SET And MYND Domain-containing Protein 3 Research Articles

THAP3 recruits SMYD3 to OXPHOS genes and epigenetically promotes mitochondrial respiration in hepatocellular carcinoma.

Mitochondria harbor the oxidative phosphorylation (OXPHOS) system to sustain cellular respiration. However, the transcriptional regulation of OXPHOS remains largely unexplored. Through the cancer genome atlas (TCGA) transcriptome analysis, transcription factor THAP domain-containing 3 (THAP3) was found to be strongly associated with OXPHOS gene expression. Mechanistically, THAP3 recruited the histone methyltransferase SET and MYND domain-containing protein 3 (SMYD3) to upregulate H3K4me3 and promote OXPHOS gene expression. The levels of THAP3 and SMYD3 were altered by metabolic cues. They collaboratively supported liver cancer cell proliferation and colony formation. In clinical human liver cancer, both of them were overexpressed. THAP3 positively correlated with OXPHOS gene expression. Together, THAP3 cooperates with SMYD3 to epigenetically upregulate cellular respiration and liver cancer cell proliferation.

Epigenetic upregulation of MNAT1 by SMYD2 is linked to PI3K/AKT activation and tumorigenesis of pancreatic adenocarcinoma.

Dysregulation of histone methyltransferase SET and MYND domain-containing protein 2 (SMYD2) has been correlated with human developmental disorders and cancers. This research aims to investigate the roles of SMYD2 and its interacted molecules in pancreatic adenocarcinoma (PAAD). Two PAAD-related gene expression datasets were downloaded to screen key molecules involved in tumor progression. SMYD2 was expressed at high levels in PAAD tissues and cells. SMYD2 silencing suppressed while its overexpression promoted proliferation, invasiveness, migration, apoptosis resistance, and cell cycle progression of PAAD cells. Target molecules of SMYD2 were predicted by online tools and validated by chromatin immunoprecipitation and luciferase assays. SMYD2 catalyzed H3K36me2 modification at the promoter region of MNAT1 component of CDK activating kinase (MNAT1), to promote its transcription. MNAT1 was correlated with an unfavorable clinical outcome of PAAD patients. Alteration of MNAT1 alone also affected the malignant behavior of PAAD cells. Moreover, MNAT1 overexpression in cells rescued the malignant phenotype of cells suppressed by SMYD2 silencing. MNAT1 activated the phosphatidyl inositol 3-kinase/protein kinase B (PI3K/AKT) signaling. In vivo, SMYD2 silencing decreased the growth rate and weight of xenograft tumors in nude mice. Overall, this paper demonstrates that SMYD2-mediated MNAT1 upregulation is linked to PAAD tumorigenesis via PI3K/AKT pathway activation.

Lysine methyltransferase SMYD2 enhances androgen receptor signaling to modulate CRPC cell resistance to enzalutamide.

Androgen receptors (ARs) play key roles in prostate cancer (PCa) progression and castration-resistant prostate cancer (CRPC) resistance to drug therapy. SET and MYND domain containing protein 2 (SMYD2), a lysine methyltransferase, has been reported to promote tumors by transcriptionally methylating important oncogenes or tumor repressor genes. However, the role of SMYD2 in CRPC drug resistance remains unclear. In this study, we found that SMYD2 expression was significantly upregulated in PCa tissues and cell lines. High SMYD2 expression indicated poor CRPC-free survival and overall survival in patients. SMYD2 knockdown dramatically inhibited the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) potential of 22Rv1 and C4-2 cells. Conversely, ectopic overexpression of SMYD2 promoted these effects in 22Rv1 and C4-2 cells. Mechanistically, SMYD2 methylated and phosphorylated ARs to affect AR ubiquitination and proteasome degradation, which further alters the AR transcriptome in CRPC cells. Importantly, the SMYD2 inhibitor AZ505 had a synergistic therapeutic effect with enzalutamide in CRPC cells and mouse models; however, it could also re-sensitize resistant CRPC cells to enzalutamide. Our findings demonstrated that SMYD2 enhances the methylation and phosphorylation of ARs and affects AR ubiquitination and proteasome degradation to modulate CRPC cell resistance to enzalutamide, indicating that SMYD2 serves as a crucial oncogene in PCa and is an ideal therapeutic target for CRPC.

The SMYD3-dependent H3K4me3 status of IGF2 intensifies local Th2 differentiation in CRSwNP via positive feedback

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous and common upper airway disease divided into various inflammatory endotypes. Recent epidemiological findings showed a T helper 2 (Th2)-skewed dominance in CRSwNP patients. Histone modification alterations can regulate transcriptional and translational expression, resulting in abnormal pathogenic changes and the occurrence of diseases. Trimethylation of histone H3 lysine 4 (H3K4me3) is considered an activator of gene expression through modulation of accessibility for transcription, which is closely related to CRSwNP. H3K4me3 levels in the human nasal epithelium may change under Th2-biased inflammatory conditions, resulting in exaggerated local nasal Th2 responses via the regulation of naïve CD4+ T-cell differentiation. Here, we revealed that the level of SET and MYND domain-containing protein 3 (SMYD3)-mediated H3K4me3 was increased in NPs from Th2 CRSwNP patients compared with those from healthy controls. We demonstrated that SMYD3-mediated H3K4me3 is increased in human nasal epithelial cells under Th2-biased inflammatory conditions via S-adenosyl-L-methionine (SAM) production and further found that the H3K4me3high status of insulin-like growth factor 2 (IGF2) produced in primary human nasal epithelial cells could promote naïve CD4+ T-cell differentiation into Th2 cells. Moreover, we found that SAM production was dependent on the c-Myc/methionine adenosyltransferase 2A (MAT2A) axis in the nasal epithelium. Understanding histone modifications in the nasal epithelium has immense potential utility in the development of novel classes of therapeutics targeting Th2 polarization in Th2 CRSwNP.Et9-hJKHbB2Mg3CRtXWvn_Video

SMYD2 regulates vascular smooth muscle cell phenotypic switching and intimal hyperplasia via interaction with myocardin.

The SET and MYND domain-containing protein 2 (SMYD2) is a histone lysine methyltransferase that has been reported to regulate carcinogenesis and inflammation. However, its role in vascular smooth muscle cell (VSMC) homeostasis and vascular diseases has not been determined. Here, we investigated the role of SMYD2 in VSMC phenotypic modulation and vascular intimal hyperplasia and elucidated the underlying mechanism. We observed that SMYD2 expression was downregulated in injured carotid arteries in mice and phenotypically modulated VSMCs in vitro. Using an SMC-specific SMYD2 knockout mouse model, we found that SMYD2 ablation in VSMCs exacerbated neointima formation after vascular injury in vivo. Conversely, SMYD2 overexpression inhibited VSMC proliferation and migration in vitro and attenuated arterial narrowing in injured vessels in mice. SMYD2 downregulation promoted VSMC phenotypic switching accompanied with enhanced proliferation and migration. Mechanistically, genome-wide transcriptome analysis and loss/gain-of-function studies revealed that SMYD2 up-regulated VSMC contractile gene expression and suppressed VSMC proliferation and migration, in part, by promoting expression and transactivation of the master transcription cofactor myocardin. In addition, myocardin directly interacted with SMYD2, thereby facilitating SMYD2 recruitment to the CArG regions of SMC contractile gene promoters and leading to an open chromatin status around SMC contractile gene promoters via SMYD2-mediated H3K4 methylation. Hence, we conclude that SMYD2 is a novel regulator of VSMC contractile phenotype and intimal hyperplasia via a myocardin-dependent epigenetic regulatory mechanism.

Histone lysine methyltransferase SMYD3 promotes oral squamous cell carcinoma tumorigenesis via H3K4me3-mediated HMGA2 transcription

BackgroundEpigenetic dysregulation is essential to the tumorigenesis of oral squamous cell carcinoma (OSCC). SET and MYND domain-containing protein 3 (SMYD3), a histone lysine methyltransferase, is implicated in gene transcription regulation and tumor development. However, the roles of SMYD3 in OSCC initiation are not fully understood. The present study investigated the biological functions and mechanisms involved in the SMYD3-mediated tumorigenesis of OSCC utilizing bioinformatic approaches and validation assays with the aim of informing the development of targeted therapies for OSCC.Results429 chromatin regulators were screened by a machine learning approach and aberrant expression of SMYD3 was found to be closely associated with OSCC formation and poor prognosis. Data profiling of single-cell and tissue demonstrated that upregulated SMYD3 significantly correlated with aggressive clinicopathological features of OSCC. Alterations in copy number and DNA methylation patterns may contribute to SMYD3 overexpression. Functional experimental results suggested that SMYD3 enhanced cancer cell stemness and proliferation in vitro and tumor growth in vivo. SMYD3 was observed to bind to the High Mobility Group AT-Hook 2 (HMGA2) promoter and elevated tri-methylation of histone H3 lysine 4 at the corresponding site was responsible for transactivating HMGA2. SMYD3 also was positively linked to HMGA2 expression in OSCC samples. Furthermore, treatment with the SMYD3 chemical inhibitor BCI-121 exerted anti-tumor effects.ConclusionsHistone methyltransferase activity and transcription-potentiating function of SMYD3 were found to be essential for tumorigenesis and the SMYD3–HMGA2 is a potential therapeutic target in OSCC.

SMYD2 Promotes Hepatocellular Carcinoma Progression by Reprogramming Glutamine Metabolism via c-Myc/GLS1 Axis

Metabolic reprogramming, such as alterations in glutamine metabolism or glycolysis, is the hallmark of hepatocellular carcinoma (HCC). However, the underlying mechanisms are still incompletely elucidated. Previous studies have identified that methyltransferase SET and MYND domain-containing protein 2(SMYD2) is responsible for the pathogenesis of numerous types of cancer. Here, we innovatively uncover how SMYD2 regulates glutamine metabolism in HCC cells and promotes HCC progression. We identified that SMYD2 expression is upregulated in HCC tissues, which correlates with unfavorable clinical outcomes. Our in vitro and in vivo results showed that the depletion of SMYD2 inhibits HCC cell growth. Mechanistically, c-Myc methylation by SMYD2 increases its protein stability through the ubiquitin-proteasome system. We showed SMYD2 depletion destabilized c-Myc protein by increasing the conjugated K48-linked polyubiquitin chain. SMYD2 increased c-Myc expression and further upregulated glutaminase1 (GLS1), a crucial enzyme that catalyzes the conversion of glutamine to glutamic acid, in HCC cells. GLS1 plays an important role in SMYD2-mediated HCC progression and glutamine metabolism regulation. The knockdown of SMYD2 inhibited glutamine metabolism in HCC cells and overcame their chemoresistance to sorafenib. Collectively, our findings demonstrated a novel mechanism of how SMYD2 promotes HCC progression by regulating glutamine metabolism through the c-Myc/GLS1signaling, implicating the therapeutic potential of targeting SMYD2 in HCC patients.

Effect of miRNA-200b on the proliferation of liver cancer cells via targeting SMYD2/p53 signaling pathway.

Our previous study has verified that high level of SET and MYND domain-containing protein 2 (SMYD2) plays an important role in acquiring aggressive ability for liver cancer cells in hepatocellular carcinoma. MiR-200b as a tumor suppressor gene involves in a variety of cancers. This study aims to investigate the correlation between miR-200b and SMYD2 in hepatocellular carcinoma and the underlying mechanism. Firstly, the levels of SMYD2 and miR-200b in hepatocellular carcinoma tissues and matched adjacent non-tumor liver tissues were tested with real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. Secondly, we evaluated the interaction between miR-200b and SMYD2 using dual-luciferase reporter assay. Thirdly, we elucidated the effect of miR-200b on SMYD2 and its downstream targets p53/CyclinE1. Finally, we silenced SMYD2 in hepatocellular carcinoma cell lines to investigate its effect on tumor proliferation and cell cycle progression, and further confirmed the correlation among SMYD2 and p53/CyclinE1. Compared with the matched adjacent non-tumor liver tissues, miR-200b was obviously decreased, and SMYD2 was significantly increased in hepatocellular carcinoma (both P<0.05). Spearman's rank correlation revealed that miR-200b expression was negatively correlated with SMYD2 (P<0.01). Computer algorithm and dual-luciferase reporter assay revealed that miR-200b directly targeted and suppressed SMYD2 in HEK 293T cells. The down-regulated miR-200b expression promoted hepatoma cell proliferation (P<0.05) and increased SMYD2 expression(P<0.01), while the up-regulated expression of miR-200b had an opposite effect. The knockdown of SMYD2 suppressed the proliferation of MHCC-97L cells (P<0.01), down-regulated CyclinE1, and up-regulated p53 expression (both P<0.05). MiR-200b is involved in hepatocellular carcinoma progression via targeting SMYD2 and regulating SMYD2/p53/CyclinE1 signaling pathway and may be used as a potential target for hepatocellular carcinoma treatment.

SMYD3 regulates gastric cancer progression and macrophage polarization through EZH2 methylation.

SET and MYND domain-containing protein 3 (SMYD3), a known histone methyltransferase, was reported to regulate cancer pathogenesis. However, its role in gastric development and progression remains unclear. EZH2 methylation had been associated with cancer metastasis, but the EZH2 methylation status in gastric cancer (GC) is unknown. Here, we report that EZH2 K421 methylation was responsible for gastric cancer cell soft agar colony formation, in vivo metastasis, and macrophage polarization. Mechanically, we identified SMYD3 as the methyltransferase of EZH2 at K421 residue which accelerates EZH2 Ubiquitin proteasome degradation. Cell harboring non-methylated EZH2 mutants promotes gastric cancer cell metastasis. Taken together, our results showed that SMYD3-EZH2 axis restricts gastric cancer metastasis via integrating epigenetic signaling.

STUB1-SMYD2 Axis Regulates Drug Resistance in Glioma cells.

SET and MYND domain-containing protein 2 (SMYD2) is an important epigenetic regulator that methylates histone and non-histone proteins. The study aimed to investigate the oncogenic role of SMYD2 in gliomas and explore its degradation mechanism induced by cisplatin. Tumor tissue microarray of 441 patients with glioma was collected for SMYD2 immunohistochemical staining. Kaplan-Meier survival curves were constructed using the overall survival values. mRNA-sequencing analysis was performed for understanding the downstream mechanisms mediated by SMYD2. The half-inhibitory concentrations (IC50) of temozolomide and cisplatin in AZ505-treated and control cells were calculated. The potential E3 ubiquitin ligase of SMYD2 was predicted in UbiBrowser and confirmed by a knockdown test. The effect of SMYD2 and its E3 ligase on apoptosis and migration of glioma cells was determined via cell-function assays. High SMYD2 expression correlated with a high WHO stage (P = 0.004) and a low survival probability (P = 0.012). The inhibition of SMYD2 suppressed the process of epithelial to mesenchymal transition (EMT) by downregulating the expression of Collagen 1A1 (COL1A1). AZ505 treatment significantly increased the drug sensitivity of glioma cells. SMYD2 expression was markedly reduced by cisplatin treatment via STIP1 Homology And U-Box Containing Protein 1 (STUB1)-mediated degradation. The knockdown of STUB1 could partly reverse the cell function impairment induced by cisplatin. Our findings suggested that SMYD2 could be a potential drug target for the treatment of gliomas, and STUB1-mediated degradation of SMYD2 plays an important role in reversing chemotherapy resistance in patients with gliomas.

Mechanistic and functional extrapolation of SET and MYND domain-containing protein 2 to pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal neoplasms worldwide and represents the vast majority of pancreatic cancer cases. Understanding the molecular pathogenesis and the underlying mechanisms involved in the initiation, maintenance, and progression of PDAC is an urgent need, which may lead to the development of novel therapeutic strategies against this deadly cancer. Here, we review the role of SET and MYND domain-containing protein 2 (SMYD2) in initiating and maintaining PDAC development through methylating multiple tumor suppressors and oncogenic proteins. Given the broad substrate specificity of SMYD2 and its involvement in diverse oncogenic signaling pathways in many other cancers, the mechanistic extrapolation of SMYD2 from these cancers to PDAC may allow for developing new hypotheses about the mechanisms driving PDAC tumor growth and metastasis, supporting a proposition that targeting SMYD2 could be a powerful strategy for the prevention and treatment of PDAC.

SMYD2 epigenetically activates MEX3A and suppresses CDX2 in colorectal cancer cells to augment cancer growth.

Dysfunction of the protein methyltransferase SET and MYND domain-containing protein 2 (SMYD2) is frequently linked to multiple diseases including cancer. The study focused on the role of SMYD2 in colorectal cancer (CRC) development. SMYD2 was expressed at high levels in CRC tissues and cells. Knockdown of SMYD2 in LOVO cells reduced cell proliferation, migration and invasiveness in vitro and it suppressed xenograft tumorigenesis in vivo. Overexpression of SMYD2 in HCT116 cells led to inverse trends. Mex-3 RNA binding family member A (MEX3A) was predicted as a target of SMYD2. Chromatin immunoprecipitation (ChIP)-reverse transcription quantitative polymerase chain reaction (qPCR) and cellular assays were performed and validated that SMYD2 activated MEX3A expression by promoting H3K36me2 modification on its promoter. Data in the STRING bioinformatics system indicated caudal type homeobox 2 (CDX2) as an important MEX3A-related gene. Silencing of MEX3A alone blocked proliferation and growth of CRC cells in vitro and in vivo, whereas MEX3A overexpression promoted cell growth by suppressing CDX2. In rescue experiments, MEX3A silencing suppressed the cell growth augmented by SMYD2, and CDX2 downregulation restored the malignance of cancer cells inhibited by MEX3A silencing. Taken together, this study reports that SMYD2-mediated activation of MEX3A augments progression of CRC by suppressing CDX2.

Clinicopathological and Prognostic Significance of SMYD3 in Human Cancers: A Systematic Review and Meta-analysis.

Background: Dysregulation of the SET and MYND domain-containing protein 3 (SMYD3) has been found in multiple cancers. This meta-analysis aimed to elucidate the association between SMYD3 expression and clinical outcomes in cancer. Methods: A systematic search of Web of Science, Embase, PubMed, Cochrane Library, and CNKI was conducted. The relationship between SMYD3 expression and cancer patients' overall survival (OS) was evaluated using pooled hazard ratios (HRs) and their corresponding confidence intervals (95% CIs). The association between SMYD3 expression and clinicopathological features was assessed using odds ratios (ORs) with 95% CIs, including tumor size, lymph node metastasis (LNM), distance metastasis, and TNM stage. Results: In total, 715 cancer patients with hepatocellular carcinoma, nonsmall cell lung carcinoma, esophageal squamous cell carcinoma, glioma, colorectal cancer, and/or bladder cancer from seven studies were included in our meta-analysis. SMYD3 overexpression was significantly associated with poor OS (HR = 1.81, 95% CI: 1.38-2.37, p < 0.01) with no heterogeneity (I2 = 0.0%, p = 0.929) in various cancers. Subgroup analysis showed that the prognostic value of SMYD3 across multiple tumors was constant as the tumor type, sample size, and methods of data extraction changed. Increased SMYD3 expression was positively associated with LNM (OR = 1.88, 95% CI = 1.33-2.66, p < 0.001), tumor size (OR = 1.68, 95% CI: 1.09-2.60, p = 0.019), and advanced TNM stage (OR = 1.84, 95% CI: 1.25-2.69, p = 0.002). Conclusions: Upregulation of SMYD3 was significantly associated with poor prognosis in various cancers, suggesting that SMYD3 may be a useful prognostic biomarker.

Ensemble Simulations and Experimental Free Energy Distributions: Evaluation and Characterization of Isoxazole Amides as SMYD3 Inhibitors.

Optimization of binding affinities for ligands to their target protein is a primary objective in rational drug discovery. Herein, we report on a collaborative study that evaluates various compounds designed to bind to the SET and MYND domain-containing protein 3 (SMYD3). SMYD3 is a histone methyltransferase and plays an important role in transcriptional regulation in cell proliferation, cell cycle, and human carcinogenesis. Experimental measurements using the scintillation proximity assay show that the distributions of binding free energies from a large number of independent measurements exhibit non-normal properties. We use ESMACS (enhanced sampling of molecular dynamics with approximation of continuum solvent) and TIES (thermodynamic integration with enhanced sampling) protocols to predict the binding free energies and to provide a detailed chemical insight into the nature of ligand–protein binding. Our results show that the 1-trajectory ESMACS protocol works well for the set of ligands studied here. Although one unexplained outlier exists, we obtain excellent statistical ranking across the set of compounds from the ESMACS protocol and good agreement between calculations and experiments for the relative binding free energies from the TIES protocol. ESMACS and TIES are again found to be powerful protocols for the accurate comparison of the binding free energies.

METHYLTRANSFERASE SMYD2 MODULATES THERAPEUTIC EFFECTS OF EPIDERMAL GROWTH FACTOR IN INFLAMMATORY BOWEL DISEASE

Abstract BACKGROUND Inflammatory bowel disease (IBD) is a chronic and remitting inflammatory disorder of the gastrointestinal tract. A prior clinical trial demonstrated the ability of epidermal growth factor receptor (EGFR) ligand EGF to induce and maintain remission in ulcerative colitis. As a protein lysine methyltransferase, SET and MYND domain-containing protein 2 (SMYD2) regulates various cellular functions, including chromatin remodeling and tumorigenesis. A bioinformatic study has shown that EGFR might be a candidate for SMYD2-mediated methylation. In this research, we aimed to investigate whether SMYD2 depletion could synergize with EGFR-activating treatment to promote intestinal goblet cell regeneration in IBD. METHODS SMYD2 flox C57BL/6 (SMYD2fl/fl) and intestine epithelial cell-specific conditional knockout of SMYD2 (SMYD2ΔIEC) male mice (8 to10-week old) were given 3 cycles of DSS treatment, each cycle including 5 days of 2% DSS in drinking water followed by 16 days of normal drinking water. EGF (50 μg/kg/day) was administered via intraperitoneal injection once per day for 6 days during the third cycle of DSS treatment (from day 42 to 47 along with DSS administration). The disease activity index (DAI), including body weight loss, stool consistency and colorectal bleeding, was monitored and calculated daily. Histologic scoring was used to evaluate the extent of histopathologic change in middle colon tissue. Goblet cell differentiation and maturation was analyzed via Alcian Blue/periodic acid-Schiff (AB/PAS) staining and immunostaining. RESULTS EGF treatment significantly increased the number of goblet cells (AB/PAS staining positive cells) in both SMYD2fl/fl and SMYD2ΔIEC mice. However, in SMYD2ΔIEC mice, more mature goblet cells were observed. In contrast, in SMYD2fl/fl mice, most goblet cells were accumulated at the lower half of colon crypts with small mucin particles. As compared with SMYD2fl/fl mice receiving EGF treatment, SMYD2 depletion combined with EGF injection (6 days) failed to significantly improve body weight loss and DAI scoring during DSS treatment, as well as histologic scoring (including inflammatory cell infiltration and epithelial tissue damage). Immunostaining of goblet cell differentiation markers (including ATOH1, SPDEF and KLF4) revealed no significant difference between SMYD2fl/fl and SMYD2ΔIEC mice. CONCLUSION SMYD2 depletion combined with EGF treatment could promote goblet cell expansion and maturation in mouse DSS-induced chronic colitis. However, the mechanism by which SMYD2 depletion facilitates goblet cell maturation needs further investigation.

METHYLTRANSFERASE SMYD2 MODULATES THERAPEUTIC EFFECTS OF EPIDERMAL GROWTH FACTOR IN INFLAMMATORY BOWEL DISEASE

Inflammatory bowel disease (IBD) is a chronic and remitting inflammatory disorder of the gastrointestinal tract. A prior clinical trial demonstrated the ability of epidermal growth factor receptor (EGFR) ligand EGF to induce and maintain remission in ulcerative colitis. As a protein lysine methyltransferase, SET and MYND domain-containing protein 2 (SMYD2) regulates various cellular functions, including chromatin remodeling and tumorigenesis. A bioinformatic study has shown that EGFR might be a candidate for SMYD2-mediated methylation. In this research, we aimed to investigate whether SMYD2 depletion could synergize with EGFR-activating treatment to promote intestinal goblet cell regeneration in IBD.

A SMYD3/ITGB6/TGFβ1 Positive Feedback Loop Promotes the Invasion and Adhesion of Ovarian Cancer Spheroids.

BackgroundImplantation metastasis is the main means of dissemination in ovarian cancer. Our previous studies showed that SET and MYND domain-containing protein 3 (SMYD3) expression was higher in ovarian cancer spheroids than in monolayers. SMYD3 enhancement of spheroid invasion and adhesion is mediated by the downstream effectors ITGB6 and ITGAM. However, the potential mechanisms underlying the SMYD3/integrin-mediated invasion and adhesion of spheroids still need to be explored.MethodsWestern blotting was used to examine the expression of SMYD3, ITGB6 and downstream molecules under different treatments. Immunofluorescence was used to detect the expression of F-actin, E-cadherin and N-cadherin. Anti-ITGB6 antibody-based inhibition and dual-luciferase reporter assays were used to confirm the binding between ITGB6 and latent TGFβ1. Transwell invasion, adherence and 3D tumor spheroid invasion assays were employed to test the effects of TGFβ1 on the invasion and adhesion of ovarian cancer spheroids. ELISA was performed to assess the release of latent TGFβ1 from ovarian cancer spheroids.ResultsSMYD3 and ITGB6 activated the TGFβ1/Smad3 pathway and then induced the upregulation of Snail, Vimentin and N-cadherin and the downregulation of E-cadherin in 3D-cultured ovarian cancer spheroids. In this process, latent TGFβ1 could bind to ITGB6 and become activated to stimulate the Smad3 pathway. Moreover, SMYD3 and ITGB6 could facilitate the release of latent TGFβ1 from 3D-cultured ovarian cancer spheroids. Interestingly, TGFβ1 could promote the expression of SMYD3 and ITGB6 via feedback. This positive feedback loop could further amplify the biological effect and promote the invasion and adhesion of ovarian cancer spheroids.ConclusionOur results demonstrated that the SMYD3/ITGB6/TGFβ1-Smad3 positive feedback loop could promote the invasion and adhesion of ovarian cancer spheroids by upregulating the expression of N-cadherin, Snail, and Vimentin and downregulating the expression of E-cadherin. Thus, our study unmasked the mechanism of SMYD3- and ITGB6-induced ovarian cancer metastasis and provides new ideas for targeted ovarian cancer treatment.

Novel inhibitors design through structural investigations and simulation studies for human PKMTs (SMYD2) involved in cancer

ABSTRACT SET and MYND domain-containing protein 2 (SMYD2) is a protein lysine methyltransferases (PKMTs) from family SMYD. It can regulate gene transcription by catalysing the methylation of lysine residues of protein substrates that play a significant role in oncogenesis. Inhibition of SMYD2 could lead to the proposal of new drugs for cancers, where it is involved. In this study, structure-based virtual screening was carried out for the identification of potential SMYD2 inhibitors. A subset of natural compounds (n = 98,071) from the ZINC database was screened by using a consensus docking approach and identified 391 potent compounds then evaluated based on ADMET parameters. Nine compounds were selected that chase line of drug-likeness criteria and re-docking. Based on docking score and protein–ligand interaction analysis, three compounds (ZINC03844862, ZINC08490711 and ZINC08764231) were identified as potential inhibitors. Finally, these three compounds were employed for 100 ns molecular dynamics simulation analysis to examine the structural stability with SMYD2. Moreover, RMSD, RMSF, H-bond, SASA and PCA analysis indicated the stable binding of potential compounds with SMYD2 structure. Computational approaches incorporated in this study provide novel putative SMYD2 inhibitors. These inhibitors could be potential leads to develop cancer therapeutics after in vivo and in vitro studies.

SMYD3 promotes hepatocellular carcinoma progression by methylating S1PR1 promoters

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. SET and MYND domain-containing protein 3 (SMYD3) has been shown to promote the progression of various types of human cancers, including liver cancer; however, the detailed molecular mechanism is still largely unknown. Here, we report that SMYD3 expression in HCC is an independent prognostic factor for survival and promotes the proliferation and migration of HCC cells. We observed that SMYD3 upregulated sphingosine-1-phosphate receptor 1 (S1PR1) promoter activity by methylating histone 3 (H3K4me3). S1PR1 was expressed at high levels in HCC samples, and high S1PR1 expression was associated with shorter survival. S1PR1 expression was also positively correlated with SMYD3 expression in HCC samples. We confirmed that SMYD3 promotes HCC cell growth and migration in vitro and in vivo by upregulating S1PR1 expression. Further investigations revealed that SMYD3 affects critical signaling pathways associated with the progression of HCC through S1PR1. These findings strongly suggest that SMYD3 has a crucial function in HCC progression that is partially mediated by histone methylation at the downstream gene S1PR1, which affects key signaling pathways associated with carcinogenesis and the progression of HCC.

Discovery of the SMYD3 Inhibitor BAY-6035 Using Thermal Shift Assay (TSA)-Based High-Throughput Screening.

SMYD3 (SET and MYND domain-containing protein 3) is a protein lysine methyltransferase that was initially described as an H3K4 methyltransferase involved in transcriptional regulation. SMYD3 has been reported to methylate and regulate several nonhistone proteins relevant to cancer, including mitogen-activated protein kinase kinase kinase 2 (MAP3K2), vascular endothelial growth factor receptor 1 (VEGFR1), and the human epidermal growth factor receptor 2 (HER2). In addition, overexpression of SMYD3 has been linked to poor prognosis in certain cancers, suggesting SMYD3 as a potential oncogene and attractive cancer drug target. Here we report the discovery of a novel SMYD3 inhibitor. We performed a thermal shift assay (TSA)-based high-throughput screening (HTS) with 410,000 compounds and identified a novel benzodiazepine-based SMYD3 inhibitor series. Crystal structures revealed that this series binds to the substrate binding site and occupies the hydrophobic lysine binding pocket via an unprecedented hydrogen bonding pattern. Biochemical assays showed substrate competitive behavior. Following optimization and extensive biophysical validation with surface plasmon resonance (SPR) analysis and isothermal titration calorimetry (ITC), we identified BAY-6035, which shows nanomolar potency and selectivity against kinases and other PKMTs. Furthermore, BAY-6035 specifically inhibits methylation of MAP3K2 by SMYD3 in a cellular mechanistic assay with an IC50 <100 nM. Moreover, we describe a congeneric negative control to BAY-6035. In summary, BAY-6035 is a novel selective and potent SMYD3 inhibitor probe that will foster the exploration of the biological role of SMYD3 in diseased and nondiseased tissues.