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Cell division cycle-associated 8 (CDCA8) is a component of chromosomal passenger complex (CPC) that participates in mitotic regulation. Although cancer-related CDCA8 hyperactivation has been widely observed, its molecular mechanism remains elusive. Here, we report that CDCA8 overexpression maintains tumorigenicity and is associated with poor clinical outcome in patients with prostate cancer (PCa). Notably, enhancer of zeste homolog 2 (EZH2) is identified to be responsible for CDCA8 activation in PCa. Genome-wide assays revealed that EZH2-induced H3K27 trimethylation represses let-7b expression and thus protects the let-7b-targeting CDCA8 transcripts. More importantly, EZH2 facilitates the self-activation of E2F1 by recruiting E2F1 to its own promoter region in a methylation-independent manner. The high level of E2F1 further promotes transcription of CDCA8 along with the other CPC subunits. Taken together, our study suggests that EZH2-mediated cell cycle regulation in PCa relies on both its methyltransferase and non-methyltransferase activities.

The N6-methyladenosine (m6A) modification influences various mRNA metabolic events and tumorigenesis, however, its functions in nonsense-mediated mRNA decay (NMD) and whether NMD detects induced carcinogenesis pathways remain undefined. Here, we showed that the m6A methyltransferase METTL3 sustained its oncogenic role by modulating NMD of splicing factors and alternative splicing isoform switches in glioblastoma (GBM). Methylated RNA immunoprecipitation-seq (MeRIP-seq) analyses showed that m6A modification peaks were enriched at metabolic pathway–related transcripts in glioma stem cells (GSC) compared with neural progenitor cells. In addition, the clinical aggressiveness of malignant gliomas was associated with elevated expression of METTL3. Furthermore, silencing METTL3 or overexpressing dominant-negative mutant METTL3 suppressed the growth and self-renewal of GSCs. Integrated transcriptome and MeRIP-seq analyses revealed that downregulating the expression of METTL3 decreased m6A modification levels of serine- and arginine-rich splicing factors (SRSF), which led to YTHDC1-dependent NMD of SRSF transcripts and decreased SRSF protein expression. Reduced expression of SRSFs led to larger changes in alternative splicing isoform switches. Importantly, the phenotypes mediated by METTL3 deficiency could be rescued by downregulating BCL-X or NCOR2 isoforms. Overall, these results establish a novel function of m6A in modulating NMD and uncover the mechanism by which METTL3 promotes GBM tumor growth and progression.Significance:These findings establish the oncogenic role of m6A writer METTL3 in glioblastoma stem cells.

Supplementary Figures and Methods

Advanced Non-alcoholic fatty liver disease (NAFLD) is associated with increased risk of cardiovascular disease (CVD).We determine whether combinations of ultrasound graphic steatosis grades, fibrosis scores and apolipoprotein levels add value to CVD risk prediction in NAFLD patients.The retrospective cohort study enrolled 10,453 individuals (3519 NAFLD; 6934 non NAFLD) from 2004 to 2018. Hepatic ultrasound measurements, lipid and apolipoprotein profiles, Fibrosis-4 and the NAFLD fibrosis scores (NFS) were assessed. The primary outcome included both clinical and subclinical CVD.During 116-month follow-up period, there were 957 clinical and 752 subclinical CVD events. NAFLD patients had a higher incidence of CVD than non NAFLD patients as the steatosis degree, NFS, and FIB4 scores increased (25.1% vs 11.9%, Log Rank: p 0.001). For the lipid and apolipoprotein profiles excluding triglyceride or ApoE, subjects with varied steatosis severity in the upper two tertiles had different risk of CVD (p for interaction 0.001). A nomogram model combination of Framingham Risk Score (FRS), NFS and apolipoprotein profiles presented a higher AUC than FRS in a time-dependent ROC curve (0.816 vs 0.752, p 0.001).The novel risk score considering ultrasonography-defined steatosis grades, non-invasive liver fibrosis scores and apolipoprotein profiles accurately predicted the 10-year risk of CVD.

N6-methyladenosine (m6A) RNA methylation and its associated methyltransferase METTL3 play an important role in tumorigenesis of a series of tumors. However, dysregulation of METTL3 in gallbladder cancer (GBC) remains obscure. Here, we showed that upregulated METTL3 level predicted poor prognosis and correlated with increased lymphatic metastasis and high TNM stage. Functionally, we found that METTL3 could promote cell proliferation, invasion, and migration of GBC-SD and NOZ cells. Mechanistically, we revealed the METTL3-mediated m6A-modification profile in GBC cells and identified DUSP5 as the downstream gene of METTL3. METTL3 promoted the degradation of DUSP5 mRNA in a YTHDF2-dependent manner. Rescue assays showed that downregulation of DUSP5 could attenuate the knockdown METTL3-mediated inhibition of cell proliferation, invasion, and migration of GBC-SD and NOZ cells. Thus, our finding shows that elevated METTL3 expression contributes to tumor aggression in GBC, suggesting that METTL3 is a possible prognostic predictor and therapeutic target against GBC.

Background Excessive delivery of free fatty acids (FFAs) to the liver promotes steatosis and insulin resistance (IR), with IR defined as reduced glucose uptake, glycogen synthesis and anti-lipolysis stimulated by normal insulin levels. Whether the associations between FFAs and diabetes development differ between patients with and without nonalcoholic fatty liver disease (NAFLD) remains unclear. Methods Consecutive subjects (2,220 NAFLD subjects and 1,790 non-NAFLD subjects according to ultrasound imaging) were enrolled from the First Affiliated Hospital of Sun Yat-sen University between 2009 and 2019. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. Results There was an approximate J-shaped relationship between FFA levels and HOMA-IR in the NAFLD group. Higher FFA concentration quartiles were associated with higher risks of IR (odds ratio [OR], 9.24; 95% confidence interval [CI], 6.43 to 13.36), prediabetes (OR, 10.48; 95% CI, 5.66 to 19.39), and type 2 diabetes mellitus (T2DM; OR, 19.43; 95% CI, 12.75 to 29.81) in the NAFLD group but not in the non-NAFLD group. The cut-off points for the FFA levels increased in a stepwise manner in discriminating IR, prediabetes and T2DM (573, 697, and 715 μmol/L) in the NAFLD group but not in non-NAFLD individuals. Conclusion A distinct dose-dependent relationship of FFA levels was found with IR, prediabetes and T2DM in NAFLD patients. Screening serum FFA levels in NAFLD patients would be valuable in preventing diabetes development.

The N6-methyladenosine (m6A) modification influences various mRNA metabolic events and tumorigenesis, however, its functions in nonsense-mediated mRNA decay (NMD) and whether NMD detects induced carcinogenesis pathways remain undefined. Here, we showed that the m6A methyltransferase METTL3 sustained its oncogenic role by modulating NMD of splicing factors and alternative splicing isoform switches in glioblastoma (GBM). Methylated RNA immunoprecipitation-seq (MeRIP-seq) analyses showed that m6A modification peaks were enriched at metabolic pathway–related transcripts in glioma stem cells (GSC) compared with neural progenitor cells. In addition, the clinical aggressiveness of malignant gliomas was associated with elevated expression of METTL3. Furthermore, silencing METTL3 or overexpressing dominant-negative mutant METTL3 suppressed the growth and self-renewal of GSCs. Integrated transcriptome and MeRIP-seq analyses revealed that downregulating the expression of METTL3 decreased m6A modification levels of serine- and arginine-rich splicing factors (SRSF), which led to YTHDC1-dependent NMD of SRSF transcripts and decreased SRSF protein expression. Reduced expression of SRSFs led to larger changes in alternative splicing isoform switches. Importantly, the phenotypes mediated by METTL3 deficiency could be rescued by downregulating BCL-X or NCOR2 isoforms. Overall, these results establish a novel function of m6A in modulating NMD and uncover the mechanism by which METTL3 promotes GBM tumor growth and progression. Significance: These findings establish the oncogenic role of m6A writer METTL3 in glioblastoma stem cells.

Nonalcoholic fatty liver disease (NAFLD) is regarded as a risk factor of cardiovascular disease (CVD). However, the association between non-obese NAFLD and CVD has not been well established.We aimed to compare the CVD risk between non-obese and obese NAFLD patients, and explored the factors associated with subclinical atherosclerosis.Consecutive NAFLD patients estimated by magnetic resonance imaging-based proton density fat fraction (MRI-PDFF) were recruited. Liver fat content (LFC) and liver stiffness were measured with MRI-PDFF and shear wave elastography, respectively. CVD risk was estimated by atherosclerosis index (AI), carotid intima-media thickness, carotid plaque, and Framingham risk score (FRS).This study included 543 NAFLD patients. The presence of carotid intima-media thickening and carotid plaque, FRS, and AI were comparable between non-obese and obese patients. Age increased per 10 years (OR 9.68; P 0.001) and liver fibrosis (liver stiffness 6.1 kPa, OR 4.42; P = 0.004) were significant factors associated with carotid intima-media thickening in non-obese patients, while age increased per 10 years (OR 2.02; P 0.001), liver fibrosis (OR 2.18; P = 0.039), and LFC 10% (OR 2.29; P = 0.021) were independent predictors in obese patients. Only elevated triglyceride was significantly associated with carotid plaque in non-obese patients (OR 2.42; P = 0.033), while age increased per 10 years (OR 1.77; P = 0.002) and LFC 10% (OR 2.83; P = 0.019) were significant predictors in obese patients.Liver stiffness and age were strongly predictive of subclinical atherosclerosis in all NAFLD, while LFC was an additional predictor in obese NAFLD patients. Our findings highlight that early CVD screening strategy should be established for NAFLD patients according to different BMIs.

Non-obese nonalcoholic fatty liver disease (NAFLD) is paradoxically associated with improved metabolic and pathological features at diagnosis but worse prognosis relative to obese NAFLD.To compare predictors of disease severity in NAFLD with different body mass index (BMI) categories.All 1509 consecutive NAFLD patients were classified as lean (20.2%), overweight (23.1%) and obese (56.7%). Liver fat content (LFC) and fibrosis were estimated with magnetic resonance imaging-based proton density fat fraction and shear wave elastography respectively.Lipid profiles and uric acid (UA) were significantly increased in parallel with BMI categories (pairwise comparison P 0.001), but insulin resistance (IR) was significantly different between the non-obese and obese groups. For LFC ≥ 10%, increased waist circumference (WC) was an independent predictor in all groups, while UA elevation (P = 0.02) was predictive in the overweight patients, but BMI ≥ 28 kg/mWC was strongly predictive of disease severity in all NAFLD, while UA and BMI plus IR were additional predictors in the overweight and obese NAFLD respectively. Individualized screening strategies should be established for NAFLD according to different BMIs.

Gallbladder cancer (GBC) is the most aggressive malignancy of the biliary tract cancer, and there is a lack of effective treatment. Here, we developed a nanoparticle platform (8P4 NP) that can deliver THZ1, a cyclin-dependent kinase 7 (CDK7) inhibitor, to treat GBC. Analysis of datasets demonstrated that CDK7 was positively correlated with poor prognosis. CDK7 inhibition suppressed cell proliferation, induced apoptosis, and caused cell cycle block in GBC cells. THZ1 downregulated CDK7-mediated phosphorylation of RNA polymerase II (RNAPII), resulting in a significant downregulation of transcriptional programs, with a preferential repression of oncogenic transcription factors. To improve the tumor targeting efficiency of THZ1, 8P4 NPs were prepared and assembled with THZ1 to form THZ1@8P4 NPs. Compared with free THZ1, THZ1@8P4 NPs showed more advantages in prolonging blood circulation, escaping from lysosomes and increasing cellular uptake. Importantly, THZ1@8P4 NPs demonstrated a more significant inhibition effect on GBC cells than free THZ1 in vitro. In addition, THZ1@8P4 NPs could efficiently deliver THZ1 to tumor sites in a patient-derived xenograft model of early recurrence, leading to tumor regression and transcriptional inhibition with minimal toxicity. In summary, we conclude that THZ1@8P4 NPs provide a potent therapeutic strategy that targets CDK7-mediated transcriptional addiction in GBC.

Background: The consistency in steatosis grading between magnetic resonance imaging-based proton density fat fraction (MRI-PDFF) and controlled attenuation parameter (CAP) before and after treatment remains unclear. This study aimed to compare the diagnostic accuracy of steatosis grading between MRI-PDFF and CAP using liver biopsy as standard and to evaluate the value of monitoring changes in steatosis grading with CAP during follow-up utilizing MRI-PDFF as a reference. Methods: Consecutive patients from a biopsy cohort and a randomized controlled trial were included in this study and classified into 3 groups (the biopsy, orlistat treatment, and routine treatment subgroups). Hepatic steatosis was measured via MRI-PDFF and CAP at baseline and at the 6th month; the accuracy and cutoffs were assessed in the liver biopsy cohort at baseline. Results: A total of 209 consecutive patients were enrolled. MRI-PDFF and CAP showed comparable diagnostic accuracy for detecting pathological steatosis [⩾S1, area under the receiver operating characteristic curve (AUC) = 0.984 and 0.972, respectively]; in contrast, CAP presented significantly lower AUCs in grades S2–3 and S3 (0.820 and 0.815, respectively). The CAP values correlated well with the MRI-PDFF values at baseline and at the 6th month ( r = 0.809 and 0.762, respectively, both p Conclusions: CAP has decreased value for the initial screening of moderate-severe steatosis and is limited in monitoring changes in steatosis during treatment. The confirmation of steatosis grading with MRI-PDFF remains necessary.

N

Dysregulated translation is a common feature of cancer. Uncovering its governing factors and underlying mechanism are important for cancer therapy. Here, we report that enhancer of zeste homologue 2 (EZH2), previously known as a transcription repressor and lysine methyltransferase, can directly interact with fibrillarin (FBL) to exert its role in translational regulation. We demonstrate that EZH2 enhances rRNA 2′-O methylation via its direct interaction with FBL. Mechanistically, EZH2 strengthens the FBL–NOP56 interaction and facilitates the assembly of box C/D small nucleolar ribonucleoprotein. Strikingly, EZH2 deficiency impairs the translation process globally and reduces internal ribosome entry site (IRES)-dependent translation initiation in cancer cells. Our findings reveal a previously unrecognized role of EZH2 in cancer-related translational regulation. Yi et al. report that EZH2 exerts a PRC2-independent function in nucleoli, where it bridges FBL and NOP56 to facilitate rRNA methylation and subsequent IRES-dependent translation.

Passive daytime radiative cooling (PDRC) emerges as an environmentally friendly cooling strategy for its zero demand of electricity and fossil energy. In this study, PDRC coating containing polymethylmethacrylate and CaSiO3 was prepared with a simple process at low cost. The solar reflectivity, atmospheric window emissivity and radiative cooling performance of the prepared coating were investigated. The coating exhibits an average solar reflectance of 96.4% and an average atmospheric window emittance of 97.0%. Under direct solar irradiation, the coating can achieved an average sub-ambient temperature drop of 5.5 °C and an average net radiative cooling power of 72 W m−2. The results are on par with those of the efficient radiative coolers in the literature. Experimental investigation also suggests that the coating has application prospect in dew condensation and retarding the melting process of ice. This study provides a cost-efficient and commercially feasible strategy to fabricate PDRC coating.

Background: The clinical burden and natural history of non-alcoholic fatty liver disease (NAFLD) vary globally. We aimed to investigate NAFLD-related mortality profiles in hospitalized patients in southern China.Methods: A multicenter retrospective investigation with a 10-year study period (2009–2018) analyzed 10,071 deaths during hospitalization (NAFLD: 2,015; other liver diseases: 1,140; without liver diseases: 6,916) was performed using a multiple cause of death analysis. Medical histories and biochemistry and imaging findings were extracted from the electronic medical record system. The underlying causes of death were classified by 10th Revision of the International Classification of Diseases (ICD-10) codes.Results: The distribution of death causes in patients with NAFLD has stabilized over time, with cardio- and cerebral vascular disease (CVD) ranked first (35.6%), followed by extrahepatic malignancies (22.6%), infection (11.0%), kidney disease (7.5%), liver-related diseases (5.2%), respiratory diseases (3.9%), digestive diseases (3.5%), endocrine diseases (3.5%), and other diseases (7.2%). NAFLD patients had more deaths attributable to CVD, extrahepatic malignancies, liver-related diseases (all P < 0.001) and multiorgan failure than the deceased controls. The severity of steatosis was independently associated with these relationships (liver-related diseases: OR = 1.37, 95% CI: 1.20–1.59, cardio- and cerebrovascular diseases: OR = 1.23, 95% CI: 1.19–1.31, infectious diseases: OR = 1.14, 95% CI: 1.04–1.26, and renal diseases: OR = 1.21, 95% CI: 1.02–1.47, all P < 0.05) after adjustment for sex, body mass index (BMI), fasting blood glucose, low-density lipoprotein cholesterol, uric acid, metabolic syndromes and fibrosis index based on the 4 factors.Conclusion : NAFLD patients had higher proportions of death due to underlying CVD and liver-related diseases than the general population in China; these proportions positively correlated with steatosis degree.

Additional file 1. Supplemental Material.

Myeloid ecotropic viral integration site 1 (MEIS1) plays an essential role in the development of several embryonic organs, such as the central nervous system and eyes. To further investigate the role of MEIS1 in embryonic development, herein, we generated a MEIS1 homozygous knockout human embryonic stem cell (hESC) line using the CRISPR/Cas9 genome-editing technology. We believe that this cell line will be a good resource for exploring the function of the MEIS1 gene in embryonic development in vitro. Furthermore, the gene-knockout method reported in this study is efficient and labor-saving, which may provide an effective strategy for hESC gene deletion.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignant cancer with complex genomic variations, and no targetable genomic lesions have been found yet. Super‐enhancers (SEs) have been found to contribute to the continuous and robust oncogenic transcription. Here, histone H3 lysine 27 acetylation (H3K27ac) is profiled in PDAC cell lines to establish SE landscapes. Concurrently, it is also shown that PDAC is vulnerable to the perturbation of the SE complex using bromodomain‐containing protein 4 (BRD4) inhibitor, JQ1, synergized with cyclin‐dependent kinase 7 (CDK7) inhibitor, THZ1. Formulations of hydrophobic l‐phenylalanine‐poly (ester amide) nanoparticles (NPs) with high drug loading of JQ1 and THZ1 (J/T@8P4s) are further designed and developed. J/T@8P4s is assessed for size, encapsulation efficiency, morphology, drug release profiles, and drug uptake in vitro. Compared to conventional free drug formulation, the nanodelivery system dramatically reduces the hepatotoxicity while significantly enhancing the tumor inhibition effects and the bioavailability of incorporated JQ1 and THZ1 at equal doses in a Gemcitabine‐resistant PDAC patient‐derived xenograft (PDX) model. Overall, the present study demonstrates that the J/T@8P4s can be a promising therapeutic treatment against the PDAC via suppression of SE‐associated oncogenic transcription, and provides a strategy utilizing NPs to assist the drug delivery targeting SEs., The H3K27ac profile defines super‐enhancer (SE) landscapes in pancreatic ductal adenocarcinoma (PDAC). PDAC is vulnerable to the perturbation of the SE complex using JQ1 synergized with THZ1. Importantly, the nanodelivery system significantly enhances the tumor inhibition effects of combination therapy on a Gemcitabine‐resistant PDAC patient‐derived xenograft model.

Background Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer. The dismal outcome of ICC patients is due to lack of early diagnosis, the aggressive biological behavior of ICC and the lack of effective therapeutic options. Early diagnosis and prognosis of ICC by non-invasive methods would be helpful in providing valuable information and developing effective treatment strategies. Methods Expression of microfibrillar-associated protein 5 (MFAP5) in the serum of ICC patients was detected by ELISA. Human ICC specimens were immunostained by MFAP5 antibodies. The growth rate of human ICC cell lines treated with MFAP5 or MFAP5 shRNAs was examined by CCK8 and colony formation assays. Cell cycle analysis was performed with PI staining. The effect of MFAP5 inhibition was assessed by xenograft models in nude mice. RNA-seq and ATAC-seq analyses were used to dissect the molecular mechanism by which MFAP5 promoted ICC aggressiveness. Results We identified MFAP5 as a biomarker for the diagnosis and prognosis of ICC. Upregulated MFAP5 is a common feature in aggressive ICC patients’ tissues. Importantly, MFAP5 level in the serum of ICC patients and healthy individuals showed significant differential expression profiles. Furthermore, we showed that MFAP5 promoted ICC cell growth and G1 to S-phase transition. Using RNA-seq expression and ATAC-seq chromatin accessibility profiling of ICC cells with suppressed MFAP5 secretion, we showed that MFAP5 regulated the expression of genes involved in the Notch1 signaling pathway. Furthermore, FLI-06, a Notch signaling inhibitor, completely abolished the MFAP5-dependent transcriptional programs. Conclusions Raised MFAP5 serum level is useful for differentiating ICC patients from healthy individuals, and could be helpful in ICC diagnosis, prognosis and therapies.

Background: The liver effect of orlistat as a weight control treatment in patients with nonalcoholic fatty liver disease (NAFLD) with obesity remains undetermined. This study quantified liver fat improvement by orlistat in a Chinese cohort with NAFLD accompanied by obesity, diagnosed by a lower body mass index threshold than that for White patients. Materials and methods: We conducted a parallel-group, open-label, 24-week, randomized clinical trial registered at the Chinese Clinical Trial Registry (ChiCTR-IPR-17012258). Obese participants with NAFLD were randomized 1:1.5 to the intervention group with orlistat or conventional care. Liver fat quantification was assessed by magnetic resonance imaging-based proton density fat fraction with Dixon sequence. Results: Overall, 170 ( n = 68, orlistat 120 mg three times/day and n = 102, conventional therapy) and 130 patients with NAFLD ( n = 56, orlistat and n = 74, conventional therapy) were included for intention-to-treat (ITT) and per-protocol (PP) analysis, respectively. Orlistat reduced liver fat content to a greater degree than conventional care [−5.45% versus −1.96%, p Conclusions: Orlistat can effectively promote steatosis improvement and may serve as a treatment option for controlling NAFLD. Chinese Clinical Trial Registry identifier: ChiCTR-IPR-17012258

Gallbladder cancer (GBC) is one of the most common and aggressive biliary tract diseases with limited therapeutic strategies and poor prognosis. Various therapeutic agents have been demonstrated effective in preclinical models, but high dose requirement and toxicity to normal cells limit their clinical applications. Considering the high concentration of glutathione (GSH) in GBC, we developed a GSH-responsive nanoparticle (NP) system based on biodegradable poly(disulfide amide) (Cys-8E Polymer) for targeted delivery of a BRD4 inhibitor (JQ1), which is known as a promising therapeutic agent for GBC treatment. JQ1-loaded Cys-8E nanoparticles (JQ1@Cys-8E NPs) possessed a high JQ1 loading, preferable stability and redox-responsive release behavior. Additionally, the NPs showed good targeted delivery into GBC tumor spheroids and GBC patient-derived xenograft (PDX) tumors. Specifically, the intracellular GSH in tumors could trigger the release of JQ1, which induced the cell cycle arrest and apoptosis of GBC cells. RNA-sequencing analysis revealed that JQ1@Cys-8E NPs enhanced the effect of JQ1 through inhibiting NF-κB pathway. Importantly, JQ1@Cys-8E NPs significantly suppressed GBC tumor growth in the PDX model of early recurrence. No obvious systemic toxicity and organ damages were observed after treatment with JQ1@Cys-8E NPs. Our results demonstrate the promising therapeutic applications of JQ1@Cys-8E NPs for adjuvant therapy in GBC treatment.

The N6-methyladenosine (m(6)A) modification influences various mRNA metabolic events and tumorigenesis, however, its functions in nonsense-mediated mRNA decay (NMD) and whether NMD detects induced carcinogenesis pathways remain undefined. Here, we showed that the m(6)A methyltransferase METTL3 sustained its oncogenic role by modulating NMD of splicing factors and alternative splicing isoform switches in glioblastoma (GBM). MeRIP-seq analyses showed that m(6)A modification peaks were enriched at metabolic pathway-related transcripts in glioma stem cells (GSCs) compared with neural progenitor cells (NPCs). In addition, the clinical aggressiveness of malignant gliomas was associated with elevated expression of METTL3. Furthermore, silencing METTL3 or overexpressing dominant-negative mutant METTL3 suppressed the growth and self-renewal of GSCs. Integrated transcriptome and MeRIP-seq analyses revealed that downregulating the expression of METTL3 decreased m(6)A modification levels of serine- and arginine-rich splicing factors (SRSFs), which led to YTHDC1-dependent NMD of SRSFs transcripts and decreased SRSFs protein expression. Reduced expression of SRSFs led to larger changes in alternative splicing isoform switches. Importantly, the phenotypes mediated by METTL3 deficiency could be rescued by downregulating BCL-X or NCOR2 isoforms. Overall, these results establish a novel function of m(6)A in modulating NMD and uncover the mechanism by which METTL3 promotes GBM tumor growth and progression.

Background H3K27me3 modification inactivates gene transcription by resulting in condensed chromatin. However, the landscape and biological functions of H3K27me3 in breast cancer remain unclear. Methods Fluorescence enzyme assay was used to analyze the cell proliferation. Transwell assay was used to test the ability of migration and invasion in MDA-MB-231 cells with designed treatment. Transfection of exogenous plasmid was used to intervene specific gene expression. Nude mouse tumor xenograft model was employed to detect the effect of GSKJ-4 in vivo. ChIP-Seq analyzed the modification state of H3K27me3 around the TSS of the gene CEMIP. RNA-Seq was used to analyze the mRNA levels after treating with GSKJ-4 in MDA-MB-231 cells. Results Loss of H3K27me3 is specific for aggressive subtypes of breast cancer and may be a useful diagnostic marker. Epigenetic chemical screening identified histone H3K27me3 demethylation inhibition as a therapeutic strategy for triple-negative breast cancer (TNBC). Functional studies and RNA-seq/ChIP-seq data revealed that inactivation of the protein CEMIP (which is translated by oncogene KIAA1199) by increasing H3K27me3 leads to decreased tumor cell growth and migration. Moreover, survival analysis showed that CEMIP was associated with poor outcome in TNBC. Conclusions Our data suggest H3K27me3 loss as an important event in CEMIP mediated breast cancer carcinogenesis and progression. Loss of H3K27me3 is specific for aggressive subtypes of breast cancer and may be a useful diagnostic marker.