SMYD2 Promotes Calcium Oxalate-Induced Glycolysis in Renal Tubular Epithelial Cells via PTEN Methylation.

Background/Objectives: Damage to renal tubular cells (RTCs) represents a critical pathological manifestation in calcium oxalate (CaOx) stone disease, but the underlying mechanism remains elusive. Energy metabolism reprogramming is a vital influencer of RTC survival, and SMYD2 is a histone methylation transferase that has been extensively implicated in various metabolic disorders. Hence, this research aimed to identify whether SMYD2 induces the reprogramming of energy metabolism in RTCs exposed to CaOx nephrolithiasis. Methods: Kidney samples were obtained from patients who underwent laparoscopic nephrectomy for non-functioning kidneys caused by nephrolithiasis. The glyoxylate-induced CaOx stone mice model was established and treated with AZ505. The SMYD2-knockout HK-2 cell line was constructed. Histological changes were evaluated by HE, VK, Tunel, Masson stainings. The molecular mechanism was explored through co-immunoprecipitation and western blotting. Results: The results found that SMYD2 upregulation led to energy reprogramming to glycolysis in human kidney tissue samples and in mice with CaOx nephrolithiasis. We also identified the substantial involvement of glycolysis in the induction of apoptosis, inflammation, and epithelial-mesenchymal transition (EMT) in HK-2 cells caused by calcium oxalate monohydrate (COM). In vivo and in vitro results demonstrated that SMYD2 inhibition reduces glycolysis, kidney injury, and fibrosis. Mechanistically, SMYD2 was found to promote metabolic reprogramming of RTCs toward glycolysis by activating the AKT/mTOR pathway via methylated PTEN, which mediates CaOx-induced renal injury and fibrosis. Conclusions: Our findings reveal an epigenetic regulatory role of SMYD2 in metabolic reprogramming in CaOx nephrolithiasis and associated kidney injury, suggesting that targeting SMYD2 and glycolysis may represent a potential therapeutic strategy for CaOx-induced kidney injury and fibrosis.

H3K36 methyltransferase SMYD2 affects cell proliferation and migration in Hirschsprung's disease by regulating METTL3.

The pathogenesis of Hirschsprung's disease (HSCR) is complex. Recently, it has been found that histone modifications can alter genetic susceptibility and play important roles in the proliferation, differentiation and migration of neural crest cells. H3K36 methylation plays a significant role in gene transcriptional activation and expression, but its pathogenic mechanism in HSCR has not yet been studied. This study aimed to elucidate its role and molecular mechanism in HSCR. Western blot analysis, immunohistochemistry (IHC) and reverse transcription-quantitative PCR (RT‒qPCR) were used to investigate H3K36 methylation and methyltransferase levels in dilated and stenotic colon tissue sections from children with. We confirm that SMYD2 is the primary cause of differential H3K36 methylation and influences cell proliferation and migration in HSCR. Subsequently, quantitative detection of m6A RNA methylation revealed that SMYD2 can alter m6A methylation levels. Western blot analysis, RT-qPCR, co-immunoprecipitation (co-IP), and immunofluorescence colocalization were utilized to confirm that SMYD2 can regulate METTL3 expression and affect m6A methylation, affecting cell proliferation and migration. These results confirm that the H3K36 methyltransferase SMYD2 can affect cell proliferation and migration in Hirschsprung's disease by regulating METTL3. Our study suggested that H3K36 methylation plays an important role in HSCR, confirming that the methyltransferase SMYD2 can affect m6A methylation levels and intestinal nervous system development by regulating METTL3 expression.

Targeting SMYD2 promotes ferroptosis and impacts the progression of pancreatic cancer through the c-Myc/NCOA4 axis-mediated ferritinophagy.

BACKGROUND: Pancreatic cancer (PC) is characterized by a poor prognosis and limited treatment options. Ferroptosis plays an important role in cancer, SET and MYND domain-containing protein 2 (SMYD2) is widely expressed in various cancers. However, the role of SMYD2 in regulating ferroptosis in PC remains unexplored. This study aimed to investigate the role of SMYD2 in mediating ferroptosis and its mechanistic implications in PC progression. METHODS: The levels of SMYD2, c-Myc, and NCOA4 were assessed in PC tissues, and peritumoral tissues. SMYD2 expression was further analyzed in human PC cell lines. In BxPC3 cells, the expression of c-Myc, NCOA4, autophagy-related proteins, and mitochondrial morphology, was evaluated following transfection with si-SMYD2 and treatment with autophagy inhibitors and ferroptosis inhibitors. Ferroptosis levels were quantified using flow cytometry and ELISA assays. RNA immunoprecipitation was conducted to elucidate the interaction between c-Myc and NCOA4 mRNA. A xenograft mouse model was constructed to validate the impact of SMYD2 knockdown on PC growth. RESULTS: SMYD2 and c-Myc were found to be highly expressed in PC tissues, while NCOA4 showed reduced expression. Among the PC cell lines studied, BxPC3 cells exhibited the highest SMYD2 expression. SMYD2 knockdown led to decreased c-Myc levels, increased NCOA4 expression, reduced autophagy-related protein expression, mitochondrial shrinkage, and heightened ferroptosis levels. Additionally, an interaction between c-Myc and NCOA4 was identified. In vivo, SMYD2 knockdown inhibited tumor growth. CONCLUSIONS: Targeting SMYD2 inhibits PC progression by promoting ferritinophagy-dependent ferroptosis through the c-Myc/NCOA4 axis. These findings provide insights into potential diagnostic and therapeutic strategies for PC.

Inhibition of SMYD2 attenuates paraquat-induced pulmonary fibrosis by inhibiting the epithelial-mesenchymal transition through the GLIPR2/ERK/p38 axis.

Paraquat (PQ) poisoning leads to irreversible fibrosis in the lungs with high mortality and no known antidote. In this study, we investigated the effect of the SET and MYND domain containing 2 (SMYD2) on PQ-induced pulmonary fibrosis (PF) and its potential mechanisms. We established an in vivo PQ-induced PF mouse model by intraperitoneal injection of PQ (20 mg/kg) and in vitro PQ (25 µM)-injured MLE-12 cell model. On the 15th day of administration, tissue injury, inflammation, and fibrosis in mice were evaluated using various methods including routine blood counts, blood biochemistry, blood gas analysis, western blotting, H&E staining, ELISA, Masson staining, and immunofluorescence. The findings indicated that AZ505 administration mitigated tissue damage, inflammation, and collagen deposition in PQ-poisoned mice. Mechanistically, both in vivo and in vitro experiments revealed that AZ505 treatment suppressed the PQ-induced epithelial-mesenchymal transition (EMT) process by downregulating GLI pathogenesis related 2 (GLIPR2) and ERK/p38 pathway. Further investigations demonstrated that SMYD2 inhibition decreased GLIPR2 methylation and facilitated GLIPR2 ubiquitination, leading to GLIPR2 destabilization in PQ-exposed MLE-12 cells. Moreover, rescue experiments conducted in vitro demonstrated that GLIPR2 overexpression eliminated the inhibitory effect of AZ505 on the ERK/p38 pathway and EMT. Our results reveal that the SMYD2 inhibitor AZ505 may act as a novel therapeutic candidate to suppress the EMT process by modulating the GLIPR2/ERK/p38 axis in PQ-induced PF.

SMYD2 induced PGC1α methylation promotes stemness maintenance of glioblastoma stem cells.

BACKGROUND: The high fatality rate of glioblastoma (GBM) is attributed to glioblastoma stem cells (GSCs), which exhibit heterogeneity and therapeutic resistance. Metabolic plasticity of mitochondria is the hallmark of GSCs. Targeting mitochondrial biogenesis of GSCs is crucial for improving clinical prognosis in GBM patients. METHODS: SMYD2-induced PGC1α methylation and followed nuclear export are confirmed by co-immunoprecipitation, cellular fractionation, and immunofluorescence. The effects of SMYD2/PGC1α/CRM1 axis on GSCs mitochondrial biogenesis are validated by oxygen consumption rate, ECAR, and intracranial glioma model. RESULTS: PGC1α methylation causes the disabled mitochondrial function to maintain the stemness, thereby enhancing the radio-resistance of GSCs. SMYD2 drives PGC1α K224 methylation (K224me), which is essential for promoting the stem-like characteristics of GSCs. PGC1α K224me is preferred binding with CRM1, accelerating PGC1α nuclear export and subsequent dysfunction. Targeting PGC1α methylation exhibits significant radiotherapeutic efficacy and prolongs patient survival. CONCLUSIONS: These findings unveil a novel regulatory pathway involving mitochondria that govern stemness in GSCs, thereby emphasizing promising therapeutic strategies targeting PGC1α and mitochondria for the treatment of GBM.

Methylation of the chromatin modifier KMT2D by SMYD2 contributes to therapeutic response in hormone-dependent breast cancer.

Activating mutations in PIK3CA are frequently found in estrogen-receptor-positive (ER+) breast cancer, and the combination of the phosphatidylinositol 3-kinase (PI3K) inhibitor alpelisib with anti-ER inhibitors is approved for therapy. We have previously demonstrated that the PI3K pathway regulates ER activity through phosphorylation of the chromatin modifier KMT2D. Here, we discovered a methylation site on KMT2D, at K1330 directly adjacent to S1331, catalyzed by the lysine methyltransferase SMYD2. SMYD2 loss attenuates alpelisib-induced KMT2D chromatin binding and alpelisib-mediated changes in gene expression, including ER-dependent transcription. Knockdown or pharmacological inhibition of SMYD2 sensitizes breast cancer cells, patient-derived organoids, and tumors to PI3K/AKT inhibition and endocrine therapy in part through KMT2D K1330 methylation. Together, our findings uncover a regulatory crosstalk between post-translational modifications that fine-tunes KMT2D function at the chromatin. This provides a rationale for the use of SMYD2 inhibitors in combination with PI3Kα/AKT inhibitors in the treatment of ER+/PIK3CA mutant breast cancer.

SMAD2/3-SMYD2 and developmental transcription factors cooperate with cell cycle inhibitors to guide tissue formation.

Tissue formation and organ homeostasis is achieved by precise coordination of proliferation and differentiation of stem cells and progenitors. While deregulation of these processes can result in degenerative disease or cancer, their molecular interplays remain unclear. Here we show that the switch of human pluripotent stem cell (hPSC) self-renewal to differentiation is associated with the induction of distinct cyclin dependent kinase inhibitors (CDKIs). In hPSCs, Activin/Nodal/TGFß signalling maintains CDKIs in a poised state via SMAD2/3-NANOG-OCT4-EZH2-SNON transcriptional complex. Upon gradual differentiation, CDKIs are induced by successive transcriptional complexes between SMAD2/3-SMYD2 and developmental regulators such as EOMES, thereby lengthening the G1 phase. This, in turn, induces SMAD2/3 transcriptional activity by blocking its linker phosphorylation. Such SMAD2/3-CDKI positive feedback loops drive the exit from pluripotency and stepwise cell fate specification that could be harnessed for producing cells for therapeutic applications. Our study uncovers fundamental mechanisms how cell fate specification is interconnected to cell cycle dynamics and provides insight to autonomous circuitries governing tissue self-formation.

The lysine methyltransferase SMYD2 facilitates neointimal hyperplasia by regulating the HDAC3-SRF axis.

Coronary restenosis is an important cause of poor long-term prognosis in patients with coronary heart disease. Here, we show that lysine methyltransferase SMYD2 expression in the nucleus is significantly elevated in serum- and PDGF-BB-induced vascular smooth muscle cells (VSMCs), and in tissues of carotid artery injury-induced neointimal hyperplasia. Smyd2 overexpression in VSMCs (Smyd2-vTg) facilitates, but treatment with its specific inhibitor LLY-507 or SMYD2 knockdown significantly inhibits VSMC phenotypic switching and carotid artery injury-induced neointima formation in mice. Transcriptome sequencing revealed that SMYD2 knockdown represses the expression of serum response factor (SRF) target genes and that SRF overexpression largely reverses the inhibitory effect of SMYD2 knockdown on VSMC proliferation. HDAC3 directly interacts with and deacetylates SRF, which enhances SRF transcriptional activity in VSMCs. Moreover, SMYD2 promotes HDAC3 expression via tri-methylation of H3K36 at its promoter. RGFP966, a specific inhibitor of HDAC3, not only counteracts the pro-proliferation effect of SMYD2 overexpression on VSMCs, but also inhibits carotid artery injury-induced neointima formation in mice. HDAC3 partially abolishes the inhibitory effect of SMYD2 knockdown on VSMC proliferation in a deacetylase activity-dependent manner. Our results reveal that the SMYD2-HDAC3-SRF axis constitutes a novel and critical epigenetic mechanism that regulates VSMC phenotypic switching and neointimal hyperplasia.

Neutrophil extracellular traps promote gastric cancer cell metastasis via the NAT10-mediated N4-acetylcytidine modification of SMYD2.

It has been reported that the formation of neutrophil extracellular traps (NETs) is associated with cancer metastasis. The current study aimed to explore the effects of NETs on gastric cancer (GC) cell metastasis and uncover their underlying mechanism. NETs were measured in the plasma of patients with GC. Then, GC cells were treated with NETs to assess cell viability, migration, and invasion using cell counting kit 8 and Transwell assay, The liver metastasis and xenograft tumor mouse models were established to assess tumor growth and metastasis. The N4-acetylcytidine (ac4C) modification of SET and MYND domain containing 2 (SMYD2) mediated by NAT10 was evaluated using acetylated RNA immunoprecipitation. The results showed that the level of NETs was increased in the plasma of patients with GC, particularly in those with metastatic GC. In addition, GC cell co-treatment with NETs promoted cell viability, migration and invasion, while NAT10 or SMYD2 knockdown abrogated this effect. NAT10 also promoted the ac4C modification of SMYD2, thus increasing SMYD2 stability. Furthermore, NETs promoted the metastasis of GC cells in the liver in vivo. Overall, the results of the present study demonstrated that NETs promoted GC cell metastasis via the NAT10-mediated ac4C modification of SMYD2. These findings suggested that inhibiting the formation of NETs could be an effective approach for attenuating GC progression.

Computational approach for assessing the involvement of SMYD2 protein in human cancers using TCGA data.

BACKGROUND: SMYD2 is a protein of the SET and MYND domain-containing family SMYD. It can methylate the lysine residue of various histone and nonhistone cancer-related proteins and plays a critical role in tumorigenesis. Although emerging evidence supports the association of SMYD2 in the progression of cancers, but its definitive effect is not yet clear. Therefore, further study of the gene in relation with cancer progression needs to be conducted. In the current study, investigators used TCGA data to determine the potential carcinogenic effect of SMYD2 in 11 cancer types. The transcriptional expression, survival rate, mutations, enriched pathways, and Gene Ontology of the SMYD2 were explored using different bioinformatics tools and servers. In addition, we also examined the correlation between SMYD2 gene expression and immunocyte infiltration in multiple cancer types. RESULTS: Findings revealed that higher expression of SMYD2 was significantly correlated with cancer incidents. In CESC and KIRC, the mRNA expression of SMYD2 was significantly correlated with overall survival (OS). In BRCA, KIRC, COAD, and HNSC, the mRNA expression of SMYD2 was significantly correlated with disease-free survival (DFS). We detected 15 missense, 4 truncating, 4 fusions, and 1 splice type of mutation. The expression of SMYD2 was significantly correlated with tumor purity and immunocyte infiltration in six cancer types. The gene GNPAT was highly associated with SMYD2. Significant pathways and Gene Ontology (GO) terms for co-expressed genes were associated to various processes linked with cancer formation. CONCLUSION: Collectively, our data-driven results may provide reasonably comprehensive insights for understanding the carcinogenic effect of SMYD2. It suggests that SMYD2 might be used as a significant target for identifying new biomarkers for various human tumors.

SMYD2 Imparts Gemcitabine Resistance to Pancreatic Adenocarcinoma Cells by Upregulating EVI2A.

Although gemcitabine (GEM) is the first­line drug for advanced pancreatic adenocarcinoma (PAAD), the development of GEM resistance severely limits the effectiveness of this chemotherapy. This study investigated the mechanisms of ecotropic viral integration site 2 A (EVI2A) for resistance to GEM and immune evasion in PAAD. GEM resistance-related biomarkers were predicted using GEO datasets, and GEM-resistant PAAD cells were generated. EVI2A was found expressed highly in GEM-resistant PAAD cells. Gain-of-function analyses revealed that EVI2A encouraged the proliferation and motility of GEM-resistant cells and prevented apoptosis. In addition, EVI2A reduced T cell effector activation. SMYD2 was overexpressed in GEM-resistant cells, and SMYD2 enhanced H3K36me2 modification of EVI2A, thereby promoting EVI2A expression. SMYD2 reduced the sensitivity of GEM-resistant cells, which was reversed by EVI2A knockdown. SMYD2 increased the amount of M2 macrophages (co-cultured with PAAD cells) and decreased T cell effector activation (co-cultured with macrophage supernatant), and the number of M2 macrophages was decreased and T cell effectors were activated following EVI2A knockdown. Our findings indicate that EVI2A, manipulated by the SMYD2-H3K36me2 epigenetic axis, promoted GEM resistance and M2 macrophage-mediated immune evasion in PAAD. Therefore, EVI2A might represent a therapeutic target for overcoming GEM resistance and immunosuppressive environment in PAAD.

Dissecting the Role of SMYD2 and Its Inhibitor (LLY-507) in the Treatment of Chemically Induced Non-Small Cell Lung Cancer (NSCLC) by Using Fe3O4 Nanoparticles Drug Delivery System.

Cancer therapies based on nanoparticles with a loaded drug can overcome the problem of the drug's toxic effects in the traditional chemotherapeutic approach. In this study, we loaded LLY-507, a potent inhibitor of SMYD2, a methyltransferase enzyme, on iron oxide nanoparticles (IONPs). The prepared nanoparticles were characterized by microscopic analysis, loading efficiency, and drug release studies. Microscopic examination revealed an average grain size of 44 nm. The in vitro effect of LLY-507-IONPs, LLY-507, and IONPs was determined by MTT analysis (A549 cells) and hemolysis studies. IONPs have almost negative hemolytic activity in blood. The cell viability assay revealed IC50 values of both LLY-507 alone and LLY-507-loaded IONPs against A549; the lower value of the drug loaded on NPs (0.71 µg/mL alone and 0.53 µg/mL loaded on NPs) shows strong synergistic anticancer potential. We further tested the role of loaded NPs in a urethane-induced lung cancer mouse model (n = 40 mice in three independent trials, 20 mice in control group) to check the role of SMYD2 at various time points of lung cancer development. The loss of SMYD2 due to LLY-507 suppressed tumor growth, emphysema, hemorrhage, and congestion considerably. Hence, it can be concluded that the SMYD2 inhibitor has an anti-inflammatory effect on the mouse lung and suppresses tumor growth by inhibiting the SMYD2 protein.

Long noncoding RNA DLEU1 promotes proliferation and glycolysis of gastric cancer cells via APOC1 upregulation by recruiting SMYD2 to induce trimethylation of H3K4 modification.

OBJECTIVES: APOC1 has been reported to promote tumor progression. Nevertheless, its impact on cell proliferation and glycolysis in gastric cancer (GC) remains to be probed. Hence, this study explored the related impacts and mechanisms. METHODS: DLEU1, SMYD2, and APOC1 expression was detected in GC cells. Afterward, ectopic expression and knockdown experiments were conducted in GC cells, followed by measurement of cell proliferation, glucose uptake capability, lactic acid production, ATP content, extracellular acidification rate (ECAR), oxygen consumption rate (OCR), and GLUT1, HK2, and LDHA expression. In addition, interactions between DLEU1 and SMYD2 were analyzed with RIP and RNA pull down assays, and the binding of SMYD2 to APOC1 promoter and the methylation modification of SMYD2 in H3K4me3 were assessed with a ChIP assay. The ectopic tumor formation experiment in nude mice was conducted for in vivo validation. RESULTS: DLEU1, SMYD2, and APOC1 were highly expressed in GC cells. The downregulation of DLEU1 or APOC1 inhibited glucose uptake capability, lactic acid production, ECAR, the expression of GLUT1, HK2, and LDHA, ATP contents, and proliferation but augmented OCR in GC cells, which was also verified in animal experiments. Mechanistically, DLEU1 interacted with SMYD2 and recruited SMYD2 to APOC1 promoter to promote H3K4me3 modification, thus facilitating APOC1 expression. Furthermore, the effects of DLEU1 silencing on GC cell proliferation and glycolysis were negated by overexpressing SMYD2 or APOC1. CONCLUSION: LncRNA DLEU1 recruited SMYD2 to upregulate APOC1 expression, thus boosting GC cell proliferation and glycolysis.

Positive selection of somatically mutated clones identifies adaptive pathways in metabolic liver disease.

Somatic mutations in nonmalignant tissues accumulate with age and injury, but whether these mutations are adaptive on the cellular or organismal levels is unclear. To interrogate genes in human metabolic disease, we performed lineage tracing in mice harboring somatic mosaicism subjected to nonalcoholic steatohepatitis (NASH). Proof-of-concept studies with mosaic loss of Mboat7, a membrane lipid acyltransferase, showed that increased steatosis accelerated clonal disappearance. Next, we induced pooled mosaicism in 63 known NASH genes, allowing us to trace mutant clones side by side. This in vivo tracing platform, which we coined MOSAICS, selected for mutations that ameliorate lipotoxicity, including mutant genes identified in human NASH. To prioritize new genes, additional screening of 472 candidates identified 23 somatic perturbations that promoted clonal expansion. In validation studies, liver-wide deletion of Tbx3, Bcl6, or Smyd2 resulted in protection against hepatic steatosis. Selection for clonal fitness in mouse and human livers identifies pathways that regulate metabolic disease.

Targeting SMYD2 inhibits prostate cancer cell growth by regulating c-Myc signaling.

SMYD2 is a lysine histone methyl transferase involved in various cancers epigenetically via methylating histone H3K4, and H3K36. c-Myc is one of the major drivers of prostate cancer (PCa) initiation and progression. The roles of SMYD2 in PCa and the regulators of c-Myc activity in PCa are still under-researched. SMYD2 expression and survival outcomes in PCa cohorts were analyzed by bioinformatics analysis. SMYD2 protein levels were detected in PCa tissues by immunohistochemistry. SMYD2 knockdown cells were established to identify the effects of SMYD2 on cell growth in vitro and in vivo. GSEA and RNA sequencing were adopted to reconnoiter the signaling regulated by SMYD2 in PCa. The relationship between SMYD2 and c-Myc was examined by western blot analysis, qPCR, and immunohistochemistry. SMYD2 specific inhibitor-AZ505 was used to pharmacologically inhibit SMYD2 function in vitro and in vivo. SMYD2 expression increased in PCa tissues compared with benign prostate tissues and higher SMYD2 expression was associated with a higher risk of biochemical relapse after radical prostatectomy. SMYD2 knockdown inhibited the growth of PCa cells both in vitro and in vivo. Furthermore, high SMYD2 levels conduced to activated c-Myc signaling in PCa cells. Importantly, the pharmacological intervention of SMYD2 by AZ505 significantly repressed PCa cell growth both in vitro and in vivo. Our findings indicate that SMYD2 inhibition restrains PCa cell proliferation by regulating c-Myc signaling and provide evidence for the potential practice of SMYD2 targeting in the treatment of PCa.

Targeting SMYD2 inhibits angiogenesis and increases the efficiency of apatinib by suppressing EGFL7 in colorectal cancer.

Angiogenesis is an essential factor affecting the occurrence and development of solid tumors. SET And MYND Domain Containing 2 (SMYD2) serves as an oncogene in various cancers. However, whether SMYD2 is involved in tumor angiogenesis remains unclear. Here, we report that SMYD2 expression is associated with microvessel density in colorectal cancer (CRC) tissues. SMYD2 promotes CRC angiogenesis in vitro and in vivo. Mechanistically, SMYD2 physically interacts with HNRNPK and mediates lysine monomethylation at K422 of HNRNPK, which substantially increases RNA binding activity. HNRNPK acts by binding and stabilizing EGFL7 mRNA. As an angiogenic stimulant, EGFL7 enhances CRC angiogenesis. H3K4me3 maintained by PHF8 mediates the abnormal overexpression of SMYD2 in CRC. Moreover, targeting SMYD2 blocks CRC angiogenesis in tumor xenografts. Treatment with BAY-598, a functional inhibitor of SMYD2, can also synergize with apatinib in patient-derived xenografts. Overall, our findings reveal a new regulatory axis of CRC angiogenesis and provide a potential strategy for antiangiogenic therapy.

Histone methyltransferase Smyd2 drives vascular aging by its enhancer-dependent activity.

BACKGROUND: Vascular aging is one of the important factors contributing to the pathogenesis of cardiovascular diseases. However, the systematic epigenetic regulatory mechanisms during vascular aging are still unclear. Histone methyltransferase SET and MYND domain-containing protein 2 (Smyd2) is associated with multiple diseases including cancer and inflammatory diseases, but whether it is involved in endothelial cell senescence and aging-related cardiovascular diseases has not been directly proved. Thus, we aim to address the effects of Smyd2 on regulating angiotensin II (Ang II)-induced vascular endothelial cells (VECs) senescence and its epigenetic mechanism. METHODS AND RESULTS: The regulatory role of Smyd2 in Ang II-induced VECs senescence was confirmed by performing loss and gain function assays. Chromatin immunoprecipitation-sequencing (ChIP-seq) analysis was used to systematically screen the potential enhancer during VECs senescence. Here, we found that Smyd2 was significantly upregulated in Ang II-triggered VECs, and deficiency of Smyd2 attenuated senescence-associated phenotypes both in vitro and in vivo. Mechanically, Ang II-induced upregulation of Smyd2 could increase the mono-methylation level of histone 3 lysine 4 (H3K4me1), resulting in a hyper-methylated chromatin state, then further activating enhancers adjacent to key aging-related genes, such as Cdkn1a and Cdkn2a, finally driving the development of vascular aging. CONCLUSIONS: Collectively, our study uncovered that Smyd2 drives a hyper-methylated chromatin state via H3K4me1 and actives the enhancer elements adjacent to key senescence genes such as Cdkn1a and Cdkn2a, and further induces the senescence-related phenotypes. Targeting Smyd2 possibly unveiled a novel therapeutic candidate for vascular aging-related diseases.

Clinical prognostic value of the SMYD2/3 as new epigenetic biomarkers in solid cancer patients: a systematic review and meta-analysis.

BACKGROUND: SET and MYND domain-containing protein (SMYD) family with methyltransferase activity is involved in cancer progression. This novel meta-analysis aimed to evaluate the association of SMYD family with the clinical and survival outcomes in solid cancer patients. METHODS: We systematically searched Embase, PubMed, Scopus and Web of Science to select relevant articles. Hazard ratios (HRs), odds ratios (ORs), and 95% confidence intervals were extracted. Heterogeneity was evaluated by chi-square-based Q and I2 tests, while publication bias by funnel plots and Egger's test. RESULTS: Thirty-two articles (4,826 patients) met inclusion criteria. SMYD2/3 overexpression was statistically associated with poor overall survival (HR = 1.794, P < 0.001), disease/relapse/progression-free survival (HR = 2.114, P < 0.001), disease/cancer-specific survival (HR = 3.220, P = 0.003), larger tumor size (OR = 1.963, P < 0.001), advanced TNM stage (OR = 2.066, P < 0.001), lymph node metastasis (OR = 2.054, P < 0.001), and distant metastasis (OR = 1.978, P = 0.004). Subgroup analysis showed more significant association between SMYD2 overexpression and reduced survival outcomes than that in SMYD3. Conversely, the relationship between SMYD3 and various clinicopathologic factors was stronger compared to SMYD2. CONCLUSION: Enhanced SMYD2/3 expression may be an unfavorable clinical prognostic factor in different solid cancer types.

Pharmacological inhibition of SMYD2 protects against cisplatin-induced acute kidney injury in mice.

The histone methyltransferase SET and MYND domain protein 2 (SMYD2) has been implicated in tumorigenesis through methylating histone H3 at lysine36 (H3K36) and some non-histone substrates. Currently, the role of SMYD2 in acute kidney injury (AKI) remains unknown. Here, we investigated the effects of AZ505, a highly selective inhibitor of SMYD2, on the development of AKI and the mechanisms involved in a murine model of cisplatin-induced AKI. SMYD2 and trimethylated histone H3K36 (H3K36Me3) were highly expressed in the kidney following cisplatin treatment; administration of AZ505 remarkedly inhibited their expression, along with improving kidney function and ameliorating kidney damage. AZ505 also attenuated kidney tubular cell injury and apoptosis as evidenced by diminished the expression of neutrophil gelatinase associated lipocalin (NGAL) and kidney injury molecule (Kim-1), reduced the number of TUNEL positive cells, decreased the expression of cleaved caspase-3 and the BAX/BCL-2 ratio in injured kidneys. Moreover, AZ505 inhibited cisplatin-induced phosphorylation of p53, a key driver of kidney cell apoptosis and reduced expression of p21, a cell cycle inhibitor. Meanwhile, AZ505 promoted expression of proliferating cell nuclear antigen and cyclin D1, two markers of cell proliferation. Furthermore, AZ505 was effective in suppressing the phosphorylation of STAT3 and NF-κB, two transcriptional factors associated with kidney inflammation, attenuating the expression of monocyte chemoattractant protein-1 and intercellular cell adhesion molecule-1 and reducing infiltration of F4/80+ macrophages to the injured kidney. Finally, in cultured HK-2 cells, silencing of SMYD2 by specific siRNA inhibited cisplatin-induced apoptosis of kidney tubular epithelial cells. Collectively, these results suggests that SMYD2 is a key determinant of cisplatin nephrotoxicity and targeting SMYD2 protects against cisplatin-induced AKI by inhibiting apoptosis and inflammation and promoting cell proliferation.

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.