The role of NSD1, NSD2, and NSD3 histone methyltransferases in solid tumors

Novel dual-targeting inhibitors of NSD2 and HDAC2 for the treatment of liver cancer: structure-based virtual screening, molecular dynamics simulation, and in vitro and in vivo biological activity evaluations

Liver cancer exhibits a high degree of heterogeneity and involves intricate mechanisms. Recent research has revealed the significant role of histone lysine methylation and acetylation in the epigenetic regulation of liver cancer development. In this study, five inhibitors capable of targeting both histone lysine methyltransferase nuclear receptor-binding SET domain 2 (NSD2) and histone deacetylase 2 (HDAC2) were identified using a structure-based virtual screening approach. Notably, DT-NH-1 displayed a potent inhibition of NSD2 (IC50 = 0.08 ± 0.03 μM) and HDAC2 (IC50 = 5.24 ± 0.87 nM). DT-NH-1 also demonstrated a strong anti-proliferative activity against various liver cancer cell lines, particularly HepG2 cells, and exhibited a high level of biological safety. In an experimental xenograft model involving HepG2 cells, DT-NH-1 showed a significant reduction in tumour growth. Consequently, these findings indicate that DT-NH-1 will be a promising lead compound for the treatment of liver cancer with epigenetic dual-target inhibitors.

Multilevel Regulation of NF-κB Signaling by NSD2 Suppresses Kras-Driven Pancreatic Tumorigenesis

Pancreatic ductal adenocarcinoma (PDAC) is a clinically challenging cancer with a dismal overall prognosis. NSD2 is an H3K36-specific di-methyltransferase that has been reported to play a crucial role in promoting tumorigenesis. Here, the study demonstrates that NSD2 acts as a putative tumor suppressor in Kras-driven pancreatic tumorigenesis. NSD2 restrains the mice from inflammation and Kras-induced ductal metaplasia, while NSD2 loss facilitates pancreatic tumorigenesis. Mechanistically, NSD2-mediated H3K36me2 promotes the expression of IκBα, which inhibits the phosphorylation of p65 and NF-κB nuclear translocation. More importantly, NSD2 interacts with the DNA binding domain of p65, attenuating NF-κB transcriptional activity. Furthermore, inhibition of NF-κB signaling relieves the symptoms of Nsd2-deficient mice and sensitizes Nsd2-null PDAC to gemcitabine. Clinically, NSD2 expression decreased in PDAC patients and negatively correlated to nuclear p65 expression. Together, the study reveals the important tumor suppressor role of NSD2 and multiple mechanisms by which NSD2 suppresses both p65 phosphorylation and downstream transcriptional activity during pancreatic tumorigenesis. This study opens therapeutic opportunities for PDAC patients with NSD2 low/loss by combined treatment with gemcitabine and NF-κBi.

Circ-FOXO3 inhibits triple-negative breast cancer growth and metastasis via regulating WHSC1-H3K36me2-Zeb2 axis

Circular RNAs (circRNAs), a subclass of non-coding RNAs characterized by covalently closed continuous loops, play a key role in tumorigenesis and aggressiveness. However, the potential molecular mechanism of circRNAs in triple-negative breast cancer (TNBC) remains largely unknown. Exploring their roles and mechanisms in TNBC progression may help identify new diagnostic markers and therapeutic targets. In this study, we found that circ-FOXO3 was dramatically downregulated in TNBC tissues and blood samples from patients with TNBC. Notably, low circ-FOXO3 expression in TNBC tissues and bloods was associated with lymph node metastasis and unfavorable outcomes in patients with TNBC. Overexpression of circ-FOXO3 significantly inhibited the growth, invasion, and metastasis of TNBC cells both in vitro and in vivo. Moreover, we demonstrated that circ-FOXO3 was predominantly expressed in the cytoplasm and directly interacted with Wolf-Hirschhorn syndrome candidate 1 (WHSC1), thereby inhibiting WHSC1 nuclear localization and activity, resulting in the inhibition of H3K36me2 modifications at the Zeb2 promoter, ultimately inhibiting Zeb2 expression and halting TNBC growth and metastasis. Taken together, these results reveal the tumor-suppressive functions of circ-FOXO3 in inhibiting WHSC1-mediated H3K36me2 modification of Zeb2, suggesting that circ-FOXO3 could serve as a potential novel predictive prognostic biomarker and therapeutic target for TNBC.

NSD family proteins: Rising stars as therapeutic targets

Epigenetic modifications, including DNA methylation and histone post-translational modifications, intricately regulate gene expression patterns by influencing DNA accessibility and chromatin structure in higher organisms. These modifications are heritable, are independent of primary DNA sequences, undergo dynamic changes during development and differentiation, and are frequently disrupted in human diseases. The reversibility of epigenetic modifications makes them promising targets for therapeutic intervention and drugs targeting epigenetic regulators (e.g., tazemetostat, targeting the H3K27 methyltransferase EZH2) have been applied in clinical therapy for multiple cancers. The NSD family of H3K36 methyltransferase enzymes-including NSD1 (KMT3B), NSD2 (MMSET/WHSC1), and NSD3 (WHSC1L1)-are now receiving drug development attention, with the exciting advent of an NSD2 inhibitor (KTX-1001) advancing to Phase I clinical trials for relapsed or refractory multiple myeloma. NSD proteins recognize and catalyze methylation of histone lysine marks, thereby regulating chromatin integrity and gene expression. Multiple studies have implicated NSD proteins in human disease, noting impacts from translocations, aberrant expression, and various dysfunctional somatic mutations. Here, we review the biological functions of NSD proteins, epigenetic cooperation related to NSD proteins, and the accumulating evidence linking these proteins to developmental disorders and tumorigenesis, while additionally considering prospects for the development of innovative epigenetic therapies.

Approach to High-Risk Multiple Myeloma

Improving the outcome of high-risk myeloma (HRMM) is a key therapeutic aim for the next decade. To achieve this aim, it is necessary to understand in detail the genetic drivers underlying this clinical behavior and to target its biology therapeutically. Advances have already been made, with a focus on consensus guidance and the application of novel immunotherapeutic approaches. Cases of HRMM are likely to have impaired prognosis even with novel strategies. However, if disease eradication and minimal disease states are achieved, then cure may be possible.

Decreased NSD2 impairs stromal cell proliferation in human endometrium via reprogramming H3K36me2

In brief

The proliferation of the endometrium is regulated by histone methylation. This study shows that decreased NSD2 impairs proliferative-phase endometrial stromal cell proliferation in patients with recurrent implantation failure via epigenetic reprogramming of H3K36me2 methylation on the promoter region of MCM7.

Abstract

Recurrent implantation failure (RIF) is a formidable challenge in assisted reproductive technology because of its unclear molecular mechanism. Impaired human endometrial stromal cell (HESC) proliferation disrupts the rhythm of the menstrual cycle, resulting in devastating disorders between the embryo and the endometrium. The molecular function of histone methylation enzymes in modulating HESC proliferation remains largely uncharacterized. Herein, we found that the levels of histone methyltransferase nuclear receptor binding SET domain protein 2 (NSD2) and the dimethylation of lysine 36 on histone H3 are decreased significantly in the proliferative-phase endometrium of patients with RIF. Knockdown of NSD2 in an HESC cell line markedly impaired cell proliferation and globally reduced H3K36me2 binding to chromatin, leading to altered expression of many genes. Transcriptomic analyses revealed that cell cycle-related gene sets were downregulated in the endometrium of patients with RIF and in NSD2‑knockdown HESCs. Furthermore, RNA-sequencing and CUT&Tag sequencing analysis suggested that NSD2 knockdown reduced the binding of H3K36me2 to the promoter region of cell cycle marker gene MCM7 (encoding minichromosome maintenance complex component 7) and downregulated its expression. The interaction of H3K36me2 with the MCM7 promoter was verified using chromatin immunoprecipitation-quantitative real-time PCR. Our results demonstrated a unifying epigenome-scale mechanism by which decreased NSD2 impairs endometrial stromal cell proliferation in the proliferative-phase endometrium of patients with RIF.

Conditional knockout of the NSD2 gene in mouse intestinal epithelial cells inhibits colorectal cancer progression

BACKGROUND

Nuclear receptor-binding SET domain 2 (NSD2) is a histone methyltransferase, that catalyzes dimethylation of lysine 36 of histone 3 (H3K36me2) and is associated with active transcription of a series of genes. NSD2 is overexpressed in multiple types of solid human tumors and has been proven to be related to unfavorable prognosis in several types of tumors.

METHODS

We established a mouse model in which the NSD2 gene was conditionally knocked out in intestinal epithelial cells. We used azoxymethane and dextran sodium sulfate to chemically induce murine colorectal cancer. The development of colorectal tumors were investigated using post-necropsy quantification, immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared with wild-type (WT) control mice, NSD2fl/fl -Vil1-Cre mice exhibited significantly decreased tumor numbers, histopathological changes, and cytokine expression in colorectal tumors.

CONCLUSIONS

Conditional knockout of NSD2 in intestinal epithelial cells significantly inhibits colorectal cancer progression.

NSD1 supports cell growth and regulates autophagy in HPV-negative head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Despite advances in therapeutic management and immunotherapy, the 5-year survival rate for head and neck cancer remains at ~66% of all diagnosed cases. A better definition of drivers of HPV-negative HNSCC that are targetable points of tumor vulnerability could lead to significant clinical advances. NSD1 is a histone methyltransferase that catalyzes histone H3 lysine 36 di-methylation (H3K36me2); mutations inactivating NSD1 have been linked to improved outcomes in HNSCC. In this study, we show that NSD1 induces H3K36me2 levels in HNSCC and that the depletion of NSD1 reduces HNSCC of cell growth in vitro and in vivo. We also find that NSD1 strongly promotes activation of the Akt/mTORC1 signaling pathway. NSD1 depletion in HNSCC induces an autophagic gene program activation, causes accumulation of the p62 and LC3B-II proteins, and decreases the autophagic signaling protein ULK1 at both protein and mRNA levels. Reflecting these signaling defects, the knockdown of NSD1 disrupts autophagic flux in HNSCC cells. Taken together, these data identify positive regulation of Akt/mTORC1 signaling and autophagy as novel NSD1 functions in HNSCC, suggesting that NSD1 may be of value as a therapeutic target in this cancer.

NSD2 modulates Drp1-mediated mitochondrial fission in chronic renal allograft interstitial fibrosis by methylating STAT1

Renal interstitial fibrosis/tubular atrophy (IF/TA) is a prominent pathological feature of chronic allograft dysfunction (CAD). Our previous study has demonstrated that epithelial-mesenchymal transition (EMT) plays a significant role in shaping the development of IF/TA. Nuclear SET domain (NSD2), a histone methyltransferase catalyzing methylation at lysine 36 of histone 3, is crucially involved in the development and progression of solid tumors. But its role in the development of renal allograft interstitial fibrosis has yet to be elucidated. Here, we characterize NSD2 as a crucial mediator in the mouse renal transplantation model in vivo and a model of tumor necrosis factor-α (TNF-α) stimulated-human renal tubular epithelial cells (HK-2) in vitro. Functionally, NSD2 knockdown inhibits EMT, dynamin-related protein 1 (Drp1)-mediated mitochondrial fission in mice. Conversely, NSD2 overexpression exacerbates fibrosis-associated phenotypes and mitochondrial fission in tubular cells. Mechanistically, tubular NSD2 aggravated the Drp-1 mediated mitochondrial fission via STAT1/ERK/PI3K/Akt signaling pathway in TNF-α-induced epithelial cell models. Momentously, mass spectrometry (MS) Analysis and site-directed mutagenesis assays revealed that NSD2 interacted with and induced Mono-methylation of STAT1 on K173, leading to its phosphorylation, IMB1-dependent nuclear translocation and subsequent influence on TNF-α-induced EMT and mitochondrial fission in NSD2-dependent manner. Collectively, these findings shed light on the mechanisms and suggest that targeting NSD2 could be a promising therapeutic approach to enhance tubular cell survival and alleviate interstitial fibrosis in renal allografts during CAD.

N6-methyladenosine methylation in kidney injury

Multiple mechanisms are involved in kidney damage, among which the role of epigenetic modifications in the occurrence and development of kidney diseases is constantly being revealed. However, N6-methyladenosine (M6A), a well-known post-transcriptional modification, has been regarded as the most prevalent epigenetic modifications in higher eukaryotic, which is involved in various biological processes of cells such as maintaining the stability of mRNA. The role of M6A modification in the mechanism of kidney damage has attracted widespread attention. In this review, we mainly summarize the role of M6A modification in the progression of kidney diseases from the following aspects: the regulatory pattern of N6-methyladenosine, the critical roles of N6-methyladenosine in chronic kidney disease, acute kidney injury and renal cell carcinoma, and then reveal its potential significance in the diagnosis and treatment of various kidney diseases. A better understanding of this field will be helpful for future research and clinical treatment of kidney diseases.

NSD1 supports cell growth and regulates autophagy in HPV-negative head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Despite advances in therapeutic management and immunotherapy, the five-year survival rate for head and neck cancer remains at ~66% of all diagnosed cases. A better definition of drivers of HPV-negative HNSCC that are targetable points of tumor vulnerability could lead to significant clinical advances. NSD1 is a histone methyltransferase which catalyzes histone H3 lysine 36 di-methylation (H3K36me2); mutations inactivating NSD1 have been linked to improved outcomes in HNSCC. In this study, we show that NSD1 induces H3K36me2 levels in HNSCC, and that the depletion of NSD1 reduces HNSCC of cell growth in vitro and in vivo. We also find that NSD1 strongly promotes activation of the Akt/mTORC1 signaling pathway. NSD1 depletion in HNSCC induces an autophagic gene program activation, causes accumulation of the p62 and LC3B-II proteins, and decreases the autophagic signaling protein ULK1 at both protein and mRNA levels. Reflecting these signaling defects, knockdown of NSD1 disrupts autophagic flux in HNSCC cells. Taken together, these data identify positive regulation of Akt/mTORC1 signaling and autophagy as novel NSD1 functions in HNSCC, suggesting that NSD1 may be of value as a therapeutic target in this cancer.

Drug Discovery Targeting Nuclear Receptor Binding SET Domain Protein 2 (NSD2)

Nuclear receptor binding SET domain proteins (NSDs) catalyze the mono- or dimethylation of histone 3 lysine 36 (H3K36me1 and H3K36me2), using S-adenosyl-l-methionine (SAM) as a methyl donor. As a key member of the NSD family of proteins, NSD2 plays an important role in the pathogenesis and progression of various diseases such as cancers, inflammations, and infectious diseases, serving as a promising drug target. Developing potent and specific NSD2 inhibitors may provide potential novel therapeutics. Several NSD2 inhibitors and degraders have been discovered while remaining in the early stage of drug development. Excitingly, KTX-1001, a selective NSD2 inhibitor, has entered clinical trials. In this Perspective, the structures and functions of NSD2, its roles in various human diseases, and the recent advances in drug discovery strategies targeting NSD2 have been summarized. The challenges, opportunities, and future directions for developing NSD2 inhibitors and degraders are also discussed.

2-Aminobenzothiazoles in anticancer drug design and discovery

Cancer is one of the major causes of mortality and morbidity worldwide. Substantial research efforts have been made to develop new chemical entities with improved anticancer efficacy. 2-Aminobenzothiazole is an important class of heterocycles containing one sulfur and two nitrogen atoms, which is associated with a broad spectrum of medical and pharmacological activities, including antitumor, antibacterial, antimalarial, anti-inflammatory, and antiviral activities. In recent years, an extraordinary collection of potent and low-toxicity 2-aminobenzothiazole compounds have been discovered as new anticancer agents. Herein, we provide a comprehensive review of this class of compounds based on their activities against tumor-related proteins, including tyrosine kinases (CSF1R, EGFR, VEGFR-2, FAK, and MET), serine/threonine kinases (Aurora, CDK, CK, RAF, and DYRK2), PI3K kinase, BCL-XL, HSP90, mutant p53 protein, DNA topoisomerase, HDAC, NSD1, LSD1, FTO, mPGES-1, SCD, hCA IX/XII, and CXCR. In addition, the anticancer potentials of 2-aminobenzothiazole-derived chelators and metal complexes are also described here. Moreover, the design strategies, mechanism of actions, structure-activity relationships (SAR) and more advanced stages of pre-clinical development of 2-aminobenzothiazoles as new anticancer agents are extensively reviewed in this article. Finally, the examples that 2-aminobenzothiazoles showcase an advantage over other heterocyclic systems are also highlighted.

NSD3: Advances in cancer therapeutic potential and inhibitors research

Nuclear receptor-binding SET domain 3, otherwise known as NSD3, is a member of the group of lysine methyltransferases and is involved in a variety of cellular processes, including transcriptional regulation, DNA damage repair, non-histone related functions and several others. NSD3 gene is mutated or loss of function in a variety of cancers, including breast, lung, pancreatic, and osteosarcoma. These mutations produce dysfunction of the corresponding tumor tissue proteins, leading to tumorigenesis, progression, chemoresistance, and unfavorable prognosis, which suggests that the development of NSD3 probe molecules is important for understanding the specific role of NSD3 in disease and drug discovery. In recent years, NSD3 has been increasingly reported, demonstrating that this target is a very hot epigenetic target. However, the number of NSD3 inhibitors available for cancer therapy is limited and none of the drugs that target NSD3 are currently available on the market. In addition, there are very few reviews describing NSD3. Within this review, we highlight the role of NSD3 in tumorigenesis and the development of NSD3 targeted small-molecule inhibitors over the last decade. We hope that this publication can serve as a guide for the development of potential drug candidates for various diseases in the field of epigenetics, especially for the NSD3 target.

Characterizing crosstalk in epigenetic signaling to understand disease physiology

Epigenetics, the inheritance of genomic information independent of DNA sequence, controls the interpretation of extracellular and intracellular signals in cell homeostasis, proliferation and differentiation. On the chromatin level, signal transduction leads to changes in epigenetic marks, such as histone post-translational modifications (PTMs), DNA methylation and chromatin accessibility to regulate gene expression. Crosstalk between different epigenetic mechanisms, such as that between histone PTMs and DNA methylation, leads to an intricate network of chromatin-binding proteins where pre-existing epigenetic marks promote or inhibit the writing of new marks. The recent technical advances in mass spectrometry (MS) -based proteomic methods and in genome-wide DNA sequencing approaches have broadened our understanding of epigenetic networks greatly. However, further development and wider application of these methods is vital in developing treatments for disorders and pathologies that are driven by epigenetic dysregulation.

Epigenetic (De)regulation in Prostate Cancer

Prostate cancer (PCa) is a heterogeneous disease exhibiting both genetic and epigenetic deregulations. Epigenetic alterations are defined as changes not based on DNA sequence, which include those of DNA methylation, histone modification, and chromatin remodeling. Androgen receptor (AR) is the main driver for PCa and androgen deprivation therapy (ADT) remains a backbone treatment for patients with PCa; however, ADT resistance almost inevitably occurs and advanced diseases develop termed castration-resistant PCa (CRPC), due to both genetic and epigenetic changes. Due to the reversible nature of epigenetic modifications, inhibitors targeting epigenetic factors have become promising anti-cancer agents. In this chapter, we focus on recent studies about the dysregulation of epigenetic regulators crucially involved in the initiation, development, and progression of PCa and discuss the potential use of inhibitors targeting epigenetic modifiers for treatment of advanced PCa.