LSD1 Research Articles

Discovery of Novel 5-Cyano-3-phenylindole-Based LSD1/HDAC Dual Inhibitors for Colorectal Cancer Treatment.

The dual inhibition of histone lysine-specific demethylase 1 (LSD1) and histone deacetylase (HDAC) has emerged as a promising strategy for cancer therapy. In this study, we report the discovery of novel 5-cyano-3-phenylindole-based LSD1/HDAC dual inhibitors, evaluated through both in vitro and in vivo assays. Among these inhibitors, compound 20c was identified as particularly potent, exhibiting high inhibitory activity against LSD1 (IC50 = 39.0 nM) and HDAC1/2/3/6/8 (IC50 = 1.4, 1.0, 1.3, 2.9, and 16.0 nM, respectively). Compound 20c effectively modulated the expression of biomarkers associated with LSD1 and HDAC inhibition and demonstrated superior antiproliferative activity compared to SAHA and 4SC-202 across multiple colorectal cancer cell lines. Following pharmacokinetic studies, 20c was further assessed in HCT-116 and HT-29 xenograft mouse models. It demonstrated significantly enhanced antitumor efficacy compared to SAHA, without causing observable toxicity. These findings highlight the potential of LSD1/HDAC dual inhibitors for the treatment of malignant cancers.

LSD1 deficiency in breast cancer cells promotes the formation of pre-metastatic niches.

Lysine-specific demethylase 1 (LSD1), a histone demethylating enzyme, plays a crucial role in cancer metastasis. Studies show LSD1 knockout promotes breast cancer lung metastasis, but it's unknown if it alters the lung microenvironment for metastasis. In this study, we investigated the effects of exosomes from LSD1-knockdown (LSD1 KD) breast cancer cells on pre-metastatic niche formation. Injecting exosomes from LSD1 KD cells in mice resulted in a substantial increase in lung colonization by breast cancer cells, while treatment with exosomes derived from LSD1 KD cells decreased the expression of the ZO-1 and occludin, leading to increased vascular permeability. The LSD1 KD reduced the expression of circDOCK1, which augmented the levels of miR-1270 in exosomes. And miR-1270 inhibited ZO-1 expression in human endothelial cells, which enhanced their permeability. Our study uncovered a novel mechanism in which the LSD1 promotes the formation of pre-metastatic niches via the regulation of exosomal miRNA.

EXTH-44. ENHANCING THERAPEUTIC APPROACHES IN HIGH-GRADE GLIOMAS: SYNERGISTIC EFFECTS OF LSD1 AND KINASE INHIBITION

Abstract BACKGROUND Glioblastoma (GBM) and Diffuse Intrinsic Pontine Glioma (DIPG) are devastating high-grade gliomas (HGGs) with poor prognoses. Lysine-specific demethylase 1 (LSD1) is a promising therapeutic target and a key regulator in tumor initiation and recurrence. Crosstalk between LSD1 and other signaling pathways, such as the MAPK pathway, frequently hyperactivated in HGG, offers an opportunity to enhance the efficacy of LSD1 inhibitors. This study investigates the combined inhibition of LSD1 and kinase signaling to improve therapeutic outcomes in HGG. METHODS Transcriptional changes following LSD1 knockdown in human GBM cells were analyzed using RNA-seq and GSEA. RPPA and western blotting assessed the impact of LSD1 inhibition on kinase signaling. Pharmacological LSD1 inhibition was tested using NCD38 or bomedemstat in HGG models and normal human astrocytes (NHA). The effects of combining LSD1 inhibitors with kinase inhibitors (osimertinib, afatinib, and ulixertinib) on cell viability were evaluated. Combination treatment was also assessed in orthotopic xenograft models of GBM. RESULTS GSEA revealed LSD1 expression was enriched for gene sets involved in kinase signaling processes. Increased phosphorylated ERK1/2 levels were observed following NCD38 treatment in MDA-GSC17, as shown by RPPA and western blot analyses. The LSD1 inhibitor, NCD38, increased phospho-ERK1/2 levels (72% increase from baseline), while co-treatment with osimertinib mitigated this effect. Combined LSD1 and kinase inhibition (EGFR and ERK inhibition) showed synergistic effects in vitro in GBM and DIPG models but not in the NHA. DISCUSSION Our results demonstrate that kinase activity can be modulated by inhibiting LSD1, potentially leading to a resistant subpopulation. This study underscores the potential of combining LSD1 and kinase inhibition to enhance therapeutic efficacy in HGG, including GBM and DIPG. Future research will focus on elucidating the mechanisms by which LSD1 regulates kinase signaling, aiming to optimize combination therapies.

TMIC-36. EVALUATING PHARMACOLOGICAL INHIBITION OF LSD1 IN MODELS OF DIFFUSE MIDLINE GLIOMA AND EFFECTS ON IMMUNE MICROENVIRONMENT SIGNALING

Abstract BACKGROUND Diffuse midline glioma (DMG) is the leading cause of death for pediatric brain tumor patients. DMG is remarkably immunologically senescent, even in comparison to other “immune-cold” tumors like adult glioblastoma. Lysine specific demethylase-1 (LSD1) is a histone demethylase exerting context-specific mechanisms of gene repression and activation and can be inhibited pharmacologically. We found LSD1 regulates the expression of inflammatory cytokines such as Interleukin 18 (IL18) and immune signaling receptors in DMG. Here, we investigated whether IL18 is transcriptionally regulated by LSD1 in vitro and in vivo using clinically relevant small molecule inhibitors. METHODS LSD1 binding to the IL-18 promoter was evaluated using chromatin immunoprecipitation. Transcript and protein expression using qRT-PCR and western blotting assessed the impact of LSD1 inhibition on IL18-related pathways and immune signaling pathways. LSD1 inhibitors (IMG-7289 or GSKLSD1) were evaluated patient-derived xenograft models. Results. We found elevated LSD1 binding on the IL18 promoter in DIPG VI cells. Subsequent qRT-PCR and western blot analyses demonstrated increased IL18 protein levels following treatment with GSKLSD1 or IMG-7289 in DIPG VI cells, alongside heightened IL18 mRNA expression compared to DMSO-treated cells. Either GSKLSD1 or IMG-7289 treatment in DIPG IV cells also led to significantly elevated IL18 binding protein mRNA levels. Orthotopic xenografts using DIPG IV bearing mice dosed with LSD1 inhibitors over the course of 35 days several weeks showed a decrease in IL-18R, and an increase in IL-18 BP transcript levels alongside a significant increase in Slamf7 transcript levels. Some evidence of tumor inhibition was seen in male but not female mice treated with GSKLSD1. CONCLUSIONS Our investigation revealed IL18 as a direct target of LSD1 specifically in DIPG VI, and gender specific effects of GSKLSD1 treatment in vivo. Future studies will prioritize validating and elucidating the underlying mechanisms the therapeutic potential of LSD1 inhibition in DMG.

LSD1 Conditional Myeloid Cell Knockout Mice have Decreased Osteoclast Differentiation Due to Increased IFN-β Gene Expression

Abstract Osteoclasts are large multinucleated cells that degrade bone mineral and extracellular matrix. Investigating the epigenetic mechanisms orchestrating osteoclast differentiation is key to our understanding of the pathogenesis of skeletal related diseases such as periodontitis and osteoporosis. Lysine specific demethylase 1 (LSD1/KDM1A) is a member of the histone demethylase family that mediates the removal of mono- and dimethyl groups from H3K4 and H3K9 to elicit dichotomous effects on gene expression. Prior to our study, little was known about the contributions of LSD1 to skeletal development and osteoclast differentiation. Here we show that conditional deletion of Lsd1 within the myeloid lineage or macrophage/osteoclast precursors results in enhanced bone mass of male and female mice accompanied by diminished osteoclast size in vivo. Furthermore, Lsd1 deletion decreased osteoclast differentiation and activity within in vitro assays. Our bulk RNA-SEQ data suggests Lsd1 ablation in male and female mice inhibits osteoclast differentiation due to enhanced expression of IFN-β target genes. Lastly, we demonstrate that LSD1 forms an immune complex with HDAC1 and HDAC2. These data suggest that the combination of methylation and acetylation of histone residues, facilitated by LSD1, mechanistically promotes osteoclast gene expression.

ZNF480 Accelerates Chemotherapy Resistance in Breast Cancer by Competing With TRIM28 and Stabilizing LSD1 to Upregulate the AKT-GSK3β-Snail Pathway.

Zinc finger protein 480 (ZNF480) may interact with lysine-specific demethylase 1 (LSD1), which is highly expressed in many malignant tumors; however, ZNF480 expression has not previously been investigated in breast cancer. Therefore, we explored the expression and molecular mechanisms of ZNF480 in breast cancer. According to public databases and immunohistochemical staining analysis, ZNF480 is highly expressed in the tissue of patients with breast cancer, and ZNF480 expression is positively correlated with advanced TNM stage (p = 0.036), lymph node metastasis (p = 0.012), and poor prognosis (p = 0.005). ZNF480 overexpression enhances breast cancer cell proliferation, migration, and stemness by activating AKT-GSK3β-Snail signaling both in vitro and in vivo. Moreover, ZNF480 binds to LSD1 through its KRAB domain, thereby activating AKT signaling. Mass spectrometry and co-immunoprecipitation revealed that ZNF480 abrogates ubiquitination degradation and subsequently stabilizes LSD1 through competitive binding with TRIM28. Ipragliflozin was identified as a small-molecule inhibitor of ZNF480 and LSD1 interaction that may block breast cancer progression. Moreover, ZNF480 expression was significantly higher in treatment-resistant patients than in treatment-sensitive patients. Thus, ipragliflozin may neutralize neoadjuvant chemotherapy resistance induced by ZNF480 overexpression. Overall, elevated ZNF480 expression is positively associated with poor patient outcomes. Mechanistically, ZNF480 accelerates proliferation and neoadjuvant chemotherapy resistance in breast cancer cells via the AKT-GSK3β-Snail pathway by interacting with and stabilizing LSD1 in a competitive manner within TRIM28. This research has implications for developing targeted drugs against chemotherapy resistance in breast cancer.

Target Ligand Separation and Identification of Isoforsythiaside as a Histone Lysine-Specific Demethylase 1 Covalent Inhibitor Against Breast Cancer Metastasis.

Histone lysine-specific demethylase 1 (LSD1) is hyperactive in breast cancer, which is associated with the metastasis of the tumor. Current irreversible LSD1 inhibitors are all synthesized by covalently binding to the flavin adenine dinucleotide cofactor, which often have side effects due to the high affinity for a variety of targets. Here, we identified isoforsythiaside (IFA), a natural phenylpropanoid glycoside isolated from Forsythia suspensa, as a novel covalent inhibitor of LSD1. The target ligand fishing technique and LC-MS/MS analysis identified that IFA could covalently bind to the Ser817 residue of LSD1 by α,β-unsaturated ketone moiety to block the amine oxidase-like domain of LSD1. Moreover, RBMS3/Twist1/MMP2, the downstream signaling pathway of LSD1, was activated after IFA treatment to inhibit the metastasis of MDA-MB-231 cells in vitro and in vivo. This study provided novel molecular templates for development of LSD1 covalence-binding inhibitor and laid a foundation for developing agents against breast carcinoma metastasis for targeting LSD1.

Functional Hexafluoroisopropyl Group Used in the Construction of Biologically Important Pyrimidine Derivatives.

A series of versatile 4-((1,1,1,3,3,3-hexafluoropropan-2-yl)oxy)pyridine intermediates have been developed to efficiently produce biaryls, amines, ethers, and thioethers. These hydrolysis-stable ether intermediates exhibit reactivity toward electron-donating groups and nucleophiles in cross-coupling and nucleophilic substitution reactions while surpassing the stability of corresponding aryl halides. In comparison to conventional coupling methods, this protocol offers an alternative pathway for accessing natural product and drug-like compounds without the need for metal catalysts. With assistance of this approach, we successfully obtained a potent P-glycoprotein inhibitor 4k (YS-370), a potent epidermal growth factor receptor inhibitor 4l (YS-363), and a promising lysine-specific demethylase 1 inhibitor 5g.

Fumarate Restrains Alveolar Bone Restoration via Regulating H3K9 Methylation

Nonresolving inflammation causes irreversible damage to periodontal ligament stem cells (PDLSCs) and impedes alveolar bone restoration. The impaired tissue regeneration ability of stem cells is associated with abnormal mitochondrial metabolism. However, the impact of specific metabolic alterations on the differentiation process of PDLSCs remains to be understood. In this study, we found that inflammation altered the metabolic flux of the tricarboxylic acid cycle and induced the accumulation of fumarate through metabolic testing and metabolic flux analysis. Transcriptome sequencing revealed the potential of fumarate in modulating epigenetics. Specifically, histone methylation typically suppresses the expression of genes related to osteogenesis. Fumarate was found to impede the osteogenic differentiation of PDLSCs that exhibited high levels of H3K9me3. Various techniques, including assay for transposase-accessible chromatin with high-throughput sequencing, chromatin immunoprecipitation sequencing, and RNA sequencing, were used to identify the target genes regulated by H3K9me3. Mechanistically, accumulated fumarate inhibited lysine-specific demethylase 4B (KDM4B) activity and increased H3K9 methylation, thus silencing asporin gene transcription. Preventing fumarate from binding to the histone demethylase KDM4B with α-ketoglutarate effectively restored the impaired osteogenic capacity of PDLSCs and improved alveolar bone recovery. Collectively, our research has revealed the significant impact of accumulated fumarate on the regulation of osteogenesis in stem cells, suggesting that inhibiting fumarate production could be a viable therapeutic approach for treating periodontal diseases.

LMK235 ameliorates inflammation and fibrosis after myocardial infarction by inhibiting LSD1-related pathway

Background: Histone deacetylase 4 (HDAC4) and histone deacetylase 5 (HDAC5) are two isoforms of class IIa HDACs, and LMK235 is an HDAC inhibitor with higher selectivity for HDAC4/5. This study aimed to explore the expression and subcellular localization of HDAC4/5 and determine the mechanisms underlying the impact of LMK235 on ventricular remodelling post-MI. Methods: The MI model was established by left anterior descending branch (LAD) ligation, and LMK235 or vehicle was intraperitoneally injected daily for 21 days. Cardiac function was determined by echocardiography. Inflammation was evaluated by HE staining and measuring inflammatory cytokine expression, and fibrosis was evaluated by Masson staining and measuring fibrotic biomarker expression. Results: We found that LMK235 ameliorated cardiac dysfunction post-MI by suppressing inflammation and fibrosis, and LMK235 inhibited upregulation of lysine-specific demethylase 1 (LSD1) expression post-MI. In macrophages, LMK235 attenuated lipopolysaccharide (LPS) - induced inflammatory cytokine expression and inhibited LSD1 expression, while overexpression of LSD1 abrogated the anti-inflammatory effect of LMK235. In cardiac fibroblasts, LMK235 attenuated transforming growth factor-β1 (TGF-β1) - induced fibrotic biomarker expression and inhibited LSD1 expression, while overexpression of LSD1 abrogated the antifibrotic effect of LMK235. Conclusion: LMK235 attenuates chronic inflammation and fibrosis post-MI, leading to improved cardiac function. The anti-inflammatory effect of LMK235 may result from inhibition of the LSD1-NF-κB pathway in macrophages. The antifibrotic effect of LMK235 may result from inhibition of the LSD1-Smad2/3 pathway in cardiac fibroblasts.

A Genome-Wide Alternative Splicing Analysis of Gossypium arboreum and Gossypium raimondii During Fiber Development

Alternative splicing (AS) is a crucial post-transcriptional regulatory mechanism that contributes to proteome complexity and versatility in different plant species. However, detailed AS exploration in diploid cotton during fiber development has not been reported. In this study, we comparatively analyzed G. arboreum and G. raimondii AS events during fiber development using transcriptome data and identified 9690 and 7617 AS events that were distributed in 6483 and 4859 genes, respectively. G. arboreum had more AS genes and AS events than G. raimondii, and most AS genes were distributed at both ends of all 13 chromosomes in both diploid cotton species. Four major AS types, including IR, SE, A3SS, and A5SS, were all experimentally validated through RT-PCR assays. G. arboreum and G. raimondii had only 1888 AS genes in common, accounting for one-third and one-half of the total number of AS genes, respectively. Furthermore, we found a lysine-specific demethylase coding gene with a different AS mechanism in G. arboreum and G. raimondii, in which AS isoforms lacked part of a key conserved domain. Our findings may provide new directions for the discovery of functional genes involved in cotton species differentiation.

Application of Machine Learning Methods in Predicting Lysine-specific Histone Demethylase 1 (LSD1) Inhibitors

Background: Lysine-specific histone demethylase 1 (LSD1) is a well-known anti-cancer target for drug discovery. Novel reversible inhibitors of LSD1 are desirable to be developed. Objective: This study aimed to build reliable predictive models to evaluate the antineoplastic efficacy of compounds and reveal the structural foundation underlying the inhibitory activity of LSD1. Methods: Multiple artificial intelligence algorithms were utilized in the development of quantitative structure-activity relationship (QSAR) models. A dataset comprising 915 compounds with welldefined IC50 values against LSD1 was assembled for analysis. The structures of these compounds were described by different descriptor packages. Principal component analysis (PCA) was performed to explore the chemical space distribution of each dataset. Y-randomization test and applicability domain (AD) analysis were deployed to validate the reliability of models. Results: For regression models, a consensus model was constructed by integrating the predictions of four top-performing individual models (SVM_ECFP4, RFR_PyDescriptor, RFR_RDKIT, and TRANSNNI), resulting in enhanced predictive performance as compared to the individual models. The consensus model achieved a determination coefficient (r2, for the test set) value of 0.82. For classification models, the consensus model was derived from the amalgamation of three individual models (ASNN_RDKIT, ASNN_ECFP4, and RFR_ECFP4), and the overall prediction accuracy of the model was 0.96 for external validation. Conclusion: The reliable models could be used to identify highly active LSD1 inhibitors for the purpose of efficient virtual screening. In addition, the important molecular properties and structural fragments derived from this work can provide guidance for the structural optimization of novel LSD1 inhibitors.

KDM1A/LSD1 inhibition enhances chemotherapy response in ovarian cancer.

Ovarian cancer (OCa) is the deadliest of all gynecological cancers. The standard treatment for OCa is platinum-based chemotherapy, such as carboplatin or cisplatin in combination with paclitaxel. Most patients are initially responsive to these treatments; however, nearly 90% will develop recurrence and inevitably succumb to chemotherapy-resistant disease. Recent studies have revealed that the epigenetic modifier lysine-specific histone demethylase 1A (KDM1A/LSD1) is highly overexpressed in OCa. However, the role of KDM1A in chemoresistance and whether its inhibition enhances chemotherapy response in OCa remains uncertain. Analysis of TCGA datasets revealed that KDM1A expression is high in patients who poorly respond to chemotherapy. Western blot analysis show that treatment with chemotherapy drugs cisplatin, carboplatin, and paclitaxel increased KDM1A expression in OCa cells. KDM1A knockdown (KD) or treatment with KDM1A inhibitors NCD38 and SP2509 sensitized established and patient-derived OCa cells to chemotherapy drugs in reducing cell viability and clonogenic survival and inducing apoptosis. Moreover, knockdown of KDM1A sensitized carboplatin-resistant A2780-CP70 cells to carboplatin treatment and paclitaxel-resistant SKOV3-TR cells to paclitaxel. RNA-seq analysis revealed that a combination of KDM1A-KD and cisplatin treatment resulted in the downregulation of genes related to epithelial-mesenchymal transition (EMT). Interestingly, cisplatin treatment increased a subset of NF-κB pathway genes, and KDM1A-KD or KDM1A inhibition reversed this effect. Importantly, KDM1A-KD, in combination with cisplatin, significantly reduced tumor growth compared to a single treatment in an orthotopic intrabursal OCa xenograft model. Collectively, these findings suggest that combination of KDM1A inhibitors with chemotherapy could be a promising therapeutic approach for the treatment of OCa.

Critical Role of Lysine-Specific Histone Demethylase 1 in Kidney Inflammation and Fibrosis

Critical Role of Lysine-Specific Histone Demethylase 1 in Kidney Inflammation and Fibrosis

Lysine-Specific Demethylase 1A Is a Targetable Kidney Disease Causal Gene

Lysine-Specific Demethylase 1A Is a Targetable Kidney Disease Causal Gene

Discovery of 2-Aryl-4-aminoquinazolin-Based LSD1 Inhibitors to Activate Immune Response in Gastric Cancer.

LSD1 (histone lysine-specific demethylase 1) has been gradually disclosed to act as an immunomodulator to enhance antitumor immune response. Despite the identification of numerous potent LSD1 inhibitors, there remains a lack of LSD1 inhibitors approved for marketing. Novel LSD1 inhibitors with different mechanisms are therefore needed. Herein, we reported a series of novel quinazoline-based LSD1 inhibitors. Among them, compound Z-1 exhibited the best LSD1 inhibitory activity (IC50 = 0.108 μM). Z-1 also acted as a selective and cellular active as an LSD1 inhibitor. Furthermore, Z-1 promoted response of gastric cancer cells to T-cell killing effect by decreasing PD-L1 expression and further attenuated the PD-1/PD-L1 interaction. In vivo, Z-1 exhibited significant suppression effect on the growth of gastric cancer cells without obvious toxicity. Therefore, Z-1 represents a potential novel immunomodulator that targets LSD1, providing a lead compound with new function mechanism for gastric cancer treatment.

Decreased histone H3K9 dimethylation in synergy with DNA demethylation of Spi-1 binding site contributes to ADAMTS-5 expression in articular cartilage of osteoarthritis mice.

Osteoarthritis (OA) is defined by articular cartilage degeneration, synovial membrane inflammation, and abnormal bone remodeling. Recent study has discovered that OA development is linked to an aberrant epigenetic modification of OA-related genes. Our previous research showed that DNA demethylation in ADAMTS-5 promoter region had a substantial impact on ADAMTS-5 expression in the mouse OA model. This process facilitated the binding of Spi-1 to ADAMTS-5 promoter. While alterations in histone methylation have been documented during embryonic development and cancer development, there is a paucity of data on the change in OA pathogenesis. Even no data have been reported on the role of histone modifications in ADAMTS-5 activation in OA. Following our previous study on the role of DNA methylation, we aimed to examine the contribution of histone H3K9 dimethylation in ADAMTS-5 activation in OA. Additionally, we aimed to elucidate the molecular mechanisms underlying the cooperative interaction between DNA methylation and histone H3K9 dimethylation. The potential for anti-OA intervention therapy which is based on modulating histone H3K9 dimethylation is also explored. We demonstrated that a reduction in histone H3K9 dimethylation, along with DNA demethylation of the Spi-1 binding site, had a role in ADAMTS-5 activation in the articular cartilage of OA mice. Significantly, the conditional deletion of histone demethylase to be identified as lysine-specific demethylase 1 (LSD1) in articular cartilage could alleviate the degenerative features of OA mice. Our study demonstrates the direct impact of histone H3K9 dimethylation on gene expression, which in turn contributes to OA development. This research enhances our understanding of the underlying causes of OA.

USP1-mediated deubiquitination of KDM1A promotes the malignant progression of triple-negative breast cancer.

Previous research has indicated the highly expressed lysine-specific histone demethylase 1A (KDM1A) in several human malignancies, including triple-negative breast cancer (TNBC). However, its detailed mechanisms in TNBC development remain poorly understood. The mRNA levels of KDM1A and Yin Yang 1 (YY1) were determined by RT-qPCR analysis. Western blot was performed to measure KDM1A and ubiquitin-specific protease 1 (USP1) protein expression. Cell proliferation, apoptosis, invasion, migration and stemness were evaluated by MTT assay, EdU assay, flow cytometry, transwell invasion assay, wound-healing assay and sphere-formation assay, respectively. ChIP and dual-luciferase reporter assays were conducted to determine the relationship between YY1 and KDM1A. Xenograft tumor experiment and IHC were carried out to investigate the roles of USP1 and KDM1A in TNBC development in vivo. The highly expressed KDM1A was demonstrated in TNBC tissues and cells, and KDM1A knockdown significantly promoted cell apoptosis, and hampered cell proliferation, invasion, migration, and stemness in TNBC cells. USP1 could increase the stability of KDM1A via deubiquitination, and USP1 depletion restrained the progression of TNBC cells through decreasing KDM1A expression. Moreover, YY1 transcriptionally activated KDM1A expression by directly binding to its promoter in TNBC cells. Additionally, USP1 inhibition reduced KDM1A expression to suppress tumor growth in TNBC mice in vivo. In conclusion, YY1 upregulation increased KDM1A expression via transcriptional activation. USP1 stabilized KDM1A through deubiquitination to promote TNBC progression.

KDM4A promotes malignant progression of breast cancer by down-regulating BMP9 inducing consequent enhancement of glutamine metabolism

BackgroundRecent studies have found that histone-modified genes play an increasingly important role in tumor progression. Lysine(K) specific demethylase 4A (KDM4A) is a histone lysine-specific demethylase highly expressed in a variety of malignant tumors, data showed that KDM4A was negatively correlated with the Bone Morphogenetic Protein 9 (BMP9) in breast cancer. And previous experiments have demonstrated that exogenous BMP9 significantly inhibits breast cancer development.Materials and methodsWe detected the expression of KDM4A in breast cancer and the relationship between KDM4A and BMP9 using real-time quantitative PCR (RT-qPCR) and Western blot, and verified the interaction between KDM4A and BMP9 by ChIP experiments. At the same time, we also detected whether KDM4A had effects on the RNA and protein stability of BMP9 using actinomycin D and cycloheximide. Measurement of alpha-ketoglutarate (α-KG) level by ELISA to observe the effect of BMP9 on glutamine metabolism in breast cancer cells. Nucleoplasmic distribution of KDM4A after exogenous BMP9 treatment in breast cancer cells were observed by immunofluorescence staining and Western blot. A subcutaneous xenograft tumor model in nude mice was used to study the therapeutic effects of exogenous BMP9 and KDM4A inhibitor (JIB-04) in breast cancer. CCK-8, conoly formation, Transwell, wound healing, and immunohistochemistry were used to monitor the growth of tumor and cell function.ResultsWe found that KDM4A was abnormally highly expressed in breast cancer, and silenced BMP9 expression by removing histone methyl groups from the BMP9 gene region. Meanwhile, KDM4A could also reduce the stability of BMP9 protein. BMP9 inhibit glutamine metabolism in breast cancer, resulting in a decrease in its product α-KG, is confirmed by ELISA. Altered nucleoplasmic distribution of KDM4A due to decreased α-KG was confirmed by immunofluorescence staining and Western blot. Animal experiments confirm that the combination of exogenous BMP9 and JIB-04 shows significantly better results in breast cancer.ConclusionsKDM4A silences BMP9 expression by removing histone methyl groups from the BMP9 gene region, leading to further enhancement of glutamine metabolism, which contributes to malignant tumor progression. In addition, using JIB-04 in combination with exogenous BMP9 could inhibit the malignant progression of breast cancer cells and the growth of tumors more significantly.

PHF8/KDM7B: A Versatile Histone Demethylase and Epigenetic Modifier in Nervous System Disease and Cancers.

Many human diseases, such as malignant tumors and neurological diseases, have a complex pathophysiological etiology, often accompanied by aberrant epigenetic changes including various histone modifications. Plant homologous domain finger protein 8 (PHF8), also known as lysine-specific demethylase 7B (KDM7B), is a critical histone lysine demethylase (KDM) playing an important role in epigenetic modification. Characterized by the zinc finger plant homology domain (PHD) and the Jumonji C (JmjC) domain, PHF8 preferentially binds to H3K4me3 and erases repressive methyl marks, including H3K9me1/2, H3K27me1, and H4K20me1. PHF8 is indispensable for developmental processes and the loss of PHF8 enzyme activity is linked to neurodevelopmental disorders. Moreover, increasing evidence shows that PHF8 is highly expressed in multiple tumors as an oncogenic factor. These findings indicate that studying the role of PHF8 will facilitate the development of novel therapeutic agents by the manipulation of PHF8 demethylation activity. Herein, we summarize the current knowledge of PHF8 about its structure and demethylation activity and its involvement in development and human diseases, with an emphasis on nervous system disorders and cancer. This review will update our understanding of PHF8 and promote the clinical transformation of its predictive and therapeutic value.