Acetylation of alpha-fetoprotein promotes hepatocellular carcinoma progression

Epigenetic Modifications in HBV-Related Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. Hepatitis B virus (HBV) is the main pathogen for HCC development. HBV covalently closed circular DNA (cccDNA) forms extra-host chromatin-like minichromosomes in the nucleus of hepatocytes with host histones, non-histones, HBV X protein (HBx) and HBV core protein (HBc). Epigenetic alterations are dynamic and reversible, which regulate gene expression without altering the DNA sequence and play a pivotal role in the regulation of HCC onset and progression. The aim of this review is to elucidate the deregulation of epigenetic mechanisms involved in the pathogenesis of HBV-related HCC (HBV-HCC), including post-translational histone and non-histone modifications, DNA hypermethylation and hypomethylation, non-coding RNA modification on HBV cccDNA minichromosomes and host factors, effecting the replication/transcription of HBV cccDNA and transcription/translation of host genes, and thus HBV-HCC progression. It is expected that the epigenetic regulation perspective provides new ways for more in-depth development of therapeutic control of HBV-HCC.

HDAC9-mediated deacetylation of CALML6 promotes excessive proliferation of glomerular mesangial cells in IgA nephropathy

PURPOSE

This study seeks to investigate the fundamental molecular processes through which histone deacetylase 9 (HDAC9) governs the proliferation of glomerular mesangial cells in the context of immunoglobulin A nephropathy (IgAN) and to identify novel targets for clinical research on IgAN.

METHODS

Data from high-throughput RNA sequencing for IgAN were procured from the Gene Expression Omnibus database to assess the expression profiles and clinical diagnostic significance of histone deacetylase family proteins (HDACs). Blood samples from 20 IgAN patients were employed in RT-qPCR analysis, and the spearman linear regression method was utilized to analyze the clinical correlation. The proliferation of glomerular mesangial cells (GMCs) under the influence of HDAC9 was examined using the 5-ethynyl-2'-deoxyuridine (EdU) assay. Proteins interacting with HDAC9 were predicted utilizing the STRING database. Immunoprecipitation and protein immunoblotting employing anti-acetylated lysine antibodies were conducted to determine the acetylation status of calmodulin-like protein 6 (CALML6).

RESULTS

Analysis of the GSE141295 dataset revealed a significant upregulation of HDAC9 expression in IgAN and the results of RT-qPCR demonstrated a substantial increase in HDAC9 expression in IgAN patients. Receiver operating characteristic (ROC) analysis indicated that the area under the curve (AUC) value for HDAC9 were 0.845 and Spearman correlation analysis showed that HDAC9 expression was positively correlated with blood levels of blood urea nitrogen (BUN) and serum creatinine (Crea). The EdU cell proliferation assay indicated that HDAC9 facilitated the excessive proliferation of GMCs. The STRING database and recovery experiments identified CALML6 as a downstream effector of HDAC9 in controlling abnormal GMC multiplication. Co-immunoprecipitation assays demonstrated that HDAC9 modulates CALML6 expression through acetylation modification.

CONCLUSION

HDAC9 is markedly upregulated in IgAN, and it mediates the excessive proliferation of GMCs by regulating the deacetylation of CALML6.

Chimeric antigen receptor-T cells targeting AFP-GPC3 mediate increased antitumor efficacy in hepatocellular carcinoma

BACKGROUND AND STUDY AIMS

As a novel immunotherapy, chimeric antigen receptor T (CAR-T) cell technology is successful in treating hematologic malignancies, and exhibits potential benefits in partial solid tumors. Therapies targeting one antigen have some weaknesses, and dual-targeted CAR-T cells may be a better option. Alpha-fetoprotein (AFP) and glypican-3 (GPC3) are both highly expressed in hepatocellular carcinoma (HCC) and serve as important markers. Our study aimed to compare the cytotoxicity effect of AFP and GPC3 dual-targeted CAR-T cells on HCC cells in vitro and its therapeutic effects on a SCID xenograft model with those of single-targeted CAR-T cells.

MATERIALS AND METHODS

pLVX lentivirus vectors loaded with AFP CAR, GPC3 CAR, or AFP-GPC3 CAR constructs were transfected into human T lymphocytes. Control T, AFP CAR-T, GPC3 CAR-T, and AFP-GPC3 CAR-T cells were used as effector cells, and HLE (AFP-GPC3-), Sh-GPC3-Huh-7 (AFP+), Sh-AFP-Huh-7 (GPC3+), and Huh-7 (AFP+GPC3+) cells were used as target cells. After their co-culture for 6 h, the LDH cytotoxicity assay was employed to estimate the cell-killing effects of CAR-T cells on the target HCC cells. SCID mice bearing Huh-7 cell-derived neoplasms were injected with CAR-T cells, after which the pathological changes, CD3ζ expression, and IL-2 and IFN-γ levels in mouse tumor tissues were determined.

RESULTS

AFP and GPC3 were highly expressed in Huh-7 cells. AFP-GPC3 CAR-T cells exerted significant cell-killing effects on the HCC cells that expressed specific targeting antigen molecules (AFP and GPC3). Besides, AFP-GPC3 CAR-T cells better promoted Th cytokine secretion by Huh-7 cells than AFP CAR-T and GPC3 CAR-T cells. In vivo results suggested that AFP-GPC3 CAR-T cells better inhibited the growth of Huh-7 cell (AFP+GPC3+)-derived neoplasms than AFP CAR-T and GPC3 CAR-T cells.

CONCLUSION

AFP and GPC3 dual-targeted CAR-T cells showed better anti-tumor effects in HCC than AFP or GPC3 single-targeted CAR-T cells.

A Network Map of Intracellular Alpha-Fetoprotein Signalling in Hepatocellular Carcinoma

Alpha fetoprotein (AFP) is a glycoprotein of foetal origin belonging to the albumin protein family. Serum AFP is a long-conceived early-diagnostic biomarker for HCC with its elevated expression in different liver pathologies ranging from hepatitis viral infections to fibrosis, cirrhosis, and HCC. Beyond their utility as biomarkers, in support of its contribution to these clinical outcomes, the function of AFP as an immune suppressor and inducer of malignant transformation in HCC patients is well reported. Multiple reports show that AFP is secreted by hepatocytes, binds to its cognate receptor, AFP-receptor (AFPR), and exerts its actions. However, there is only limited information available in this context. There is an urgent need to gather more insight into the AFP signalling pathway and consider it a classical intracellular signalling pathway, among others. AFP is a highly potent intracellular molecule that has the potential to bind to many interactors like PTEN, Caspase, RAR, and so on. It has been shown that cellular AFP and secreted AFP have different roles in HCC pathophysiology, and a comprehensive map of the AFP signalling pathway is warranted for further theranostic applications.

Early Alpha-Fetoprotein Response Predicts Sustained Tumor Response Following Immune Checkpoint Inhibitors Combined with Targeted Therapy in Liver Cancer

Background: Although immune checkpoint inhibitors (ICI) have revolutionized liver cancer treatment, some patients experience early tumor progression after therapy, missing the window for other potential treatments, such as neoadjuvant therapy. Therefore, identifying the predictive factors for early progression is critical for timely therapeutic adjustment and the optimization of patient outcomes. Methods: This retrospective study enrolled patients with liver cancer who received their first ICI combined with targeted therapy at the Fifth Medical Center of the PLA General Hospital between June 2022 and December 2023. Early tumor progression was defined as tumor progression within 6 months of therapy initiation. Multivariate logistic regression analysis was used to identify independent risk factors for early tumor progression, and overall survival (OS) curves were generated using the Kaplan-Meier method. Results: A total of 159 patients were enrolled. Multivariate logistic regression analysis indicated that patients with an early alpha-fetoprotein (AFP) response had a significantly reduced risk of early tumor progression (OR = 0.34, 95% CI: 0.13-0.84, p = 0.019), suggesting that an early AFP response is a protective factor against early progression. The area under curve (AUC) for the predictive model was 0.73 (95% CI: 0.63-0.83, p < 0.001). Stratified survival analysis showed that the median overall survival (mOS) in the early AFP response group was significantly longer than that in the poor response group (17.3 months vs. 6.1 months, HR = 2.11, 95% CI: 1.19-2.74, p = 0.009). Conclusions: Early AFP response is not only an effective biomarker for identifying high-risk patients prone to early tumor progression but is also significantly associated with long-term survival in liver cancer patients treated with ICI combined with targeted therapy. This finding will enable clinicians to make timely therapeutic adjustments and optimize treatment outcomes, thereby improving both progression-free survival and overall survival.

Chimeric Antigen Receptor (CAR)-T Cells: A New Era for Hepatocellular Carcinoma Treatment

Hepatocellular carcinoma (HCC) is one of the most common cancers and a worldwide health concern that requires novel treatment approaches. Tyrosine kinase inhibitors (TKIs) and immune checkpoint blockades (ICBs) are the current standard of care; however, their clinical benefits are limited in some advanced and metastatic patients. With the help of gene engineering techniques, a novel adoptive cellular therapy (ACT) called chimeric antigen receptor (CAR)-T cells was recently introduced for treating HCC. A plethora of current clinical and preclinical studies are attempting to improve the efficacy of CAR-T cells by dominating the immunosuppressive environment of HCC and finding the best tumor-specific antigens (TSAs). The future of care for HCC patients might be drastically improved due to the convergence of novel therapeutic methods and the continuous progress in ACT research. However, the clinical application of CAR-T cells in solid tumors is still facing several challenges. In this study, we provide an overview of the advancement and prospects of CAR-T cell immunotherapy in HCC, as well as an investigation of how cutting-edge engineering could improve CAR-T cell efficacy and safety profile.

In-silico studies on evaluating the liver-protective effectiveness of a polyherbal formulation in preventing hepatocellular carcinoma progression

Liv-52, an herbal formulation consisting of seven distinct plants and Mandur Bhasma, is recognized for its hepatoprotective, anti-inflammatory, and antioxidant properties. To investigate the pharmacological potential of each phytochemical from these plants, we conducted ADMET analysis, molecular docking, and molecular dynamic simulations to identify potent molecules capable of inhibiting the interaction between Alpha-fetoprotein (AFP) and Cysteine aspartyl protease 3 (Caspase-3/CASP3). In our study, we have used molecular docking of all the compounds against AFP and filtered them on the basis of ADME properties. Among the compounds analyzed, (-) Syringaresinol from Solanum nigrum, exhibited good binding interactions with AFP, the highest binding free energy, and maintained stability throughout the simulation along with favorable drug likeness properties based on ADME and Toxicity analysis. These findings have strongly indicated that (-) Syringaresinol is a potential inhibitor of AFP, providing a promising therapeutic avenue for hepatocellular carcinoma (HCC) treatment by inhibiting the interaction between AFP and CASP3, thereby reinstating normal CASP3 activity. Further in vitro studies are imperative to validate the therapeutic efficacy of (-) Syringaresinol as an AFP inhibitor, potentially impeding the progression of HCC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-024-00285-2.

An Insight Into the Role of Alpha-Fetoprotein (AFP) in the Development and Progression of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the primary malignancy of hepatocytes and the second most common cause of cancer-related mortality across the globe. Despite significant advancements in screening, diagnosis, and treatment modalities for HCC, the mortality-to-incidence ratio remain unacceptably high. A recent study indicates that a minor population of HCCs are AFP negative or express the normal range of AFP levels. Although it is a gold standard and a more reliable biomarker in the advanced stage of HCC and poorly differentiated tumors, it does not serve as a suitable means for screening HCC. AFP plays a significant role in the development and progression of HCC and understanding its role is crucial. By examining the molecular mechanisms involved in AFP-mediated tumorigenesis, we can better understand HCC pathogenesis and identify potential therapeutic targets. This article details the role of alpha-fetoprotein (AFP) in the carcinogenic transformation of hepatocytes. The article also focuses on information about the structure, biosynthesis, and regulation of AFP at the gene level. Additionally, it discusses the immune evasion, metastasis, and control of gene expression that AFP mediates during HCC.

Recent advancements in improving the efficacy and safety of chimeric antigen receptor (CAR)-T cell therapy for hepatocellular carcinoma

The liver is one of the most frequent sites of primary malignancies in humans. Hepatocellular carcinoma (HCC) is one of the most prevalent solid tumors with poor prognosis. Current treatments showed limited efficacy in some patients, and, therefore, alternative strategies, such as immunotherapy, cancer vaccines, adoptive cell therapy (ACT), and recently chimeric antigen receptors (CAR)-T cells, are developed to offer better efficacy and safety profile in patients with HCC. Unlike other ACTs like tumor-infiltrating lymphocytes (TILs), CAR-T cells are equipped with engineered CAR receptors that effectively identify tumor antigens and eliminate cancer cells without major histocompatibility complex (MHC) restriction. This process induces intracellular signaling, leading to T lymphocyte recruitment and subsequent activation of other effector cells in the tumor microenvironment (TME). Until today, novel approaches have been used to develop more potent CAR-T cells with robust persistence, specificity, trafficking, and safety. However, the clinical application of CAR-T cells in solid tumors is still challenging. Therefore, this study aims to review the advancement, prospects, and possible avenues of CAR-T cell application in HCC following an outline of the CAR structure and function.

Targeting AFP-RARβ complex formation: a potential strategy for treating AFP-positive hepatocellular carcinoma

Alpha-fetoprotein (AFP) is a glycoprotein primarily expressed during embryogenesis, with declining levels postnatally. Elevated AFP levels correlate with pathological conditions such as liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Recent investigations underscore AFP's intracellular role in HCC progression, wherein it forms complexes with proteins like Phosphatase and tensin homolog (PTEN), Caspase 3 (CASP3), and Retinoic acid receptors and Retinoid X receptors (RAR/RXR). RAR and RXR regulate gene expression linked to cell death and tumorigenesis in normal physiology. AFP impedes RAR/RXR dimerization, nuclear translocation, and function, promoting gene expression favoring cancer progression in HCC that provoked us to target AFP as a drug candidate. Despite extensive studies, inhibitors targeting AFP to disrupt complex formation and activities remain scarce. In this study, employing protein-protein docking, amino acid residues involved in AFP-RARβ interaction were identified, guiding the definition of AFP's active site for potential inhibitor screening. Currently, kinase inhibitors play a significant role in cancer treatment and, the present study explores the potential of repurposing FDA-approved protein kinase inhibitors to target AFP. Molecular docking with kinase inhibitors revealed Lapatinib as a candidate drug of the AFP-RARβ complex. Molecular dynamics simulations and binding energy calculations, employing Mechanic/Poisson-Boltzmann Surface Area (MM-PBSA), confirmed Lapatinib's stability with AFP. The study suggests Lapatinib's potential in disrupting the AFP-RARβ complex, providing a promising avenue for treating molecularly stratified AFP-positive HCC or its early stages.

Alpha-fetoprotein: Past, present, and future

Alpha-fetoprotein (AFP) is a glycoprotein that plays an important role in immune regulation with critical involvement in early human development and maintaining the immune balance during pregnancy. Postfetal development, the regulatory mechanisms controlling AFP undergo a shift and AFP gene transcription is suppressed. Instead, these enhancers refocus their activity to maintain albumin gene transcription throughout adulthood. During the postnatal period, AFP expression can increase in the setting of hepatocyte injury, regeneration, and malignant transformation. It is the first oncoprotein discovered and is routinely used as part of a screening strategy for HCC. AFP has been shown to be a powerful prognostic biomarker, and multiple HCC prognosis models confirmed the independent prognostic utility of AFP. AFP is also a useful predictive biomarker for monitoring the treatment response of HCC. In addition to its role as a biomarker, AFP plays important roles in immune modulation to promote tumorigenesis and thus has been investigated as a therapeutic target in HCC. In this review article, we aim to provide an overview of AFP, encompassing the discovery, biological role, and utility as an HCC biomarker in combination with other biomarkers and how it impacts clinical practice and future direction.

Chimeric Antigen Receptor T Cell Therapy for Hepatocellular Carcinoma: Where Do We Stand?

Hepatocellular carcinoma (HCC) remains a global health challenge that urgently calls for innovative therapeutic strategies. Chimeric antigen receptor T cell (CAR T) therapy has emerged as a promising avenue for HCC treatment. However, the therapeutic efficacy of CAR T immunotherapy in HCC patients is significantly compromised by some major issues including the immunosuppressive environment within the tumor, antigen heterogeneity, CAR T cell exhaustion, and the advanced risk for on-target/off-tumor toxicity. To overcome these challenges, many ongoing preclinical and clinical trials are underway focusing on the identification of optimal target antigens and the decryption of the immunosuppressive milieu of HCC. Moreover, limited tumor infiltration constitutes a significant obstacle of CAR T cell therapy that should be addressed. The continuous effort to design molecular targets for CAR cells highlights the importance for a more practical approach for CAR-modified cell manufacturing. This review critically examines the current landscape of CAR T cell therapy for HCC, shedding light on the changes in innate and adaptive immune responses in the context of HCC, identifying potential CAR T cell targets, and exploring approaches to overcome inherent challenges. Ongoing advancements in scientific research and convergence of diverse treatment modalities offer the potential to greatly enhance HCC patients' care in the future.

Hepatocellular Carcinoma: Old and Emerging Therapeutic Targets

Liver cancer, predominantly hepatocellular carcinoma (HCC), globally ranks sixth in incidence and third in cancer-related deaths. HCC risk factors include non-viral hepatitis, alcohol abuse, environmental exposures, and genetic factors. No specific genetic alterations are unequivocally linked to HCC tumorigenesis. Current standard therapies include surgical options, systemic chemotherapy, and kinase inhibitors, like sorafenib and regorafenib. Immunotherapy, targeting immune checkpoints, represents a promising avenue. FDA-approved checkpoint inhibitors, such as atezolizumab and pembrolizumab, show efficacy, and combination therapies enhance clinical responses. Despite this, the treatment of hepatocellular carcinoma (HCC) remains a challenge, as the complex tumor ecosystem and the immunosuppressive microenvironment associated with it hamper the efficacy of the available therapeutic approaches. This review explores current and advanced approaches to treat HCC, considering both known and new potential targets, especially derived from proteomic analysis, which is today considered as the most promising approach. Exploring novel strategies, this review discusses antibody drug conjugates (ADCs), chimeric antigen receptor T-cell therapy (CAR-T), and engineered antibodies. It then reports a systematic analysis of the main ligand/receptor pairs and molecular pathways reported to be overexpressed in tumor cells, highlighting their potential and limitations. Finally, it discusses TGFβ, one of the most promising targets of the HCC microenvironment.

Lysosomes Initiating and DNAzyme-Assisted Intracellular Signal Amplification Strategy for Quantification of Alpha-Fetoprotein in a Single Cell

Cellular trace proteins are critical for maintaining normal cell functions, with their quantitative analysis in individual cells aiding our understanding of the role of cell proteins in biological processes. This study proposes a strategy for the quantitative analysis of alpha-fetoprotein in single cells, utilizing a lysosome microenvironment initiation and a DNAzyme-assisted intracellular signal amplification technique based on electrophoretic separation. A nanoprobe targeting lysosomes was prepared, facilitating the intracellular signal amplification of alpha-fetoprotein. Following intracellular signal amplification, the levels of alpha-fetoprotein (AFP) in 20 HepG2 hepatoma cells and 20 normal HL-7702 hepatocytes were individually evaluated using microchip electrophoresis with laser-induced fluorescence detection (MCE-LIF). Results demonstrated overexpression of alpha-fetoprotein in hepatocellular carcinoma cells. This strategy represents a novel technique for single-cell protein analysis and holds significant potential as a powerful tool for such analyses.

Role of Alpha-Fetoprotein in the Pathogenesis of Cancer

Alpha-fetoprotein (AFP) belongs to the albuminoid protein family and is considered as the fetal analog of serum albumin. This plasma protein is initially synthesized in the fetal liver and yolk sac and shows a maximum peak near the end of the first trimester. Later, concentrations begin to decline prenatally and drop precipitously after birth. This protein has three key ligand-binding pockets for interactions with various biomolecules. It contains multiple phosphorylation and acetylation sites for the regulation of physiological and pathophysiological states. High serum AFP titer is an established biomarker for yolk sac, embryonal and hepatocellular carcinoma. The present review critically analyzes the chemical nature, receptors, clinical implications, and therapeutic aspects of AFP, underpinning the development of different types of cancer.

Cellular gp96 upregulates AFP expression by blocking NR5A2 SUMOylation and ubiquitination in hepatocellular carcinoma

Alpha-fetoprotein (AFP) is the most widely used biomarker for the diagnosis of hepatocellular carcinoma (HCC). However, a substantial proportion of HCC patients have either normal or marginally increased AFP levels in serum, and the underlying mechanisms are not fully understood. In the present study, we provided in vitro and in vivo evidence that heat shock protein gp96 promoted AFP expression at the transcriptional level in HCC. NR5A2 was identified as a key transcription factor for the AFP gene, and its stability was enhanced by gp96. A further mechanistic study by co-immunoprecipitation, GST pull-down, and molecular docking showed gp96 and the SUMO E3 ligase RanBP2 competitively binding to NR5A2 at the sites spanning from aa 507 to aa 539. The binding of gp96 inhibited SUMOylation, ubiquitination, and subsequent degradation of NR5A2. In addition, clinical analysis of HCC patients indicated that gp96 expression in tumors was positively correlated with serum AFP levels. Therefore, our study uncovered a novel mechanism that gp96 regulates the stability of its client proteins by directly affecting their SUMOylation and ubiquitination. These findings will help in designing more accurate AFP-based HCC diagnosis and progression monitoring approaches.

Diagnostic and Prognostic Value of Protein Post-translational Modifications in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common malignant tumor with high incidence and cancer mortality worldwide. Post-translational modifications (PTMs) of proteins have a great impact on protein function. Almost all proteins can undergo PTMs, including phosphorylation, acetylation, methylation, glycosylation, ubiquitination, and so on. Many studies have shown that PTMs are related to the occurrence and development of cancers. The findings provide novel therapeutic targets for cancers, such as glypican-3 and mucin-1. Other clinical implications are also found in the studies of PTMs. Diagnostic or prognostic value, and response to therapy have been identified. In HCC, it has been shown that glycosylated alpha-fetoprotein (AFP) has a higher detection rate for early liver cancer than conventional AFP. In this review, we mainly focused on the diagnostic and prognostic value of PTM, in order to provide new insights into the clinical implication of PTM in HCC.

Novel insights into the progression and prognosis of the calpain family members in hepatocellular carcinoma: a comprehensive integrated analysis

Objectives: The goal of our bioinformatics study was to comprehensively analyze the association between the whole calpain family members and the progression and prognosis of hepatocellular carcinoma (HCC). Methods: The data were collected from The Cancer Genome Atlas (TCGA). The landscape of the gene expression, copy number variation (CNV), mutation, and DNA methylation of calpain members were analyzed. Clustering analysis was performed to stratify the calpain-related groups. The least absolute shrinkage and selection operator (LASSO)-based Cox model was used to select hub survival genes. Results: We found 14 out of 16 calpain members expressed differently between tumor and normal tissues of HCC. The clustering analyses revealed high- and low-risk calpain groups which had prognostic difference. We found the high-risk calpain group had higher B cell infiltration and higher expression of immune checkpoint genes HAVCR2, PDCD1, and TIGHT. The CMap analysis found that the histone deacetylase (HDAC) inhibitor trichostatin A and the PI3K-AKT-mTOR pathway inhibitors LY-294002 and wortmannin might have a therapeutic effect on the high-risk calpain group. The DEGs between calpain groups were identified. Subsequent univariate Cox analysis of each DEG and LASSO-based Cox model obtained a calpain-related prognostic signature. The risk score model of this signature showed good ability to predict the overall survival of HCC patients in TCGA datasets and external validation datasets from the Gene Expression Omnibus database and the International Cancer Genome Consortium database. Conclusion: We found that calpain family members were associated with the progression, prognosis, and drug response of HCC. Our results require further studies to confirm.

Glucose metabolism reprogramming promotes immune escape of hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is a complex process that plays an important role in its progression. Abnormal glucose metabolism in HCC cells can meet the nutrients required for the occurrence and development of liver cancer, better adapt to changes in the surrounding microenvironment, and escape the attack of the immune system on the tumor. There is a close relationship between reprogramming of glucose metabolism and immune escape. This article reviews the current status and progress of glucose metabolism reprogramming in promoting immune escape in liver cancer, aiming to provide new strategies for clinical immunotherapy of liver cancer.

Adoptive Cell Therapy in Hepatocellular Carcinoma: A Review of Clinical Trials

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Immune checkpoint inhibitors (ICIs) have become the new reference standard in first-line HCC treatment, replacing tyrosine kinase inhibitors (TKIs) such as sorafenib. Many clinical trials with different combinations are already in development to validate novel immunotherapies for the treatment of patients with HCC. Adoptive cell therapy (ACT), also known as cellular immunotherapy, with chimeric antigen receptors (CAR) or gene-modified T cells expressing novel T cell receptors (TCR) may represent a promising alternative approach to modify the immune system to recognize tumor cells with better clinical outcomes. In this review, we briefly discuss the overview of ACT as a promising treatment modality in HCC, along with recent updates of ongoing clinical trials.

Acetylation stabilizes the signaling protein WISP2 by preventing its degradation to suppress the progression of acute myeloid leukemia

Acute myeloid leukemia (AML) is challenging to treat due to its heterogeneity, prompting a deep understanding of its pathogenesis mechanisms, diagnosis, and treatment. Here, we found reduced expression and acetylation levels of WISP2 in bone marrow mononuclear cells from AML patients and that AML patients with lower WISP2 expression tended to have reduced survival. At the functional level, overexpression of WISP2 in leukemia cells (HL-60 and Kasumi-1) suppressed cell proliferation, induced cell apoptosis, and exerted antileukemic effects in an in vivo model of AML. Our mechanistic investigation demonstrated that WISP2 deacetylation was regulated by the deacetylase histone deacetylase (HDAC)3. In addition, we determined that crosstalk between acetylation and ubiquitination was involved in the modulation of WISP2 expression in AML. Deacetylation of WISP2 decreased the stability of the WISP2 protein by boosting its ubiquitination mediated by NEDD4 and proteasomal degradation. Moreover, pan-HDAC inhibitors (valproic acid and trichostatin A) and an HDAC3-specific inhibitor (RGFP966) induced WISP2 acetylation at lysine K6 and prevented WISP2 degradation. This regulation led to inhibition of proliferation and induction of apoptosis in AML cells. In summary, our study revealed that WISP2 contributes to tumor suppression in AML, which provided an experimental framework for WISP2 as a candidate for gene therapy of AML.

MiR-652-3p promotes malignancy and metastasis of cancer cells via inhibiting TNRC6A in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) was one of the most prevalent life-threatening cancers. Metastasis is the leading cause of cancer-related death in HCC. MiRNAs play essential roles in cancer metastasis.

METHODS

Expression of miR-652-3p in HCC was assessed. Function experiments of miR-652-3p and trinucleotide repeat-containing gene 6A protein (TNRC6A) were performed both in vitro and in vivo. mRNA sequencing, PCR, and western blot were performed to verify the target genes and pathway of miR-652-3p. The lung metastasis and xenograft cancer model in nude mice was established to investigate the effects of the miR-652-3p and TRNC6A on tumor metastasis in vivo. The relationship between the expression of the miR-652-3p, TNRC6A and the prognosis of HCC patients was analyzed.

RESULTS

Upregulated miR-652-3p was found in the tumor tissues of HCC, especially in metastatic HCC patients. Overexpression of miR-652-3p promoted and knockdown of miR-652-3p suppressed HCC metastasis both in vitro and in vivo. MiR-652-3p promoted HCC metastasis via regulating the EMT pathway. TNRC6A was identified as a direct target of miR-652-3p, and the knockdown of TNRC6A restored repressed EMT and HCC metastasis caused by the inhibition of miR-652-3p. Clinical results revealed that high expression of miR-652-3p and low expression of TNRC6A were positively correlated to shortened overall survival and disease-free survival in HCC patients.

CONCLUSIONS

MiR-652-3p promotes EMT and HCC metastasis by inhibiting TNRC6A expression in HCC. MiR-652-3p and TNRC6A may serve as potential biomarkers to predict prognosis in HCC patients with metastasis.

A pan-cancer analysis of the oncogenic role of ribonucleotide reductase subunit M2 in human tumors

Background

Recent studies have identified ribonucleotide reductase subunit M2 (RRM2) as a putative promoter of tumors. However, no systematic analysis of its carcinogenicity has been conducted.

Methods

The potential functions of RRM2 in various tumor types were investigated using data from the Genotype-Tissue Expression (GTEx), the Clinical Proteomic Tumor Analysis Consortium (CPTAC), the Cancer Genome Atlas (TCGA), the Human Protein Atlas (HPA), cBioPortal, GEPIA, String, and Gene Set Enrichment Analysis (GSEA). We analyzed the difference in mRNA and protein expression, pathological stage, survival, mutation, tumor microenvironment (TME), and immune cell infiltration in relation to RRM2. Meanwhile, using TCGA and the Tumor Immune Estimation Resource 2 (TIMER 2), the associations between RRM2 expression, immune infiltration, and immune-related genes were assessed. Additionally, CCK-8, Edu and RT-PCR assays were used to validate that RRM2 acts as an oncogene in liver cancer cells and its association with HBx. A cohort of liver hepatocellular carcinoma (LIHC) patients (n=154) from Huashan Hospital was analyzed for the expression of RRM2 and the association between RRM2 and immune infiltration.

Results

Using the GTEx and TCGA databases, we discovered that 28 tumors expressed RRM2 at significantly higher levels than the corresponding normal tissues. Increased RRM2 expression may be predictive of a poor overall survival (OS) in patients with seven different cancers. GO, KEGG, and GSEA analyses revealed that the biological process of RRM2 was associated with the regulation of carcinogenic processes and immune pathways in a variety of tumor types. The expression of RRM2 was highly correlated with maker genes involved in immune activation and immunosuppression, immune checkpoints, DNA mismatch repair system (MMR), and the infiltration levels of Tregs and macrophages (TAMs), suggesting that the carcinogenic effect of RRM2 may be achieved by regulating immune related genes. Moreover, as demonstrated by CCK-8 and Edu assays, RRM2 was an oncogene in liver cancer cells. We confirmed for the first time that RRM2 was significantly upregulated by HBx, suggesting that RRM2 may be a key regulator of LIHC induced by HBV. IHC analysis validated the upregulated expression of RRM2 protein and its correlation with immune infiltration makers in a LIHC patient cohort.

Conclusion

RRM2 may be a valuable molecular biomarker for predicting prognosis and immunotherapeutic efficacy in pan-cancer, particularly in LIHC.

Dynamic regulation of eEF1A1 acetylation affects colorectal carcinogenesis

The dysregulation of the translation elongation factor families which are responsible for reprogramming of mRNA translation has been shown to contribute to tumor progression. Here, we report that the acetylation of eukaryotic Elongation Factor 1 Alpha 1 (eEF1A1/EF1A1) is required for genotoxic stress response and maintaining the malignancy of colorectal cancer (CRC) cells. The evolutionarily conserved site K439 is identified as the key acetylation site. Tissue expression analysis demonstrates that the acetylation level of eEF1A1 K439 is higher than paired normal tissues. Most importantly, hyperacetylation of eEF1A1 at K439 negatively correlates with CRC patient survival. Mechanistically, CBP and SIRT1 are the major acetyltransferase and deacetylase of eEF1A1. Hyperacetylation of eEF1A1 at K439 shows a significant tumor-promoting effect by increasing the capacity of proliferation, migration, and invasion of CRC cells. Our findings identify the altered post-translational modification at the translation machines as a critical factor in stress response and susceptibility to colorectal carcinogenesis.

The role of protein acetylation in carcinogenesis and targeted drug discovery

Protein acetylation is a reversible post-translational modification, and is involved in many biological processes in cells, such as transcriptional regulation, DNA damage repair, and energy metabolism, which is an important molecular event and is associated with a wide range of diseases such as cancers. Protein acetylation is dynamically regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs) in homeostasis. The abnormal acetylation level might lead to the occurrence and deterioration of a cancer, and is closely related to various pathophysiological characteristics of a cancer, such as malignant phenotypes, and promotes cancer cells to adapt to tumor microenvironment. Therapeutic modalities targeting protein acetylation are a potential therapeutic strategy. This article discussed the roles of protein acetylation in tumor pathology and therapeutic drugs targeting protein acetylation, which offers the contributions of protein acetylation in clarification of carcinogenesis, and discovery of therapeutic drugs for cancers, and lays the foundation for precision medicine in oncology.

Profiles of Acetylation Regulation Genes Contribute to Malignant Progression and Have a Clinical Prognostic Impact on Liver Cancer

Background

Several studies have demonstrated that acetylation was involved in the process of liver cancer. This study aimed to establish an effective predictive prognostic model using acetylation regulation genes in liver cancer.

Methods

Two datasets were downloaded from the Cancer Genome Atlas (TCGA) database and International Cancer Genome Consortium (ICGC) database. Differentially expressed acetylation regulation genes were identified in the TCGA-LIHC dataset, and then, Gene Ontology (GO) functional annotation analysis was used to investigate the molecular mechanism. After grouping the patients into clusters based on consensus clustering, we explored the correlation between clusters and clinical characteristics. A risk model was constructed by the least absolute shrinkage and selection operator (LASSO) regression analysis to calculate the risk score. Patients were divided into high-risk and low-risk groups according to the risk score using the acetylation regulation genes. Data downloaded from LIRI-JP were used for external validation. Univariate and multivariate Cox regressions were performed to identify independent risk factors. A prognostic nomogram was constructed according to the TCGA-LIHC dataset. The effect of HDAC11 expression on the proliferation and migration of liver cancer was detected by the CCK-8 method and cell scratch test, respectively.

Results

Eleven of 29 acetylation regulation genes were identified as upregulated differentially expressed genes. Go enrichment analysis showed that they were involved in "protein and histone deacylation and deacetylation." Patients were categorized into two clusters according to the expression of 29 acetylation regulation genes. Compared with cluster 2, cluster 1 correlated with shorter overall survival (OS) and higher expression. Stage, T stage, grade, gender, age, and follow-up state were significantly different between two clusters. Pathways involved in DNA repair were significantly enriched in cluster 1. The risk score was calculated by HDAC1, HDAC2, HDAC4, HDAC11, HAT1, and SIRT6. Patients in the high-risk group had a worse prognosis in both datasets. Risk score was not only an independent prognostic marker but could also predict the clinicopathological features of liver cancer. A nomogram containing risk score, T stage, and M stage was built to predict overall survival. After transfection with HDAC11 overexpression plasmid, the proliferation ability of HepG2 cells increased, while the migration ability had no change.

Conclusions

Our findings suggested that acetylation regulation genes contribute to malignant progression and have a clinical prognostic impact on liver cancer.

The tumor microenvironment of hepatocellular carcinoma and its targeting strategy by CAR-T cell immunotherapy

Hepatocellular carcinoma (HCC) is the major subtype of liver cancer, which ranks sixth in cancer incidence and third in mortality. Although great strides have been made in novel therapy for HCC, such as immunotherapy, the prognosis remains less than satisfactory. Increasing evidence demonstrates that the tumor immune microenvironment (TME) exerts a significant role in the evolution of HCC and has a non-negligible impact on the efficacy of HCC treatment. In the past two decades, the success in hematological malignancies made by chimeric antigen receptor-modified T (CAR-T) cell therapy leveraging it holds great promise for cancer treatment. However, in the face of a hostile TME in solid tumors like HCC, the efficacy of CAR-T cells will be greatly compromised. Here, we provide an overview of TME features in HCC, discuss recent advances and challenges of CAR-T immunotherapy in HCC.

Roles and regulation of histone acetylation in hepatocellular carcinoma

Hepatocellular Carcinoma (HCC) is the most frequent malignant tumor of the liver, but its prognosis is poor. Histone acetylation is an important epigenetic regulatory mode that modulates chromatin structure and transcriptional status to control gene expression in eukaryotic cells. Generally, histone acetylation and deacetylation processes are controlled by the opposing activities of histone acetyltransferases (HATs) and histone deacetylases (HDACs). Dysregulation of histone modification is reported to drive aberrant transcriptional programmes that facilitate liver cancer onset and progression. Emerging studies have demonstrated that several HDAC inhibitors exert tumor-suppressive properties via activation of various cell death molecular pathways in HCC. However, the complexity involved in the epigenetic transcription modifications and non-epigenetic cellular signaling processes limit their potential clinical applications. This review brings an in-depth view of the oncogenic mechanisms reported to be related to aberrant HCC-associated histone acetylation, which might provide new insights into the effective therapeutic strategies to prevent and treat HCC.

HBx Mediated Increase of DDX17 Contributes to HBV-Related Hepatocellular Carcinoma Tumorigenesis

HBV is strongly associated with HCC development and DEAD-box RNA helicase 17 (DDX17) is a very important member of the DEAD box family that plays key roles in HCC development by promoting cancer metastasis. However, the important role of DDX17 in the pathogenesis of HBV-related HCC remains unclear. In this study, we investigated the role of DDX17 in the replication of HBV and the development of HBV-associated HCC. Based on data from the GEO database and HBV-infected cells, we found that DDX17 was upregulated by the HBV viral protein X (HBx). Mechanistically, increased DDX17 expression promoted HBV replication and transcription by upregulating ZWINT. Further study showed that DDX17 could promote HBx-mediated HCC metastasis. Finally, the promotive effect of DDX17 on HBV and HBV-related HCC was confirmed in vivo. In summary, the results revealed the novel role of DDX17 in the replication of HBV and the metastasis of HBV-associated HCC.

HBx increases chromatin accessibility and ETV4 expression to regulate dishevelled-2 and promote HCC progression

Hepatitis B virus (HBV) infection is the predominant causes of hepatocellular carcinoma (HCC). HBV X protein (HBx), as the most frequently integrated viral gene sequence following HBV infection, plays a critical role in the pathogenesis of HCC. H3K27ac is a characteristic marker for identifying active enhancers and even indicates chromatin accessibility associated with super-enhancers (SEs). In this study, H3K27ac ChIP-seq was applied for high-quality SE annotation of HBx-induced SEs and chromatin accessibility evaluation. The results indicated that HBx preferentially affects enrichment of H3K27ac in transcription factor signaling pathway genes, including ETV4. RNA-seq indicated that ETV4 is upregulated by HBx and that upregulated ETV4 promotes HCC progression. Interestingly, ETV4 was also included in the 568 cancer driver gene pool obtained by the Integrative OncoGenomics pipeline. However, the biological function and mechanism of ETV4 remain incompletely understood. In vivo and in vitro, we found that increased ETV4 expression promotes HCC cell migration and invasion by upregulating DVL2 and activating Wnt/β-catenin. The mRNA and protein levels of ETV4 are higher in tumor tissues compared with adjacent tissues, and high expression of ETV4 is associated with poor prognosis in HCC patients. In summary, we first confirm that ETV4 is significantly upregulated by HBx and involved in SE-associated chromatin accessibility. Increased expression of ETV4 promotes HCC cell invasion and metastasis by upregulating DVL2. The present study provides insight into the ETV4-DVL2-β-catenin axis in HBV-related HCC, which will be helpful for treating patients with aggressive HCC.

Potential Biomarkers for Liver Cancer Diagnosis Based on Multi-Omics Strategy

Liver cancer is the fourth leading cause of cancer-related death worldwide. Hepatocellular carcinoma (HCC) accounts for about 85%-90% of all primary liver malignancies. However, only 20-30% of HCC patients are eligible for curative therapy mainly due to the lack of early-detection strategies, highlighting the significance of reliable and accurate biomarkers. The integration of multi-omics became an important tool for biomarker screening and unique alterations in tumor-associated genes, transcripts, proteins, post-translational modifications and metabolites have been observed. We here summarized the novel biomarkers for HCC diagnosis based on multi-omics technology as well as the clinical significance of these potential biomarkers in the early detection of HCC.

Metabolic Reprogramming and Risk Stratification of Hepatocellular Carcinoma Studied by Using Gas Chromatography-Mass Spectrometry-Based Metabolomics

Hepatocellular carcinoma (HCC) displays a high degree of metabolic and phenotypic heterogeneity and has dismal prognosis in most patients. Here, a gas chromatography-mass spectrometry (GC-MS)-based nontargeted metabolomics method was applied to analyze the metabolic profiling of 130 pairs of hepatocellular tumor tissues and matched adjacent noncancerous tissues from HCC patients. A total of 81 differential metabolites were identified by paired nonparametric test with false discovery rate correction to compare tumor tissues with adjacent noncancerous tissues. Results demonstrated that the metabolic reprogramming of HCC was mainly characterized by highly active glycolysis, enhanced fatty acid metabolism and inhibited tricarboxylic acid cycle, which satisfied the energy and biomass demands for tumor initiation and progression, meanwhile reducing apoptosis by counteracting oxidative stress. Risk stratification was performed based on the differential metabolites between tumor and adjacent noncancerous tissues by using nonnegative matrix factorization clustering. Three metabolic clusters displaying different characteristics were identified, and the cluster with higher levels of free fatty acids (FFAs) in tumors showed a worse prognosis. Finally, a metabolite classifier composed of six FFAs was further verified in a dependent sample set to have potential to define the patients with poor prognosis. Together, our results offered insights into the molecular pathological characteristics of HCC.

Comprehensive clinicopathologic study of alpha fetoprotein-expression in a large cohort of patients with hepatocellular carcinoma

Alpha fetoprotein (AFP) is the most widely used diagnostic and prognostic serum biomarker for hepatocellular carcinoma (HCC). Despite its wide clinical use, a systematic clinicopathologic study comparing AFP expression in HCC in situ with serum AFP concentrations has not yet been conducted. To analyze AFP expression in a large cohort of patients by immunohistochemistry, we employed a comprehensive tissue microarray with 871 different HCCs of overall 561 patients. AFP immunoreactivity was detected in only about 20% of HCC core biopsies, whereas 48.9% of the patients displayed increased serum values (>12 ng/mL). Immunostaining of whole tumor slides revealed that lack of detectable immunoreactivity in core biopsies in a subgroup of patients with elevated AFP serum concentrations is due to heterogeneous intratumoral AFP expression. Serum AFP concentrations and AFP expression in situ were moderately correlated (Spearman's rank correlation coefficient .53, P = 1.2e - 13). High AFP expression detected in serum (>227.3 ng/mL) or in situ predicted unfavorable prognosis and was associated with vascular invasion, higher tumor grade and macrotrabecular-massive tumor subtype. Multivariate and ROC curve analysis demonstrated that high AFP concentrations in serum is an independent prognostic parameter and represents the more robust prognostic predictor in comparison to AFP immunostaining of core biopsies. The previously published vessels encapsulating tumor clusters (VETC) pattern turned out as an additional, statistically independent prognostic parameter. AFP-positivity was associated with increased tumor cell apoptosis, but not with increased vascular densities. Additionally, AFP-positive tumors displayed increased proliferation rates, urea cycle dysregulation and signs of genomic instability, which may constitute the basis for their increased aggressiveness.

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

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

Overexpression of EWSR1 (Ewing sarcoma breakpoint region 1/EWS RNA binding protein 1) predicts poor survival in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent malignant neoplasms with high relapse and mortality rate. It is of great importance to identify novel and effective molecular markers to predict prognosis for the treatment of HCC. The Ewing sarcoma breakpoint region 1 (EWSR1) gene is well known to fuse with various partner genes and involved in promoting the development of multiple sarcomas, especially the Ewing sarcoma family of tumors. Nevertheless, seldom studies have focused on the role of EWSR1 in cancers of epithelial origin, let alone in HCC. In the current study, the transcriptional and clinical data of EWSR1 in HCC patients were obtained from TCGA and GEO databases, as well as 124 cases from the department of Pathology of Sichuan Jianyang People's Hospital. Kaplan-Meier and Cox regression analysis were used to assess patient prognosis. EWSR1 mRNA levels were significantly upregulated in HCC tissues than in normal liver tissues (P < 0.001). The TCGA database analysis showed upregulation of EWSR1 was associated with histological grade, pathologic T stage and death, in addition to that, the T staging, N staging, TNM staging, Ki67, AFP expression were extremely higher in the EWSR1 over-expression group in our cohort. Univariate and multivariate Cox hazard regression analysis results revealed that EWSR1 was an independent prognostic factor for OS in HCC, and bioinformatics analysis showed RNA splicing process represented the major function and pathway. In conclusion, our data showed EWSR1 could serve as a novel promising prognostic biomarker for HCC patients.Abbreviations: AFP, Alpha-fetoprotein; CCL14, C-C motif chemokine ligand 14; CK19, Cytokeratin 19; CI, coefficient interval; COL1A1, Collagen 1A1; DFS, Disease-free Survival; EWSR1, Ewing Sarcoma breakpoint region 1/EWS RNA binding protein 1; FLI1, Friend leukemia virus integration 1; GEO, Gene Expression Omnibus; GO, Gene Ontology; HCC, Hepatocellular carcinoma; HR, Hazard ratio; KEGG, Kyoto Encyclopedia of Genes and Genomes; mRNA, messenger Ribonucleic Acid; N, nodule; OS, Overall survival; PPI, Protein-Protein Interaction analysis; RNA, Ribonucleic Acid; SD, Standard Deviation; TCGA, The Cancer Genome Atlas; T, tumor; TNM, tumor-nodule-metastasis.

Role of Nitric Oxide in Gene Expression Regulation during Cancer: Epigenetic Modifications and Non-Coding RNAs

Nitric oxide (NO) has been identified and described as a dual mediator in cancer according to dose-, time- and compartment-dependent NO generation. The present review addresses the different epigenetic mechanisms, such as histone modifications and non-coding RNAs (ncRNAs), miRNA and lncRNA, which regulate directly or indirectly nitric oxide synthase (NOS) expression and NO production, impacting all hallmarks of the oncogenic process. Among lncRNA, HEIH and UCA1 develop their oncogenic functions by inhibiting their target miRNAs and consequently reversing the inhibition of NOS and promoting tumor proliferation. The connection between miRNAs and NO is also involved in two important features in cancer, such as the tumor microenvironment that includes key cellular components such as tumor-associated macrophages (TAMs), cancer associated fibroblasts (CAFs) and cancer stem cells (CSCs).

P300-mediated NEDD4 acetylation drives ebolavirus VP40 egress by enhancing NEDD4 ligase activity

The final stage of Ebola virus (EBOV) replication is budding from host cells, where the matrix protein VP40 is essential for driving this process. Many post-translational modifications such as ubiquitination are involved in VP40 egress, but acetylation has not been studied yet. Here, we characterize NEDD4 is acetylated at a conserved Lys667 mediated by the acetyltransferase P300 which drives VP40 egress process. Importantly, P300-mediated NEDD4 acetylation promotes NEDD4-VP40 interaction which enhances NEDD4 E3 ligase activity and is essential for the activation of VP40 ubiquitination and subsequent egress. Finally, we find that Zaire ebolavirus production is dramatically reduced in P300 knockout cell lines, suggesting that P300-mediated NEDD4 acetylation may have a physiological effect on Ebola virus life cycle. Thus, our study identifies an acetylation-dependent regulatory mechanism that governs VP40 ubiquitination and provides insights into how acetylation controls EBOV VP40 egress.

Ebola virus (EBOV) is one of the deadliest pathogens, causing fatal hemorrhagic fever diseases in humans and primates. In this study, we find that P300-mediated NEDD4 acetylation facilitates EBOV egress. Acetylation promotes NEDD4-VP40 interactions which enhances NEDD4 E3 ligase activity and is essential for the activation of VP40 ubiquitination and subsequent egress. This study implies that inhibitory effect of acetylation can be regarded as an attractive candidate of drug target for the treatment of Ebola virus disease.

Potential of HBx Gene for Hepatocarcinogenesis in Noncirrhotic Liver

Current treatments for hepatitis B virus (HBV) using nucleos(t)ide analogs cannot eliminate the risk of hepatocellular carcinoma (HCC) development. As HBV-associated HCC can develop even in the absence of liver cirrhosis, HBV is regarded to possess direct oncogenic potential. HBV regulatory protein X (HBx) has been identified as a primary mediator of HBV-mediated hepatocarcinogenesis. A fragment of the HBV genome that contains the coding region of HBx is commonly integrated into the host genome, resulting in the production of aberrant proteins and subsequent hepatocarcinogenesis. Besides, HBx interferes with the host DNA or deoxyribonucleic acid damage repair pathways, signal transduction, epigenetic regulation of gene expression, and cancer immunity, thereby promoting carcinogenesis in the noncirrhotic liver. However, numerous molecules and pathways have been implicated in the development of HBx-associated HCC, suggesting that the mechanisms underlying HBx-mediated hepatocarcinogenesis remain to be elucidated.

AFP-Inhibiting Fragments for Drug Delivery: The Promise and Challenges of Targeting Therapeutics to Cancers

Alpha fetoprotein (AFP) plays a key role in stimulating the growth, metastasis and drug resistance of hepatocellular carcinoma (HCC). AFP is an important target molecule in the treatment of HCC. The application of AFP-derived peptides, AFP fragments and recombinant AFP (AFP-inhibiting fragments, AIFs) to inhibit the binding of AFP to intracellular proteins or its receptors is the basis of a new strategy for the treatment of HCC and other cancers. In addition, AIFs can be combined with drugs and delivery agents to target treatments to cancer. AIFs conjugated to anticancer drugs not only destroy cancer cells with these drugs but also activate immune cells to kill cancer cells. Furthermore, AIF delivery of drugs relieves immunosuppression and enhances chemotherapy effects. The synergism of immunotherapy and targeted chemotherapy is expected to play an important role in enhancing the treatment effect of patients with cancer. AIF delivery of drugs will be an available strategy for the targeted treatment of cancer in the future.

Profibrotic Signaling and HCC Risk during Chronic Viral Hepatitis: Biomarker Development

Despite breakthroughs in antiviral therapies, chronic viral hepatitis B and C are still the major causes of liver fibrosis and hepatocellular carcinoma (HCC). Importantly, even in patients with controlled infection or viral cure, the cancer risk cannot be fully eliminated, highlighting a persisting oncogenic pressure imposed by epigenetic imprinting and advanced liver disease. Reliable and minimally invasive biomarkers for early fibrosis and for residual HCC risk in HCV-cured patients are urgently needed. Chronic infection with HBV and/or HCV dysregulates oncogenic and profibrogenic signaling within the host, also displayed in the secretion of soluble factors to the blood. The study of virus-dysregulated signaling pathways may, therefore, contribute to the identification of reliable minimally invasive biomarkers for the detection of patients at early-stage liver disease potentially complementing existing noninvasive methods in clinics. With a focus on virus-induced signaling events, this review provides an overview of candidate blood biomarkers for liver disease and HCC risk associated with chronic viral hepatitis and epigenetic viral footprints.

Quantitative acetylome analysis reveals histone modifications that may predict prognosis in hepatitis B-related hepatocellular carcinoma

Lysine acetylation (Kac) as an important posttranslational modification of histones is essential for the regulation of gene expression in hepatocellular carcinoma (HCC). However, the atlas of whole acetylated proteins in HCC tissues and the difference in protein acetylation between normal human tissues and HCC tissues are unknown. In this report, we characterized the proteome and acetyl proteome (acetylome) profile of normal, paracancerous, and HCC liver tissues in human clinical samples by quantitative proteomics techniques. We identified 6781 acetylation sites of 2582 proteins and quantified 2492 acetylation sites of 1190 proteins in normal, paracancerous, and HCC liver tissues. Among them, 15 proteins were multiacetylated with more than 10 lysine residues. The histone acetyltransferases p300 and CBP were found to be hyperacetylated in hepatitis B virus pathway. Moreover, we found that 250 Kac sites of 214 proteins were upregulated and 662 Kac sites of 451 proteins were downregulated in HCC compared with normal liver tissues. Additionally, the acetylation levels of lysine 120 in histone H2B (H2BK120ac), lysine 18 in histone H3.3 (H3.3K18ac), and lysine 77 in histone H4 (H4K77ac) were increased in HCC. Interestingly, the higher levels of H2BK120ac, H3.3K18ac, and H4K77ac were significantly associated with worse prognosis, such as poorer survival and higher recurrence in an independent clinical cohort of HCC patients. Overall, this study lays a foundation for understanding the functions of acetylation in HCC and provides potential prognostic factors for the diagnosis and therapy of HCC.

Alpha-Fetoprotein Binding Mucin and Scavenger Receptors: An Available Bio-Target for Treating Cancer

Alpha-fetoprotein (AFP) entrance into cancer cells is mediated by AFP receptors (AFPRs) and exerts malignant effects. Therefore, understanding the structure of AFPRs will facilitate the development of rational approaches for vaccine design, drug delivery, antagonizing immune suppression and diagnostic imaging to treat cancer effectively. Throughout the last three decades, the identification of universal receptors for AFP has failed due to their complex carbohydrate polymer structures. Here, we focused on the two types of binding proteins or receptors that may serve as AFPRs, namely, the A) mucin receptors family, and B) the scavenger family. We presented an informative review with detailed descriptions of the signal transduction, cross-talk, and interplay of various transcription factors which highlight the downstream events following AFP binding to mucin or scavenger receptors. We mainly explored the underlying mechanisms involved mucin or scavenger receptors that interact with AFP, provide more evidence to support these receptors as tumor AFPRs, and establish a theoretical basis for targeting therapy of cancer.