Elevated expression of nuclear receptor-binding SET domain 3 promotes pancreatic cancer cell growth

NSD3: A Promising Target for Cancer Therapy

Over the past 24 years, nuclear receptor-binding SET domain protein 3 (NSD3) has emerged as a critical regulator of cellular physiological processes. As a histone methyltransferase targeting H3K36, NSD3 catalyzes the addition of methyl groups to histone residues, a process that profoundly influences genome imprinting, gene transcription, and genome stability, thereby modulating gene expression. Amplification, mutations, and fusion events involving the NSD3 gene have been strongly linked to the pathogenesis of various cancers, highlighting its role as a key regulator of tumorigenesis. This review provides an overview of the general structure and biological functions of NSD3, followed by an analysis of NSD3's role in relation to the hallmarks of cancer as described by Hanahan and Weinberg. Targeting NSD3 has become a major focus of research, with significant efforts directed toward the development and clinical application of NSD3 inhibitors. However, challenges related to specificity and selectivity have hindered progress in this area. Despite these obstacles, the successful development and clinical advancement of other histone methyltransferase inhibitors have provided encouragement to researchers, driving the active pursuit of NSD3-targeted therapies for cancer treatment.

Histones Methyltransferase NSD3 Inhibits Lung Adenocarcinoma Glycolysis Through Interacting with PPP1CB to Decrease STAT3 Signaling Pathway

Histones methyltransferase NSD3 targeting H3K36 is frequently disordered and mutant in various cancers, while the function of NSD3 during cancer initiation and progression remains unclear. In this study, it is proved that downregulated level of NSD3 is linked to clinical features and poor survival in lung adenocarcinoma. In vivo, NSD3 inhibited the proliferation, immigration, and invasion ability of lung adenocarcinoma. Meanwhile, NSD3 suppressed glycolysis by inhibiting HK2 translation, transcription, glucose uptake, and lactate production in lung adenocarcinoma. Mechanistically, as an intermediary, NSD3 binds to PPP1CB and p-STAT3 in protein levels, thus forming a trimer to dephosphorylate the level of p-STAT3 by PPP1CB, leading to the suppression of HK2 transcription. Interestingly, the phosphorylation function of PPP1CB is related to the concentration of carbon dioxide and pH value in the culture environment. Together, this study revealed the critical non-epigenetic role of NSD3 in the regulation of STAT3-dependent glycolysis, providing a piece of compelling evidence for targeting the NSD3/PPP1CB/p-STAT3 in lung adenocarcinoma.

Identification of Gαi3 as a promising molecular oncotarget of pancreatic cancer

The increasing mortality rate of pancreatic cancer globally necessitates the urgent identification for novel therapeutic targets. This study investigated the expression, functions, and mechanistic insight of G protein inhibitory subunit 3 (Gαi3) in pancreatic cancer. Bioinformatics analyses reveal that Gαi3 is overexpressed in human pancreatic cancer, correlating with poor prognosis, higher tumor grade, and advanced classification. Elevated Gαi3 levels are also confirmed in human pancreatic cancer tissues and primary/immortalized cancer cells. Gαi3 shRNA or knockout (KO) significantly reduced cell viability, proliferation, cell cycle progression, and mobility in primary/immortalized pancreatic cancer cells. Conversely, Gαi3 overexpression enhanced pancreatic cancer cell growth. RNA-sequencing and bioinformatics analyses of Gαi3-depleted cells indicated Gαi3's role in modulating the Akt-mTOR and PKA-Hippo-YAP pathways. Akt-S6 phosphorylation was decreased in Gαi3-depleted cells, but was increased with Gαi3 overexpression. Additionally, Gαi3 depletion elevated PKA activity and activated the Hippo pathway kinase LATS1/2, leading to YAP/TAZ inactivation, while Gαi3 overexpression exerted the opposite effects. There is an increased binding between Gαi3 promoter and the transcription factor TCF7L2 in pancreatic cancer tissues and cells. Gαi3 expression was significantly decreased following TCF7L2 silencing, but increased with TCF7L2 overexpression. In vivo, intratumoral injection of Gαi3 shRNA-expressing adeno-associated virus significantly inhibited subcutaneous pancreatic cancer xenografts growth in nude mice. A significant growth reduction was also observed in xenografts from Gαi3 knockout pancreatic cancer cells. Akt-mTOR inactivation and increased PKA activity coupled with YAP/TAZ inactivation were also detected in xenograft tumors upon Gαi3 depletion. Furthermore, bioinformatic analysis and multiplex immunohistochemistry (mIHC) staining on pancreatic cancer tissue microarrays showed a reduced proportion of M1-type macrophages and an increase in PD-L1 positive cells in Gαi3-high pancreatic cancer tissues. Collectively, these findings highlight Gαi3's critical role in promoting pancreatic cancer cell growth, potentially through the modulation of the Akt-mTOR and PKA-Hippo-YAP pathways and its influence on the immune landscape.

Recent advances in targeting histone H3 lysine 36 methyltransferases for cancer therapy

Histone H3 lysine 36 (H3K36) methylation is a typical epigenetic histone modification that is involved in various biological processes such as DNA transcription, repair and recombination in vivo. Mutations, translocations, and aberrant gene expression associated with H3K36 methyltransferases have been implicated in different malignancies such as acute myeloid leukemia, lung cancer, multiple myeloma, and others. Herein, we provided a comprehensive overview of the latest advances in small molecule inhibitors targeting H3K36 methyltransferases. We analyzed the structures and biological functions of the H3K36 methyltransferases family members. Additionally, we discussed the potential directions for future development of inhibitors targeting H3K36 methyltransferases.

Discovery of potent small molecule inhibitors of histone lysine methyltransferase NSDs

Nuclear receptor binding SET domain (NSD) proteins are a class of histone lysine methyltransferases and implicated in multiple cancer types with aberrant expression and involvement of cancer related signaling pathways. In this study, a series of small-molecule compounds including compound 2 and 3 are identified against the SET domain of NSDs through structure-based virtual screening. Our lead compound 3 exhibits potent inhibitory activities in vitro towards the NSD2-SET and NSD3-SET with an IC50 of 0.81 μM and 0.84 μM, respectively, and efficiently inhibits histone H3 lysine 36 dimethylation and decreases the expression of NSDs-targeted genes in non-small cell lung cancer cells at 100 nM. Compound 3 suppresses cell proliferation and reduces the clonogenicity in H460 and H1299 non-small cell lung cancer cells, and induces s-phase cell cycle arrest and apoptosis. These data establish our compounds as a valuable tool-kit for the study of the biological roles of NSDs in cancer.

NSD3 in Cancer: Unraveling Methyltransferase-Dependent and Isoform-Specific Functions

NSD3 (nuclear receptor-binding SET domain protein 3) is a member of the NSD histone methyltransferase family of proteins. In recent years, it has been identified as a potential oncogene in certain types of cancer. The NSD3 gene encodes three isoforms, the long version (NSD3L), a short version (NSD3S) and the WHISTLE isoforms. Importantly, the NSD3S isoform corresponds to the N-terminal region of the full-length protein, lacking the methyltransferase domain. The chromosomal location of NSD3 is frequently amplified across cancer types, such as breast, lung, and colon, among others. Recently, this amplification has been correlated to a chromothripsis event, that could explain the different NSD3 alterations found in cancer. The fusion proteins containing NSD3 have also been reported in leukemia (NSD3-NUP98), and in NUT (nuclear protein of the testis) midline carcinoma (NSD3-NUT). Its role as an oncogene has been described by modulating different cancer pathways through its methyltransferase activity, or the short isoform of the protein, through protein interactions. Specifically, in this review we will focus on the functions that have been characterized as methyltransferase dependent, and those that have been correlated with the expression of the NSD3S isoform. There is evidence that both the NSD3L and NSD3S isoforms are relevant for cancer progression, establishing NSD3 as a therapeutic target. However, further functional studies are needed to differentiate NSD3 oncogenic activity as dependent or independent of the catalytic domain of the protein, as well as the contribution of each isoform and its clinical significance in cancer progression.

Systematic perturbations of SETD2, NSD1, NSD2, NSD3 and ASH1L reveals their distinct contributions to H3K36 methylation

Background

Methylation of histone 3 lysine 36 (H3K36me) has emerged as an essential epigenetic component for the faithful regulation of gene expression. Despite its importance in development, disease, and cancer, how the molecular agents collectively shape the H3K36me landscape is unclear.

Results

We use a mouse mesenchymal stem cell model to perturb the H3K36me deposition machinery and infer the activities of the five most prominent players: SETD2, NSD1, NSD2, NSD3, and ASH1L. We find that H3K36me2 is the most abundant of the three methylation states and is predominantly deposited at intergenic regions by NSD1, and partly by NSD2. In contrast, H3K36me1/3 are most abundant within exons and are positively correlated with gene expression. We demonstrate that while SETD2 deposits most H3K36me3, it also deposits H3K36me2 within transcribed genes. Additionally, loss of SETD2 results in an increase of exonic H3K36me1, suggesting other H3K36 methyltransferases (K36MTs) prime gene bodies with lower methylation states ahead of transcription. Through a reductive approach, we uncover the distribution patterns of NSD3- and ASH1L-catalyzed H3K36me2. While NSD1/2 establish broad intergenic H3K36me2 domains, NSD3 deposits H3K36me2 peaks on active promoters and enhancers. Meanwhile, the activity of ASH1L is restricted to the regulatory elements of developmentally relevant genes, and our analyses implicate PBX2 as a potential recruitment factor.

Conclusions

Within genes, SETD2 deposits both H3K36me2/3, while the other K36MTs are capable of depositing H3K36me1/2 independently of SETD2 activity. For the deposition of H3K36me1/2, we find a hierarchy of K36MT activities where NSD1>NSD2>NSD3>ASH1L. While NSD1 and NSD2 are responsible for most genome-wide propagation of H3K36me2, the activities of NSD3 and ASH1L are confined to active regulatory elements.

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.

Prospect of targeting lysine methyltransferase NSD3 for tumor therapy

Nuclear receptor binding SET domain protein 3 (NSD3) has recently been recognized as a new epigenetic target in the fight against cancer. NSD3, which is amplified, overexpressed or mutated in a variety of tumors, promotes tumor development by regulating the cell cycle, apoptosis, DNA repair and EMT. Therefore, the inhibition, silencing or knockdown of NSD3 are highly promising antitumor strategies. This paper summarizes the structure and biological functions of NSD3 with an emphasis on its carcinogenic or cancer-promoting activity. The development of NSD3-specific inhibitors or degraders is also discussed and reviewed in this paper.

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.

The Role of Histone Modification in DNA Replication-Coupled Nucleosome Assembly and Cancer

Histone modification regulates replication-coupled nucleosome assembly, DNA damage repair, and gene transcription. Changes or mutations in factors involved in nucleosome assembly are closely related to the development and pathogenesis of cancer and other human diseases and are essential for maintaining genomic stability and epigenetic information transmission. In this review, we discuss the role of different types of histone posttranslational modifications in DNA replication-coupled nucleosome assembly and disease. In recent years, histone modification has been found to affect the deposition of newly synthesized histones and the repair of DNA damage, further affecting the assembly process of DNA replication-coupled nucleosomes. We summarize the role of histone modification in the nucleosome assembly process. At the same time, we review the mechanism of histone modification in cancer development and briefly describe the application of histone modification small molecule inhibitors in cancer therapy.

Structural and functional specificity of H3K36 methylation

The methylation of histone H3 at lysine 36 (H3K36me) is essential for maintaining genomic stability. Indeed, this methylation mark is essential for proper transcription, recombination, and DNA damage response. Loss- and gain-of-function mutations in H3K36 methyltransferases are closely linked to human developmental disorders and various cancers. Structural analyses suggest that nucleosomal components such as the linker DNA and a hydrophobic patch constituted by histone H2A and H3 are likely determinants of H3K36 methylation in addition to the histone H3 tail, which encompasses H3K36 and the catalytic SET domain. Interaction of H3K36 methyltransferases with the nucleosome collaborates with regulation of their auto-inhibitory changes fine-tunes the precision of H3K36me in mediating dimethylation by NSD2 and NSD3 as well as trimethylation by Set2/SETD2. The identification of specific structural features and various cis-acting factors that bind to different forms of H3K36me, particularly the di-(H3K36me2) and tri-(H3K36me3) methylated forms of H3K36, have highlighted the intricacy of H3K36me functional significance. Here, we consolidate these findings and offer structural insight to the regulation of H3K36me2 to H3K36me3 conversion. We also discuss the mechanisms that underlie the cooperation between H3K36me and other chromatin modifications (in particular, H3K27me3, H3 acetylation, DNA methylation and N6-methyladenosine in RNAs) in the physiological regulation of the epigenomic functions of chromatin.

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

NSD1, NSD2, and NSD3 constitute the nuclear receptor-binding SET Domain (NSD) family of histone 3 lysine 36 (H3K36) methyltransferases. These structurally similar enzymes mono- and di-methylate H3K36, which contribute to the maintenance of chromatin integrity and regulate the expression of genes that control cell division, apoptosis, DNA repair, and epithelial-mesenchymal transition (EMT). Aberrant expression or mutation of members of the NSD family is associated with developmental defects and the occurrence of some types of cancer. In this review, we discuss the effect of alterations in NSDs on cancer patient's prognosis and response to treatment. We summarize the current understanding of the biological functions of NSD proteins, focusing on their activities and the role in the formation and progression in solid tumors biology, as well as how it depends on tumor etiologies. This review also discusses ongoing efforts to develop NSD inhibitors as a promising new class of cancer therapeutic agents.