Aberrant JMJD3 Expression Upregulates Slug to Promote Migration, Invasion, and Stem Cell-Like Behaviors in Hepatocellular Carcinoma

2-Oxoglutarate-dependent dioxygenases as oxygen sensors: their importance in health and disease

Since low oxygen conditions below physiological levels, hypoxia, are associated with various diseases, it is crucial to understand the molecular basis behind cellular response to hypoxia. Hypoxia-inducible factors (HIFs) have been revealed to primarily orchestrate the hypoxic response at the transcription level and have continuously attracted great attention over the past three decades. In addition to these hypoxia-responsive effector proteins, 2-oxoglutarate-dependent dioxygenase (2-OGDD) superfamily including prolyl-4-hydroxylase domain-containing proteins (PHDs) and factor inhibiting HIF-1 (FIH-1) has attracted even greater attention in recent years as factors that act as direct oxygen sensors due to their necessity of oxygen for the regulation of the expression and activity of the regulatory subunit of HIFs. Herein, we present a detailed classification of 2-OGDD superfamily proteins, such as Jumonji C-domain-containing histone demethylases, ten-eleven translocation enzymes, AlkB family of DNA/RNA demethylases and lysyl hydroxylases, and discuss their specific functions and associations with various diseases. By introducing the multifaceted roles of 2-OGDD superfamily proteins in the hypoxic response, this review aims to summarize the accumulated knowledge about the complex mechanisms governing cellular adaptation to hypoxia in various physiological and pathophysiological contexts.

The role of histone post-translational modifications in cancer and cancer immunity: functions, mechanisms and therapeutic implications

Histones play crucial roles in both promoting and repressing gene expression, primarily regulated through post-translational modifications (PTMs) at specific amino acid residues. Histone PTMs, including methylation, acetylation, ubiquitination, phosphorylation, lactylation, butyrylation, and propionylation, act as important epigenetic markers. These modifications influence not only chromatin compaction but also gene expression. Their importance extends to the treatment and prevention of various human diseases, particularly cancer, due to their involvement in key cellular processes. Abnormal histone modifications and the enzymes responsible for these alterations often serve as critical drivers in tumor cell proliferation, invasion, apoptosis, and stemness. This review introduces key histone PTMs and the enzymes responsible for these modifications, examining their impact on tumorigenesis and cancer progression. Furthermore, it explores therapeutic strategies targeting histone PTMs and offers recommendations for identifying new potential therapeutic targets.

Hepatitis B Virus-Mediated m6A Demethylation Increases Hepatocellular Carcinoma Stemness and Immune Escape

Hepatitis B viral (HBV) persistent infection plays a significant role in hepatocellular carcinoma (HCC) tumorigenesis. Many studies have revealed the pivotal roles of N6-methyladenosine (m6A) in multiple cancers, while the regulatory mechanism in stemness maintenance of HBV persistent infection-related HCC remains elusive. Here, we demonstrated that the level of m6A modification was downregulated by HBV in HBV-positive HCC, through enhanced stability of ALKBH5 mRNA. More specifically, we also identified that ALKBH5 mRNA was functionally required for the stemness maintenance and self-renewal in the HBV-positive HCC, but dispensable in HBV-negative HCC. Mechanistically, ALKBH5 demethylated the m6A modification in the 3' untranslated region of the oncogenic gene SNAI2 to prevent the recognition of YTHDF2 therewith stabilize SNAI2 transcripts, contributing to cancer stem cell traits in HBV-positive HCC. Moreover, the expression of SNAI2 reversed the suppression of stemness properties by knocking down ALKBH5. In addition, ALKBH5/SNAI2 axis accelerates tumor immune evasion through activated ligand of immune checkpoint CD155. Our study unveiled that the ALKBH5 induces m6A demethylation of the SNAI2 as a key regulator in HBV-related HCC, and identifies the function of ALKBH5/SNAI2/YTHDF2 axis in promoting the stem-like cells phenotype and immune escape during HBV infection.

IMPLICATIONS

HBV promotes HCC stemness maintenance through elevate m6A modification of SNAI2 in an ALKBH5-YTHDF2-dependent manner and increases the expression of the ligand of immune checkpoint CD155.

Transcriptomic screening of novel targets of sericin in human hepatocellular carcinoma cells

Sericin, a natural protein derived from Bombyx mori, is known to ameliorate liver tissue damage; however, its molecular mechanism remains unclear. Herein, we aimed to identify the possible novel targets of sericin in hepatocytes and related cellular pathways. RNA sequencing analysis indicated that a low dose of sericin resulted in 18 differentially expressed genes (DEGs) being upregulated and 68 DEGs being downregulated, while 61 DEGs were upregulated and 265 DEGs were downregulated in response to a high dose of sericin (FDR ≤ 0.05, fold change > 1.50). Functional analysis revealed that a low dose of sericin regulated pathways associated with the complement and coagulation cascade, metallothionine, and histone demethylate (HDMs), whereas a high dose of sericin was associated with pathways involved in lipid metabolism, mitogen-activated protein kinase (MAPK) signaling and autophagy. The gene network analysis highlighted twelve genes, A2M, SERPINA5, MT2A, MT1G, MT1E, ARID5B, POU2F1, APOB, TRAF6, HSPA8, FGFR1, and OGT, as novel targets of sericin. Network analysis of transcription factor activity revealed that sericin affects NFE2L2, TFAP2C, STAT1, GATA3, CREB1 and CEBPA. Additionally, the protective effects of sericin depended on the counterregulation of APOB, POU2F1, OGT, TRAF6, and HSPA5. These findings suggest that sericin exerts hepatoprotective effects through diverse pathways at different doses, providing novel potential targets for the treatment of liver diseases.

JMJD3 and SNAI2 synergistically protect against Parkinson's disease by mediating the YAP/HIF1α signaling pathway in a mouse model

This study aimed to characterize the functional relevance and mechanistic basis of the histone demethylase Jumonji domain-containing protein-3 (JMJD3) in preserving dopaminergic neuron survival in Parkinson's disease (PD). Mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced lesions and MN9D dopaminergic neuronal cell lines exposed to 6-OHDA, respectively, were used to simulate in vivo and in vitro PD-like environments. PD-related genes with differential expressions were identified using RNA sequencing of hippocampal tissues collected from MPTP-lesioned mice. A specific lentiviral shRNA vector was used to investigate the effects of JMJD3 on neuron activities in vitro and PD-like phenotypes in vivo. JMJD3 was found to up-regulate the expression of Snail family transcriptional repressor 2 (SNAI2) through the inhibition of H3 on lysine 27 (H3K27me3) enrichment in the SNAI2 promoter region. As a result, the viability of 6-OHDA-exposed MN9D cells was stimulated, and cell apoptosis was diminished. Knockdown of SNAI2 decreased the expression of yes-associated protein (YAP) and HIF1α while also reducing the viability of 6-OHDA-exposed MN9D cells and increasing cell apoptosis. The in vivo experiments demonstrated that JMJD3 activated the SNAI2/YAP/HIF1α signaling pathway, inhibiting PD-like phenotypes in MPTP-lesioned mice. Thus, the findings provide evidence that JMJD3 inhibits the enrichment of H3K27me3 at the SNAI2 promoter, leading to the upregulation of SNAI2 expression and activation of the YAP/HIF1α signaling pathway, ultimately exerting a protective effect on PD mice. This finding suggests that targeting the JMJD3-SNAI2 pathway could be a promising therapeutic strategy for PD. Further in-depth studies are needed to elucidate the underlying mechanisms and identify potential downstream targets of this pathway.

USP15 Represses Hepatocellular Carcinoma Progression by Regulation of Pathways of Cell Proliferation and Cell Migration: A System Biology Analysis

BACKGROUND

Hepatocellular carcinoma (HCC) leads to 600,000 people's deaths every year. The protein ubiquitin carboxyl-terminal hydrolase 15 (USP15) is a ubiquitin-specific protease. The role of USP15 in HCC is still unclear.

METHOD

We studied the function of USP15 in HCC from the viewpoint of systems biology and investigated possible implications using experimental methods, such as real-time polymerase chain reaction (qPCR), Western blotting, clustered regularly interspaced short palindromic repeats (CRISPR), and next-generation sequencing (NGS). We investigated tissues samples of 102 patients who underwent liver resection between January 2006 and December 2010 at the Sir Run Run Shaw Hospital (SRRSH). Tissue samples were immunochemically stained; a trained pathologist then scored the tissue by visual inspection, and we compared the survival data of two groups of patients by means of Kaplan-Meier curves. We applied assays for cell migration, cell growth, and wound healing. We studied tumor formation in a mouse model.

RESULTS

HCC patients (n = 26) with high expression of USP15 had a higher survival rate than patients (n = 76) with low expression. We confirmed a suppressive role of USP15 in HCC using in vitro and in vivo tests. Based on publicly available data, we constructed a PPI network in which 143 genes were related to USP15 (HCC genes). We combined the 143 HCC genes with results of an experimental investigation to identify 225 pathways that may be related simultaneously to USP15 and HCC (tumor pathways). We found the 225 pathways enriched in the functional groups of cell proliferation and cell migration. The 225 pathways determined six clusters of pathways in which terms such as signal transduction, cell cycle, gene expression, and DNA repair related the expression of USP15 to tumorigenesis.

CONCLUSION

USP15 may suppress tumorigenesis of HCC by regulating pathway clusters of signal transduction for gene expression, cell cycle, and DNA repair. For the first time, the tumorigenesis of HCC is studied from the viewpoint of the pathway cluster.

Context-Dependent Functions of KDM6 Lysine Demethylases in Physiology and Disease

Histone lysine methylation is a major epigenetic modification that participates in several cellular processes including gene regulation and chromatin structure. This mark can go awry in disease contexts such as cancer. Two decades ago, the discovery of histone demethylase enzymes thirteen years ago sheds light on the complexity of the regulation of this mark. Here we address the roles of lysine demethylases JMJD3 and UTX in physiological and disease contexts. The two demethylases play pivotal roles in many developmental and disease contexts via regulation of di- and trimethylation of lysine 27 on histone H3 (H3K27me2/3) in repressing gene expression programs. JMJD3 and UTX participate in several biochemical settings including methyltransferase and chromatin remodeling complexes. They have histone demethylase-dependent and -independent activities and a variety of context-specific interacting factors. The structure, amounts, and function of the demethylases can be altered in disease due to genetic alterations or aberrant gene regulation. Therefore, academic and industrial initiatives have targeted these enzymes using a number of small molecule compounds in therapeutic approaches. In this chapter, we will touch upon inhibitor formulations, their properties, and current efforts to test them in preclinical contexts to optimize their therapeutic outcomes. Demethylase inhibitors are currently used in targeted therapeutic approaches that might be particularly effective when used in conjunction with systemic approaches such as chemotherapy.

KDM6B promotes gastric carcinogenesis and metastasis via upregulation of CXCR4 expression

KDM6B (Lysine-specific demethylase 6B) is a histone lysine demethyltransferase that plays a key role in many types of cancers. However, its potential role in gastric cancer (GC) remains unclear. Here, we focused on the clinical significance and potential role of KDM6B in GC. We found that the KDM6B expression is upregulated in GC tissues and that its high expression in patients is related to poor prognosis. KDM6B ectopic expression promotes GC cells' proliferation and metastasis, while its inhibition has opposite effects in vitro and in vivo. Mechanistically, KDM6B promotes GC cells proliferation and metastasis through its enzymatic activity through the induction of H3K27me3 demethylation near the CXCR4 (C-X-C chemokine receptor type 4) promoter region, resulting in the upregulation of CXCR4 expression. Furthermore, H. pylori was found to induce KDM6B expression. In conclusion, our results suggest that KDM6B is aberrantly expressed in GC and plays a key role in gastric carcinogenesis and metastasis through CXCR4 upregulation. Our work also suggests that KDM6B may be a potential oncogenic factor and a therapeutic target for GC.

Differential glutamine metabolism in the tumor microenvironment – studies in diversity and heterogeneity: A mini-review

Increased glutamine metabolism is a hallmark of many cancer types. In recent years, our understanding of the distinct and diverse metabolic pathways through which glutamine can be utilized has grown more refined. Additionally, the different metabolic requirements of the diverse array of cell types within the tumor microenvironment complicate the strategy of targeting any particular glutamine pathway as cancer therapy. In this Mini-Review, we discuss recent advances in further clarifying the cellular fate of glutamine through different metabolic pathways. We further discuss potential promising strategies which exploit the different requirements of cells in the tumor microenvironment as it pertains to glutamine metabolism in an attempt to suppress cancer growth and enhance anti-tumor immune responses.

TGF-β1-induced bone marrow mesenchymal stem cells (BMSCs) migration via histone demethylase KDM6B mediated inhibition of methylation marker H3K27me3

Mesenchymal stem cells (MSCs) are widely used in clinical research and therapy. Since the number of MSCs migration is extremely crucial at the lesion site, exploring the mechanisms to enhance the migration of MSCs is necessary. Therefore, this study focused on the epigenetic mechanisms in MSCs migration. TGF-β1 stimulated bone marrow mesenchymal stem cells (BMSCs) to promote cell migration at lesion sites in vitro and in vivo. The mRNA and protein levels of several migration-related genes (N cadherin, CXCR4, FN1) were enhanced. The trimethylation marker H3K27me3 recruitment on the promoter of these genes were studied to dissect the epigenetic mechanisms. TGF-β1 elevated the levels of KDM6B leading to removal of repression marker H3K27me3 in the promoter region of N cadherins and FN1. Congruently, knockdown of demethylase KDM6B substantially affected the TGF-β1 induced BMSCs migration. This promoted the down-regulation of various migration-related genes. Collectively, epigenetic regulation played an important role in BMSCs migration, and H3K27me3 was at least partially involved in the migration of BMSCs induced by TGF-β1.

JMJD3 suppresses tumor progression in oral tongue squamous cell carcinoma patients receiving surgical resection

Background

Jumonji domain-containing-3 (JMJD3) is reported to be a histone H3 lysine 27 (H3K27) demethylase and a tumor suppressor gene. The present study designed to investigate the crucial role of JMJD3 in oral tongue squamous cell carcinoma (OTSCC) patients who received surgical resection.

Methods

We enrolled a total of 156 OTSCC patients receiving surgical resection, including 73 patients (47%) with high expression of JMJD3 and 83 patients (53%) harboring low expression of JMJD3. Two OTSCC cell lines, SAS and Cal 27, were used to explore the modulation of cancer. GSK-J4, a potent inhibitor of JMJD3, was used to treat the two OTSCC cell lines. The Chi-square test was performed to examine between-group differences in categorical variables; the Kaplan-Meier method was used to investigate survival outcome in univariate analysis, and the Cox regression model was used for multivariate analysis.

Results

The median follow-up period was 59.2 months and he five-year disease-free survival (DFS) and overall survival (OS) rates were 46.2% and 50.0%, respectively. Better five-year DFS (59% versus 35%) and five-year OS (63% versus 39%) were mentioned in patients with high expression of JMJD3 compared to those with low expression of JMJD3. High expression of JMJD3 was significantly associated with superior DFS and OS in the univariate and multivariate analyses. Following successful inhibition of JMJD3 by GSK-J4, western blotting analysis showed the decreased expression of Rb and p21.

Conclusion

Our study showed that high expression of JMJD3 is a good prognostic factor in OTSCC patients who underwent surgical resection.

Emerging roles of JMJD3 in cancer

Histone lysine methylation plays a key role in gene activation and repression. The trimethylation of histone H3 on lysine-27 (H3K27me3) is a critical epigenetic event that is controlled by Jumonji domain-containing protein-3 (JMJD3). JMJD3 is a histone demethylase that specifically removes methyl groups. Previous studies have suggested that JMJD3 has a dual role in cancer cells. JMJD3 stimulates the expression of proliferative-related genes and increases tumor cell growth, propagation, and migration in various cancers, including neural, prostate, ovary, skin, esophagus, leukemia, hepatic, head and neck, renal, lymphoma, and lung. In contrast, JMJD3 can suppress the propagation of tumor cells, and enhance their apoptosis in colorectal, breast, and pancreatic cancers. In this review, we summarized the recent advances of JMJD3 function in cancer cells.

The Histone H3K27me3 Demethylases KDM6A/B Resist Anoikis and Transcriptionally Regulate Stemness-Related Genes

Epithelial cancer cells that lose attachment from the extracellular matrix (ECM) to seed in a distant organ often undergo anoikis’s specialized form of apoptosis. Recently, KDM3A (H3K9 demethylase) has been identified as a critical effector of anoikis in cancer cells. However, whether other histone demethylases are involved in promoting or resisting anoikis remains elusive. We screened the major histone demethylases and found that both H3K27 histone demethylases, namely, KDM6A/B were highly expressed during ECM detachment. Inhibition of the KDM6A/B activity by using a specific inhibitor results in reduced sphere formation capacity and increased apoptosis. Knockout of KDM6B leads to the loss of stem cell properties in solitary cells. Furthermore, we found that KDM6B maintains stemness by transcriptionally regulating the expression of stemness genes SOX2, SOX9, and CD44 in detached cells. KDM6B occupies the promoter region of both SOX2 and CD44 to regulate their expression epigenetically. We also noticed an increased occupancy of the HIF1α promoter by KDM6B, suggesting its regulatory role in maintaining hypoxia in detached cancer cells. This observation was further strengthened as we found a significant positive association in the expression of both KDM6B and HIF1α in various cancer types. Overall, our results reveal a novel transcriptional program that regulates resistance against anoikis and maintains stemness-like properties.

LncRNA RSU1P2-microRNA let-7a-Testis-Expressed Protein 10 axis modulates tumorigenesis and cancer stem cell-like properties in liver cancer

LncRNAs exert important functions in the modulation of tumorigenesis and cancer stem cell-like properties in liver cancer. However, the role of LncRNA Ras suppressor protein 1 pseudogene 2 (RSU1P2) in modulating tumorigenesis and cancer stem cell-like properties in liver cancer is still not known. In this study, the expression of LncRNA RSU1P2 was significantly elevated in liver cancer tissues and cells. Besides, knockdown of RSU1P2 repressed cell viability, invasion, epithelial-mesenchymal transition (EMT) of liver cancer cells and the expressions of cancer stem cell-related genes, whereas facilitated the apoptosis of liver cancer cells. In addition, LncRNA RSU1P2 can interact with microRNA let-7a (let-7a), and repress let-7a expression. Testis-Expressed Protein 10 (Tex10) was identified to be a target of let-7a, and let-7a repressed Tex10 expression. Finally, RSU1P2 knockdown suppressed tumor volume, tumor weight, and EMT in a xenograft model. Therefore, LncRNA RSU1P2 promotes tumorigenesis and cancer stem cell-like properties in liver cancer through let-7a/Tex10 pathway.

Inhibition of histone demethylase KDM4 by ML324 induces apoptosis through the unfolded protein response and Bim upregulation in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is an extremely aggressive malignancy that ranks as the sixth-leading cause of cancer-associated death worldwide. Recently, various epigenetic mechanisms including gene methylation were reported to be potential next era HCC therapeutics and biomarkers. Although inhibition of epigenetic enzymes including histone lysine demethylase 4 (KDM4) enhanced cell death in HCC cells, the detailed mechanism of cell death machinery is poorly understood. In this study, we found that ML324, a small molecule KDM4-specific inhibitor, induced the death of HCC cells in a general cell culture system and 3D spheroid culture with increased cleavage of caspase-3. Mechanistically, we identified that unfolded protein responses (UPR) were involved in ML324-induced HCC cell death. Incubation of HCC cells with ML324 upregulated death receptor 5 (DR5) expression through the activation transcription factor 3 (ATF3)-C/EBP homologous protein (CHOP)-dependent pathway. Moreover, we identified BIM protein as a mediator of ML324-induced apoptosis using CRISPR/Cas9 knockout analysis. We showed that the loss of Bim suppressed ML324-induced apoptosis by flow cytometry analysis, colony formation assay, and caspase-3 activation assay. Interestingly, BIM protein expression by ML324 was regulated by ATF3, CHOP, and DR5 which are factors involved in UPR. Specifically, we confirmed the regulating roles of KDM4E in Bim and CHOP expression using a chromatin immune precipitation (ChIP) assay. Physical binding of KDM4E to Bim and CHOP promoters decreased the response to ML324. Our findings suggest that KDM4 inhibition is a potent anti-tumor therapeutic strategy for human HCC, and further studies of UPR-induced apoptosis and the associated epigenetic functional mechanisms may lead to the discovery of novel target for future cancer therapy.

KDM6 Demethylases and Their Roles in Human Cancers

Cancer therapy is moving beyond traditional chemotherapy to include epigenetic approaches. KDM6 demethylases are dynamic regulation of gene expression by histone demethylation in response to diverse stimuli, and thus their dysregulation has been observed in various cancers. In this review, we first briefly introduce structural features of KDM6 subfamily, and then discuss the regulation of KDM6, which involves the coordinated control between cellular metabolism (intrinsic regulators) and tumor microenvironment (extrinsic stimuli). We further describe the aberrant functions of KDM6 in human cancers, acting as either a tumor suppressor or an oncoprotein in a context-dependent manner. Finally, we propose potential therapy of KDM6 enzymes based on their structural features, epigenetics, and immunomodulatory mechanisms, providing novel insights for prevention and treatment of cancers.

KDM6B promotes activation of the oncogenic CDK4/6-pRB-E2F pathway by maintaining enhancer activity in MYCN-amplified neuroblastoma

The H3K27me2/me3 histone demethylase KDM6B is essential to neuroblastoma cell survival. However, the mechanism of KDM6B action remains poorly defined. We demonstrate that inhibition of KDM6B activity 1) reduces the chromatin accessibility of E2F target genes and MYCN, 2) selectively leads to an increase of H3K27me3 but a decrease of the enhancer mark H3K4me1 at the CTCF and BORIS binding sites, which may, consequently, disrupt the long-range chromatin interaction of MYCN and E2F target genes, and 3) phenocopies the transcriptome induced by the specific CDK4/6 inhibitor palbociclib. Overexpression of CDK4/6 or Rb1 knockout confers neuroblastoma cell resistance to both palbociclib and the KDM6 inhibitor GSK-J4. These data indicate that KDM6B promotes an oncogenic CDK4/6-pRB-E2F pathway in neuroblastoma cells via H3K27me3-dependent enhancer-promoter interactions, providing a rationale to target KDM6B for high-risk neuroblastoma.

The histone demethylase KDM6B is reported to be essential for neuroblastoma cell survival. Here the authors show that KDM6B regulates CDK4/6-pRB-E2F pathway through H3K27me3-dependent enhancer-promoter interactions in neuroblastoma.

Prognostic Significance of JMJD3 Expression in Pleural Mesotheliomas

Pleural mesothelioma is a disease associated with asbestos exposure and patients often have poor prognosis. Biomarkers that can stratify tumours more efficiently are much sought after to enable more personalized treatment options and predict prognosis. Jumonji domain-containing protein D3 (JMJD3) has variable expression in a range of tumours. However, there has been much discordance in the immunohistochemical labelling of JMJD3 between cancers at different sites and ambiguity exists regarding its functional significance. Recent evidence suggests that although nuclear expression of JMJD3 has a demethylase role in most cancers, there are also demethylase-independent actions of JMJD3 that need to be explored including its cytoplasmic expression. We analysed JMJD3 labelling in 99 pleural mesothelioma tissues and correlated nuclear and cytoplasmic expression with survival outcomes. We found that low nuclear and high cytoplasmic expression were associated with poor survival outcomes in our cohort (p = 0.014 and p = 0.041, respectively). Additionally, we found that low nuclear expression of JMJD3 was frequent in the sarcomatoid subtype (p < 0.001). Finally, we showed that cytoplasmic labelling is an independent prognostic marker of poor survival. Our cohort only contained a small number of tumours with high cytoplasmic expression of JMJD3, and a larger cohort study may provide clearer stratification.

Histone demethylase KDM6B inhibits breast cancer metastasis by regulating Wnt/β-catenin signaling

Tumor metastasis remains a major challenge for patients with breast cancer. Aberrant epigenetic factor lysine‐specific demethylase 6B (KDM6B) has been associated with tumor progression. Here, we show that KDM6B is significantly down‐regulated in human breast cancer tissues, and its low expression is associated with poor prognosis of patients with breast cancer. Furthermore, overexpression of KDM6B remarkably inhibited cell proliferation, invasion, migration and epithelial–mesenchymal transition markers of breast cancer cells in vitro and tumor growth and lung metastasis in vivo. Notably, the expression of KDM6B in breast cancer tissues was negatively correlated with that of β‐catenin, and overexpression of KDM6B decreased the expression of β‐catenin and its accumulation in the nucleus of breast cancer cells. Overall, our findings provide novel insights into suppression of metastasis of breast cancer cells by KDM6B via β‐catenin and suggest involvement of the KDM6B‐Wnt/β‐catenin axis in breast cancer progression.

Loss of SNAI2 in Prostate Cancer Correlates With Clinical Response to Androgen Deprivation Therapy

PURPOSE

Androgen receptor (AR) signaling is important in prostate cancer progression, and therapies that target this pathway have been the mainstay of treatment for advanced disease for over 70 years. Tumors eventually progress despite castration through a number of well-characterized mechanisms; however, little is known about what determines the magnitude of response to short-term pathway inhibition.

METHODS

We evaluated a novel combination of AR-targeting therapies (degarelix, abiraterone, and bicalutamide) and noted that the objective patient response to therapy was highly variable. To investigate what was driving treatment resistance in poorly responding patients, as a secondary outcome we comprehensively characterized pre- and post-treatment samples using both whole-genome and RNA sequencing.

RESULTS

We find that resistance following short-term treatment differs molecularly from typical progressive castration-resistant disease, associated with transcriptional reprogramming, to a transitional epithelial-to-mesenchymal transition (EMT) phenotype rather than an upregulation of AR signaling. Unexpectedly, tolerance to therapy appears to be the default state, with treatment response correlating with the prevalence of tumor cells deficient for SNAI2, a key regulator of EMT reprogramming.

CONCLUSION

We show that EMT characterizes acutely resistant prostate tumors and that deletion of SNAI2, a key transcriptional regulator of EMT, correlates with clinical response.

W436, a novel SMART derivative, exhibits anti-hepatocarcinoma activity by inducing apoptosis and G2/M cell cycle arrest in vitro and in vivo and induces protective autophagy

Hepatocellular carcinoma (HCC) is considered one of the most common primary liver cancers and the second leading cause of cancer-associated mortality around the world annually. Therefore, it is urgent to develop novel drugs for HCC therapy. We synthesized a novel 4-substituted-methoxybenzoyl-aryl-thiazole (SMART) analog, (5-(4-aminopiperidin-1-yl)-2-phenyl-2H-1,2,3-triazol-4-yl) (3,4,5-trimethoxyphenyl) methanone (W436), with higher solubility, stability, and antitumor activity than SMART against HCC cells in vivo. The purpose of this study was to investigate the mechanisms by which W436 inhibited cell growth in HCC cells. We observed that W436 inhibited the proliferation of HepG2 and Hep3B cells in a dose-dependent manner. Importantly, the anticancer activity of W436 against HCC cells was even higher than that of SMART in vivo. In addition, the antiproliferative effects of W436 on HCC cells were associated with G2/M cell cycle arrest and apoptosis via the activation of reactive oxygen species-mediated mitochondrial apoptotic pathway. W436 also induced protective autophagy by inhibiting the protein kinase B/mammalian target of rapamycin pathway. At the same time, W436 treatment inhibited the cell adhesion and invasion as well as the process of epithelial-to-mesenchymal transition Taken together, our results showed that W436 had the promising potential for the therapeutic treatment of HCC with improved solubility, stability, and bioavailability.

Plasticity of Cancer Stem Cell: Origin and Role in Disease Progression and Therapy Resistance

In embryonic development and throughout life, there are some cells can exhibit phenotypic plasticity. Phenotypic plasticity is the ability of cells to differentiate into multiple lineages. In normal development, plasticity is highly regulated whereas cancer cells re-activate this dynamic ability for their own progression. The re-activation of these mechanisms enables cancer cells to acquire a cancer stem cell (CSC) phenotype- a subpopulation of cells with increased ability to survive in a hostile environment and resist therapeutic insults. There are several contributors fuel CSC plasticity in different stages of disease progression such as a complex network of tumour stroma, epidermal microenvironment and different sub-compartments within tumour. These factors play a key role in the transformation of tumour cells from a stable condition to a progressive state. In addition, flexibility in the metabolic state of CSCs helps in disease progression. Moreover, epigenetic changes such as chromatin, DNA methylation could stimulate the phenotypic change of CSCs. Development of resistance to therapy due to highly plastic behaviour of CSCs is a major cause of treatment failure in cancers. However, recent studies explored that plasticity can also expose the weaknesses in CSCs, thereby could be utilized for future therapeutic development. Therefore, in this review, we discuss how cancer cells acquire the plasticity, especially the role of the normal developmental process, tumour microenvironment, and epigenetic changes in the development of plasticity. We further highlight the therapeutic resistance property of CSCs attributed by plasticity. Also, outline some potential therapeutic options against plasticity of CSCs. Graphical Abstract .

The Multifaceted Nature of Nucleobindin-2 in Carcinogenesis

Nucb2 is a multifunctional protein associated with a variety of biological processes. Multiple studies have revealed that Nucb2, and its derivative nesfatin-1, are involved in carcinogenesis. Interestingly, the role of Nucb2/nesfatin-1 in tumorigenesis seems to be dual-both pro-metastatic and anti-metastatic. The implication of Nucb2/nesfatin-1 in carcinogenesis seems to be tissue dependent. Herein, we review the role of Nucb2/nesfatin-1 in both carcinogenesis and the apoptosis process, and we also highlight the multifaceted nature of Nucb2/nesfatin-1.

Site-specific glycoproteomic analysis revealing increased core-fucosylation on FOLR1 enhances folate uptake capacity of HCC cells to promote EMT

Rationale: Epithelial-mesenchymal transition (EMT) has been recognized as an important step toward high invasion and metastasis of many cancers including hepatocellular carcinoma (HCC), while the mechanism for EMT promotion is still ambiguous.

Methods: The dynamic alterations of site-specific glycosylation during HGF/TGF-β1-induced EMT process of three HCC cell lines were systematically investigated using precision glycoproteomic methods. The possible roles of EMT-related glycoproteins and site-specific glycans were further confirmed by various molecular biological approaches.

Results: Using mass spectrometry-based glycoproteomic methods, we totally identified 2306 unique intact glycopeptides from SMMC-7721 and HepG2 cell lines, and found that core-fucosylated glycans were accounted for the largest proportion of complex N-glycans. Through quantification analysis of intact glycopeptides, we found that the majority of core-fucosylated intact glycopeptides from folate receptor α (FOLR1) were up-regulated in the three HGF-treated cell lines. Similarly, core-fucosylation of FOLR1 were up-regulated in SMMC-7721 and Hep3B cells with TGF-β1 treatment. Using molecular approaches, we further demonstrated that FUT8 was a driver for HGF/TGF-β1-induced EMT. The silencing of FUT8 reduced core-fucosylation and partially blocked the progress of HGF-induced EMT. Finally, we confirmed that the level of core-fucosylation on FOLR1 especially at the glycosite Asn-201 positively regulated the cellular uptake capacity of folates, and enhanced uptake of folates could promote the EMT of HCC cells.

Conclusions: Based on the results, we proposed a potential pathway for HGF or TGF-β1-induced EMT of HCC cells: HGF or TGF-β1 treatment of HCC cells can increase the expression of glycosyltransferase FUT8 to up-regulate the core-fucosylation of N-glycans on glycoproteins including the FOLR1; core-fucosylation on FOLR1 can then enhance the folate uptake capacity to finally promote the EMT progress of HCC cells.

Expression pattern of histone lysine-specific demethylase 6B in gastric cancer

Over the last few decades, predictive markers for the prognosis of gastric cancer have not been extensively investigated. The present study aimed to evaluate the expression profile of histone demethylase lysine (K)-specific demethylase 6B (KDM6B) in gastric cancer and healthy control tissues, as well as its value in prognosis prediction as a clinical marker. Within the framework of these criteria, the diagnostic role of KMD6B for gastric cancer was investigated, which may provide insights into novel treatment targets. Immunohistochemistry was applied to detect KMD6B expression in 100 gastric cancer tissues and matching para-cancerous tissues to analyze the association between KMD6B expression and clinicopathological features. Based on the follow-up data, the value of KMD6B in prognosis assessment was further explored. The role of KMD6B in gastric cancer cell proliferation, cell cycle distribution and the expression of cell cycle-associated proteins was investigated by inhibiting KMD6B activity using the specific inhibitor GSK J4. KMD6B was mostly distributed in cytoplasm and nucleus in gastric cancer tissue. The expression level was significantly higher in cancer tissues compared with that in the corresponding non-cancerous tissues. The expression of KMD6B was significantly associated with sex, lymph node and distant metastasis status and clinical stage (P<0.05). Cell proliferation was significantly decreased with the inhibition of KMD6B activity, and the cell cycle in HGC27 cells was arrested in the G₂/M phase after being treated with GSK J4 for 24 h. The expression of cyclin B and Cdc2 were significantly decreased, while p21 was upregulated. It was concluded that the dysregulated expression of KMD6B is associated with the malignant progression of gastric cancer and could be a potential marker for prognosis. Blocking the demethylase activity of KMD6B induced G₂/M arrest and inhibited the proliferation of gastric cancer cells, suggesting that KMD6B is a potential novel therapeutic target for gastric cancer.

An IFNγ/STAT1/JMJD3 Axis Induces ZEB1 Expression and Promotes Aggressiveness in Lung Adenocarcinoma

Active IFNγ signaling is a common feature of tumors responding to PD-1 checkpoint blockade. IFNγ exhibits both anti- and protumor activities. Here, we show that the treatment of lung adenocarcinoma cells with IFNγ led to a rapid increase of ZEB1 expression and a significant change in epithelial-to-mesenchymal transition (EMT)-associated gene expression pattern. Moreover, functional analyses show that IFNγ promoted cell migration in vitro and metastasis in vivo. We demonstrate that ZEB1 is required for IFNγ-promoted EMT, cell migration, and metastasis, as RNAi-mediated knockdown of ZEB1 abrogated EMT, cell migration, and metastasis induced by IFNγ. We show that IFNγ induced upregulation of JMJD3 significantly reduced H3K27 trimethylation in the promoter of the ZEB1 gene, which led to activation of ZEB1 gene transcription. IFNγ-induced JMJD3 expression was JAK1/2-STAT1 dependent. Inhibition of JMJD3 abrogated IFNγ-induced ZEB1 expression. IFNγ-induced ZEB1 also reduced miR-200 expression. Downregulation of ZEB1 increased miR-200 expression, which led to a reduction of PD-L1 expression induced by IFNγ. It is worth noting that knockdown of ZEB1 did not affect IFNγ-mediated antiproliferation and induction of CXCL9 and CXCL10. Thus, downregulation of ZEB1 may prevent the protumor activity of IFNγ while retaining its antitumor function. This study expands our understanding of IFNγ-mediated signaling and helps to identify therapeutic targets to improve current immunotherapies. IMPLICATIONS: IFNγ increases ZEB1 expression in a STAT1-JMJD3 dependent manner, and consequently promotes cancer cell aggressiveness. This study provides a potential target to minimize the procancer effect of IFNγ while preserving its antitumor function.

KDM6B (JMJD3) and its dual role in cancer

Epigenetic modifications play a fundamental role in the regulation of gene expression and cell fate. During the development of cancer, epigenetic modifications appear that favor cell proliferation and migration, but at the same time prevent differentiation and apoptosis, among other processes. KDM6B is a histone demethylase that specifically removes methyl groups from H3K27me3, thus allowing re-expression of its target genes. It is currently known that KDM6B can act as both a tumor suppressor and an oncogene depending on the cellular context. Therefore, in this work we summarize the current knowledge of the role that KDM6B plays in different oncological contexts, and we try to orient it towards its clinical application.

A Computational Systems Biology Approach Identifies SLUG as a Mediator of Partial Epithelial-Mesenchymal Transition (EMT)

Epithelial-mesenchymal plasticity comprises reversible transitions among epithelial, hybrid epithelial/mesenchymal (E/M) and mesenchymal phenotypes, and underlies various aspects of aggressive tumor progression such as metastasis, therapy resistance, and immune evasion. The process of cells attaining one or more hybrid E/M phenotypes is termed as partial epithelial mesenchymal transition (EMT). Cells in hybrid E/M phenotype(s) can be more aggressive than those in either fully epithelial or mesenchymal state. Thus, identifying regulators of hybrid E/M phenotypes is essential to decipher the rheostats of phenotypic plasticity and consequent accelerators of metastasis. Here, using a computational systems biology approach, we demonstrate that SLUG (SNAIL2) - an EMT-inducing transcription factor - can inhibit cells from undergoing a complete EMT and thus stabilize them in hybrid E/M phenotype(s). It expands the parametric range enabling the existence of a hybrid E/M phenotype, thereby behaving as a phenotypic stability factor. Our simulations suggest that this specific property of SLUG emerges from the topology of the regulatory network it forms with other key regulators of epithelial-mesenchymal plasticity. Clinical data suggest that SLUG associates with worse patient prognosis across multiple carcinomas. Together, our results indicate that SLUG can stabilize hybrid E/M phenotype(s).

The Functions of the Demethylase JMJD3 in Cancer

Cancer is a major cause of death worldwide. Epigenetic changes in response to external (diet, sports activities, etc.) and internal events are increasingly implicated in tumor initiation and progression. In this review, we focused on post-translational changes in histones and, more particularly, the tri methylation of lysine from histone 3 (H3K27me3) mark, a repressive epigenetic mark often under- or overexpressed in a wide range of cancers. Two actors regulate H3K27 methylation: Jumonji Domain-Containing Protein 3 demethylase (JMJD3) and Enhancer of zeste homolog 2 (EZH2) methyltransferase. A number of studies have highlighted the deregulation of these actors, which is why this scientific review will focus on the role of JMJD3 and, consequently, H3K27me3 in cancer development. Data on JMJD3’s involvement in cancer are classified by cancer type: nervous system, prostate, blood, colorectal, breast, lung, liver, ovarian, and gastric cancers.

Tumor-associated mesenchymal stem cells promote hepatocellular carcinoma metastasis via a DNM3OS/KDM6B/TIAM1 axis

Tumor-associated mesenchymal stem cells (MSCs) play a critical role in the growth and metastasis of hepatocellular carcinoma (HCC). However, the mechanism underlying the crosstalk between MSCs and HCC cells is not completely understood. Here, HCC cells were treated with or without conditioned medium of MSCs (CM-MSC), and examined for differential expression of long non-coding RNAs (lncRNAs). Knockdown and overexpression experiments were conducted to explore the function of the lncRNA DNM3OS in MSC-induced HCC growth and metastasis. CM-MSC treatment led to a concentration-dependent induction of DNM3OS in HCC cells. DNM3OS was significantly upregulated in HCC compared to adjacent liver tissues. High DNM3OS expression was associated with TNM stage, vascular invasion, and poor prognosis of HCC patients. Silencing of DNM3OS inhibited HCC cell proliferation and invasion in vitro and tumorigenesis and metastasis in vivo. Overexpression of DNM3OS enhanced HCC cell proliferation, invasion, and metastasis. Biochemically, DNM3OS was mainly localized in the nucleus and physically interacted with KDM6B. The association of DNM3OS with KDM6B induced the expression of TIAM1 through reduction of H3K27me3 at the TIAM1 promoter. TIAM1 overexpression restored the proliferation and invasion of DNM3OS-depleted HCC cells. Our data delineate a mechanism by which MSCs accelerate HCC growth and metastasis through a DNM3OS/KDM6B/TIAM1 axis.

LncRNA TTN-AS1 intensifies sorafenib resistance in hepatocellular carcinoma by sponging miR-16-5p and upregulation of cyclin E1

Drug resistance has always been an important problem affecting the therapeutic effect of hepatocellular carcinoma (HCC). To investigate the potential role of lncRNA TTN-AS1 in HCC cells with sorafenib (SOR) resistance, and explore the underlying pathways, quantitative real time polymerase chain reaction (qRT-PCR) was used to test the expression of TTN-AS1 in HCC tissues and cells. Then, the expression of TTN-AS1 was down-regulated by shRNA, the activity changes, apoptosis and related protein expression in HCC cells with/without SOR treatment were observed in succession. Expression levels of the downstream target of TTN-AS1, miR-16-5p were studied by dual-luciferase binding assay, cell proliferation, and western blotting analysis. Nude mice models of human HCC with TTN-AS1 gene knockdown were established to observe the tumor growth. As the results revealed, TTN-AS1 silencing in HCC cells induced apoptosis by enhancing the sensitivity of cells to SOR, and the tumor in nude mice became smaller. The mechanism study showed that miR-16-5p was affected by TTN-AS1 sponge, up-regulated cyclin E1 expression, and regulated PTEN/Akt signaling pathway, thereby significantly alleviating the inhibition of apoptosis of HCC cells induced by TTN-AS1 gene. Collectively, our results provided TTN-AS1 as a potential therapeutic target for sorafenib resistance in HCC.

EZH2 and KDM6B Expressions Are Associated with Specific Epigenetic Signatures during EMT in Non Small Cell Lung Carcinomas

The role of Epigenetics in Epithelial Mesenchymal Transition (EMT) has recently emerged. Two epigenetic enzymes with paradoxical roles have previously been associated to EMT, EZH2 (Enhancer of Zeste 2 Polycomb Repressive Complex 2 (PRC2) Subunit), a lysine methyltranserase able to add the H3K27me3 mark, and the histone demethylase KDM6B (Lysine Demethylase 6B), which can remove the H3K27me3 mark. Nevertheless, it still remains unclear how these enzymes, with apparent opposite activities, could both promote EMT. In this study, we evaluated the function of these two enzymes using an EMT-inducible model, the lung cancer A549 cell line. ChIP-seq coupled with transcriptomic analysis showed that EZH2 and KDM6B were able to target and modulate the expression of different genes during EMT. Based on this analysis, we described INHBB, WTN5B, and ADAMTS6 as new EMT markers regulated by epigenetic modifications and directly implicated in EMT induction.

[Association of JMJD3, MMP-2 and VEGF expressions with clinicopathological features of invasive ductal breast carcinoma]

OBJECTIVE

To examine the expressions of JMJD3, matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF) in invasive ductal breast carcinoma, their association with the clinicopathological features of the patients and the effect of JMJD3 overexpression on proliferation and MMP-2 and VEGF expressions in breast cancer cells.

METHODS

The protein and mRNA expressions of JMJD3, MMP-2, and VEGF in invasive ductal breast carcinoma and paired adjacent tissues were detected by immunohistochemistry and RT-PCR, respectively, and their correlation with the clinicopathological characteristics of the patients was analyzed. Kaplan-Meier survival analysis was used to evaluate the correlation of JMJD3, MMP-2 and VEGF expression levels with the survival of the patients. In breast cancer MDA-MB-231 cells transfected with a JMJD3-expression plasmid, the expression of Ki67 was examined immunohistochemically, the cell proliferation was assessed with CCK8 assay, and the mRNA expressions of MMP-2 and VEGF were detected with RT-PCR.

RESULTS

Breast cancer tissues had significantly lower JMJD3 expression and higher MMP-2 and VEGF expressions at both the mRNA and protein levels than the adjacent tissue (P < 0.05). The positivity rates of JMJD3, MMP-2 and VEGF in breast cancer tissues were significantly correlated with tumor diameter, differentiation, TNM stage, lymph node metastasis, and molecular subtypes (P < 0.05). KaplanMeier analysis showed that JMJD3 expression level was positively while MMP-2 and VEGF were inversely correlated with the disease-free survival time of the patients (P < 0.05). Cox regression analysis identified JMJD3, MMP-2, VEGF and tumor differentiation as independent prognostic factors of breast cancer. Spearman correlation analysis suggested a negative correlation of JMJD3 with MMP2 (r=-0.569, P < 0.05) and VEGF (r=-0.533, P < 0.05) and a positive correlation between MMP2 and VEGF (r=0.923, P < 0.05). In MDA-MB-231 cells, overexpression of JMJD3 inhibited the proliferation of MDA-MB-231 cells and the expression of MMP-2 and VEGF.

CONCLUSIONS

The expressions of JMJD3, MMP-2 and VEGF in invasive ductal breast carcinoma are closely correlated to tumor proliferation, invasion, metastasis and prognosis and can be used for prognostic evaluation of breast cancer.

Epigenetics in hepatocellular carcinoma development and therapy: The tip of the iceberg

Hepatocellular carcinoma (HCC) is a deadly tumour whose causative agents are generally well known, but whose pathogenesis remains poorly understood. Nevertheless, key genetic alterations are emerging from a heterogeneous molecular landscape, providing information on the tumorigenic process from initiation to progression. Among these molecular alterations, those that affect epigenetic processes are increasingly recognised as contributing to carcinogenesis from preneoplastic stages. The epigenetic machinery regulates gene expression through intertwined and partially characterised circuits involving chromatin remodelers, covalent DNA and histone modifications, and dedicated proteins reading these modifications. In this review, we summarise recent findings on HCC epigenetics, focusing mainly on changes in DNA and histone modifications and their carcinogenic implications. We also discuss the potential drugs that target epigenetic mechanisms for HCC treatment, either alone or in combination with current therapies, including immunotherapies.

Human cathelicidin antimicrobial peptide suppresses proliferation, migration and invasion of oral carcinoma HSC-3 cells via a novel mechanism involving caspase-3 mediated apoptosis

Human cathelicidin antimicrobial peptide and its active product, LL-37 (CAMP/LL-37), exhibit a broad spectrum of antimicrobial effects. An increasing number of studies have shown that human CAMP/LL-37 also serves significant roles in various types of cancer. The primary aims of the present study were to investigate the roles and mechanisms of human CAMP/LL-37 in oral squamous cell carcinoma (OSCC) cells. The results indicated that either LL-37 C-terminal deletion mutants (CDEL) or CAMP stable expression in HSC-3 cells reduced colony formation, proliferation, migration and invasion ability of the cells. Expression analysis demonstrated that either CDEL or CAMP stable expression in HSC-3 cells induced caspase-3 mediated apoptosis via the P53-Bcl-2/BAX signalling pathway, whereas the levels of cell cycle-related proteins, cyclin B1 and PKR-like ER kinase, were significantly upregulated in the CAMP, but not in the CDEL overexpressing cells. Transcriptional profile comparisons revealed that CDEL or CAMP stable expression in HSC-3 cells upregulated expression of genes involved in the IL-17-dependent pathway compared with the control. Taken together, these results suggest that CAMP may act as a tumour suppressor in OSCC cells, and the underlying mechanism involves the induction of caspase-3 mediated apoptosis via the P53-Bcl-2/BAX signalling pathway.

Aberrant JmjC domain-containing protein 8 (JMJD8) expression promotes activation of AKT and tumor epithelial-mesenchymal transition

Posttranslational modifications of histone and nonhistone proteins greatly influence numerous molecular events in multiple diseases. Jumonji domain-containing proteins are a family functioning as histone demethylase. Jumonji domain-containing protein 8 (JMJD8) is Jumonji C (JmjC) domain-only member of this family, and its physiological functions remain largely unknown. In this study, we investigated the mechanism by which aberrant JMJD8 stimulates phosphorylation of AKT and activate AKT/GSK3β/β-catenin signaling pathway thereby promotes tumor cell epithelial-mesenchymal transition (EMT). We demonstrated that knockdown of JMJD8 increased the interaction of SETDB1 and phosphoinositide-dependent kinase 1 (PDK1) with AKT1 and resulted in enhanced trimethylation of AKT1 at lysine 142 (K142), which is crucial for cell membrane recruitment, phosphorylation, and activation of AKT. Moreover, the mutation of histidine 200 of JMJD8 (JMJD8-H200Q) disrupted its binding with AKT1 and increased interaction of SETDB1 and PDK1 with AKT1. Furthermore, histone demethylase jumonji domain-containing protein 2B functioned as an adapter to recruit β-catenin to the methylated AKT1 upon JMJD8 depression, which facilitated the phosphorylation of β-catenin at Ser552 and its accumulation in cell nucleus where the activated β-catenin transcriptionally stimulated the expression of genes involved in EMT. In conclusion, our data unraveled a novel role of JMJD8 in regulating the migration and invasion of tumor via modulating AKT methylation and activation. In addition, this study showed that JMJD8 is a potential biomarker and drug design target for tumor EMT.

Puerarin 6″-O-xyloside suppressed HCC via regulating proliferation, stemness, and apoptosis with inhibited PI3K/AKT/mTOR

Puerarin 6″-O-xyloside is a tumor suppressive derivate of Puerarin that is recently characterized as a lysine-specific demethylase 6B inhibitor. Here we investigated the effects of Puerarin 6″-O-xyloside in hepatocellular carcinoma (HCC) cell lines SMMC-7721 and HepG2. Cell viability, proliferation, stemness, protein expression, and autophagy were tested by CCK-8, colony formation, sphere formation, western blotting, and LC3B GFP puncta per cell, respectively. Apoptosis, CD133-positive cells, and JC-1-labeled mitochondrial membrane potential were measured by flow cytometry. The effects of Puerarin 6″-O-xyloside in vivo were explored in HepG2 xenograft mice. Puerarin 6″-O-xyloside inhibited cell viability, proliferation, and stemness, and promoted apoptosis in both SMMC-7721 and HepG2 cells. Further experiments showed promoted autophagy and decreased mitochondrial membrane potential, and decreased expression of p-PI3K, p-AKT, and p-mTOR in HepG2 cells. Co-administration of 3-MA with Puerarin 6″-O-xyloside obviously augmented these effects including inhibited protein expression of p-PI3K, p-AKT, and p-mTOR, and inhibited proliferation, promoted apoptosis, and decreased stemness. In HepG2 xenograft mice, 100 mg/kg/d Puerarin 6″-O-xyloside significantly suppressed tumor growth, stemness, and apoptosis. In conclusion, our study indicated that Puerarin 6″-O-xyloside decreased cell viability, proliferation, and stemness, and promoted autophagy and mitochondria-dependent apoptosis of HCC, at least partly through inhibiting PI3K/AKT/mTOR. These results highlighted Puerarin 6″-O-xyloside as a promising prodrug that could inhibit both PI3K/AKT/mTOR and epigenetic demethylation.

Targeted inhibition of KDM6 histone demethylases eradicates tumor-initiating cells via enhancer reprogramming in colorectal cancer

Tumor-initiating cells (TICs) maintain heterogeneity within tumors and seed metastases at distant sites, contributing to therapeutic resistance and disease recurrence. In colorectal cancer (CRC), strategy that effectively eradicates TICs and is of potential value for clinical use still remains in need. Methods: The anti-tumorigenic activity of a small-molecule inhibitor of KDM6 histone demethylases named GSK-J4 in CRC was evaluated by in vitro assays and in vivo imaging of xenografted tumors. Sphere formation, flow cytometry analysis of cell surface markers and intestinal organoid formation were performed to examine the impact of GSK-J4 on TIC properties. Transcriptome analysis and global profiling of H3K27ac, H3K27me3, and KDM6A levels by ChIP-seq were conducted to elucidate how KDM6 inhibition reshapes epigenetic landscape and thereby eliminating TICs. Results: GSK-J4 alleviated the malignant phenotypes of CRC cells in vitro and in vivo, sensitized them to chemotherapeutic treatment, and strongly repressed TIC properties and stemness-associated gene signatures in these cells. Mechanistically, KDM6 inhibition induced global enhancer reprogramming with a preferential impact on super-enhancer-associated genes, including some key genes that control stemness in CRC such as ID1. Besides, expression of both Kdm6a and Kdm6b was more abundant in mouse intestinal crypt when compared with upper villus and inhibition of their activities blocked intestinal organoid formation. Finally, we unveiled the power of KDM6B in predicting both the overall survival outcome and recurrence of CRC patients. Conclusions: Our study provides a novel rational strategy to eradicate TICs through reshaping epigenetic landscape in CRC, which might also be beneficial for optimizing current therapeutics.

Histone Deacetylases Inhibit the Snail2-Mediated EMT During Metastasis of Hepatocellular Carcinoma Cells

Snail2 has an important role in the epithelial-mesenchymal transition (EMT) and tumor metastasis. Here, we report that Snail2 is highly expressed during TGF-β induced EMT in HL-7702 cells. Additionally, overexpression of Snail2 successfully promotes the migration and invasion of these cells, both in vitro and in a mouse model. Furthermore, our results show that HDAC1 and HDAC3 could suppress the Snail2 gene promoter. Moreover, we find that the acetylation of H3K4 and H3K56 are significantly reduced during the EMT process of liver HL-7702 cells. Thus, our results indicate that HDAC1 and HDAC3 epigenetically suppress the expression of Snail2 during the EMT of liver cells, revealing an opposing function of HDACs during the migration of malignant tumors.

The role of histone methylation in the development of digestive cancers: a potential direction for cancer management

Digestive cancers are the leading cause of cancer-related death worldwide and have high risks of morbidity and mortality. Histone methylation, which is mediated mainly by lysine methyltransferases, lysine demethylases, and protein arginine methyltransferases, has emerged as an essential mechanism regulating pathological processes in digestive cancers. Under certain conditions, aberrant expression of these modifiers leads to abnormal histone methylation or demethylation in the corresponding cancer-related genes, which contributes to different processes and phenotypes, such as carcinogenesis, proliferation, metabolic reprogramming, epithelial–mesenchymal transition, invasion, and migration, during digestive cancer development. In this review, we focus on the association between histone methylation regulation and the development of digestive cancers, including gastric cancer, liver cancer, pancreatic cancer, and colorectal cancer, as well as on its clinical application prospects, aiming to provide a new perspective on the management of digestive cancers.

The histone demethylase JMJD2B regulates endothelial-to-mesenchymal transition

Here we show that the histone demethylase JMJD2B is induced in endothelial cells by EndMT provoking stimuli and thereby contributes to the acquirement of a mesenchymal/smooth muscle phenotype. Silencing of JMJD2B inhibited EndMT in vitro and reduced the induction of EndMT after myocardial infarction in vivo. Inhibition of JMJD2B prevents the demethylation of repressive trimethylated histone H3 at lysine 9 (H3K9me3) at promoters of mesenchymal and EndMT-controlling genes, thereby reducing EndMT. Together, our study reports a crucial role for JMJD2B in controlling histone modifications during the transition of endothelial cells toward a mesenchymal phenotype.

Endothelial cells play an important role in maintenance of the vascular system and the repair after injury. Under proinflammatory conditions, endothelial cells can acquire a mesenchymal phenotype by a process named endothelial-to-mesenchymal transition (EndMT), which affects the functional properties of endothelial cells. Here, we investigated the epigenetic control of EndMT. We show that the histone demethylase JMJD2B is induced by EndMT-promoting, proinflammatory, and hypoxic conditions. Silencing of JMJD2B reduced TGF-β2-induced expression of mesenchymal genes, prevented the alterations in endothelial morphology and impaired endothelial barrier function. Endothelial-specific deletion of JMJD2B in vivo confirmed a reduction of EndMT after myocardial infarction. EndMT did not affect global H3K9me3 levels but induced a site-specific reduction of repressive H3K9me3 marks at promoters of mesenchymal genes, such as Calponin (CNN1), and genes involved in TGF-β signaling, such as AKT Serine/Threonine Kinase 3 (AKT3) and Sulfatase 1 (SULF1). Silencing of JMJD2B prevented the EndMT-induced reduction of H3K9me3 marks at these promotors and further repressed these EndMT-related genes. Our study reveals that endothelial identity and function is critically controlled by the histone demethylase JMJD2B, which is induced by EndMT-promoting, proinflammatory, and hypoxic conditions, and supports the acquirement of a mesenchymal phenotype.

Therapeutically targeting head and neck squamous cell carcinoma through synergistic inhibition of LSD1 and JMJD3 by TCP and GSK-J1

BACKGROUND

The histone demethylase LSD1 is a key mediator driving tumorigenesis, which holds potential as a promising therapeutic target. However, treatment with LSD1 inhibitors alone failed to result in complete cancer regression.

METHODS

The synergistic effects of TCP (a LSD1 inhibitor) and GSK-J1 (a JMJD3 inhibitor) against HNSCC were determined in vitro and in preclinical animal models. Genes modulated by chemical agents or siRNAs in HNSCC cells were identified by RNA-seq and further functionally interrogated by bioinformatics approach. Integrative siRNA-mediated gene knockdown, rescue experiment and ChIP-qPCR assays were utilised to characterise the mediators underlying the therapeutic effects conferred by TCP and GSK-J1.

RESULTS

Treatment with TCP and GSK-J1 impaired cell proliferation, induced apoptosis and senescence in vitro, which were largely recapitulated by simultaneous LSD1 and JMJD3 knockdown. Combinational treatment inhibited tumour growth and progression in vivo. Differentially expressed genes modulated by TCP and GSK-J1 were significantly enriched in cell proliferation, apoptosis and cancer-related pathways. SPP1 was identified as the mediator of synergy underlying the pro-apoptosis effects conferred by TCP and GSK-J1. Co-upregulation of LSD1 and JMJD3 associated with worse prognosis in patients with HNSCC.

CONCLUSIONS

Our findings revealed a novel therapeutic strategy of simultaneous LSD1 and JMJD3 inhibition against HNSCC.

Molecular regulation of Snai2 in development and disease

The transcription factor Snai2, encoded by the SNAI2 gene, is an evolutionarily conserved C2H2 zinc finger protein that orchestrates biological processes critical to tissue development and tumorigenesis. Initially characterized as a prototypical epithelial-to-mesenchymal transition (EMT) transcription factor, Snai2 has been shown more recently to participate in a wider variety of biological processes, including tumor metastasis, stem and/or progenitor cell biology, cellular differentiation, vascular remodeling and DNA damage repair. The main role of Snai2 in controlling such processes involves facilitating the epigenetic regulation of transcriptional programs, and, as such, its dysregulation manifests in developmental defects, disruption of tissue homeostasis, and other disease conditions. Here, we discuss our current understanding of the molecular mechanisms regulating Snai2 expression, abundance and activity. In addition, we outline how these mechanisms contribute to disease phenotypes or how they may impact rational therapeutic targeting of Snai2 dysregulation in human disease.

Identification of upstream miRNAs of SNAI2 and their influence on the metastasis of gastrointestinal stromal tumors

Background

SNAI2, a member of the snail zinc finger protein family, plays an important role in the metastasis of several types of carcinoma.

Objective

This study aims to investigate the upstream miRNAs of SNAI2 and their influence on the metastasis of gastrointestinal stromal tumors (GISTs).

Methods

The expression levels of SNAI2, CDH1, and CDH2 in GISTs were determined by immunohistochemistry, and the correlations with their clinicopathologic characteristics were analyzed. Subsequently, the miRNAs involved in regulating SNAI2 expression were predicted by bioinformatics technique, screened by miRNA microarray tests, and verified by real-time PCR, dual luciferase reporter assay, and invasion assay. The influence of SNAI2 and miRNAs on the invasive ability of the GIST cells and the related mechanism were detected.

Outcomes

SNAI2 expression significantly increased and CDH1 expression markedly decreased in the cases of GISTs with distant metastasis. Silencing of the SNAI2 gene impaired the invasiveness of GIST cells in vitro. MiR-200b-3p, miR-30c-1-3P, and miR-363-3P were verified as the upstream metastasis-associated miRNAs of SNAI2 in GISTs by miRNA microarray, real-time PCR, dual luciferase reporter assay, and invasion assay. They bound to the 3′-UTR of SNAI2, downregulated SNAI2 expression, and inhibited the invasiveness of GIST cells. SNAI2 targetedly bound to the promoter of the CDH1 gene, downregulated the expression of CDH1, and contributed to the metastasis of GISTs.

Conclusion

SNAI2 and CDH1 correlated with the metastasis of GISTs, and silencing of the SNAI2 gene impaired the invasiveness of GIST cells. MiR-200b-3p, miR-30c-1-3P, and miR-363-3P contribute to the metastasis of GISTs in vitro by mediating the SNAI2/CDH1 axis. SNAI2 may be a potential target for the treatment of GISTs in the future.

The Prognostic Significance Of JMJD3 In Primary Sarcomatoid Carcinoma Of The Lung, A Rare Subtype Of Lung Cancer

Introduction

Primary sarcomatoid carcinoma of the lung (PSC) is a rare subtype of non-small cell lung cancer, which has a bad prognosis and lacks biomarkers for its diagnosis and prognosis. Recent studies suggested that KDM6B (lysine demethylase 6B), also known as Jumonji domain-containing protein D3 (JMJD3), plays an oncogenic role in various human cancers. However, abnormalities of JMJD3 in sarcomatoid carcinoma of the lung and its clinical prognostic significance have not been determined. Therefore, the present study aimed to ascertain the relationship between JMJD3 and PSC.

Materials and methods

In this study, immunohistochemistry (IHC) was performed to examine the expression of JMJD3 in a tissue microarray (TMA) containing 96 cases of PSC.

Result

Overexpression of JMJD3 was observed in nuclei of the PSC cells. Further analyses indicated that the overexpression of JMJD3 was significantly associated with tumor size, pN stage, and clinical stage. By univariate survival analysis, positive expression of JMJD3 was significantly correlated with shortened patient survival. More importantly, multivariate analysis identified JMJD3 as an independent prognostic factor for sarcomatoid carcinoma of the lung.

Conclusion

These findings provide evidence that JMJD3 protein levels, as examined by IHC, may act as a novel prognostic biomarker for patients with primary sarcomatoid carcinoma of the lung.

Long noncoding RNA ARHGAP27P1 inhibits gastric cancer cell proliferation and cell cycle progression through epigenetically regulating p15 and p16

Long noncoding RNAs (lncRNAs) have emerged as important regulators in the development and progression of gastric cancer (GC). ARHGAP27P1 is a pseudogene-derived lncRNA, and it has been found to be associated with GC in our preliminary study, but this association has not been studied further. Herein, we confirmed that ARHGAP27P1 was significantly downregulated in GC tissues, plasma and cells. Low expression of ARHGAP27P1 was closely associated with advanced TNM stage, increased invasion depth and lymphatic metastasis. Low ARHGAP27P1 expression also predicted a poor prognosis in GC patients. Functionally, overexpression of ARHGAP27P1 inhibited proliferation, invasion, and migration in GC cells, while silencing of ARHGAP27P1 showed the opposite effects. Mechanistic investigations showed that ARHGAP27P1 had a key role in G0/G1 arrest. We further demonstrated that ARHGAP27P1 was associated with Jumonji-domain containing 3 (JMJD3) and that this association was required for the demethylation of H3K27me3, thereby epigenetically activating expression of p15, p16 and p57. Moreover, knockdown of JMJD3, p15, or p16 consistently reversed the inhibitory effects of ARHGAP27P1 in cell proliferation and cell cycle progression. Taken together, these results suggest that lncRNA ARHGAP27P1, as a novel cell cycle regulator, may serve as a potential target for GC prevention and treatment in human GC.

Screening of inhibitors against histone demethylation jumonji domain-containing protein 3 by capillary electrophoresis

Jumonji domain-containing proteins (JMJDs) play an important role in the epigenetic regulation of gene expression. Aberrant regulation of histone modification has been observed in the progression of a variety of diseases, such as neurological disorders and cancer. Therefore, discovery of selective modulators of JMJDs is very attractive in new drug discovery. Herein, a simple capillary electrophoresis (CE) method was developed for screening of inhibitors against JMJD3. A known JMJD3 inhibitor GSK-J1, 5-carboxyfluorescein labeled substrate peptide with an amino acid sequence of KAPRKQLATKAARK(me3)SAPATGG (truncated from histone H3), as well as a small chemical library composed of 37 purified natural compounds and 30 natural extracts were used for method development and validation. The separation of substrate from its demethylated product was achieved by addition of polycation hexadimethrine bromide (HDB) in the running buffer. The enzyme activity was thus assayed accurately through separating the demethylated product from the substrate and then measuring the peak area of the product. The enzyme inhibition can be read out by comparing the peak area of the demethylated product obtained in the present of inhibitors and that of the negative control in the absence of any inhibitor. The merit of the method is proved by discovering two new JMJD3 inhibitors: salvianic acid A and puerarin 6''-O-xyloside.