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SETDB2 is a H3K9 histone methyltransferase required for accurate chromosome segregation. Its H3K9 histone methyltransferase activity was reported to be associated with chromosomes during metaphase. Here, we confirm that SETDB2 is required for mitosis and accurate chromosome segregation. However, these functions are independent of its histone methyltransferase activity. Further analysis showed that SETDB2 can interact with BUBR1, and is required for CDC20 binding to BUBR1 and APC/C complex and CYCLIN B1 degradation. The ability of SETDB2 to regulate the binding of CDC20 to BUBR1 or APC/C complex, and stabilization of CYCLIN B1 are also independent of its histone methyltransferase activity. These results suggest that SETDB2 interacts with BUBR1 to promote binding of CDC20 to BUBR1 and APC3, then degrades CYCLIN B1 to ensure accurate chromosome segregation and mitosis, independently of its histone methyltransferase activity.

SETDB2 is a H3K9 histone methyltransferase required for accurate chromosome segregation. Its H3K9 histone methyltransferase activity was reported to be associated with chromosomes during metaphase. Here, we confirm that SETDB2 is required for mitosis and accurate chromosome segregation. However, these functions are independent of its histone methyltransferase activity. Further analysis showed that SETDB2 can interact with BUBR1, and is required for CDC20 binding to BUBR1 and APC/C complex and CYCLIN B1 degradation. The ability of SETDB2 to regulate the binding of CDC20 to BUBR1 or APC/C complex, and stabilization of CYCLIN B1 are also independent of its histone methyltransferase activity. These results suggest that SETDB2 interacts with BUBR1 to promote binding of CDC20 to BUBR1 and APC3, then degrades CYCLIN B1 to ensure accurate chromosome segregation and mitosis, independently of its histone methyltransferase activity. [ABSTRACT FROM AUTHOR]

Abstract Objective Aberrant epigenetic remodeling represents a molecular hallmark in lung adenocarcinoma (LUAD). We aim to investigate the biological roles of SETDB2 and its underlying associations with oxidative stress, providing therapeutic targets for individualized treatment of LUAD. Methods Differential analysis was conducted via Limma package, and Kaplan–Meier analysis was performed with survival package. CCK‐8, cell proliferation assay, transwell assay, and in vivo assays were conducted to assess the function of SETDB2. Western blot assay, RT‐qPCR, and immunohistochemistry (IHC) were conducted to assess the expression levels of SETDB2/NRF2. Chromatin immunoprecipitation (ChIP) assay and ChIP‐qPCR were conducted to assess the epigenetic roles of SETDB2. Results We found that SETDB2 expression is decreased in tumor samples versus normal tissues in TCGA‐LUAD cohort, LUAD‐EAS cohort, GSE72094 dataset, and independent Soochow‐LUAD dataset. Patients with low SETDB2 levels had a worse prognosis relative to those with high SETDB2. SETDB2 inhibition could significantly promote cell growth, migration ability, and stemness maintenance. Gene set enrichment analysis (GSEA) suggested that SETDB2 correlated with oxidative stress crosstalk and regulated NRF2 mRNA levels. ChIP assay suggested that SETDB2 mainly recruited the H3K9me3 enrichment at the NRF2 promoter region to suppress the mRNA levels of NRF2. Downregulated SETDB2 could activate NRF2 transcription and expression, thereby promoting its downstream targets, like NQO1, FTH1, and ME1. Functional experiments demonstrated that low SETDB2 allowed NRF2 to drive malignant processes of LUAD. SETDB2 overexpression attenuated the ability of NRF2 signaling to neutralize cellular reactive oxygen species (ROS) levels, leading to enhanced cell apoptosis. Overexpressed SETDB2 could inhibit tumor progression in vivo and further render LUAD cells sensitive to chemotherapy. Conclusions In conclusion, these findings uncovered the suppressive role of SETDB2 in LUAD. SETDB2 negatively regulates NRF2 signaling to modulate tumor progression, which creates a therapeutic vulnerability in LUAD.

Objective: Aberrant epigenetic remodeling represents a molecular hallmark in lung adenocarcinoma (LUAD). We aim to investigate the biological roles of SETDB2 and its underlying associations with oxidative stress, providing therapeutic targets for individualized treatment of LUAD. Methods: Differential analysis was conducted via Limma package, and Kaplan–Meier analysis was performed with survival package. CCK‐8, cell proliferation assay, transwell assay, and in vivo assays were conducted to assess the function of SETDB2. Western blot assay, RT‐qPCR, and immunohistochemistry (IHC) were conducted to assess the expression levels of SETDB2/NRF2. Chromatin immunoprecipitation (ChIP) assay and ChIP‐qPCR were conducted to assess the epigenetic roles of SETDB2. Results: We found that SETDB2 expression is decreased in tumor samples versus normal tissues in TCGA‐LUAD cohort, LUAD‐EAS cohort, GSE72094 dataset, and independent Soochow‐LUAD dataset. Patients with low SETDB2 levels had a worse prognosis relative to those with high SETDB2. SETDB2 inhibition could significantly promote cell growth, migration ability, and stemness maintenance. Gene set enrichment analysis (GSEA) suggested that SETDB2 correlated with oxidative stress crosstalk and regulated NRF2 mRNA levels. ChIP assay suggested that SETDB2 mainly recruited the H3K9me3 enrichment at the NRF2 promoter region to suppress the mRNA levels of NRF2. Downregulated SETDB2 could activate NRF2 transcription and expression, thereby promoting its downstream targets, like NQO1, FTH1, and ME1. Functional experiments demonstrated that low SETDB2 allowed NRF2 to drive malignant processes of LUAD. SETDB2 overexpression attenuated the ability of NRF2 signaling to neutralize cellular reactive oxygen species (ROS) levels, leading to enhanced cell apoptosis. Overexpressed SETDB2 could inhibit tumor progression in vivo and further render LUAD cells sensitive to chemotherapy. Conclusions: In conclusion, these findings uncovered the suppressive role of SETDB2 in LUAD. SETDB2 negatively regulates NRF2 signaling to modulate tumor progression, which creates a therapeutic vulnerability in LUAD. [ABSTRACT FROM AUTHOR]

Non-alcoholic fatty liver disease (NAFLD) stands as the most prevalent hepatic disorder, with bariatric surgery emerging as the most effective intervention for NAFLD remission. Sleeve gastrectomy (SG) has notably ascended as the predominant procedure due to its comparative simplicity and consistent surgical outcomes. Nonetheless, the underlying mechanisms remain unclear. In this study, we probed the therapeutic potential of SG for NAFLD induced by a high-fat diet (HFD) in mice, with a focus on its impact on liver lipid accumulation, macrophage polarization, and the role of the histone methyltransferase Setdb2. SG prompted significant weight loss, diminished liver size and liver-to-body weight ratio, and enhanced liver function, evidenced by reduced serum levels of triglycerides (TG), total cholesterol (T-CHO), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Histological examination confirmed a reduction in liver lipid accumulation. Additionally, flow cytometry unveiled an increased proportion of M2 macrophages and a decrease in Setdb2 expression was shown in the SG group, suggesting an association between Setdb2 levels and postsurgical macrophage polarization. Furthermore, the conditional knockout of Setdb2 in mice further mitigated HFD-induced steatosis and promoted the M2 macrophage phenotype. Mechanistically, Setdb2 knockout in bone marrow-derived macrophages (BMDMs) favored M2 polarization, with RNA sequencing and western blotting analyses corroborating the upregulation of the PI3K/Akt signaling pathway. The effects of Setdb2 on macrophage activation were nullified by the PI3K inhibitor LY294002, suggesting that Setdb2 facilitates alternative macrophage activation through the PI3K/Akt signaling pathway. These comprehensive findings underscore the potential of SG as a therapeutic intervention for NAFLD by regulating the critical function of Setdb2 in macrophage polarization and activation, thereby offering novel insights into NAFLD pathogenesis and therapeutic targets. • SG decreased body weight, liver size, and enhanced liver function in NAFLD mice. • SG resulted in higher M2 macrophage ratio and lower Setdb2 expression. • Setdb2 levels and post-surgery macrophage polarization may be linked. • Setdb2 may facilitate alternative macrophage activation via the PI3K/Akt pathway. [ABSTRACT FROM AUTHOR]

Guangfu Mu, Fangping Chen Department of Hematology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, People’s Republic of ChinaCorrespondence: Fangping ChenDepartment of Hematology, The Third Xiangya Hospital, Central South University, Tongzipo Road No. 138, Changsha, Hunan 410013, People’s Republic of ChinaTel/Fax +86 073 1861 8841Email xychenfpcs@126.comIntroduction: AML1-ETO produced by t(8;21) abnomality has multiple effects on the leukemogenesis of acute myeloid leukemia (AML). SET domain, bifurcated 2 (SETDB2) can mediate gene silencing by trimethylation of the ninth lysine residue of histone H3 protein (H3K9) of the promoter and has been confirmed as an oncogene in many cancers. The role of SETDB2 in AML1-ETO positive AML is not clear.Methods: Quantitative reverse transcription PCR was performed to measure SETDB2 expression in bone marrow from AML patients and healthy people. Kaplan-Meier analysis was performed to investigate the effect of SETDB2 on prognosis of AML patients. Dual luciferase reporter gene assay, chromatin immunoprecipitation were performed to investigate the regulatory mechanism of AML1-ETO on SETDB2. CCK-8 and colony formation assay were performed to measure the effect of SETDB2 on leukemic cells.Results: SETDB2 is highly expressed in AML1-ETO positive AML. The overall survival, event-free and relapse-free survival rate of patients with high SETDB2 expression was lower than those of patients with low SETDB2 expression. SETDB2 is epigenetically upregulated by AML1-ETO fusion protein. Downregulation of SETDB2 expression significantly inhibits the proliferation and clonality of leukemic cells and promotes the sensitivity of leukemic cells to an epigenetic inhibitor JQ1.Conclusion: AML1-ETO/SETDB2 is a novel epigenetic pathway of leukemogenesis and SETDB2 is a potential therapeutic target of t(8;21) AML.Keywords: acute myeloid leukemia, AML1-ETO, SETDB2, epigenetic, clinical biomarker

SETDB1 and SETDB2 mediate trimethylation of histone H3 lysine 9 (H3K9), an epigenetic hallmark of repressive chromatin. They contain a non-canonical methyl-CpG-binding domain (MBD) and bifurcated SET domain, implying interplay between H3K9 trimethylation and DNA methylation in SETDB functions. Here, we report the crystal structure of human SETDB2 MBD bound to the cysteine-rich domain of a zinc-binding protein, C11orf46. SETDB2 MBD comprises the conserved MBD core and a unique N-terminal extension. Although the MBD core has the conserved basic concave surface for DNA binding, it utilizes it for recognition of the cysteine-rich domain of C11orf46. This interaction involves the conserved arginine finger motif and the unique N-terminal extension of SETDB2 MBD, with a contribution from intermolecular β-sheet formation. Thus, the non-canonical MBD of SETDB1/2 seems to have lost methylated DNA-binding ability but gained a protein-protein interaction surface. Our findings provide insight into the molecular assembly of SETDB-associated repression complexes. [Display omitted] • SETDB1/2 directly interacts with C11orf46 CRD through their non-canonical MBDs • Crystal structure of the SETDB2 MBD–C11orf46 CRD complex at 1.82 Å resolution • Conserved and divergent characteristics of the non-canonical MBD of SETDB proteins • The zinc-binding motifs in C11orf46 CRD contribute to maintaining its core fold C11orf46 has been identified in SETDB-associated repression complexes. Mahana et al. demonstrate that the non-canonical MBD of SETDB2, despite its conserved MBD architecture, mediates a protein-protein interaction with C11orf46 CRD rather than methylated DNA binding. This finding highlights the diverse functional roles of MBDs in transcriptional repression. [ABSTRACT FROM AUTHOR]

Abstract Background A multitude of recent studies has observed common epigenetic changes develop in tumour cells of multiple lineages following exposure to stresses such as hypoxia, chemotherapeutics, immunotherapy or targeted therapies. A significant increase in the transcriptionally repressive mark trimethylated H3K9 (H3K9me3) is becoming associated with treatment-resistant phenotypes suggesting upstream mechanisms may be a good target for therapy. We have reported that the increase in H3K9me3 is derived from the methyltransferases SETDB1 and SETDB2 following treatment in melanoma, lung, breast and colorectal cancer cell lines, as well as melanoma patient data. Other groups have observed a number of characteristics such as epigenetic remodelling, increased interferon signalling, cell cycle inhibition and apoptotic resistance that have also been reported by us suggesting these independent studies are investigating similar or identical phenomena. Main body Firstly, this review introduces reports of therapy-induced reprogramming in cancer populations with highly similar slow-cycling phenotypes that suggest a role for both IFN signalling and epigenetic remodelling in the acquisition of drug tolerance. We then describe plausible connections between the type 1 IFN pathway, slow-cycling phenotypes and these epigenetic mechanisms before reviewing recent evidence on the roles of SETDB1 and SETDB2, alongside their product H3K9me3, in treatment-induced reprogramming and promotion of drug resistance. The potential mechanisms for the activation of SETDB1 and SETDB2 and how they might arise in treatment is also discussed mechanistically, with a focus on their putative induction by inflammatory signalling. Moreover, we theorise their timely role in attenuating inflammation after their activation in order to promote a more resilient phenotype through homeostatic coordination of H3K9me3. We also examine the relatively uncharacterized functions of SETDB2 with some comparison to the more well-known qualities of SETDB1. Finally, an emerging overall mechanism for the epigenetic maintenance of this transient phenotype is outlined by summarising the collective literature herein. Conclusion A number of converging phenotypes outline a stress-responsive mechanism for SETDB1 and SETDB2 activation and subsequent increased survival, providing novel insights into epigenetic biology. A clearer understanding of how SETDB1/2-mediated transcriptional reprogramming can subvert treatment responses will be invaluable in improving length and efficacy of modern therapies.

Increasing detection of small renal masses by imaging techniques entails the need for accurate discrimination between benign and malignant renal cell tumors (RCTs) as well as among malignant RCTs, owing to differential risk of progression through metastization. Although histone methylation has been implicated in renal tumorigenesis, its potential as biomarker for renal cell carcinoma (RCC) progression remains largely unexplored. Thus, we aimed to characterize the differential expression of histone methyltransferases (HMTs) and histone demethylases (HDMs) in RCTs to assess their potential as metastasis biomarkers. We found that SETDB2 and RIOX2 (encoding for an HMT and an HDM, respectively) expression levels was significantly altered in RCTs; these genes were further selected for validation by quantitative RT-PCR in 160 RCTs. Moreover, SETDB2, RIOX2, and three genes encoding for enzymes involved in histone methylation (NO66, SETD3, and SMYD2), previously reported by our group, were quantified (RT-PCR) in an independent series of 62 clear cell renal cell carcinoma (ccRCC) to assess its potential role in ccRCC metastasis development. Additional validation was performed using TCGA dataset. SETDB2 and RIOX2 transcripts were overexpressed in RCTs compared to renal normal tissues (RNTs) and in oncocytomas vs. RCCs, with ccRCC and papillary renal cell carcinoma (pRCC) displaying the lowest levels. Low SETDB2 expression levels and higher stage independently predicted shorter disease-free survival. In our 62 ccRCC cohort, significantly higher RIOX2, but not SETDB2, expression levels were depicted in cases that developed metastasis during follow-up. These findings were not apparent in TCGA dataset. We concluded that SETDB2 and RIOX2 might be involved in renal tumorigenesis and RCC progression, especially in metastatic spread. Moreover, SETDB2 expression levels might independently discriminate among RCC subgroups with distinct outcome, whereas higher RIOX2 transcript levels might identify ccRCC cases with more propensity to endure metastatic dissemination.

Abstract: Systemic bacterial infections are prone to secondary Candida albicans super‐infection. However, the molecular mechanisms involved remain poorly understood. In this study, a model comprising sublethal cecal ligation and puncture plus C. albicans intravenous injection was applied to mimic the situation in super‐infection. Compared with mice without systemic bacterial infection, mice with systemic bacterial infection had lower antifungal gene expression (including Il1b, Tnf, Il6, Ifnb, Ifng, Cxcl1, and Ccr2) in monocytes and less inflammatory monocytes and neutrophils infiltrating into the kidney when challenged with C. albicans. Further, lentivirus‐mediated Setdb2‐knockout and overexpression experiments verified that Setdb2 levels in monocytes correlated negatively with antifungal gene expression and survival rates. Transcriptional repression was probably achieved by Setdb2 through H3 methylation at lysine 9 in promoter regions of these antifungal genes. [ABSTRACT FROM AUTHOR]

Summary Acute lymphoblastic leukemia (ALL) is associated with significant morbidity and mortality, necessitating further improvements in diagnosis and therapy. Targeted therapies directed against chromatin regulators are emerging as promising approaches in preclinical studies and early clinical trials. Here, we demonstrate an oncogenic role for the protein lysine methyltransferase SETDB2 in leukemia pathogenesis. It is overexpressed in pre-BCR + ALL and required for their maintenance in vitro and in vivo . SETDB2 expression is maintained as a direct target gene of the chimeric transcription factor E2A-PBX1 in a subset of ALL and suppresses expression of the cell-cycle inhibitor CDKN2C through histone H3K9 tri-methylation, thus establishing an oncogenic pathway subordinate to E2A-PBX1 that silences a major tumor suppressor in ALL. In contrast, SETDB2 was relatively dispensable for normal hematopoietic stem and progenitor cell proliferation. SETDB2 knockdown enhances sensitivity to kinase and chromatin inhibitors, providing a mechanistic rationale for targeting SETDB2 therapeutically in ALL. [ABSTRACT FROM AUTHOR]

Increasing detection of small renal masses by imaging techniques entails the need for accurate discrimination between benign and malignant renal cell tumors (RCTs) as well as among malignant RCTs, owing to differential risk of progression through metastization. Although histone methylation has been implicated in renal tumorigenesis, its potential as biomarker for renal cell carcinoma (RCC) progression remains largely unexplored. Thus, we aimed to characterize the differential expression of histone methyltransferases (HMTs) and histone demethylases (HDMs) in RCTs to assess their potential as metastasis biomarkers. We found thatSETDB2andRIOX2(encoding for an HMT and an HDM, respectively) expression levels was significantly altered in RCTs; these genes were further selected for validation by quantitative RT-PCR in 160 RCTs. Moreover,SETDB2, RIOX2, and three genes encoding for enzymes involved in histone methylation (NO66, SETD3, andSMYD2), previously reported by our group, were quantified (RT-PCR) in an independent series of 62 clear cell renal cell carcinoma (ccRCC) to assess its potential role in ccRCC metastasis development. Additional validation was performed using TCGA dataset.SETDB2andRIOX2transcripts were overexpressed in RCTs compared to renal normal tissues (RNTs) and in oncocytomas vs. RCCs, with ccRCC and papillary renal cell carcinoma (pRCC) displaying the lowest levels. LowSETDB2expression levels and higher stage independently predicted shorter disease-free survival. In our 62 ccRCC cohort, significantly higherRIOX2, but notSETDB2, expression levels were depicted in cases that developed metastasis during follow-up. These findings were not apparent in TCGA dataset. We concluded thatSETDB2andRIOX2might be involved in renal tumorigenesis and RCC progression, especially in metastatic spread. Moreover,SETDB2expression levels might independently discriminate among RCC subgroups with distinct outcome, whereas higherRIOX2transcript levels might identify ccRCC cases with more propensity to endure metastatic dissemination. [ABSTRACT FROM PUBLISHER]

Summary Transcriptional and chromatin regulations mediate the liver response to nutrient availability. The role of chromatin factors involved in hormonal regulation in response to fasting is not fully understood. We have identified SETDB2, a glucocorticoid-induced putative epigenetic modifier, as a positive regulator of GR-mediated gene activation in liver. Insig2a increases during fasting to limit lipid synthesis, but the mechanism of induction is unknown. We show Insig2a induction is GR-SETDB2 dependent. SETDB2 facilitates GR chromatin enrichment and is key to glucocorticoid-dependent enhancer-promoter interactions. INSIG2 is a negative regulator of SREBP, and acute glucocorticoid treatment decreased active SREBP during refeeding or in livers of Ob/Ob mice, both systems of elevated SREBP-1c-driven lipogenesis. Knockdown of SETDB2 or INSIG2 reversed the inhibition of SREBP processing. Overall, these studies identify a GR-SETDB2 regulatory axis of hepatic transcriptional reprogramming and identify SETDB2 as a potential target for metabolic disorders with aberrant glucocorticoid actions. [ABSTRACT FROM AUTHOR]

As the primary driving forces of gastrulation, convergence and extension (C&E) movements lead to a medio-lateral narrowing and an anterior-posterior elongation of the embryonic body axis. Histone methylation as a post-translational modification plays a critical role in early embryonic development, but its functions in C&E movements remain largely unknown. Here, we show that the setdb2-dvr1 transcriptional cascade plays a critical role in C&E movements during zebrafish gastrulation. Knockdown of Setdb2, a SET domain-containing protein possessing a potential histone H3K9 methyltransferase activity, induced abnormal C&E movements, resulting in anterior-posterior shortening and medio-lateral expansion of the embryonic axis, as well as abnormal notochord cell polarity. Furthermore, we found that Setdb2 functions through fine-tuning the expression of dvr1, a ligand of the TGF-β superfamily, to an appropriate level to ensure proper C&E movements in a non-cell-autonomous manner. In addition, both overexpression and knockdown of Dvr1 at the one-cell stage resulted in defects at epiboly and C&E. These data demonstrate that Setdb2 is a novel regulator for C&E movements and acts by modulating the expression level of dvr1, suggesting that Dvr1 acts as a direct and essential mediator for C&E cell movements. [ABSTRACT FROM AUTHOR]

The article presents a study on finding the somatic mutation genes, involved in metabolic regulation, in an adult acute myeloid leukaemia (AML) genome. As per the study, the discovered somatic mutation genes include isocitrate dehydrogenases (IDH1/IDH2) and mitochondrially encoded NADH dehydrogenase 4 (MT-ND4). The study states that the mutated MT-ND4 leads to improper functioning of mitochondrial oxidative phosphorylation.

The histone H3K9 methyltransferase SETDB2 is involved in cell cycle dysregulation in acute leukemia and has oncogenic roles in gastric cancer. In our study, we found that SETDB2 plays essential roles in breast cancer stem cell maintenance. Depleted SETDB2 significantly decreased the breast cancer stem cell population and mammosphere formation in vitro and also inhibited breast tumor initiation and growth in vivo . Restoring SETDB2 expression rescued the defect in breast cancer stem cell maintenance. A mechanistic analysis showed that SETDB2 upregulated the transcription of the ΔNp63α downstream Hedgehog pathway gene. SETDB2 also interacted with and methylated ΔNp63α, and stabilized ΔNp63α protein. Restoring ΔNp63α expression rescued the breast cancer stem cell maintenance defect which mediated by SETDB2 knockdown. In conclusion, our study reveals a novel function of SETDB2 in cancer stem cell maintenance in breast cancer., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

SETDB2 is a histone H3 lysine 9 (H3K9) tri-methyltransferase that is involved in transcriptional gene silencing. Since it is still unknown whether SETDB2 is linked to carcinogenesis, we studied alterations and functions of SETDB2 in human gastric cancers (GCs). SETDB2 protein was highly expressed in 30 of 72 (41.7%) primary GC tissues compared with their normal counterparts by immunohistochemistry. SETDB2 overexpression was significantly associated with the late stage of GCs (P<0.05) and poor prognosis of GC patients (P<0.05). The GC cell lines with SETDB2 knockdown and overexpression significantly decreased and increased cell proliferation, migration and invasion, respectively (P<0.05). Knockdown of SETDB2 in MKN74 and MKN45 cells reduced global H3K9 tri-methylation (me3) levels. Microarray analysis indicated that expression of WWOX and CADM1, tumor suppressor genes, was significantly enhanced in MKN74 cells after SETDB2 knockdown. Chromatin immunoprecipitation assays showed that the H3K9me3 levels at the promoter regions of these two genes corresponded to the SETDB2 expression levels in GC cells. Moreover, ectopic SETDB2 protein was recruited to their promoter regions. Our data suggest that SETDB2 is associated with transcriptional repression of WWOX and CADM1, and hence overexpression of SETDB2 may contribute to GC progression.

As the primary driving forces of gastrulation, convergence and extension (C&E) movements lead to a medio-lateral narrowing and an anterior-posterior elongation of the embryonic body axis. Histone methylation as a post-translational modification plays a critical role in early embryonic development, but its functions in C&E movements remain largely unknown. Here, we show that the setdb2-dvr1 transcriptional cascade plays a critical role in C&E movements during zebrafish gastrulation. Knockdown of Setdb2, a SET domain-containing protein possessing a potential histone H3K9 methyltransferase activity, induced abnormal C&E movements, resulting in anterior-posterior shortening and medio-lateral expansion of the embryonic axis, as well as abnormal notochord cell polarity. Furthermore, we found that Setdb2 functions through fine-tuning the expression of dvr1, a ligand of the TGF-β superfamily, to an appropriate level to ensure proper C&E movements in a non-cell-autonomous manner. In addition, both overexpression and knockdown of Dvr1 at the one-cell stage resulted in defects at epiboly and C&E. These data demonstrate that Setdb2 is a novel regulator for C&E movements and acts by modulating the expression level of dvr1, suggesting that Dvr1 acts as a direct and essential mediator for C&E cell movements., (Copyright © 2014 Elsevier Inc. All rights reserved.)