knockdown reduced the levels of Wnt6 and β-catenin in hBMSCs, indicating the inactivation of Wnt/β-catenin pathway.

CONCLUSION

Knockdown of circ_FBLN1 inhibited the proliferation and osteogenesis of hBMSCs by regulating let-7i-5p/FZD4 axis and repressing Wnt/β-catenin pathway.

Exosomal non-coding RNAs in Hepatobiliary Cancer: A Rising Star

Hepatobiliary cancers are a heterogeneous group of malignancies with a dismal prognosis. Despite intensive research efforts focused on these tumors, methods for early diagnosis and effective targeted therapies are still lacking. Exosomes, released by most cells, exist in all kinds of body fluids and play an important role in cell-to-cell communication. They are small membranous vesicles containing biological molecules, such as noncoding RNAs (ncRNAs), which are not translated into proteins, but they exert effects on the regulation of gene transcription and translation. There is growing evidence for the essential roles of ncRNAs in exosomes in both physiological and pathological conditions of hepatobiliary cancers. They have been identified as sensitive diagnostic biomarkers as well as potential therapeutic targets. The present review discusses recent findings in the crosstalk between hepatobiliary cancers cells and the surrounding cells of the microenvironment and discuss their potential clinical usage.

The regulation of CD47-SIRPα signaling axis by microRNAs in combination with conventional cytotoxic drugs together with the help of nano-delivery: a choice for therapy?

CD47, a member of the immunoglobulin superfamily, is an important "Don't Eat-Me" signal in phagocytosis process [clearance of apoptotic cells] as well as a regulator of the adaptive immune response. The lower level of CD47 on the cell surface leads to the clearance of apoptotic cells. Dysregulation of CD47 plays a critical role in the development of disorders, particularly cancers. In cancers, recognition of CD47 overexpression on the surface of cancer cells by its receptor, SIRPα on the phagocytic cells, inhibits phagocytosis of cancer cells. Thus, blocking of CD47-SIRPα signaling axis might be as a promising therapeutic target, which promotes phagocytosis of cancer cells, antigen-presenting cell function as well as adaptive T cell-mediated anti-cancer immunity. In this respect, it has been reported that CD47 expression can be regulated by microRNAs (miRNAs). MiRNAs can regulate phagocytosis of macrophages apoptotic process, drug resistance, relapse of disease, radio-sensitivity, and suppress cell proliferation, migration, and invasion through post-transcriptional regulation of CD47-SIRPα signaling axis. Moreover, the regulation of CD47 expression by miRNAs and combination with conventional cytotoxic drugs together with the help of nano-delivery represent a valuable opportunity for effective cancer treatment. In this review, we review studies that evaluate the role of miRNAs in the regulation of CD47-SIRPα in disorders to achieve a novel preventive, diagnostic, and therapeutic strategy.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Also, kindly confirm the details in the metadata are correct. Confirmed.Journal standard instruction requires a structured abstract; however, none was provided. Please supply an Abstract with subsections..Not confirmed. This is a review article. According to submission guidelines: "The abstract should be presented divided into subheadings (unless it is a mini or full review article)". Kindly check and confirm whether the corresponding authors and mail ID are correctly identified. Confirmed.

SMARCA4 oncogenic potential via IRAK1 enhancer to activate Gankyrin and AKR1B10 in liver cancer

SWItch/Sucrose Non-Fermentable (SWI/SNF) is a multiprotein complex essential for the regulation of eukaryotic gene expression. SWI/SNF complex genes are genetically altered in over 20% of human malignancies, but the aberrant regulation of the SWI/SNF subunit genes and subsequent dysfunction caused by abnormal expression of subunit gene in cancer, remain poorly understood. Among the SWI/SNF subunit genes, SMARCA4, SMARCC1, and SMARCA2 were identified to be overexpressed in human hepatocellular carcinoma (HCC). Modulation of SMARCA4, SMARCC1, and SMARCA2 inhibited in vitro tumorigenesis of HCC cells. However, SMARCA4-targeting elicited remarkable inhibition in an in vivo Ras-transgenic mouse HCC model (Ras-Tg), and high expression levels of SMARCA4 significantly associated with poor prognosis in HCC patients. Furthermore, most HCC patients (72-86%) showed SMARCA4 overexpression compared to healthy controls. To identify SMARCA4-specific active enhancers, mapping, and analysis of chromatin state in liver cancer cells were performed. Integrative analysis of SMARCA4-regulated genes and active chromatin enhancers suggested 37 genes that are strongly activated by SMARCA4 in HCC. Through chromatin immunoprecipitation-qPCR and luciferase assays, we demonstrated that SMARCA4 activates Interleukin-1 receptor-associated kinase 1 (IRAK1) expression through IRAK1 active enhancer in HCC. We then showed that transcriptional activation of IRAK1 induces oncoprotein Gankyrin and aldo-keto reductase family 1 member B10 (AKR1B10) in HCC. The regulatory mechanism of the SMARCA4-IRAK1-Gankyrin, AKR1B10 axis was further demonstrated in HCC cells and in vivo Ras-Tg mice. Our results suggest that aberrant overexpression of SMARCA4 causes SWI/SNF to promote IRAK1 enhancer to activate oncoprotein Gankyrin and AKR1B10, thereby contributing to hepatocarcinogenesis.

Functions of Thrombospondin-1 in the Tumor Microenvironment

The identification of thrombospondin-1 as an angiogenesis inhibitor in 1990 prompted interest in its role in cancer biology and potential as a therapeutic target. Decreased thrombospondin-1 mRNA and protein expression are associated with progression in several cancers, while expression by nonmalignant cells in the tumor microenvironment and circulating levels in cancer patients can be elevated. THBS1 is not a tumor suppressor gene, but the regulation of its expression in malignant cells by oncogenes and tumor suppressor genes mediates some of their effects on carcinogenesis, tumor progression, and metastasis. In addition to regulating angiogenesis and perfusion of the tumor vasculature, thrombospondin-1 limits antitumor immunity by CD47-dependent regulation of innate and adaptive immune cells. Conversely, thrombospondin-1 is a component of particles released by immune cells that mediate tumor cell killing. Thrombospondin-1 differentially regulates the sensitivity of malignant and nonmalignant cells to genotoxic stress caused by radiotherapy and chemotherapy. The diverse activities of thrombospondin-1 to regulate autophagy, senescence, stem cell maintenance, extracellular vesicle function, and metabolic responses to ischemic and genotoxic stress are mediated by several cell surface receptors and by regulating the functions of several secreted proteins. This review highlights progress in understanding thrombospondin-1 functions in cancer and the challenges that remain in harnessing its therapeutic potential.

Let-7i-5p enhances cell proliferation, migration and invasion of ccRCC by targeting HABP4

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is one of the best-characterized and most pervasive renal cancers. The present study aimed to explore the effects and potential mechanisms of let-7i-5p in ccRCC cells.

METHODS

Using bioinformatics analyses, we investigated the expression of let-7i-5p in The Cancer Genome Atlas (TCGA) database and predicted biological functions and possible target genes of let-7i-5p in ccRCC cells. Cell proliferation assay, wound healing assay and transwell invasion assay were conducted to characterize the effects of let-7i-5p in ccRCC cells. To verify the interactions between let-7i-5p and HABP4, dual-luciferase reporter assay, quantitative real-time polymerase chain reaction, and western blotting were conducted. Rescue experiments were used to investigate the relationship between let-7i-5p and HABP4.

RESULTS

TCGA data analysis revealed that ccRCC tissues had significantly increased let-7i-5p expression, which was robustly associated with poor overall survival. Further verification showed that ccRCC cell proliferation, migration and invasion were inhibited by let-7i-5p inhibitor but enhanced by let-7i-5p mimics. Subsequently, HABP4 was predicted to be the target gene of let-7i-5p. TCGA data showed that ccRCC tissues had decreased expression of HABP4 and that HABP4 expression was negatively correlated with let-7i-5p. Further verification showed that downregulation of HABP4 expression promoted cell proliferation, migration and invasion. The dual-luciferase reporter gene assay suggested that the let-7i-5p/HABP4 axis was responsible for the development of ccRCC.

CONCLUSION

Our results provide evidence that let-7i-5p functions as a tumor promoter in ccRCC and facilitates cell proliferation, migration and invasion by targeting HABP4. These results clarify the pathogenesis of ccRCC and offer a potential target for its treatment.

Exosomal Non-Coding RNAs: Regulatory and Therapeutic Target of Hepatocellular Carcinoma

Exosomes are small extracellular vesicles secreted by most somatic cells, which can carry a variety of biologically active substances to participate in intercellular communication and regulate the pathophysiological process of recipient cells. Recent studies have confirmed that non-coding RNAs (ncRNAs) carried by tumor cell/non-tumor cell-derived exosomes have the function of regulating the cancerous derivation of target cells and remodeling the tumor microenvironment (TME). In addition, due to the unique low immunogenicity and high stability, exosomes can be used as natural vehicles for the delivery of therapeutic ncRNAs in vivo. This article aims to review the potential regulatory mechanism and the therapeutic value of exosomal ncRNAs in hepatocellular carcinoma (HCC), in order to provide promising targets for early diagnosis and precise therapy of HCC.

The role of CD47-SIRPα immune checkpoint in tumor immune evasion and innate immunotherapy

As a transmembrane protein, CD47 plays an important role in mediating cell proliferation, migration, phagocytosis, apoptosis, immune homeostasis, inhibition of NO signal transduction and other related reactions. Upon the interaction of innate immune checkpoint CD47-SIRPα occurrence, they send a "don't eat me" signal to the macrophages. This signal ultimately helps tumors achieve immune escape by inhibiting macrophage contraction to prevent tumor cells from phagocytosis. Therefore, the importance of CD47-SIRPα immune checkpoint inhibitors in tumor immunotherapy has attracted more attention in recent years. Based on the cognitive improvement of the effect with CD47 in tumor microenvironment and tumor characteristics, the pace of tumor treatment strategies for CD47-SIRPα immune checkpoint inhibitors has gradually accelerated. In this review, we introduced the high expression of CD47 in cancer cells to avoid phagocytosis by immune cells and the importance of CD47 in the structure of cancer microenvironment and the maintenance of cancer cell characteristics. Given the role of the innate immune system in tumorigenesis and development, an improved understanding of the anti-tumor process of innate immune checkpoint inhibitors can lay the foundation for more effective combinations with other anti-tumor treatment strategies.

Overcome the tumor immunotherapy resistance by combination of the HDAC6 inhibitors with antitumor immunomodulatory agents

Tumor immunotherapy is currently subject of intense scientific and clinical developments. In previous decade, therapists used natural immune system from the human body to treat several diseases. Although tumor immune disease is a big challenge, combinatorial therapeutic strategy has been succeeded to show the clinical significance. In this context, we discuss the HDAC6 and tumor immune diseases relationship. Also, we summarized the current state of knowledge that based on the combination treatments of the HDAC6 inhibitors (HDAC6is) with antitumor immunomodulatory agents. We observed that, the combination therapies slow down the tumor immune diseases by blocking the aggresome and proteasome pathway. The combination therapy was able to reduce M2 macrophage and increasing PD-L1 blockade sensitivity. Most importantly, multiple combinations of HDAC6is with other agents may consider as potential strategies to treat tumor immune diseases, by reducing the side effects and improve efficacy for the future clinical development.

The Role of Tumor Associated Macrophages in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and represents a classic paradigm of inflammation-related cancer. Various inflammation-related risk factors jointly contribute to the development of chronic inflammation in the liver. Chronic inflammation, in turn, leads to continuous cycles of destruction-regeneration in the liver, contributing to HCC development and progression. Tumor associated macrophages are abundant in the tumor microenvironment of HCC, promoting chronic inflammation and HCC progression. Hence, better understanding of the mechanism by which tumor associated macrophages contribute to the pathogenesis of HCC would allow for the development of novel macrophage-targeting immunotherapies. This review summarizes the current knowledge regarding the mechanisms by which macrophages promote HCC development and progression, as well as information from ongoing therapies and clinical trials assessing the efficacy of macrophage-modulating therapies in HCC patients.

Immunological mechanisms and therapeutic targets of fatty liver diseases

Alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) are the two major types of chronic liver disease worldwide. Inflammatory processes play key roles in the pathogeneses of fatty liver diseases, and continuous inflammation promotes the progression of alcoholic steatohepatitis (ASH) and nonalcoholic steatohepatitis (NASH). Although both ALD and NAFLD are closely related to inflammation, their respective developmental mechanisms differ to some extent. Here, we review the roles of multiple immunological mechanisms and therapeutic targets related to the inflammation associated with fatty liver diseases and the differences in the progression of ASH and NASH. Multiple cell types in the liver, including macrophages, neutrophils, other immune cell types and hepatocytes, are involved in fatty liver disease inflammation. In addition, microRNAs (miRNAs), extracellular vesicles (EVs), and complement also contribute to the inflammatory process, as does intertissue crosstalk between the liver and the intestine, adipose tissue, and the nervous system. We point out that inflammation also plays important roles in promoting liver repair and controlling bacterial infections. Understanding the complex regulatory process of disrupted homeostasis during the development of fatty liver diseases may lead to the development of improved targeted therapeutic intervention strategies.

Growing Evidence of Exosomal MicroRNA-Related Metastasis of Hepatocellular Carcinoma

Metastasis is the prominent cause of death in patients with hepatocellular carcinoma (HCC); however, the mechanisms behind HCC metastasis are not well understood. MicroRNAs (miRs) can regulate gene expression and affect HCC metastasis. Exosomes can transport miRs and other cargoes to and from different cells, thus being associated with tumour-distant metastasis. Exosomal miRs involve different processes of HCC metastasis through their functional effects, such as their induction of epithelial-to-mesenchymal transition, angiogenesis, and distant niche. In this review, data from the literature were analysed and summarised, with a focus on the evidence extraction of exosomal miRs in HCC metastasis with the purpose of increasing the understanding of the mechanisms behind HCC metastasis and acquiring implications for application.

Non-coding RNA derived from extracellular vesicles in cancer immune escape: Biological functions and potential clinical applications

The tumor microenvironment represents a dynamically composed matrix into which cancer cells and many other cell types are embedded to form organ-like structures. The tumor immune microenvironment (TIME), composed of immune cells, is an inseparable part of the tumor microenvironment. Extracellular vesicles (EVs) participate in the occurrence and development of tumors by delivering various biologically active molecules between cells; their role in cancer immune escape in particular has been widely proven. EVs can carry a wide array of cargo, such as non-coding RNAs (ncRNAs), including miRNAs, lncRNAs, and circRNAs, which are selectively loaded by EVs, secreted, and transported to participate in the proliferation of immune cells. Hence, strategies to specifically target EV-ncRNAs could be attractive therapeutic options. In this review, we summarize the current research on the role of EV-ncRNAs in cancer immune escape, and discuss the latest research on the function and regulation mechanism of EV-ncRNAs in cancer immune escape, highlighting and elucidating the potential clinical applications of EV-ncRNAs, including in diagnosis and immunotherapy.

Novel Pharmacotherapies for Recurrent Pericarditis: Current Options in 2020

Abstract

Recent advances have shown impressive results by anti-interleukin 1 (IL-1) agents in refractory idiopathic recurrent pericarditis.

Purpose of Review

We critically discuss the current state of the art of therapy of relapsing pericarditis, with a focus on new pharmacological approaches and on specific clinical settings such as pregnancy, pediatric patients, and secondary forms of relapsing pericarditis.

Recent Findings

Antagonism of the IL-1 is highly effective in idiopathic recurrent pericarditis with autoinflammatory features. Currently, available anti-IL-1 agents are anakinra and canakinumab. Rilonacept is another IL-1 antagonist, currently studied in the phase-3 clinical trial RHAPSODY. Available data suggest similar efficacy and safety profiles of these three agents, although only anakinra has been tested in randomized clinical trials. These agents have slightly different pharmacological properties, being canakinumab a specific IL-1ß antagonist while anakinra and rilonacept are unselective IL-1α and IL-1ß blockers. To date, there is no evidence that specificity against IL-1ß affects safety and efficacy in patients with relapsing pericarditis, although it has been proposed that unspecific blockage might be useful in severe disease.

Summary

Anakinra is the first anti-IL-1 agent with well-documented efficacy and safety in adult and pediatric patients with idiopathic relapsing pericarditis. Other anti-IL-1 agents are currently under study. Future research should clarify the optimal duration of therapy and tapering schedule of treatment with these agents. Moreover, biomarkers would be required to understand which patients will benefit from early administration of IL-1 blockers due to refractoriness to conventional therapy and which others will suffer from recurrences during the tapering of these agents. Lastly, future studies should focus on the subjects with the autoimmune or the pauci-inflammatory phenotype of idiopathic refractory pericarditis.

THBS1 (thrombospondin-1)

Thrombospondins are encoded in vertebrates by a family of 5 THBS genes. THBS1 is infrequently mutated in most cancers, but its expression is positively regulated by several tumor suppressor genes and negatively regulated by activated oncogenes and promoter hypermethylation. Consequently, thrombospondin-1 expression is frequently lost during oncogenesis and is correlated with a poor prognosis for some cancers. Thrombospondin-1 is a secreted protein that acts in the tumor microenvironment to inhibit angiogenesis, regulate antitumor immunity, stimulate tumor cell migration, and regulate the activities of extracellular proteases and growth factors. Differential effects of thrombospondin-1 on the sensitivity of normal versus malignant cells to ischemic and genotoxic stress also regulate the responses to tumors to therapeutic radiation and chemotherapy.

TSP1 ameliorates age-related macular degeneration by regulating the STAT3-iNOS signaling pathway

Age-related macular degeneration is a progressive ocular disease that is the leading cause of vision loss among elderly. AMD usually is divided into two types: wet and dry AMD, which is linked with inflammation. Choroidal Neovascularization (CNV) formation or wet AMD is also associated with oxidative stress. Previously, TSP1 has been shown to have a significant alleviating effect on CNV in TSP1 knockout (TSP1-/-) mice. However, the mechanism by which TSP1 ameliorates CNV remains unclear. Here we report that TSP1 reduces nitric oxide production to prevent cells from forming tubes formation and reduced the levels of vascular endothelial growth factor (VEGF) and lipid peroxides (LPO) during oxidative stress. We measured RF/6A cell viability by CCK-8 assay and apoptosis by flow cytometry. RF/6A cell were transfected with TSP1 and STAT3 overexpression, and then the mRNA and protein levels of TSP1 and also the signal pathways were detected by qRT-PCR and Western blot analysis. Migration assays were performed using a transwell system. Co-Immunoprecipitation was used to analyze the binding relationship between CD47 and SHP-2. The results show that overexpression of TSP1 alleviated the damage of oxidative stress to RF/6A cells including increased cell activity and migration, decreased apoptosis and reduced migration compared to the control group. SHP-2 was activated by TSP1 through its receptor CD47 and STAT3 phosphorylation was reduced by activation of SHP-2, thereby blocking STAT3-iNOS pathway and reducing NO concentration in RF/6A cells ultimately protecting them from oxidative stress. Finally, the CNV mice model confirmed that TSP1 overexpression could protect the mice against CNV in vivo, modified the antioxidants levels and decreased the expression of TNF-α and IL-6 under laser irradiation. These results indicate a potential mechanism of TSP1 to slow down formation of CNV in wet AMD, which may bring hope for new treatment strategies.

CAMSAP2-mediated noncentrosomal microtubule acetylation drives hepatocellular carcinoma metastasis

Rationale: Emerging evidence suggests that noncentrosomal microtubules play an essential role in intracellular transport, cell polarity and cell motility. Whether these noncentrosomal microtubules exist or function in cancer cells remains unclear.

Methods: The expression and prognostic values of CAMSAP2 and its functional targets were analyzed by immunohistochemistry in two independent HCC cohorts. Immunofluorescence and co-immunoprecipitation were used for detection of CAMSAP2-decorated noncentrosomal microtubule. Chromatin immunoprecipitation and luciferase report assays were used to determine the c-Jun binding sites in HDAC6 promoter region. In vitro migration and invasion assays and in vivo orthotopic metastatic models were utilized to investigate invasion and metastasis.

Results: We reported a microtubule minus‑end‑targeting protein, CAMSAP2, is significantly upregulated in hepatocellular carcinoma (HCC) and correlated with poor prognosis. CAMSAP2 was specifically deposited on microtubule minus ends to serve as a “seed” for noncentrosomal microtubule outgrowth in HCC cells. Upon depletion of CAMSAP2, the noncentrosomal microtubule array was transformed into a completely radial centrosomal pattern, thereby impairing HCC cell migration and invasion. We further demonstrated that CAMSAP2 cooperates with EB1 to regulate microtubule dynamics and invasive cell migration via Trio/Rac1 signaling. Strikingly, both immunofluorescence staining and western blotting showed that CAMSAP2 depletion strongly reduced the abundance of acetylated microtubules in HCC cells. Our results revealed that HDAC6, a promising target for cancer therapy, was inversely downregulated in HCC and uniquely endowed with tumor-suppressive activity by regulation CAMSAP2-mediated microtubule acetylation. Mechanistically, CAMSAP2 activates c-Jun to induce transrepression of HDAC6 through Trio-dependent Rac1/JNK pathway. Furthermore, NSC23766, a Rac1-specific inhibitor significantly inhibited CAMSAP2-mediated HCC invasion and metastasis.

Conclusions: CAMSAP2 is functionally, mechanistically, and clinically oncogenic in HCC. Targeting CAMSAP2-mediated noncentrosomal microtubule acetylation may provide new therapeutic strategies for HCC metastasis.

CD47 blockade alleviates acute rejection of allogeneic mouse liver transplantation by reducing ischemia/reperfusion injury

Despite advances in immunosuppressive therapies, acute rejection response is still a serious concern especially in the early phase after liver transplantation. This study aimed to evaluate whether blocking the TSP1-CD47 signaling pathway could attenuate the acute rejection after liver transplantation. An allogeneic mouse orthotopic liver transplantation model (Balb/c→C3H) with prolonged cold ischemic phase was used to induce severe IRI and lethal acute rejection. CD47mAb or isotype matched-control IgG_2a was administered to donor liver during graft perfusion. Recipients were sacrificed at 1d, 3d, 5d and 7d after reperfusion. Blood samples were collected to evaluate serum alanine aminotransferase, total bilirubin, HMGB-1,TNF-α, IL-2 and INF-γ level. Flow cytometric analysis was used to detect the strength of innate and adaptive immune response. Liver tissue was obtained for HE, TUNEL staining and F4/80 immumohistochemical staining. Moreover, we conducted a mixed lymphocyte reaction treated with IgG_2a or CD47mAb. Mice in CD47mAb-treated group demonstrated improved survival and significantly lower increase in Suzuki score, apoptosis index, acute rejection index, serum alanine aminotransferase, total bilirubin, HMGB-1, TNF-α, IL-2, INF-γ level and the degree of Kupffer cells' activation especially in the early phase of acute rejection. In addition, Pearson's correlation analysis confirmed significant correlation between Suzuki score/ALT and acute rejection index. The in vitro inhibition assay showed that CD47 blockade couldn't directly inhibit recipient lymphocyte proliferation. Based on the evidence that TSP1-CD47 signaling blockade with CD47mAb could alleviate acute rejection by reducing the extent of IRI after liver transplantation indirectly, this study provided a basis for new interventions and management methods to support better transplant outcomes.

Long noncoding RNA LINC00662 promotes M2 macrophage polarization and hepatocellular carcinoma progression via activating Wnt/β-catenin signaling

Tumor-associated macrophages have important roles in hepatocellular carcinoma (HCC) initiation and progression. Long noncoding RNAs (lncRNAs) have also been reported to be involved in HCC. In this study, we explored how lncRNA LINC00662 may influence HCC progression through both tumor cell-dependent and macrophage-dependent mechanisms. LINC00662 was found to be upregulated in HCC, and high LINC00662 levels correlated with poor survival of HCC patients. LINC00662 upregulated WNT3A expression and secretion via competitively binding miR-15a, miR-16, and miR-107. Through inducing WNT3A secretion, LINC00662 activated Wnt/β-catenin signaling in HCC cells in an autocrine manner and further promoted HCC cell proliferation, cell cycle, and tumor cell invasion, while repressing HCC cell apoptosis. In addition, acting through WNT3A secretion, LINC00662 activated Wnt/β-catenin signaling in macrophages in a paracrine manner and further promoted M2 macrophage polarization. Via activating Wnt/β-catenin signaling and M2 macrophages polarization, LINC00662 significantly promoted HCC tumor growth and metastasis in vivo. Hence, targeting LINC00662 may provide novel therapeutic strategy against HCC.