TWEAK/Fn14 signalling driven super-enhancer reprogramming promotes pro-metastatic metabolic rewiring in triple-negative breast cancer.

Triple Negative Breast Cancer (TNBC) is the most aggressive breast cancer subtype suffering from limited targeted treatment options. Following recent reports correlating Fibroblast growth factor-inducible 14 (Fn14) receptor overexpression in Estrogen Receptor (ER)-negative breast cancers with metastatic events, we show that Fn14 is specifically overexpressed in TNBC patients and associated with poor survival. We demonstrate that constitutive Fn14 signalling rewires the transcriptomic and epigenomic landscape of TNBC, leading to enhanced tumour growth and metastasis. We further illustrate that such mechanisms activate TNBC-specific super enhancers (SE) to drive the transcriptional activation of cancer dependency genes via chromatin looping. In particular, we uncover the SE-driven upregulation of Nicotinamide phosphoribosyltransferase (NAMPT), which promotes NAD+ and ATP metabolic reprogramming critical for filopodia formation and metastasis. Collectively, our study details the complex mechanistic link between TWEAK/Fn14 signalling and TNBC metastasis, which reveals several vulnerabilities which could be pursued for the targeted treatment of TNBC patients.

Microbial creation of ß-Nicotinamide mononucleotide and its regulation of lipid metabolism in the liver of high-fat diet mice.

ß-Nicotinamide mononucleotide (NMN) is a biologically active nucleotide that regulates the physiological metabolism of the body by rapidly increasing nicotinamide adenine dinucleotide (NAD+). To determine the safety and biological activity of NMN resources, we constructed a recombinant strain of P. pastoris that heterologously expresses nicotinamide-phosphate ribosyltransferase (NAMPT), and subsequently catalyzed and purified the expressed product to obtain NMN. Consequently, this study established a high-fat diet (HFD) obese model to investigate the lipid-lowering activity of NMN. The findings showed that NMN supplementation directly increased the NAD+ levels, and reduced HFD-induced liver injury and lipid deposition. NMN treatment significantly decreased total cholesterol (TC) and triglyceride (TG) in serum and liver, as well as alanine aminotransferase (ALT) and insulin levels in serum (p < .05 or p < .01). In conclusion, this study combined synthetic biology with nutritional evaluation to confirm that P. pastoris-generated NMN modulated lipid metabolism in HFD mice, offering a theoretical framework and evidence for the application of microbially created NMN.

Targeting NAD Metabolism: Rational Design, Synthesis and In Vitro Evaluation of NAMPT/PARP1 Dual-Target Inhibitors as Anti-Breast Cancer Agents.

The malignancy of breast cancer poses a global challenge, with existing treatments often falling short of desired efficacy. Extensive research has underscored the effectiveness of targeting the metabolism of nicotinamide adenine dinucleotide (NAD), a pivotal molecule crucial for cancer cell survival and growth, as a promising anticancer strategy. Within mammalian cells, sustaining optimal NAD concentrations relies on two key enzymes, namely nicotinamide phosphoribosyltransferase (NAMPT) and poly(ADP-ribose) polymer 1 (PARP1). Recent studies have accentuated the potential benefits of combining NAMPT inhibitors and PARP1 inhibitors to enhance therapeutic outcomes, particularly in breast cancer. In this study, we designed and synthesized eleven novel NAMPT/PARP1 dual-target inhibitors. Among them, compound DDY02 exhibited acceptable inhibitory activities against both NAMPT and PARP1, with IC50 values of 0.01 and 0.05 µM, respectively. Moreover, in vitro evaluations revealed that treatment with DDY02 resulted in proliferation inhibition, NAD depletion, DNA damage, apoptosis, and migration inhibition in MDA-MB-468 cells. These results posit DDY02, by targeting NAD metabolism through inhibiting both NAMPT and PARP1, as a promising lead compound for the development of breast cancer therapy.

Visfatin impact on the proteome of porcine luteal cells during implantation.

Visfatin (VIS) is a hormone belonging to the adipokines' group secreted mainly by the adipose tissue. VIS plays a crucial role in the control of energy homeostasis, inflammation, cell differentiation, and angiogenesis. VIS expression was confirmed in the hypothalamic-pituitary-gonadal (HPG) axis structures, as well as in the uterus, placenta, and conceptuses. We hypothesised that VIS may affect the abundance of proteins involved in the regulation of key processes occurring in the corpus luteum (CL) during the implantation process in pigs. In the present study, we performed the high-throughput proteomic analysis (liquid chromatography with tandem mass spectrometry, LC-MS/MS) to examine the in vitro influence of VIS (100 ng/mL) on differentially regulated proteins (DRPs) in the porcine luteal cells (LCs) on days 15-16 of pregnancy (implantation period). We have identified 511 DRPs, 276 of them were up-regulated, and 235 down-regulated in the presence of VIS. Revealed DRPs were assigned to 162 gene ontology terms. Western blot analysis of five chosen DRPs, ADAM metallopeptidase with thrombospondin type 1 motif 1 (ADAMTS1), lanosterol 14-α demethylase (CYP51A1), inhibin subunit beta A (INHBA), notch receptor 3 (NOTCH3), and prostaglandin E synthase 2 (mPGES2) confirmed the veracity and accuracy of LC-MS/MS method. We indicated that VIS modulates the expression of proteins connected with the regulation of lipogenesis and cholesterologenesis, and, in consequence, may be involved in the synthesis of steroid hormones, as well as prostaglandins' metabolism. Moreover, we revealed that VIS affects the abundance of protein associated with ovarian cell proliferation, differentiation, and apoptosis, as well as CL new vessel formation and tissue remodelling. Our results suggest important roles for VIS in the regulation of ovarian functions during the peri-implantation period.

In vitro effect of visfatin on endocrine functions of the porcine corpus luteum.

Previously, we demonstrated the expression of visfatin in porcine reproductive tissues and its effect on pituitary endocrinology. The objective of this study was to examine the visfatin effect on the secretion of steroid (P4, E2) and prostaglandin (PGE2, PGF2α), the mRNA and protein abundance of steroidogenic markers (STAR, CYP11A1, HSD3B, CYP19A1), prostaglandin receptors (PTGER2, PTGFR), insulin receptor (INSR), and activity of kinases (MAPK/ERK1/2, AKT, AMPK) in the porcine corpus luteum. We noted that the visfatin effect strongly depends on the phase of the estrous cycle: on days 2-3 and 14-16 it reduced P4, while on days 10-12 it stimulated P4. Visfatin increased secretion of E2 on days 2-3, PGE2 on days 2-3 and 10-12, reduced PGF2α release on days 14-16, as well as stimulated the expression of steroidogenic markers on days 10-12 of the estrous cycle. Moreover, visfatin elevated PTGER mRNA expression and decreased its protein level, while we noted the opposite changes for PTGFR. Additionally, visfatin activated ERK1/2, AKT, and AMPK, while reduced INSR phosphorylation. Interestingly, after inhibition of INSR and signalling pathways visfatin action was abolished. These findings suggest a regulatory role of visfatin in the porcine corpus luteum.

Dual-targeted NAMPT inhibitors as a progressive strategy for cancer therapy.

In mammals, nicotinamide phosphoribosyltransferase (NAMPT) is a crucial enzyme in the nicotinamide adenine dinucleotide (NAD+) synthesis pathway catalyzing the condensation of nicotinamide (NAM) with 5-phosphoribosyl-1-pyrophosphate (PRPP) to produce nicotinamide mononucleotide (NMN). Given the pivotal role of NAD+ in a range of cellular functions, including DNA synthesis, redox reactions, cytokine generation, metabolism, and aging, NAMPT has become a promising target for many diseases, notably cancer. Therefore, various NAMPT inhibitors have been reported and classified as first and second-generation based on their chemical structures and design strategies, dual-targeted being one. However, most NAMPT inhibitors suffer from several limitations, such as dose-dependent toxicity and poor pharmacokinetic properties. Consequently, there is no clinically approved NAMPT inhibitor. Hence, research on discovering more effective and less toxic dual-targeted NAMPT inhibitors with desirable pharmacokinetic properties has drawn attention recently. This review summarizes the previously reported dual-targeted NAMPT inhibitors, focusing on their design strategies and advantages over the single-targeted therapies.

Thiophenyl Derivatives of Nicotinamide Are Metabolized by the NAD Salvage Pathway into Unnatural NAD Derivatives That Inhibit IMPDH and Are Toxic to Peripheral Nerve Cancers.

N-Pyridinylthiophene carboxamide (compound 21) displays activity against peripheral nerve sheath cancer cells and mouse xenografts by an unknown mechanism. Through medicinal chemistry, we identified a more active derivative, compound 9, and found that only analogues with structures similar to nicotinamide retained activity. Genetic screens using compound 9 found that both NAMPT and NMNAT1, enzymes in the NAD salvage pathway, are necessary for activity. Compound 9 is metabolized by NAMPT and NMNAT1 into an adenine dinucleotide (AD) derivative in a cell-free system, cultured cells, and mice, and inhibition of this metabolism blocked compound activity. AD analogues derived from compound 9 inhibit IMPDH in vitro and cause cell death by inhibiting IMPDH in cells. These findings nominate these compounds as preclinical candidates for the development of tumor-activated IMPDH inhibitors to treat neuronal cancers.

Estrogen counteracts age-related decline in beige adipogenesis through the NAMPT-regulated ER stress response.

Thermogenic beige adipocytes are recognized as potential therapeutic targets for combating metabolic diseases. However, the metabolic advantages that they offer are compromised with aging. Here we show that treating mice with estrogen (E2), a hormone that decreases with age, can counteract the age-related decline in beige adipogenesis when exposed to cold temperature while concurrently enhancing energy expenditure and improving glucose tolerance in mice. Mechanistically, we found that nicotinamide phosphoribosyl transferase (NAMPT) plays a pivotal role in facilitating the formation of E2-induced beige adipocytes, which subsequently suppresses the onset of age-related endoplasmic reticulum (ER) stress. Furthermore, we found that targeting NAMPT signaling, either genetically or pharmacologically, can restore the formation of beige adipocytes by increasing the number of perivascular adipocyte progenitor cells. Conversely, the absence of NAMPT signaling prevents this process. Together, our findings shed light on the mechanisms regulating the age-dependent impairment of beige adipocyte formation and underscore the E2-NAMPT-controlled ER stress pathway as a key regulator of this process.

Inhibition of nicotinamide phosphoribosyltransferase (NAMPT) in cancer: a patent review.

INTRODUCTION: Nicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme in the biosynthesis of nicotinamide adenine dinucleotide (NAD) from nicotinamide. In addition to its role as essential redox cofactor, NAD also functions as a substrate for NAD-consuming enzymes, regulating multiple cellular processes such as DNA repair and gene expression, fundamental to sustain energetic needs for tumor growth. In this sense, NAMPT over-expression represents a common strategy that several tumor types adopt to sustain NAD production. In addition to its enzymatic role, NAMPT behaves as cytokine-like protein with pro-inflammatory function. Increasing evidence demonstrated that NAMPT inhibition represents a promising anti-cancer strategy to deplete NAD and impair cellular metabolism in cancer conditions. AREAS COVERED: By using Espacenet, we collected the patents which identified new molecules, compounds, formulations and methods able to inhibit NAMPT from 2007 to date. EXPERT OPINION: Most of the collected patents focused the attention on the ability of different compounds to inhibit the enzymatic activity of NAMPT, lacking other important aspects related to the extracellular role of NAMPT and the ability of alternative enzymes to counteract NAMPT-mediated NAD depletion. It is necessary to consider also these aspects to promote novel strategies and create novel inhibitors and molecules useful as anti-cancer compounds.

Oxygen-Dependent Interactions between the Ruthenium Cage and the Photoreleased Inhibitor in NAMPT-Targeted Photoactivated Chemotherapy.

Photoactivated chemotherapy agents form a new branch of physically targeted anticancer agents with potentially lower systemic side effects for patients. On the other hand, limited information exists on the intracellular interactions between the photoreleased metal cage and the photoreleased anticancer inhibitor. In this work, we report a new biological study of the known photoactivated compound Ru-STF31 in the glioblastoma cancer cell line, U87MG. Ru-STF31 targets nicotinamide phosphoribosyltransferase (NAMPT), an enzyme overexpressed in U87MG. Ru-STF31 is activated by red light irradiation and releases two photoproducts: the ruthenium cage and the cytotoxic inhibitor STF31. This study shows that Ru-STF31 can significantly decrease intracellular NAD+ levels in both normoxic (21% O2) and hypoxic (1% O2) U87MG cells. Strikingly, NAD+ depletion by light activation of Ru-STF31 in hypoxic U87MG cells could not be rescued by the addition of extracellular NAD+. Our data suggest an oxygen-dependent active role of the ruthenium photocage released by light activation.

NAMPT-targeting PROTAC and nicotinic acid co-administration elicit safe and robust anti-tumor efficacy in NAPRT-deficient pan-cancers.

Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the biosynthesis of nicotinamide adenine dinucleotide (NAD+), making it a potential target for cancer therapy. Two challenges hinder its translation in the clinic: targeting the extracellular form of NAMPT (eNAMPT) remains insufficient, and side effects are observed in normal tissues. We previously utilized proteolysis-targeting chimera (PROTAC) to develop two compounds capable of simultaneously degrading iNAMPT and eNAMPT. Unfortunately, the pharmacokinetic properties were inadequate, and toxicities similar to those associated with traditional inhibitors arose. We have developed a next-generation PROTAC molecule 632005 to address these challenges, demonstrating exceptional target selectivity and bioavailability, improved in vivo exposure, extended half-life, and reduced clearance rate. When combined with nicotinic acid, 632005 exhibits safety and robust efficacy in treating NAPRT-deficient pan-cancers, including xenograft models with hematologic malignancy and prostate cancer and patient-derived xenograft (PDX) models with liver cancer. Our findings provide clinical references for patient selection and treatment strategies involving NAMPT-targeting PROTACs.

Adipocyte-specific inactivation of NAMPT, a key NAD+ biosynthetic enzyme, causes a metabolically unhealthy lean phenotype in female mice during aging.

Nicotinamide adenine dinucleotide (NAD+) is a universal coenzyme regulating cellular energy metabolism in many cell types. Recent studies have demonstrated the close relationships between defective NAD+ metabolism and aging and age-associated metabolic diseases. The major purpose of the present study was to test the hypothesis that NAD+ biosynthesis, mediated by a rate-limiting NAD+ biosynthetic enzyme, nicotinamide phosphoribosyltransferase (NAMPT), is essential for maintaining normal adipose tissue function and whole body metabolic health during the aging process. To this end, we provided in-depth and comprehensive metabolic assessments for female adipocyte-specific Nampt knockout (ANKO) mice during aging. We first evaluated body fat mass in young (≤4-mo-old), middle aged (10-14-mo-old), and old (≥18-mo-old) mice. Intriguingly, adipocyte-specific Nampt deletion protected against age-induced obesity without changing energy balance. However, data obtained from the hyperinsulinemic-euglycemic clamp procedure (HECP) demonstrated that, despite the lean phenotype, old ANKO mice had severe insulin resistance in skeletal muscle, heart, and white adipose tissue (WAT). Old ANKO mice also exhibited hyperinsulinemia and hypoadiponectinemia. Mechanistically, loss of Nampt caused marked decreases in WAT gene expression of lipogenic targets of peroxisome proliferator-activated receptor gamma (PPAR-γ) in an age-dependent manner. In addition, administration of a PPAR-γ agonist rosiglitazone restored fat mass and improved metabolic abnormalities in old ANKO mice. In conclusion, these findings highlight the importance of the NAMPT-NAD+-PPAR-γ axis in maintaining functional integrity and quantity of adipose tissue, and whole body metabolic function in female mice during aging.NEW & NOTEWORTHY Defective NAD+ metabolism is associated with aging and age-associated metabolic diseases. In the present study, we provided in-depth metabolic assessments in female mice with adipocyte-specific inactivation of a key NAD+ biosynthetic enzyme NAMPT and revealed an unexpected role of adipose tissue NAMPT-NAD+-PPAR-γ axis in maintaining functional integrity and quantity of adipose tissue and whole body metabolic health during the aging process.

The interplay between extracellular NAMPT and inflammatory cytokines in preeclampsia.

Preeclampsia (PE) is the major cause of maternal-fetal mortality and morbidity. Its pathophysiology is not elucidated, but there is evidence for the role of visfatin/nicotinamide phosphoribosyl transferase (NAMPT), mainly due to its relation to endothelial dysfunction, a hallmark of PE. However, there is heterogeneous data regarding visfatin/NAMPT in healthy pregnancy (HP) and PE. Therefore, we performed a search on MEDLINE/PubMed using the terms "visfatin and preeclampsia" and "NAMPT and preeclampsia, and we selected 23 original articles: 12 articles reported increased levels in PE compared to HP, only four articles showed lower levels and eight articles did not find differences regarding visfatin/NAMPT in the groups studied. It is widely acknowledged that levels detected in plasma, serum, or placenta can be influenced by the size of the population and sample analyzed, as well as genetic factors. We further discussed the correlations of visfatin/NAMPT with clinical biomarkers in PE and inflammatory pathways. Considering the common inflammatory mechanisms between PE and visfatin/NAMPT, few studies have recently performed serum or plasma dosages. In conclusion, further studies are needed to highlight the potential role of visfatin/NAMPT in the pathophysiology of PE. This will provide comparative evidence to establish it as a biomarker for disease outcomes and treatment.

Possible involvement of NAMPT in neuronal survival in cerebral ischemic injury under high-glucose conditions through the FoxO3a/LC3 pathway.

The incidence of cerebral infarction triggered by abnormal glucose tolerance has increased; however, the relationship between glucose concentration in the brain and the detailed mechanism of post ischemic cell death remains unclear. Nicotinamide phosphoribosyltransferase (NAMPT), an adipocytokine, is the rate-limiting enzyme for NAD+ synthesis in the salvage pathway. Although NAMPT activation prevents neuronal injury, the relationship between NAMPT activity, glucose metabolism disorders, and cerebral ischemia-induced neuronal cell death is unknown. In this study, we determined changes in NAMPT on cerebral ischemic injuries with diabetes using a db/db mouse model of type 2 diabetes and then identified the underlying mechanisms using Neuro2a cells. The expression of inflammatory cytokine mRNAs was increased in db/db and db/+ middle cerebral artery occlusion and reperfusion (MCAO/R) mice. Although NeuN-positive cells were decreased after MCAO/R, the number of NAMPT and NeuN double-positive cells in NeuN-positive neuronal cells increased in db/db MCAO/R mice. Next, the role of NAMPT in Neuro2a cells under conditions of high glucose (HGC) and oxygen-glucose deprivation (OGD), which mimics diabetes-complicated cerebral infarction, was examined. Treatment with P7C3-A20, a NAMPT activator, suppressed the decrease in cell viability caused by HGC/OGD; however, there were no significant differences in the levels of cleaved caspase-3 and Bax proteins. Moreover, increased FoxO3a and LC3-II levels after HGC/OGD were inhibited by P7C3-A20 treatment. Our findings indicate that NAMPT activation is associated with neuronal survival under ischemic conditions with abnormal glucose tolerance through the regulation of FoxO3a/LC3.

Visfatin Facilitates VEGF-D-Induced Lymphangiogenesis through Activating HIF-1α and Suppressing miR-2277-3p in Human Chondrosarcoma.

Chondrosarcoma is a malignant bone tumor that arises from abnormalities in cartilaginous tissue and is associated with lung metastases. Lymphangiogenesis plays an essential role in cancer metastasis. Visfatin is an adipokine reported to enhance tumor metastasis, but its relationship with VEGF-D generation and lymphangiogenesis in chondrosarcoma remains undetermined. Our results from clinical samples reveal that VEGF-D levels are markedly higher in chondrosarcoma patients than in normal individuals. Visfatin stimulation promotes VEGF-D-dependent lymphatic endothelial cell lymphangiogenesis. We also found that visfatin induces VEGF-D production by activating HIF-1α and reducing miR-2277-3p generation through the Raf/MEK/ERK signaling cascade. Importantly, visfatin controls chondrosarcoma-related lymphangiogenesis in vivo. Therefore, visfatin is a promising target in the treatment of chondrosarcoma lymphangiogenesis.

Expression of visfatin in gingival crevicular fluid and gingival tissues in different periodontal conditions: a cross-sectional study.

BACKGROUND: Studies have shown that visfatin is an inflammatory factor closely related to periodontitis. We examined the levels of visfatin in gingival crevicular fluid (GCF) and gingival tissues under different periodontal conditions, in order to provide more theoretical basis for exploring the role of visfatin in the pathogenesis of periodontitis. METHODS: We enrolled 87 subjects, with 43 in the chronic periodontitis (CP) group, 21 in the chronic gingivitis (CG) group, and 23 in the periodontal health (PH) group. Periodontal indexes (PD, AL, PLI, and BI) were recorded. GCF samples were collected for visfatin quantification, and gingival tissues were assessed via immunohistochemical staining. RESULTS: Visfatin levels in GCF decreased sequentially from CP to CG and PH groups, with statistically significant differences (P < 0.05). The CP group exhibited the highest visfatin levels, while the PH group had the lowest. Gingival tissues showed a similar trend, with significant differences between groups (P < 0.001). Periodontal indexes were positively correlated with visfatin levels in both GCF and gingival tissues (P < 0.001). A strong positive correlation was observed between visfatin levels in GCF and gingival tissues (rs = 0.772, P < 0.001). CONCLUSION: Greater periodontal destruction corresponded to higher visfatin levels in GCF and gingival tissues, indicating their potential collaboration in damaging periodontal tissues. Visfatin emerges as a promising biomarker for periodontitis and may play a role in its pathogenesis.

Expression dynamics of adipokines during induced ovulation in the bovine follicles and early corpus luteum.

The study aimed to assess the local gene expression of adipokine members, namely vaspin, adiponectin, visfatin, resistin and their associated receptors - heat shock 70 protein 5 (HSPA5), adiponectin receptor 1 (AdipoR1) and adiponectin receptor 2 (AdipoR2) - in bovine follicles during the preovulatory period and early corpus luteum development. Follicles were collected before gonadotropin-releasing hormone (GnRH) treatment (0 h) and at 4, 10, 20, 25 and 60 h after GnRH application through transvaginal ovariectomy (n = 5 samples/group). Relative mRNA expression levels were quantified using real-time reverse transcription polymerase chain reaction (RT-qPCR). Vaspin exhibited high mRNA levels immediately 4 h after GnRH application, followed by a significant decrease. Adiponectin mRNA levels were elevated at 25 h after GnRH treatment. AdipoR2 exhibited late-stage upregulation, displaying increased expression at 20, 25 and 60 h following GnRH application. Visfatin showed upregulation at 20 h post-GnRH application. In conclusion, the observed changes in adipokine family members within preovulatory follicles, following experimentally induced ovulation, may constitute crucial components of the local mechanisms regulating final follicle growth and development.

An oncolytic HSV-1 armed with Visfatin enhances antitumor effects by remodeling tumor microenvironment against murine pancreatic cancer.

Oncolytic viruses (OVs) have shown potential in converting a "cold" tumor into a "hot" one and exhibit effectiveness in various cancer types. However, only a subset of patients respond to oncolytic virotherapy. It is important to understand the resistance mechanisms to OV treatment in pancreatic ductal adenocarcinoma (PDAC) to engineer oncolytic viruses. In this study, we used transcriptome RNA sequencing (RNA-seq) to identify Visfatin, which was highly expressed in the responsive tumors following OV treatment. To explore the antitumor efficacy, we modified OV-mVisfatin, which effectively inhibited tumor growth. For the first time, we revealed that Visfatin promoted the antitumor efficacy of OV by remodeling the tumor microenvironment, which involved enhancing CD8+ T cell and DC cell infiltration and activation, repolarizing macrophages towards the M1-like phenotype, and decreasing Treg cells using single-cell RNA sequencing (scRNA-seq) and flow cytometry. Furthermore, PD-1 blockade significantly enhanced OV-mVisfatin antitumor efficacy, offering a promising new therapeutic strategy for PDAC.

Status of visfatin in female reproductive function under normal and pathological conditions: a mini review.

Adipokines are now well-known to regulate reproduction. Visfatin is an adipokine expressed in the hypothalamus, pituitary, ovary, uterus, and placenta of different species, and since it has been found to modulate the endocrine secretion of the hypothalamus, pituitary gland and ovary, it may be considered a novel regulator of female reproduction. Although the majority of the literature explored its role in ovarian regulation, visfatin has also been shown to regulate uterine remodeling, endometrial receptivity and embryo development, and its expression in the uterus is steroid dependent. Like other adipokines, visfatin expression and levels are deregulated in pathological conditions including polycystic ovary syndrome. Thus, the present mini-review focuses on the role of visfatin in female reproduction under both physiological and pathological conditions.

Discovery of potent and novel dual NAMPT/BRD4 inhibitors for efficient treatment of hepatocellular carcinoma.

The NAPRT-induced increase in NAD+ levels was proposed as a mechanism contributing to hepatocellular carcinoma (HCC) resistance to NAMPT inhibitors. Thus, concurrently targeting NAMPT and NAPRT could be considered to overcome drug resistance. A BRD4 inhibitor downregulates the expression of NAPRT in HCC, and the combination of NAMPT inhibitors with BRD4 inhibitors simultaneously blocks NAD+ generation via salvage and the PH synthesis pathway. Moreover, the combination of the two agents significantly downregulated the expression of tumor-promoting genes and strongly promoted apoptosis. The present work identified various NAMPT/BRD4 dual inhibitors based on the multitargeted drug rationale. Among them, compound A2, which demonstrated the strongest effect, exhibited potent inhibition of NAMPT and BRD4 (IC50 = 35 and 58 nM, respectively). It significantly suppressed the growth and migration of HCC cells and facilitated their apoptosis. Furthermore, compound A2 also manifested a robust anticancer effect in HCCLM3 xenograft mouse models, with no apparent toxic effects. Our findings in this study provide an effective approach to target NAD+ metabolism for HCC treatment.