PRMT9 promotes hepatocellular carcinoma invasion and metastasis via activating PI3K/Akt/GSK-3β/Snail signaling

Biomedical effects of protein arginine methyltransferase inhibitors

Protein arginine methyltransferases (PRMTs) are enzymes that catalyze the methylation of arginine residues in eukaryotic proteins, playing critical roles in modulating diverse cellular processes. The importance of PRMTs in the incidence and progression of a wide range of diseases, particularly cancers, such as breast, liver, lung, colorectal cancer, lymphoma, leukemia, and acute myeloid leukemia is increasingly recognized. This underscores the critical need for the development of effective PRMT inhibitors as therapeutic intervention. The field of PRMT inhibitors is in the rapidly growing phase and it is necessary to conduct a summative review of how the so-far developed inhibitors impact PRMT functions and cellular physiology. Our review aims to summarize molecular action mechanisms of these PRMT inhibitors and particularly elaborate their triggered biomedical effects. We describe the cellular phenotype consequences of select PRMT inhibitors across various disease models, thereby providing an understanding of the pharmacological mechanisms underpinning PRMT inhibition. The promising effects of PRMT5 inhibitors in targeted therapy of methylthioadenosine phosphorylase-deleted cancers are particularly highlighted. At last, we provide a perspective on the challenges and further opportunities of developing and applying novel PRMT inhibitors for clinical advancement.

Phase Ib study of the oral PI3Kδ inhibitor linperlisib in patients with advanced solid tumors

BACKGROUND

Patients with advanced solid tumors have a suboptimal prognosis. This study investigated the safety and feasibility of linperlisib, a selective phosphatidylinositol 3-kinase delta isoform (PI3Kδ) inhibitor, for treating patients with advanced solid tumors.

METHODS

In this phase Ib, single-arm, open-label, multi-center clinical trial, patients with histologically confirmed advanced solid tumors from eight centers in China were enrolled to receive oral linperlisib (80 mg/day). The primary endpoint was safety.

RESULTS

Between August 2019 and June 2022, 94 patients were enrolled in the trial and received the study treatment. The most common (≥ 20%) treatment emergent adverse events (TEAEs) of all grades irrespective of causality were increased aspartate aminotransferase (AST) (26.6%), proteinuria (26.6%), decreased appetite (25.5%), increased alanine aminotransferase (ALT) (22.3%), weight loss (21.3%), and anemia (21.3%). The most common grade ≥ 3 TEAEs were diarrhea (4.3%), increased AST (3.2%), increased ALT (3.2%), neutropenia (3.2%), anemia (3.2%), increased blood alkaline phosphatase (3.2%). The objective response rate (ORR) was 1.1% (95% confidence interval [CI] 0.0-5.8), and the disease control rate (DCR) was 37.2% (95% CI 27.5-47.8). As of the data cutoff, the median follow-up time was 4.2 months (95% CI 2.8-6.9). The median progression-free survival (PFS) was 1.85 months (95% CI 1.79-1.88). The median overall survival (OS) was not reached.

CONCLUSION

Linperlisib showed an acceptable safety profile and preliminary clinical benefit in patients with a range of advanced solid tumors. Further studies of linperlisib safety and efficacy are warranted.

A new pathway for ferroptosis regulation: The PRMTs

Protein arginine methyltransferases (PRMTs) play an essential role in the regulation of ferroptosis, a form of programmed cell death characterized by abnormal iron ion metabolism, lipid peroxidation, and DNA damage. Through methylation, PRMTs modify specific proteins, thereby altering their activity, localizations, or interactions with other molecules to control the ferroptosis process. This study was conducted to provide a comprehensive overview of the relationship between PRMTs and ferroptosis, with a focus on the mechanisms by which PRMTs regulate ferroptosis and their effect on this cell death pathway. Currently, only a few studies have been conducted on the regulation of ferroptosis by PRMTs. However, this review provides insights into the effects of PRMTs on ferroptosis regulators, suggesting that the regulation of ferroptosis by PRMTs holds potential as a new therapeutic target for related diseases.

Targeting non-histone methylation in gastrointestinal cancers: From biology to clinic

Gastrointestinal (GI) cancers, encompassing a range of malignancies within the digestive tract, present significant challenges in both diagnosis and treatment, reflecting a dire need for innovative therapeutic strategies. This article delves into the profound influence of non-histone methylation on the pathogenesis and evolution of gastrointestinal (GI) cancers. Non-histone proteins, undergoing methylation by enzymes such as Protein Arginine Methyltransferases (PRMTs) and Lysine Methyltransferases (KMTs), play pivotal roles in cellular signaling, metabolism, chromatin remodeling, and other processes crucial for cancer development. This review illuminates the complex mechanisms by which non-histone methylation affects key aspects of tumor biology, including oncogenesis, growth, proliferation, invasion, migration, metabolic reprogramming, and immune escape in GI malignancies. Highlighting recent discoveries, this work underscores the importance of non-histone methylation in cancer biology and its potential as a target for innovative therapeutic strategies aimed at improving outcomes for patients with GI cancers.

Deciphering the potential role of post-translational modifications of histones in gastrointestinal cancers: a proteomics-based review with therapeutic challenges and opportunities

Oncogenesis is a complex and multi-step process, controlled by several factors including epigenetic modifications. It is considered that histone modifications are critical components in the regulation of gene expression, protein functions, and molecular interactions. Dysregulated post-translationally modified histones and the related enzymatic systems are key players in the control of cell proliferation and differentiation, which are associated with the onset and progression of cancers. The most of traditional investigations on cancer have focused on mutations of oncogenes and tumor suppressor genes. However, increasing evidence indicates that epigenetics, especially histone post-translational modifications (PTMs) play important roles in various cancer types. Mass spectrometry-based proteomic approaches have demonstrated tremendous potential in PTMs profiling and quantitation in different biological systems. In this paper, we have made a proteomics-based review on the role of histone modifications involved in gastrointestinal cancers (GCs) tumorigenesis processes. These alterations function not only as diagnostic or prognostic biomarkers for GCs, but a deeper comprehension of the epigenetic regulation of GCs could facilitate the treatment of this prevalent malignancy through the creation of more effective targeted therapies.

Arginine methylation and respiratory disease

Arginine methylation, a vital post-translational modification, plays a pivotal role in numerous cellular functions such as signal transduction, DNA damage response and repair, regulation of gene transcription, mRNA splicing, and protein interactions. Central to this modification is the role of protein arginine methyltransferases (PRMTs), which have been increasingly recognized for their involvement in the pathogenesis of various respiratory diseases. This review begins with an exploration of the biochemical underpinnings of arginine methylation, shedding light on the intricate molecular regulatory mechanisms governed by PRMTs. It then delves into the impact of arginine methylation and the dysregulation of arginine methyltransferases in diverse pulmonary disorders. Concluding with a focus on the therapeutic potential and recent advancements in PRMT inhibitors, this article aims to offer novel perspectives and therapeutic avenues for the management and treatment of respiratory diseases.

Metastasis and basement membrane-related signature enhances hepatocellular carcinoma prognosis and diagnosis by integrating single-cell RNA sequencing analysis and immune microenvironment assessment

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and second leading cause of cancer-related deaths worldwide. The heightened mortality associated with HCC is largely attributed to its propensity for metastasis, which cannot be achieved without remodeling or loss of the basement membrane (BM). Despite advancements in targeted therapies and immunotherapies, resistance and limited efficacy in late-stage HCC underscore the urgent need for better therapeutic options and early diagnostic biomarkers. Our study aimed to address these gaps by investigating and evaluating potential biomarkers to improve survival outcomes and treatment efficacy in patients with HCC.

METHOD

In this study, we collected the transcriptome sequencing, clinical, and mutation data of 424 patients with HCC from The Cancer Genome Atlas (TCGA) and 240 from the International Cancer Genome Consortium (ICGC) databases. We then constructed and validated a prognostic model based on metastasis and basement membrane-related genes (MBRGs) using univariate and multivariate Cox regression analyses. Five immune-related algorithms (CIBERSORT, QUANTISEQ, MCP counter, ssGSEA, and TIMER) were then utilized to examine the immune landscape and activity across high- and low-risk groups. We also analyzed Tumor Mutation Burden (TMB) values, Tumor Immune Dysfunction and Exclusion (TIDE) scores, mutation frequency, and immune checkpoint gene expression to evaluate immune treatment sensitivity. We analyzed integrin subunit alpha 3 (ITGA3) expression in HCC by performing single-cell RNA sequencing (scRNA-seq) analysis using the TISCH 2.0 database. Lastly, wound healing and transwell assays were conducted to elucidate the role of ITGA3 in tumor metastasis.

RESULTS

Patients with HCC were categorized into high- and low-risk groups based on the median values, with higher risk scores indicating worse overall survival. Five immune-related algorithms revealed that the abundance of immune cells, particularly T cells, was greater in the high-risk group than in the low-risk group. The high-risk group also exhibited a higher TMB value, mutation frequency, and immune checkpoint gene expression and a lower tumor TIDE score, suggesting the potential for better immunotherapy outcomes. Additionally, scRNA-seq analysis revealed higher ITGA3 expression in tumor cells compared with normal hepatocytes. Wound healing scratch and transwell cell migration assays revealed that overexpression of the MBRG ITGA3 enhanced migration of HCC HepG2 cells.

CONCLUSION

This study established a direct molecular correlation between metastasis and BM, encompassing clinical features, tumor microenvironment, and immune response, thereby offering valuable insights for predicting clinical outcomes and immunotherapy responses in HCC.

UBQLN4 promotes the proliferation and invasion of non-small cell lung cancer cell by regulating PI3K/AKT pathway

BACKGROUND

Ubiquilin-4 (UBQLN4), a member of the ubiquilin family, has received limited attention in cancer research to date. Here, we investigated for the first time the functional role and mechanism of UBQLN4 in non-small cell lung cancer (NSCLC).

METHODS

The Cancer Genome Atlas (TCGA) database was employed to validate UBQLN4 as a differentially expressed gene. Expression differences of UBQLN4 in NSCLC cells and tissues were assessed using immunohistochemistry (IHC) experiment and western blotting (WB) experiment. Kaplan-Meier analysis was conducted to examine the association between UBQLN4 expression and NSCLC prognosis. Functional analyses of UBQLN4 were performed through cell counting kit-8 (CCK-8), colony formation, and transwell invasion assays. The impact of UBQLN4 on tumor-associated signaling pathways was assessed using the path scan intracellular signaling array. In vivo tumorigenesis experiments were conducted to further investigate the influence of UBQLN4 on tumor formation.

RESULTS

UBQLN4 exhibited up-regulation in both NSCLC tissues and cells. Additionally, over-expression of UBQLN4 was associated with an unfavorable prognosis in NSCLC patients. Functional loss analyses demonstrated that inhibiting UBQLN4 could suppress the proliferation and invasion of NSCLC cells in both in vitro and in vivo settings. Conversely, functional gain experiments yielded opposite results. Path scan intracellular signaling array results suggested that the role of UBQLN4 is associated with the PI3K/AKT pathway, a correlation substantiated by in vitro and in vivo tumorigenesis experiments.

CONCLUSION

We validated that UBQLN4 promotes proliferation and invasion of NSCLC cells by activating the PI3K/AKT pathway, thereby facilitating the progression of NSCLC. These findings underscore the potential of targeting UBQLN4 as a therapeutic strategy for NSCLC.

Dysregulation of arginine methylation in tumorigenesis

Protein methylation, similar to DNA methylation, primarily involves post-translational modification (PTM) targeting residues of nitrogen-containing side-chains and other residues. Protein arginine methylation, occurred on arginine residue, is mainly mediated by protein arginine methyltransferases (PRMTs), which are ubiquitously present in a multitude of organisms and are intricately involved in the regulation of numerous biological processes. Specifically, PRMTs are pivotal in the process of gene transcription regulation, and protein function modulation. Abnormal arginine methylation, particularly in histones, can induce dysregulation of gene expression, thereby leading to the development of cancer. The recent advancements in modification mediated by PRMTs and cancer research have had a profound impact on our understanding of the abnormal modification involved in carcinogenesis and progression. This review will provide a defined overview of these recent progression, with the aim of augmenting our knowledge on the role of PRMTs in progression and their potential application in cancer therapy.

Network pharmacology analysis and experimental verification of the antitumor effect and molecular mechanism of isocryptomerin on HepG2 cells

Isocryptomerin (ISO) is a flavonoid isolated from the natural medicine Selaginellae Herba, which has various pharmacological activities. This study investigated the antitumor effect and underlying molecular mechanism of ISO on hepatocellular carcinoma (HCC) HepG2 cells. The cell viability assay revealed that ISO has a considerable killing effect on HCC cell lines. The apoptosis assay showed that ISO induced mitochondria-dependent apoptosis through the Bad/cyto-c/cleaved (cle)-caspase-3/cleaved (cle)-PARP pathway. The network pharmacological analysis found 13 key target genes, and epidermal growth factor receptor (EGFR), AKT, mitogen-activated protein kinase (MAPK), and reactive oxygen species (ROS) signaling pathways were strongly associated with ISO against HCC. Further verification of the results showed that ISO induced apoptosis by increasing p-p38 and p-JNK expression and decreasing p-EGFR, p-SRC, p-ERK, and p-STAT3 expression. Furthermore, ISO induced G0/G1 phase arrest by downregulating p-AKT, Cyclin D, and CDK 4 expression and upregulating p21 and p27 expression in HepG2 cells. Moreover, ISO inhibited HepG2 cell migration by decreasing p-GSK-3β, β-catenin, and N-cadherin expression and increasing E-cadherin expression. Additionally, ISO promoted ROS accumulation in HepG2 cells, and ISO-induced apoptosis, arrest cell cycle, and inhibition of migration were reversed by an ROS scavenger, N-acetyl- l-cysteine. Overall, ISO induced cell apoptosis and cell cycle arrest and inhibited cell migration by ROS-mediated EGFR, AKT, and MAPK signaling pathways in HepG2 cells.

Overview of the development of protein arginine methyltransferase modulators: Achievements and future directions

Protein methylation is a post-translational modification (PTM) that organisms undergo. This process is considered a part of epigenetics research. In recent years, there has been an increasing interest in protein methylation, particularly histone methylation, as research has advanced. Methylation of histones is a dynamic process that is subject to fine control by histone methyltransferases and demethylases. In addition, many non-histone proteins also undergo methylation, and these modifications collectively regulate physiological phenomena, including RNA transcription, translation, signal transduction, DNA damage response, and cell cycle. Protein arginine methylation is a crucial aspect of protein methylation, which plays a significant role in regulating the cell cycle and repairing DNA. It is also linked to various diseases. Therefore, protein arginine methyltransferases (PRMTs) that are involved in this process have gained considerable attention as a potential therapeutic target for treating diseases. Several PRMT inhibitors are in phase I/II clinical trials. This paper aims to introduce the structure, biochemical functions, and bioactivity assays of PRMTs. Additionally, we will review the structure-function of currently popular PRMT inhibitors. Through the analysis of various data on known PRMT inhibitors, we hope to provide valuable assistance for future drug design and development.

A hsa_circ_001726 axis regulated by E2F6 contributes to metastasis of hepatocellular carcinoma

BACKGROUND

CircRNAs participate in the development of hepatocellular carcinoma (HCC). This work aims to explore the key tumor promoting circRNA as a gene therapy target.

METHODS

The differentially expressed gene circRNAs in HCC tumor tissues was identified by mining GSE121714 dataset. EdU staining, wound healing, transwell invasion assay, TUNEL staining and western blotting examined proliferation, migration, invasion, apoptosis and epithelial mesenchymal transition (EMT). Xenograft mouse model and orthotopic transplantation tumor mouse model were constructed to verify the role of hsa_circ_001726 in growth and metastasis of HCC. The relationship among CCT2, E2F6, hsa_circ_001726, miR-671-5p and PRMT9 was identified by RNA-fluorescence in situ hybridization, luciferase reporter assay and RNA Immunoprecipitation.

RESULTS

Eleven differentially expressed circRNAs were found in HCC tumors. Among them, hsa_circ_001726 was highly expressed in HCC tumors and cells, which was transcribed from CCT2. As a transcription factor of CCT2, E2F6 knockdown inactivated CCT2 promoter and reduced hsa_circ_001726 expression. Moreover, hsa_circ_001726 elevated PRMT9 expression by sponging miR-671-5p, and then activated Notch signaling pathway. Additionally, hsa_circ_001726 deficiency repressed malignant phenotypes of HCC cells, including proliferation, migration, invasion, EMT and apoptosis. In vivo, hsa_circ_001726 deficiency reduced tumor growth and lung metastasis of HCC in xenograft mouse models and orthotopic transplantation tumor mouse models.

CONCLUSION

Hsa_circ_001726 functioned as an oncogene in HCC, which was derived from CCT2 and regulated by E2F6. Hsa_circ_001726 elevated PRMT9 expression by sponging miR-671-5p, and then activated Notch signaling pathway, thereby accelerating malignant phenotypes of HCC. Therefore, targeting hsa_circ_001726 may be a new avenue for HCC treatment.

EMT-related gene risk model establishment for prognosis and drug treatment efficiency prediction in hepatocellular carcinoma

This study was designed to evaluate the prognosis and pharmacological therapy sensitivity of epithelial mesenchymal transition-related genes (EMTRGs) that obtained from the EMTome database in hepatocellular carcinoma (HCC) using bioinformatical method. The expression status of EMTRGs were also investigated using the clinical information of HCC patients supported by TCGA database and the ICGC database to establish the TCGA cohort as the training set and the ICGC cohort as the validation set. Analyze the EMTRGs between HCC tissue and liver tissue in the TCGA cohort in the order of univariate COX regression, LASSO regression, and multivariate COX regression, and construct a risk model for EMTRGs. In addition, enrichment pathways, gene mutation status, immune infiltration, and response to drugs were also analyzed in the high-risk and low-risk groups of the TCGA cohort, and the protein expression status of EMTRGs was verified. The results showed a total of 286 differentially expressed EMTRGs in the TCGA cohort, and EZH2, S100A9, TNFRSF11B, SPINK5, and CCL21 were used for modeling. The TCGA cohort was found to have a worse outcome in the high-risk group of HCC patients, and the ICGC cohort confirmed this finding. In addition, EMTRGs risk score was shown to be an independent prognostic factor in both cohorts by univariate and multivariate COX regression. The results of GSEA analysis showed that most of the enriched pathways in the high-risk group were associated with tumor, and the pathways enriched in the low-risk group were mainly associated with metabolism. Patients in various risk groups had varying immunological conditions, and the high-risk group might benefit more from targeted treatments. To sum up, the EMTRGs risk model was developed to forecast the prognosis for HCC patients, and the model might be useful in assisting in the choice of treatment drugs for HCC patients.

The protein arginine methyltransferase family (PRMTs) regulates metastases in various tumors: From experimental study to clinical application

Tumor metastasis is the leading cause of mortality among advanced cancer patients. Understanding its mechanisms and treatment strategies is vital for clinical application. Arginine methylation, a post-translational modification catalyzed by protein arginine methyltransferases (PRMTs), is implicated in diverse physiological processes and disease progressions. Previous research has demonstrated PRMTs' involvement in tumor occurrence, progression, and metastasis. This review offers a comprehensive summary of the relationship between PRMTs, prognosis, and metastasis in various cancers. Our focus centers on elucidating the molecular mechanisms through which PRMTs regulate tumor metastasis. We also discuss relevant clinical trials and effective PRMT inhibitors, including chemical compounds, long non-coding RNA (lncRNA), micro-RNA (miRNA), and nanomaterials, for treating tumor metastasis. While a few studies present conflicting results, the overall trajectory suggests that inhibiting arginine methylation exhibits promise in curtailing tumor metastasis across various cancers. Nonetheless, the underlying mechanisms and molecular interactions are diverse. The development of inhibitors targeting arginine methylation, along with the progression of clinical trials, holds substantial potential in the field of tumor metastasis, meriting sustained attention.

Identification of a Protein Arginine Methyltransferase 7 (PRMT7)/Protein Arginine Methyltransferase 9 (PRMT9) Inhibitor

Less studied than the other protein arginine methyltransferase isoforms, PRMT7 and PRMT9 have recently been identified as important therapeutic targets. Yet, most of their biological roles and functions are still to be defined, as well as the structural requirements that could drive the identification of selective modulators of their activity. We recently described the structural requirements that led to the identification of potent and selective PRMT4 inhibitors spanning both the substrate and the cosubstrate pockets. The reanalysis of the data suggested a PRMT7 preferential binding for shorter derivatives and prompted us to extend these structural studies to PRMT9. Here, we report the identification of the first potent PRMT7/9 inhibitor and its binding mode to the two PRMT enzymes. Label-free quantification mass spectrometry confirmed significant inhibition of PRMT activity in cells. We also report the setup of an effective AlphaLISA assay to screen small molecule inhibitors of PRMT9.

Arginine methylation of HSPA8 by PRMT9 inhibits ferroptosis to accelerate hepatitis B virus-associated hepatocellular carcinoma progression

BACKGROUND

The hepatitis B virus X (HBx) protein is an established cause of hepatitis B virus (HBV)-induced hepatocellular carcinoma (HCC). Whether arginine methylation regulates ferroptosis involved in HBx-induced HCC progression has not been reported. This study aimed to explore whether HBx-regulated protein arginine methyltransferase 9 (PRMT9) mediates the involvement of ferroptosis in the development of HCC.

METHODS AND RESULTS

HBx inhibited ferroptosis through promoting PRMT9 expression in HCC cells. PRMT9 suppressed ferroptosis to accelerate HCC progression in vivo. PRMT9 targeted HSPA8 and enhanced arginine methylation of HSPA8 at R76 and R100 to regulate ferroptosis in HCC. HSPA8 overexpression altered the transcriptome profile of HepG2 cells, in particular, ferroptosis and immune-related pathways were significantly enriched by differentially expressed genes, including CD44. HSPA8 overexpression up-regulated CD44 expression and knockdown of CD44 significantly reversed the inhibition of ferroptosis caused by PRMT9 overexpression.

CONCLUSIONS

In conclusion, HBx/PRMT9/HSPA8/CD44 axis is a vital signal pathway regulating ferroptosis in HCC cells. This study provides new opportunities and targets for the treatment of HBV-induced HCC.

Roles of NOLC1 in cancers and viral infection

BACKGROUND

The nucleolus is considered the center of metabolic control and an important organelle for the biogenesis of ribosomal RNA (rRNA). Nucleolar and coiled-body phosphoprotein 1(NOLC1), which was originally identified as a nuclear localization signal-binding protein is a nucleolar protein responsible for nucleolus construction and rRNA synthesis, as well as chaperone shuttling between the nucleolus and cytoplasm. NOLC1 plays an important role in a variety of cellular life activities, including ribosome biosynthesis, DNA replication, transcription regulation, RNA processing, cell cycle regulation, apoptosis, and cell regeneration.

PURPOSE

In this review, we introduce the structure and function of NOLC1. Then we elaborate its upstream post-translational modification and downstream regulation. Meanwhile, we describe its role in cancer development and viral infection which provide a direction for future clinical applications.

METHODS

The relevant literatures from PubMed have been reviewed for this article.

CONCLUSION

NOLC1 plays an important role in the progression of multiple cancers and viral infection. In-depth study of NOLC1 provides a new perspective for accurate diagnosis of patients and selection of therapeutic targets.

Hepatocellular Carcinoma with Hepatic Vein and Inferior Vena Cava Invasion

Hepatocellular carcinoma (HCC) invades intrahepatic vessels causing tumor thrombosis. Infrequently, there is involvement of the hepatic vein (HV) and inferior vena cava (IVC). In this review, we summarize the epidemiology, classification, clinical features, and management of HCC with HV and IVC invasion. While the involvement of HV and IVC usually portends an overall poor survival, selected patients may be candidates for aggressive treatment and thus improving outcomes.

Integrative Evaluation of the Clinical Significance Underlying Protein Arginine Methyltransferases in Hepatocellular Carcinoma

HCC is a major contributor to cancer-related mortality worldwide. Curative treatments are available for a minority of patients diagnosed at early stages; however, only a few multikinase inhibitors are available and are marginally effective in advanced cases, highlighting the need for novel therapeutic targets. One potential target is the protein arginine methyltransferase, which catalyzes various forms of arginine methylation and is often overexpressed in various cancers. However, the diverse expression patterns and clinical values of PRMTs in HCC remain unclear. In the present study, we evaluated the transcriptional expression of PRMTs in HCC cohorts using publicly available datasets. Our results revealed a significant association between PRMTs and prognosis in HCC patients with diverse clinical characteristics and backgrounds. This highlights the promising potential of PRMTs as prognostic biomarkers in patients with HCC. In particular, single-cell RNA (scRNA) sequencing analysis coupled with another human cohort study highlighted the pivotal role of PRMT1 in HCC progression, particularly in the context of Tex. Translating these findings into specific therapeutic decisions may address the unmet therapeutic needs of patients with HCC.

A review on regulation of cell cycle by extracellular matrix

The extracellular matrix (ECM) is a network of structural proteins, glycoproteins and proteoglycans that assists independent cells in aggregating and forming highly organized functional structures. ECM serves numerous purposes and is an essential component of tissue structure and functions. Initially, the role of ECM was considered to be confined to passive functions like providing mechanical strength and structural identity to tissues, serving as barriers and platforms for cells. The doors to understanding ECM's proper role in tissue functioning opened with the discovery of cellular receptors, integrins to which ECM components binds and influences cellular activities. Understanding and utilizing ECM's potential to control cellular function has become a topic of much interest in recent decades, providing different outlooks to study processes involved in developmental programs, wound healing and tumour progression. On another front, the regulatory mechanisms operating to prevent errors in the cell cycle have been topics of a titanic amount of studies. This is expected as many diseases, most infamously cancer, are associated with defects in their functioning. This review focuses on how ECM, through different methods, influences the progression of the somatic cell cycle and provides deeper insights into molecular mechanisms of functional communication between adhesion complex, signalling pathways and cell cycle machinery.

Elucidating the role of PRMTs in prostate cancer using open access databases and a patient cohort dataset

Protein arginine methylation is an understudied epigenetic mechanism catalyzed by enzymes known as Protein Methyltransferases of Arginine (PRMTs), while the opposite reaction is performed by Jumonji domain- containing protein 6 (JMJD6). There is increasing evidence that PRMTs are deregulated in prostate cancer (PCa). In this study, the expression of two PRMT members, PRMT2 and PRMT7 as well as JMJD6, a demethylase, was analyzed in PCa. Initially, we retrieved data from The Cancer Genome Atlas (TCGA) project and the Gene Expression Omnibus (GEO) database to explore the differential expression of various PRMT family members in patients with PCa and then applied immunohistochemistry in a patient cohort across the spectrum of PCa, including non-neoplastic prostate tissue and lymph node metastatic foci. The results from the TCGA analysis revealed that PRMT7, PRMT6 and PRMT3 expression increased while PRMT2, PRMT9 and JMJD6 levels decreased in the tumor compared to non-neoplastic prostate. Results from the GEO datasets were similar, albeit not identical with the TCGA results, with PRMT7 and PRMT3 being upregulated and PRMT2 and JMJD6 being downregulated in the tumor compared to non-neoplastic tissue in some of them. In addition, PRMT7 levels decreased with stage and grade progression in the TCGA analysis. In the patient cohort, both PRMTs and JMJD6 were overexpressed in PCa compared to non-neoplastic tissue, and nuclear PRMT2 and JMJD6 were upregulated in lymph node metastasis, too. PRMT7 and JMJD6 expression were upregulated with the progression of stage and JMJD6 was also increased with the elevation of grade. After androgen ablation therapy, nuclear expression of PRMT7 and JMJD6 were elevated compared to untreated tumors. PRMT2, PRMT7 and JMD6 were also correlated with markers of EMT and cell cycle regulators. Finally, our findings indicate that PRMTs and JMJD6 are involved in prostate cancer progression and revealed a potential interplay of PRMTs with EMT mediators, underscoring the need for therapeutic targeting of arginine methylation in prostate cancer.

Identification of THSD7B and PRMT9 mutations as risk factors for familial lung adenocarcinoma: A case report

RATIONALE

Lung tumors arise from the unrestrained malignant growth of pulmonary epithelial cells. Lung cancer cases include both small and non-small cell lung cancers, with lung adenocarcinoma (LUAD) accounting for roughly half of all non-small cell lung cancer cases. Research focused on familial cancers suggests that approximately 8% of lung cancer cases are linked to genetic susceptibility or heritability. The precise genetic factors that underlie the onset of lung cancer, however, remain to be firmly established.

PATIENT CONCERNS

A 43-year-old presented with nodules in the lower left lung lobe. Following initial antibiotic treatment in a local hospital, these nodules remained present and the patient subsequently underwent the resection of the left lower lobe of the lung. The patient also had 4 family members with a history of LUAD.

DIAGNOSIS

Immunohistochemical staining results including cytokeratin 7 (+), TTF-1 (+), new aspartic proteinase A (+), CK5/6 (-), P63 (-), and Ki-67 (5%+) were consistent with a diagnosis of LUAD.

INTERVENTION

Whole exome sequencing analyses of 5 patients and 6 healthy family members were performed to explore potential mutations associated with familial LUAD.

OUTCOMES

Whole exome sequencing was conducted, confirming that the proband and their 4 other family members with LUAD harbored heterozygous THSD7B (c.A4000G:p.S1334G) mutations and homozygous PRMT9 (c.G40T:p.G14C) mutations, as further confirmed via Sanger sequencing. These mutations were predicted to be deleterious using the SIFT, PolyPhen2, and MutationTaster algorithms. Protein structure analyses indicated that the mutation of the serine at amino acid position 1334 in THSD7B to a glycine would reduce the minimum free energy from 8.08 kcal/mol to 68.57 kcal/mol. The identified mutation in the PRMT9 mutation was not present in the predicted protein structure. I-Mutant2.0 predictions indicated that both of these mutations (THSD7B:p.S1334G and PRMT9: p.G14C) were predicted to reduce protein stability.

LESSONS

Heterozygous THSD7B (c.A4000G:p.S1334G) and the homozygous PRMT9 (c.G40T:p.G14C) mutations were found to be linked to LUAD incidence in the analyzed family. Early analyses of these genetic loci and timely genetic counseling may provide benefits and aid in the early diagnosis of familial LUAD.

PI3K δ inhibitor PI-3065 induces apoptosis in hepatocellular carcinoma cells by targeting survivin

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, and its clinical treatment remains challenging. The development of new treatment regimens is important for effective HCC treatment. Phosphoinositide 3-kinase (PI3K) is a lipid kinase that plays an important role in cell growth and metabolism and is overexpressed in nearly 50% of patients with HCC. Studies have shown that PI-3065, a small-molecule inhibitor of phosphatidylinositol 3-kinase delta, significantly inhibits solid breast cancer. However, its antitumor effects against HCC and the underlying mechanisms remain unclear. In the present study, we found that PI-3065 dose- and time-dependently reduced HCC cell viability and induced apoptosis while posing no obvious apoptotic toxicity in normal liver cells. Further mechanistic analysis showed that PI-3065 induced apoptosis mainly by inhibiting survivin protein expression, decreasing mitochondrial membrane potential, and promoting cytochrome C release. Simultaneously, PI-3065 markedly suppressed the colony formation, migration, and epithelial-mesenchymal transition abilities of HCC cells. Furthermore, transplantation of nude mice with HCC tumors showed that PI-3065 inhibits HCC tumor growth in vivo by targeting survivin. In summary, PI-3065 specifically inhibited survivin expression and exerted anti-HCC activity in vivo and in vitro, suggesting that it may serve as an effective antitumor drug for HCC treatment, which warrants further study.

Capn4 regulates Snail to promote the epithelial-mesenchymal transition of nasopharyngeal carcinoma by mediating the transcriptional activity of claudin-11

The metastasis and recurrence of nasopharyngeal carcinoma (NPC) contribute to the poor prognosis of patients. Inhibiting epithelial-mesenchymal transition (EMT) is an effective strategy to obstruct metastasis. Therefore, this study aimed to explore the effects of Capn4 on the EMT of NPC cells and its specific mechanism of action. The mRNA and protein expression levels of objective genes in NPC cell lines (5-8F and CNE-2) were evaluated by qRT-PCR and western blotting methods. The subcellular localization of Capn4 was detected by immunofluorescence (IF). Migration and invasion abilities of NPC cells were examined via wound-healing and trans-well methods, and the linkage between Snail and its downstream effector gene (claudin-11) was validated by chromatin immunoprecipitation (ChIP), dual-luciferase, and the yeast one-hybrid assays in series. Over-expression of Capn4 activated the PI3K/AKT signaling pathway and improved the expression of Snail, thus promoting the migration and invasion abilities of NPC cells. Mechanically, claudin-11 is one of the target genes in NPC cells that Snail regulates in a transcriptional regulatory manner. By blocking the regulatory axis of CAPN4/AKT/Snail/claudin-11 can significantly inhibit the invasion and metastasis of NPC cells. Capn4 promoted the EMT of NPC cells by activating the PI3K/AKT/Snail/claudin-11 axis, thereby promoting the malignant development of NPC. The Capn4/PI3K/AKT/Snail/claudin-11 axis might be a novel target to prevent NPC progression.

Biological impact and therapeutic perspective of targeting PI3K/Akt signaling in hepatocellular carcinoma: Promises and Challenges

Cancer progression results from activation of various signaling networks. Among these, PI3K/Akt signaling contributes to proliferation, invasion, and inhibition of apoptosis. Hepatocellular carcinoma (HCC) is a primary liver cancer with high incidence rate, especially in regions with high prevalence of viral hepatitis infection. Autoimmune disorders, diabetes mellitus, obesity, alcohol consumption, and inflammation can also lead to initiation and development of HCC. The treatment of HCC depends on the identification of oncogenic factors that lead tumor cells to develop resistance to therapy. The present review article focuses on the role of PI3K/Akt signaling in HCC progression. Activation of PI3K/Akt signaling promotes glucose uptake, favors glycolysis and increases tumor cell proliferation. It inhibits both apoptosis and autophagy while promoting HCC cell survival. PI3K/Akt stimulates epithelial-to-mesenchymal transition (EMT) and increases matrix-metalloproteinase (MMP) expression during HCC metastasis. In addition to increasing colony formation capacity and facilitating the spread of tumor cells, PI3K/Akt signaling stimulates angiogenesis. Therefore, silencing PI3K/Akt signaling prevents aggressive HCC cell behavior. Activation of PI3K/Akt signaling can confer drug resistance, particularly to sorafenib, and decreases the radio-sensitivity of HCC cells. Anti-cancer agents, like phytochemicals and small molecules can suppress PI3K/Akt signaling by limiting HCC progression. Being upregulated in tumor tissues and clinical samples, PI3K/Akt can also be used as a biomarker to predict patients' response to therapy.

The role of LncRNA LBX2-AS1 in cancers: functions, mechanisms and potential clinical utility

Increasingly advanced biology technique has revealed that long non-coding RNAs (lncRNA) as critical factors that exert significant regulatory effects on biological functions by modulating gene transcription, epigenetic modifications and protein translation. A newly emerging lncRNA, ladybird homeobox 2 (LBX2)-antisense RNA 1 (LBX2-AS1), was found to be highly expressed in various tumors. Moreover, it is functionally linked to the regulation of essential tumor-related biological processes, such as cell proliferation and apoptosis, through interactions with multiple signaling molecules/pathways. The important roles played by LBX2-AS1 in cancer initiation and progression suggest that this lncRNA has enormous clinical potential for use as a novel biomarker or therapeutic target. In this article, we retrospectively review the latest advances in research exploring the roles of the lncRNA LBX2-AS1 in oncology field, highlighting its involvement in a comprehensive network of molecular mechanisms underlying diverse cancers and examining its potential applications in clinical practice.

Circular RNA hsa_circ_0004689 (circSWT1) promotes NSCLC progression via the miR‐370‐3p/SNAIL axis by inducing cell epithelial‐mesenchymal transition (EMT)

BACKGROUND

Previous studies have reported the role of circular RNAs (circRNAs) in the progression of non-small-cell lung cancer (NSCLC). SWT1-derived circRNAs were confirmed to affect the apoptosis of cardiomyocytes; however, the biological functions of SWT1-derived circRNAs in cancers are still unknown. Here, we investigated the potential role of SWT1-derived circRNAs in NSCLC.

METHODS

We used quantitative real-time polymerase chain reaction (qRT-PCR) to measure the expression of circSWT1 in NSCLC tissues and paired normal tissues. The potential functions of circSWT1 in tumor progression were assessed by CCK-8, colony formation, wound healing, and matrigel transwell assays in vitro and by xenograft tumor models in vivo. Next, epithelial-mesenchymal transition (EMT) was evaluated by western blotting, immunofluorescence, and immunohistochemistry (IHC). Moreover, circRIP, RNA pulldown assays, luciferase reporter gene assays, and FISH were conducted to illuminate the molecular mechanisms of circSWT1 via the miR-370-3p/SNAIL signal pathway. Then, we knocked out SNAIL in A549 and H1299 cells to identify the roles of circSWT1 in the progression and EMT of NSCLC through SNAIL. Finally, circSWT1 functions were confirmed in vivo using xenograft tumor models.

RESULTS

CircSWT1 expression was significantly upregulated in NSCLC tissues, and high expression of circSWT1 predicted poor prognosis in NSCLC via survival analysis. In addition, overexpression of circSWT1 promoted the invasion and migration of NSCLC cells. Subsequently, we found that overexpression of circSWT1 induced EMT and that knockdown of circSWT1 inhibited EMT in NSCLC cells. Mechanistically, circSWT1 relieved the inhibition of downstream SNAIL by sponging miR-370-3p. Moreover, we found that these effects could be reversed by knocking out SNAIL. Finally, we verified that circSWT1 promoted NSCLC progression and EMT in xenograft tumor models.

CONCLUSION

CircSWT1 promoted the invasion, migration, and EMT of NSCLC. CircSWT1 could serve as a potential biomarker and a potential therapeutic target for NSCLC.

microRNA-206 prevents hepatocellular carcinoma growth and metastasis via down-regulating CREB5 and inhibiting the PI3K/AKT signaling pathway

Hepatocellular carcinoma (HCC) is one of the most common cancers and has continued to increase in incidence worldwide. Moreover, the involvement of microRNAs (miRs) has been reported in the development and progression of HCC. Here, we investigated the role of miR-206 in HCC growth and metastasis. HCC-related microarray datasets were harvested to screen differentially expressed miRNAs in HCC samples followed by prediction of downstream target genes. The dual-luciferase reporter assay verified the target-binding relationship between miR-206 and CREB5. The human HCC cell line MHCC97-H was cultured in vitro and transfected with miR-206 mimic/inhibitor or sh-/oe-CREB5 for analyzing MHCC97-H cell biological functions. The orthotopic xenograft model of HCC mice was constructed to observe the tumorigenic ability of HCC cells in vivo. Bioinformatics analysis found that miR-206 may be involved in HCC growth and metastasis by targeting CREB5 and regulating PI3K/AKT signaling pathway. In vivo animal experiments found that CREB5 was significantly overexpressed in mouse HCC tissues. In HCC cells, miR-206 can target down-regulate the expression of CREB5, thereby inhibiting the activation of PI3K/AKT signaling pathway. Furthermore, in vitro cell experiments confirmed that overexpression of miR-206 could inhibit the PI3K/AKT signaling pathway by down-regulating CREB5 expression, thereby inhibiting the proliferation, migration and invasion of HCC cells. In conclusion, our results revealed that miR-206 could down-regulate the expression of CREB5 and inhibit the activation of PI3K/AKT signaling pathway, thereby preventing HCC growth and metastasis.Abbreviations: HCC: hepatocellular carcinoma; HBV or HCV: hepatitis B or C virus; miRNAs: microRNAs; CREB: cAMP response element-binding protein; CRE: cAMP response elements.

An updated patent review of protein arginine N-methyltransferase inhibitors (2019-2022)

Protein arginine methyltransferases (PRMTs), enzymes catalyzing the methylation of target proteins, play an essential role in maintaining functional homeostasis in normal physiology. Aberrant expressions and enhanced enzymatic activities of PRMTs have been closely associated with pathological states such as cancer, inflammatory, immune, metabolic, and neurodegenerative diseases. Therefore, the development of inhibitors targeting PRMTs has attracted a great deal of attention in both pharmaceutical industries and academic community. This review focuses on the small-molecule inhibitors targeting PRMTs in cancer therapy in the patents published since 2019. The recent clinical development is also discussed here. In recent years, the discovery of small-molecule PRMT inhibitors, especially PRMT5 inhibitors has become a rapidly expanding research area for cancer therapy. Although a number of potent PRMT inhibitors with different chemical scaffolds have been developed and nine of them have entered into clinical trials, their scaffolds are relatively less diverse. Sub-type selectivity should be considered in drug discovery as nonselective inhibition of PRMTs may cause undesirable pharmacological effects. Hence, the development of new effective inhibitors with isoform-specific and tumor-biased distributions remains an important area for further studies.

Arginine methylation in the epithelial-to-mesenchymal transition

Epithelial cells acquire mesenchymal characteristics during embryonic development, wound healing, fibrosis, and in cancer in a processed termed epithelial-to-mesenchymal transition (EMT). Regulatory networks of EMT are controlled by post-transcriptional, translational, and post-translational mechanisms, in which arginine methylation is critically involved. Here, we review arginine methylation-dependent mechanisms that regulate EMT in the aspects of signaling, transcriptional, and splicing regulation.

Leptin Promotes HTR-8/SVneo Cell Invasion via the Crosstalk between MTA1/WNT and PI3K/AKT Pathways

The process of placental invasion is essential for a successful pregnancy. Leptin is involved in trophoblast invasiveness, and its dysregulation is connected with a series of diseases, including preeclampsia. However, the knowledge of the precise mechanisms in leptin-induced trophoblast invasiveness is still limited. According to the present research, transwell assay suggested that leptin is a dose- and time-dependent regulator in inducing HTR-8/SVneo cell invasion. Western blot analysis and immunofluorescence staining revealed that leptin-induced MMP9 expression is essential in the invasion process of HTR-8/SVneo cells. Mechanistically, we demonstrated that leptin activated β-catenin via the crosstalk between the MTA1/WNT and PI3K/AKT pathways. Besides, we showed that downregulating the key molecules in the signaling pathways by siRNA can inhibit leptin-induced MMP9 expression and further suppress invasion of HTR-8/SVneo cells. In conclusion, our study revealed a new regulatory mechanism of leptin-induced HTR-8/SVneo cell invasiveness and will provide novel insights into the causes and potential therapeutic targets for diseases related to dysregulation of trophoblast invasion in the future.

CXC Motif Chemokine Receptor Type 4 Disrupts Blood-Brain Barrier and Promotes Brain Metastasis Through Activation of the PI3K/AKT Pathway in Lung Cancer

BACKGROUND

CXC motif chemokine receptor type 4 (CXCR4) is an indispensable factor in the process of lung cancer brain metastasis (LCBM). The PI3K/AKT signal pathway is crucial in affecting cell invasion and metastasis and serves as a pivotal regulator in LCBM. However, the relationship between CXCR4 and the PI3K/AKT signal pathway is unclear. This study aimed to explore the underlying mechanisms of CXCR4 and PI3K/AKT in LCBM.

METHODS

Two lung cancer cells (A549 and H1299) and cells transfected with short hairpin RNA (shRNA)-CXCR4 were cocultured with normal human astrocyte cells and human brain endothelial (hCMEC/D3) cells to establish a blood-brain barrier model in vitro. The proliferation, migration, and invasion tight junction proteins (claudin-5, occludin, and ZO-1) were examined. Finally, results were verified in a nude mice model.

RESULTS

The abilities of cell proliferation, migration, and invasion were significantly reduced in A549 and H1299 cells transfected with shRNA-CXCR4 compared with the negative control group. The proteins phosphorylated PI3K and phosphorylated AKT were downregulated in lung cancer cells transfected with shRNA-CXCR4. The proteins claudin-5, occludin, and ZO-1 were upregulated in the A549 and H1299 cells transfected with shRNA-CXCR4. In vivo experiment results confirmed that the knockdown of CXCR4 played a protective role in the process of LCBM.

CONCLUSIONS

Our findings revealed that CXCR4 promotes LCBM by regulating the PI3K/Akt signal pathway. We also demonstrated that inhibiting CXCR4 could lead to prevention of LCBM. This study provides further rationale for clinical therapy that targets CXCR4/PI3K/AKT.

The protein arginine methyltransferase PRMT9 attenuates MAVS activation through arginine methylation

The signaling adaptor MAVS forms prion-like aggregates to activate the innate antiviral immune response after viral infection. However, spontaneous aggregation of MAVS can lead to autoimmune diseases. The molecular mechanism that prevents MAVS from spontaneous aggregation in resting cells has been enigmatic. Here we report that protein arginine methyltransferase 9 targets MAVS directly and catalyzes the arginine methylation of MAVS at the Arg41 and Arg43. In the resting state, this modification inhibits MAVS aggregation and autoactivation of MAVS. Upon virus infection, PRMT9 dissociates from the mitochondria, leading to the aggregation and activation of MAVS. Our study implicates a form of post-translational modification on MAVS, which can keep MAVS inactive in physiological conditions to maintain innate immune homeostasis.

Cribriform Patterned Lesions in the Prostate Gland with Emphasis on Differential Diagnosis and Clinical Significance

Simple Summary

A cribriform structure is defined as a continuous proliferation of cells with intermingled lumina. Various entities may have a cribriform morphology within the prostate gland, ranging from normal, to benign, to borderline and even to malignant lesions. This review summarizes the morphologic features of entities that have a cribriform morphology within the prostate gland, with an emphasis on their differential diagnosis, molecular profile and clinical significance. The basic aim is to assist the pathologist with challenging and controversial cases and inform the clinician on the clinical implications of cribriform morphology.

Abstract

Cribriform glandular formations are characterized by a continuous proliferation of cells with intermingled lumina and can constitute a major or minor part of physiologic (normal central zone glands), benign (clear cell cribriform hyperplasia and basal cell hyperplasia), premalignant (high-grade prostatic intraepithelial neoplasia), borderline (atypical intraductal cribriform proliferation) or clearly malignant (intraductal, acinar, ductal and basal cell carcinoma) lesions. Each displays a different clinical course and variability in clinical management and prognosis. The aim of this review is to summarize the current knowledge regarding the morphological features, differential diagnosis, molecular profile and clinical significance of the cribriform-patterned entities of the prostate gland. Areas of controversy regarding their management, i.e., the grading of Intaductal Carcinoma, will also be discussed. Understanding the distinct nature of each cribriform lesion leads to the correct diagnosis and ensures accuracy in clinical decision-making, prognosis prediction and personalized risk stratification of patients.

Emodin inhibits invasion and migration of hepatocellular carcinoma cells via regulating autophagy-mediated degradation of snail and β-catenin

BACKGROUND

Previous studies reported that emodin extracted from Rheum palmatum L. exerts antiproliferation and antimetastatic effects in a variety of human cancer types. However, the role of emodin in hepatocellular carcinoma (HCC) remain unknown.

METHODS

EdU and colony formation assays were performed to evaluate the effects of emodin on proliferation. The mobility capacities of HCC treated with emodin were evaluated using wound healing assay. Transwell invasion and migration assays were performed to evaluate anti-migratory and anti-invasive effects of emodin on HCC. Annexin V-FITC/PI was performed to analyze the apoptosis. PI stain was performed to analyze cell cycle. RNA sequencing technology was used to identify the differentially expressed genes (DEGs) induced by emodin in HCC. The impact of emodin on autophagic flux in HepG2 cells was examined by mCherry-GFP-LC3 analysis. Western blot was used to assess the protein expressions of epithelial-mesenchymal transition (EMT), autophagy, PI3K/AKT/mTOR and Wnt/β-catenin signaling pathway.

RESULTS

We found that emodin inhibited the growth of HepG2 cells in a dose- and time-dependent manner. In addition, emodin inhibited cell proliferation, induced S and G2/M phases arrest, and promoted apoptosis in HepG2 cells. The migration and invasion of HepG2 cells were also suppressed by emodin. Enrichment analysis revealed that DEGs involved in cell adhesion, cancer metastasis and cell cycle arrest. Moreover, western bolt results show that emodin-induced autophagy promotes Snail and β-catenin degradation. We also found that blocking autophagic flux after emodin treatment caused EMT reversal. Furthermore, the PI3K agonist Y-P 740 significantly reversed the phosphorylation levels of GSK3β and mTOR. These results indicated that emodin induced autophagy and inhibited the EMT in part through suppression of the PI3K/AKT/mTOR and Wnt/β-catenin pathways.

CONCLUSION

Our study indicated that emodin inhibited cell metastasis in HCC via the crosstalk between autophagy and EMT.

Mechanisms of chronic alcohol exposure-induced aggressiveness in cellular model of HCC and recovery after alcohol withdrawal

Alcohol-related liver disease is the most prevalent chronic liver disease worldwide, accounting for 30% of hepatocellular carcinoma (HCC) cases and HCC-specific deaths. However, the knowledge on mechanisms by which alcohol consumption leads to cancer progression and its aggressiveness is limited. Better understanding of the clinical features and the mechanisms of alcohol-induced HCC are of critical importance for prevention and the development of novel treatments. Early stage Huh-7 and advanced SNU449 liver cancer cell lines were subjected to chronic alcohol exposure (CAE), at different doses for 6 months followed by 1-month alcohol withdrawal period. ADH activity and ALDH expression were much lower in SNU449 compared with Huh-7 cells and at the 270 mM dose, CAE decreased cell viability by about 50% and 80%, respectively, in Huh-7 and SNU449 cells but induced mortality only in Huh-7 cells. Thus, Huh-7 may be more vulnerable to ethanol toxicity because of the higher levels of acetaldehyde. CAE induced a dose-dependent increase in cell migration and invasion and also in the expression of cancer stem cells markers (CD133, CD44, CD90). CAE in Huh-7 cells selectively activated ERK1/2 and inhibited GSK3β signaling pathways. Most of the changes induced by CAE were reversed after alcohol withdrawal. Interestingly, we confirmed the increase in CD133 mRNA levels in the tumoral tissue of patients with ethanol-related HCC compared to other HCC etiologies. Our results may explain the benefits observed in epidemiological studies showing a significant increase of overall survival in abstinent compared with non-abstinent patients.

Development an Immune-Related MicroRNA Risk Index in Hepatocellular Carcinoma

Purpose

Hepatocellular carcinoma (HC) has emerged as one of the most prevalent malignancies on a global scale. Recently, immunotherapy has achieved favorable effectiveness in the management of multiple cancers. However, there are limited therapeutic options for advanced HC. As the liver is a special immune organ, we intend to uncover potential and effective immunotherapeutic modalities for HC. Our study was designed to develop specific immune-related miRNAs (IRMs) for outcome assessment and individualized strategies for the management of HC.

Methods

The miRNA-seq and survival data of TCGA-LIHC dataset was enrolled into this program. We first collected IRMs from Immune-miR website. Differentially expression analysis was applied to screen aberrantly expressed IRMs. In order to set up an IRM-related index (IRMRI) in HC, we conducted the Cox relevant methods. Next, the statistical approaches (survival curve and ROC curve analyses) were utilized to detect the evaluation capacity of our IRMRI. Subsequently, we obtained the target genes of hub miRNAs from IRMRI through three miRNA-related predictive online tools (miRDB, miRTarBase, and TargetScan websites).

Results

Five IRMs were determined to develop the IRMRI. It can effectively segregate all HC cases from two different risk subgroups. We identified a marked discrepancy in survival outcome between the two groups by survival analysis and confirmed the reliability of IRMRI in two testing sets. Moreover, we collected 10 hub target genes (ESR1, IGF1, PDGFRB, JUN, MYC, ZWINT, MAD2L1, TOP2A, KIF11, and CDCA8) which were strongly linked to HC progression and malignant behavior.

Conclusion

We screened out five hub IRMs with clinical value and constructed a risk index model in HC, which can precisely assess the risk status and outcome of patients to a certain extent.

MicroRNA-148a Inhibits Hepatocellular Carcinoma Cell Growth via Epithelial-to-Mesenchymal Transition and PI3K/AKT Signaling Pathways by Targeting Death Receptor-5

The purpose of this study was to investigate the role of microRNA-148a (miR-148a) in hepatocellular carcinoma (HCC) metastasis and explore its potential mechanism in HCC cells. Expression levels of miR-148a were measured using qRT-PCR in 120 HCC tissue samples and two HCC cell lines. Migration and invasion assays were used to determine the role of miR-148a in HCC cells. Flow cytometry was used to access the effect of miR-148a on cell cycle of HCC cells. Western blot was performed to analyze the effect of miR-148a on epithelial-to-mesenchymal transition (EMT) and PI3K/AKT signaling pathways in HCC cells. Luciferase reporter assay was conducted to explore the downstream targets and biological function of miR-148a in HCC cells. The results showed that level of miR-148a was significantly downregulated in both HCC tissue and plasma samples in HCC patients. A higher level of miR-148a was positively correlated with better survival time and prognosis of HCC patients. Transfection of miR-148a inhibited the proliferation, migration and invasion of HCC cell lines. Transfection of miR-148a arrested HCC cells at S phase and promoted apoptosis of HCC cells. Death receptor-5 (DR-5) was identified as a direct target of miR-148a in HCC cell lines. Western blot and qRT-PCR analyses showed that miR-148a upregulated EMT and downregulated PI3K/AKT signaling pathways in HCC cell lines. In conclusion, data in the current study indicate that miR-148a inhibits HCC cells growth via downregulation of EMT and PI3K/AKT signaling pathways by targeting death receptor. These data suggest that miR-148a may serve as a therapeutic target for HCC cancer therapy in the future.

The Emerging Role of PRMT6 in Cancer

Protein arginine methyltransferase 6 (PRMT6) is a type I PRMT that is involved in epigenetic regulation of gene expression through methylating histone or non-histone proteins, and other processes such as alternative splicing, DNA repair, cell proliferation and senescence, and cell signaling. In addition, PRMT6 also plays different roles in various cancers via influencing cell growth, migration, invasion, apoptosis, and drug resistant, which make PRMT6 an anti-tumor therapeutic target for a variety of cancers. As a result, many PRMT6 inhibitors are being utilized to explore their efficacy as potential drugs for various cancers. In this review, we summarize the current knowledge on the function and structure of PRMT6. At the same time, we highlight the role of PRMT6 in different cancers, including the differentiation of its promotive or inhibitory effects and the underlying mechanisms. Apart from the above, current research progress and the potential mechanisms of PRMT6 behind them were also summarized.

COL11A1-Driven Epithelial-Mesenchymal Transition and Stemness of Pancreatic Cancer Cells Induce Cell Migration and Invasion by Modulating the AKT/GSK-3β/Snail Pathway

BACKGROUND

Collagen type XI α1 (COL11A1) is associated with tumorigenesis and development in many human malignancies. Previous reports indicate that COL11A1 may be a significant diagnostic marker for pancreatic ductal adenocarcinoma (PDAC); however, its biological role in PDAC progression remains unclear. In this study, we investigated the influence of COL11A1 on the invasion and migration abilities of pancreatic cancer cells and explored its potential molecular mechanisms.

METHODS

Cell migration and invasion were assessed using Transwell assays in pancreatic cancer cells transfected with siCOL11A1 and pCNV3-COL11A1 plasmids. The protein and mRNA expression levels of N-cadherin, E-cadherin, Vimentin, cluster of differentiation (CD)-24, CD44, serine-threonine kinase (AKT), glycogen synthase kinase (GSK)-3β, phospho (p)-AKTSer473, p-GSK-3βSer9, and Snail were analyzed using Western blotting and real-time polymerase chain reaction (PCR). The effect of COL11A1 on cell stemness was tested using flow cytometry and clone formation assays.

RESULTS

These results demonstrated that COL11A1 significantly promoted the invasion and migration abilities of PDAC cells. Furthermore, COL11A1 facilitated the occurrence of epithelial-mesenchymal transition (EMT) and cell stemness by upregulating the expression levels of p-AKTSer473, p-GSK-3βSer9, and Snail.

CONCLUSIONS

This study suggests that the activation of the AKT/GSK-3β/Snail signaling pathway induced by COL11A1 plays a major role in the progression of PDAC. Therefore, COL11A1 could serve as a potential target for PDAC treatment.

Agrin Promotes Non-Small Cell Lung Cancer Progression and Stimulates Regulatory T Cells via Increasing IL-6 Secretion Through PI3K/AKT Pathway

Non-small cell lung cancer (NSCLC) has high mortality rates worldwide. Agrin contributes to immune synapse information and is involved in tumor metastasis. However, its roles in NSCLC and tumor immune microenvironment remain unclear. This study examined the effects and the underlying mechanisms of Agrin in NSCLC and tumor-infiltrated immune cells. Clinical tissue samples were used to confirm the bioinformatic predictions. NSCLC cells were used to investigate the effects of Agrin on cell cycle and proliferation, as well as invasion and migration. Tumor xenograft mouse model was used to confirm the effects of Agrin on NSCLC growth and tumor-infiltrated regulatory T cells (Tregs) in vivo. Agrin levels in NSCLC cells were closely related to tumor progression and metastasis, and its function was enriched in the PI3K/AKT pathway. In vitro assays demonstrated that Agrin knockdown suppressed NSCLC cell proliferation and metastasis, while PI3K/AKT activators reversed the inhibitory effects of Agrin deficiency on NSCLC cell behaviors. Agrin expression was negatively associated with immunotherapy responses in NSCLC patients. Agrin knockdown suppressed Tregs, as well as interleukin (IL)-6 expression and secretion, while PI3K/AKT activators and exogenous IL-6 rescued the inhibitory effects. In the mouse model, Agrin downregulation alleviated NSCLC cell growth and Treg infiltration in vivo. Our results indicated that Agrin promotes tumor cell growth and Treg infiltration via increasing IL-6 expression and secretion through PI3K/AKT pathway in NSCLC. Our studies suggested Agrin as a therapeutically potential target to increase the efficacy of immunotherapy in NSCLC patients.

Fascinating Transformation of SAM-Competitive Protein Methyltransferase Inhibitors from Nucleoside Analogues to Non-Nucleoside Analogues

The abnormal expression of protein methyltransferase (PMT) has been linked with many diseases such as diabetes, neurological disorders, and cancer. S-Adenyl-l-methionine (SAM) is a universal methyl donor and gets converted to S-adenyl-l-homocysteine (SAH), an endogenous competitive inhibitor of SAM. Initially developed SAM/SAH mimetic nucleoside analogues were pan methyltransferase inhibitors. The gradual understanding achieved through ligand-receptor interaction paved the way for various rational approaches of drug design leading to potent and selective nucleoside inhibitors. The present perspective is based on the systematic evolution of selective SAM-competitive heterocyclic non-nucleoside inhibitors from nucleoside inhibitors. This fascinating transition has resolved several issues inherent to nucleoside analogues such as poor pharmacokinetics leading to poor in vivo efficacy. The perspective has brought together various concepts and strategies of drug design that contributed to this rational transition. We firmly believe that the strategies described herein will serve as a template for the future development of drugs in general.

Hepatocellular Carcinoma and Obesity, Type 2 Diabetes Mellitus, Cardiovascular Disease: Causing Factors, Molecular Links, and Treatment Options

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, which will affect more than a million people by the year 2025. However, current treatment options have limited benefits. Nonalcoholic fatty liver disease (NAFLD) is the fastest growing factor that causes HCC in western countries, including the United States. In addition, NAFLD co-morbidities including obesity, type 2 diabetes mellitus (T2DM), and cardiovascular diseases (CVDs) promote HCC development. Alteration of metabolites and inflammation in the tumor microenvironment plays a pivotal role in HCC progression. However, the underlying molecular mechanisms are still not totally clear. Herein, in this review, we explored the latest molecules that are involved in obesity, T2DM, and CVDs-mediated progression of HCC, as they share some common pathologic features. Meanwhile, several therapeutic options by targeting these key factors and molecules were discussed for HCC treatment. Overall, obesity, T2DM, and CVDs as chronic metabolic disease factors are tightly implicated in the development of HCC and its progression. Molecules and factors involved in these NAFLD comorbidities are potential therapeutic targets for HCC treatment.

Downregulation of amine oxidase copper containing 1 inhibits tumor progression by suppressing IL-6/JAK/STAT3 pathway activation in hepatocellular carcinoma

Amine oxidase copper containing 1 (AOC1) is a copper-containing amine oxidase that catalyzes the deamination of polyamines. AOC1 functions as an oncogene in human gastric cancer. There is little information available regarding the function of AOC1 in hepatocellular carcinoma (HCC). In the present study, reverse transcription-quantitative PCR was used to detect the expression levels of AOC1 in HCC tissues, and the role of AOC1 in HCC progression was determined using western blot, Cell Counting Kit 8, clone formation, wound-healing and Transwell assays. An AOC1 survival curve was generated with data downloaded from The Cancer Genome Atlas, and Gene Set Enrichment Analysis was performed to investigate the potential biological mechanisms of AOC1 in HCC. AOC1 was found to be upregulated in HCC tissues, which was associated with a poor prognosis. Furthermore, AOC1-knockdown inhibited HCC cell proliferation, migration and invasiveness, suppressed IL-6 expression, as well as decreasing JAK2 and STAT3 phosphorylation. Ultimately, the results of the present study illustrate that AOC1 promoted the proliferation, migration and invasiveness of HCC cells by regulating the IL-6/JAK/STAT3 pathway.

HSD17B6 downregulation predicts poor prognosis and drives tumor progression via activating Akt signaling pathway in lung adenocarcinoma

Lung adenocarcinoma is one of the most frequent tumor subtypes, involving changes in a variety of oncogenes and tumor suppressor genes. Hydroxysteroid 17-Beta Dehydrogenase 6 (HSD17B6) could synthetize dihydrotestosterone, abnormal levels of which are associated with progression of multiple tumors. Previously, we showed that HSD17B6 inhibits malignant progression of hepatocellular carcinoma. However, the mechanisms underlying inhibiting tumor development by HSD17B6 are not clear. Moreover, its role in lung adenocarcinoma (LUAD) is yet unknown. Here, we investigated its expression profile and biological functions in LUAD. Analysis of data from the LUAD datasets of TCGA, CPTAC, Oncomine, and GEO revealed that HSD17B6 mRNA and protein expression was frequently lower in LUAD than in non-neoplastic lung tissues, and its low expression correlated significantly with advanced tumor stage, large tumor size, poor tumor differentiation, high tumor grade, smoking, and poor prognosis in LUAD. In addition, its expression was negatively regulated by miR-31-5p in LUAD. HSD17B6 suppressed LUAD cell proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), and radioresistance. Furthermore, HSD17B6 overexpression in LUAD cell lines enhanced PTEN expression and inhibited AKT phosphorylation, inactivating downstream oncogenes like GSK3β, β-catenin, and Cyclin-D independent of dihydrotestosterone, revealing an underlying antitumor mechanism of HSD17B6 in LUAD. Our findings indicate that HSD17B6 may function as a tumor suppressor in LUAD and could be a promising prognostic indicator for LUAD patients, especially for those receiving radiotherapy.

RNA binding protein serine/arginine splicing factor 1 promotes the proliferation, migration and invasion of hepatocellular carcinoma by interacting with RecQ protein-like 4 mRNA

Abnormally high expression of RecQ protein-like 4 (RECQL4) has been observed in many cancers, including hepatocellular carcinoma (HCC). We aimed to explore the effects of RECQL4 on HCC progression and the possible mechanisms. RECQL4 expression in HCC tissues and its correlation with the prognosis of HCC patients were analyzed using GEPIA2 and UALCAN databases. After detecting RECQL4 levels in several human HC cell lines, RECQL4 was silenced by siRNA transfection. Cell viability, migration and invasion were tested with CCK-8, wound healing and transwell assays. The levels of epithelial–mesenchymal transition (EMT) proteins were evaluated by western blotting. The ENCORI database was adopted for the analysis of the correlation between RECQL4 and serine/arginine splicing factor 1 (SRSF1) in HCC tissues. RNA immunoprecipitation and actinomycin D addition assay were employed to evaluate the combination of these two genes. SRSF1 was overexpressed to assess the biological function of HCC cells with RECQL4 silencing. Results suggested that RECQL4 was overexpressed in HCC tissues and cell lines, which was related to poor prognosis of HCC patients. RECQL4 loss-of-function repressed the proliferation, migration, invasion and EMT of HCC cells. RECQL4 was positively correlated with SRSF1 in HCC tissues. Moreover, SRSF1 was confirmed as an RNA binding protein of RECQL4. Further experiments found that SRSF1 knockdown reduced the stability of RECQL4 mRNA. Rescue assays indicated that SRSF1 overexpression crippled the braking effects of RECQL4 knockdown on the progression of HCC cells. Collectively, SRSF1 can bind to RECQL4 mRNA and enhance its stability, thereby promoting the progression of HCC.

Apatinib inhibits the proliferation of gastric cancer cells via the AKT/GSK signaling pathway in vivo

Gastric cancer (GC) is the third leading cause of cancer-associated mortality globally. Although the diagnosis and therapeutic strategies for GC have improved, the prognosis for advanced gastric cancer (AGC) remains poor. Hence, the present study sought to design a zebrafish model established by microinjecting human MGC-803 GC cell line for studying personalized molecular-targeted cancer therapy. Apatinib, a novel molecular-targeted agent, was evaluated for its in vivo efficacy through a comparison among the control groups (no treatment) and subject groups (treatment). Newly formed vessel length and tumor volume were measured in all of the groups for further study. The length of newly formed vessels was obviously shortened after apatinib treatment in the zebrafish model established in this study. Meanwhile, apatinib exhibited the best antitumor growth effect with dose and time dependence by suppressing AKT/GSK3α/β signaling, which may be the mechanism underlying the profound antitumor clinical effect of apatinib. The data indicated that apatinib therapy exerts an anti-angiogenesis effect and it can be recommended as a proper antitumor growth therapy for GC patients. Additionally, zebrafish models could be designed as a potential practical tool to explore new anti-GC cancer drugs.

PRMT4 promotes hepatocellular carcinoma progression by activating AKT/mTOR signaling and indicates poor prognosis

Background: Protein arginine methyltransferase 4 (PRMT4) has been reported to play a role in several common cancers; however, the function and mechanism of PRMT4 in hepatocellular carcinoma (HCC) are not fully understood. This study aimed to investigate the role and mechanism of PRMT4 in the progression of HCC. Methods: PRMT4 expression and clinicopathological characteristics were investigated using an HCC tissue microarray (TMA) consisting of 140 patient samples analyzed by immunohistochemistry. CCK-8, crystal violet and Transwell assays were used to determine cell proliferation, colony formation, migration, and invasion of HCC cell lines in which PRMT4 was overexpressed or downregulated. The underlying mechanism of PRMT4 function was explored by Western blot assays. Results: PRMT4 was highly expressed in HCC tumor tissues compared to adjacent nontumor tissues. PRMT4 expression was significantly associated with alpha-fetoprotein levels, tumor size, satellite nodules, and microvascular invasion. Patients with higher PRMT4 expression had a shorter survival time and higher recurrence rate. Functional studies demonstrated that PRMT4 overexpression promoted HCC cell proliferation, migration, and invasion in vitro, while knocking down PRMT4 inhibited these malignant behaviors. Additional results revealed that PRMT4 promoted the progression of HCC cells via activation of the AKT/mTOR signaling pathway. Furthermore, inhibition of the AKT/mTOR signaling by MK2206 or rapamycin significantly attenuated PRMT4-mediated malignant phenotypes. Conclusions: This study suggests that PRMT4 may promote the progression of HCC cells by activating the AKT/mTOR signaling pathway, which may be a valuable biomarker and potential target for HCC.

Protein arginine methyltransferases and hepatocellular carcinoma: A review

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Protein arginine methylation is essential in multiple biological processes.

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The family of PRMTs is a novel regulator of liver diseases.

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Deregulation of PRMTs is correlated with HCC prognosis and clinical features.

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PRMTs play a vital role in HCC malignancy, immune responses and metabolism.

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PRMTs may represent druggable targets as novel strategies for HCC therapy.

Hepatocellular carcinoma (HCC) is one of the most frequently diagnosed cancers with a high mortality rate worldwide. The complexity of HCC initiation and progression poses a great challenge to the diagnosis and treatment. An increasing number of studies have focused on the emerging roles of protein arginine methylation in cancers, including tumor growth, invasion, metastasis, metabolism, immune responses, chemotherapy sensitivity, etc. The family of protein arginine methyltransferases (PRMTs) is the most important proteins that mediate arginine methylation. The deregulation of PRMTs’ expression and functions in cancers have been gradually unveiled, and many PRMTs inhibitors are in preclinical and clinical investigations now. This review focuses predominantly on the aberrant expression of PRMTs, underlying mechanisms, as well as their potential applications in HCC, and provide novel insights into HCC therapy.