Extracellular NAMPT/Visfatin induces proliferation through ERK1/2 and AKT and inhibits apoptosis in breast cancer cells

The role of visfatin in peripheral immune organs and intestines of weaned piglets under lipopolysaccharide induced immune stress

To investigate the regulatory mechanisms and pathways of visfatin under immune stress injury in weaned piglets, we established a lipopolysaccharide-induced immune stress model in weaned piglets to study how visfatin affects peripheral immune organs and intestinal function. The results revealed that visfatin improved the inflammatory response in immune-stressed weaned piglets by reducing the levels of pro-inflammatory cytokines interleukin-1β, interleukin-6 and monocyte chemoattractant protein-1, as well as decreasing the neutrophil/lymphocyte ratio. Visfatin ameliorated oxidative stress in piglets by promoting the expression of superoxide dismutase and glutathione peroxidase. It also enhanced cell proliferation in peripheral immune organs (spleen and mesenteric lymph nodes) and suppressed cell apoptosis in these organs through the death receptor apoptosis pathway, thereby improving the immune function of weaned piglets under immune stress. Moreover, it alleviated intestinal villi damage, increased the abundance of beneficial bacteria, and elevated the levels of short-chain fatty acids, thus preserving the intestinal barrier's integrity and the balance of intestinal microbiota. Hence, these data indicate that visfatin can ameliorate immune stress injury in weaned piglets by exerting anti-inflammatory and antioxidant effects, enhancing immune organ and intestinal function.

Visfatin exerts an anti-proliferative and pro-apoptotic effect in the human placenta cells†

Visfatin regulates energy homeostasis, metabolism, inflammation, and reproduction via the hypothalamus-pituitary-ovary axis. Our previous study showed the visfatin gene and protein expression in the human placenta. This study aimed to investigate the in vitro effect of visfatin on the proliferation and apoptosis of placental JEG-3 and BeWo cells but also in villous explants collected from normal pregnancies and complicated by intrauterine growth restriction (IUGR), preeclampsia (PE), and gestational diabetes mellitus (GDM). We studied placenta cells viability, proliferation, cell cycle, proliferation/apoptotic factors and insulin receptor (INSR) expression, DNA fragmentation, CASP3/7 activity, and phosphorylation of ERK1/2, AKT, AMPKα, STAT3 with their involvement after pharmacological inhibition in visfatin action on proliferation and apoptosis. Visfatin (1, 10, 100 ng/mL) decreased the viability and proliferation of JEG-3 after 48 h, and a similar effect was observed via co-administration of visfatin (10 ng/mL) and insulin (10 ng/mL) in JEG-3 and BeWo after 48 h and 72 h, respectively. Visfatin reduced the transition from the G2/M phase, and expression of PCNA or cyclins D, E, A, and B in JEG-3 and PCNA in normal, IUGR, PE, and GDM placentas. It increased DNA fragmentation, CASP3/7 activity, P53, BAX/BCL2, CASP9, CASP 8, CASP3 levels in BeWo, and CASP3 expression in tested placentas. Furthermore, visfatin modulated INSR, ERK1/2, AKT, AMPKα, and STAT3 expression in JEG-3 and BeWo, and its anti-proliferative and pro-apoptotic effects occurred via mentioned factors. In conclusion, visfatin, by affecting the proliferation and apoptosis of human placenta cells, may be an important factor in the development and function of the organ.

Novel perspectives on the link between obesity and cancer risk: from mechanisms to clinical implications

Existing epidemiologic and clinical studies have demonstrated that obesity is associated with the risk of a variety of cancers. In recent years, an increasing number of experimental and clinical studies have unraveled the complex relationship between obesity and cancer risk and the underlying mechanisms. Obesity-induced abnormalities in immunity and biochemical metabolism, including chronic inflammation, hormonal disorders, dysregulation of adipokines, and microbial dysbiosis, may be important contributors to cancer development and progression. These contributors play different roles in cancer development and progression at different sites. Lifestyle changes, weight loss medications, and bariatric surgery are key approaches for weight-centered, obesity-related cancer prevention. Treatment of obesity-related inflammation and hormonal or metabolic dysregulation with medications has also shown promise in preventing obesity-related cancers. In this review, we summarize the mechanisms through which obesity affects the risk of cancer at different sites and explore intervention strategies for the prevention of obesity-associated cancers, concluding with unresolved questions and future directions regarding the link between obesity and cancer. The aim is to provide valuable theoretical foundations and insights for the in-depth exploration of the complex relationship between obesity and cancer risk and its clinical applications.

Revealing the role of serum exosomal novel long non-coding RNA NAMPT-AS as a promising diagnostic/prognostic biomarker in colorectal cancer patients

AIMS

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. Nicotinamide phosphoribosyl-transferase (NAMPT) was found to be over-expressed in several cancers including CRC. NAMPT-Antisense (NAMPT-AS) is a novel long non-coding RNA (lncRNA) recently reported to be associated with triple negative breast cancer. However, its role in CRC has not been investigated. This study was designed to explore the role of lncRNA NAMPT-AS in CRC, and to investigate its circulating serum exosomal levels in subjects with/without CRC.

MAIN METHODS

We analyzed CRC patients' data in The Cancer Genome Atlas (TCGA). LncRNA NAMPT-AS and NAMPT mRNA levels were measured in serum exosomes isolated from CRC patients and healthy control subjects and were also measured in CRC-tissues using qRT-PCR. Serum NAMPT protein levels were measured by ELISA, and immunohistochemical analyses were done for NAMPT and Ki67 in CRC tissues.

KEY FINDINGS

Serum exosomal NAMPT-AS levels were found to be significantly higher in CRC patients compared to control subjects and significantly positively correlated with serum exosomal NAMPT mRNA and circulating NAMPT protein. Tissue NAMPT-AS was found to be significantly positively associated with tissue and serum exosomal NAMPT levels. Higher serum exosomal NAMPT-AS levels were found to be associated with higher susceptibility for CRC. Gene-ontology results and survival analysis of TCGA-data showed a potential classification of CRC samples based on NAMPT-AS levels and association of NAMPT-AS upregulation with poor CRC prognosis and survival.

SIGNIFICANCE

These results portray NAMPT-AS as a novel potential diagnostic/prognostic biomarker and key molecular mediator in CRC.

Exploring the multifaceted role of obesity in breast cancer progression

Obesity is a multifaceted metabolic disorder characterized by excessive accumulation of adipose tissue. It is a well-established risk factor for the development and progression of breast cancer. Adipose tissue, which was once regarded solely as a passive energy storage depot, is now acknowledged as an active endocrine organ producing a plethora of bioactive molecules known as adipokines that contribute to the elevation of proinflammatory cytokines and estrogen production due to enhanced aromatase activity. In the context of breast cancer, the crosstalk between adipocytes and cancer cells within the adipose microenvironment exerts profound effects on tumor initiation, progression, and therapeutic resistance. Moreover, adipocytes can engage in direct interactions with breast cancer cells through physical contact and paracrine signaling, thereby facilitating cancer cell survival and invasion. This review endeavors to summarize the current understanding of the intricate interplay between adipocyte-associated factors and breast cancer progression. Furthermore, by discussing the different aspects of breast cancer that can be adversely affected by obesity, this review aims to shed light on potential avenues for new and novel therapeutic interventions.

Differential effect of visfatin inhibition on the testicular androgen and estrogen receptors expression in early pubertal mice

BACKGROUND

It is now well known that visfatin is expressed in the testis and ovary of various animals. Visfatin is known to regulate gonadal functions such as steroidogenesis, proliferation, and apoptosis in the ovary and testis of mice. Recently, we have shown that visfatin has an inhibitory role in the infantile mice testis. It has also been shown that visfatin stimulates testicular steroidogenesis in adult rats. However, the role of visfatin during puberty has not been investigated in relation to the above-mentioned process.

OBJECTIVE

The objective of the present study was to examine the effect of visfatin inhibition by FK866 from PND25 to PND35 (pre-pubertal to early pubertal) in male Swiss albino mice on steroidogenesis, proliferation, and apoptosis.

METHODS

Sixteen mice (25 days old) were divided into two groups, one group was given normal saline and the other group was administered with an inhibitor of visfatin (FK866) at the dose of 1.5 mg/kg by intraperitoneal injection for 10 days. Histopathological and immunohistochemical analysis, western blot analysis and hormonal assay were done.

RESULTS

Visfatin inhibition resulted in increased estrogen secretion, body weight, seminiferous tubule diameter, germinal epithelium height, and proliferation along with increased expression of BCl2, casapse3, ERs and aromatase expression in the mice testis. Visfatin inhibition down-regulated the testicular visfatin expression and also decreased abundance in the adipose tissues.

CONCLUSION

In conclusion, decreased AR expression and increased ERs expression by FK866, suggest that visfatin might have a stimulatory effect on AR signaling than ERs in the early pubertal stage of mice.

Targeting NAD+ Metabolism: Preclinical Insights into Potential Cancer Therapy Strategies

NAD+ is one of the most important metabolites for cellular activities, and its biosynthesis mainly occurs through the salvage pathway using the nicotinamide phosphoribosyl transferase (NAMPT) enzyme. The main nicotinamide adenine dinucleotide (NAD) consumers, poly-ADP-ribose-polymerases and sirtuins enzymes, are heavily involved in DNA repair and chromatin remodeling. Since cancer cells shift their energy production pathway, NAD levels are significantly affected. NAD's roles in cell survival led to the use of NAD depletion in cancer therapies. NAMPT inhibition (alone or in combination with other cancer therapies, including endocrine therapy and chemotherapy) results in decreased cell viability and tumor burden for many cancer types. Many NAMPT inhibitors (NAMPTi) tested before were discontinued due to toxicity; however, a novel NAMPTi, KPT-9274, is a promising, low-toxicity option currently in clinical trials.

The Effect of Visfatin on the Functioning of the Porcine Pituitary Gland: An In Vitro Study

Visfatin (VIS), also known as nicotinamide phosphoribosyltransferase (NAMPT), is the rate-limiting enzyme in the biosynthesis of nicotinamide adenine dinucleotide (NAD+). Recently, VIS has been also recognized as an adipokine. Our previous study revealed that VIS is produced in the anterior and posterior lobes of the porcine pituitary. Moreover, the expression and secretion of VIS are dependent on the phase of the estrous cycle and/or the stage of early pregnancy. Based on this, we hypothesized that VIS may regulate porcine pituitary function. This study was conducted on anterior pituitary (AP) glands harvested from pigs during specific phases of the estrous cycle. We have shown the modulatory effect of VIS in vitro on LH and FSH secretion by porcine AP cells (determined by ELISA). VIS was also found to stimulate cell proliferation (determined by Alamar Blue) without affecting apoptosis in these cells (determined using flow cytometry technique). Moreover, it was indicated that VIS may act in porcine AP cells through the INSR, AKT/PI3K, MAPK/ERK1/2, and AMPK signaling pathways (determined by ELISA or Western Blot). This observation was further supported by the finding that simultaneous treatment of cells with VIS and inhibitors of these pathways abolished the observed VIS impact on LH and FSH secretion (determined by ELISA). In addition, our research indicated that VIS affected the mentioned processes in a manner that was dependent on the dose of VIS and/or the phase of the estrous cycle. Thus, these findings suggest that VIS may regulate the functioning of the porcine pituitary gland during the estrous cycle.

Targeting NAD+ metabolism: dual roles in cancer treatment

Nicotinamide adenine dinucleotide (NAD+) is indispensable for various oxidation-reduction reactions in mammalian cells, particularly during energy production. Malignant cells increase the expression levels of NAD+ biosynthesis enzymes for rapid proliferation and biomass production. Furthermore, mounting proof has indicated that NAD-degrading enzymes (NADases) play a role in creating the immunosuppressive tumor microenvironment (TME). Interestingly, both inhibiting NAD+ synthesis and targeting NADase have positive implications for cancer treatment. Here we summarize the detrimental outcomes of increased NAD+ production, the functions of NAD+ metabolic enzymes in creating an immunosuppressive TME, and discuss the progress and clinical translational potential of inhibitors for NAD+ synthesis and therapies targeting NADase.

Extracellular nicotinamide phosphoribosyltransferase: role in disease pathophysiology and as a biomarker

Nicotinamide phosphoribosyltransferase (NAMPT) plays a central role in mammalian cell metabolism by contributing to nicotinamide adenine dinucleotide biosynthesis. However, NAMPT activity is not limited to the intracellular compartment, as once secreted, the protein accomplishes diverse functions in the extracellular space. Extracellular NAMPT (eNAMPT, also called visfatin or pre-B-cell colony enhancing factor) has been shown to possess adipocytokine, pro-inflammatory, and pro-angiogenic activities. Numerous studies have reported the association between elevated levels of circulating eNAMPT and various inflammatory and metabolic disorders such as obesity, diabetes, atherosclerosis, arthritis, inflammatory bowel disease, lung injury and cancer. In this review, we summarize the current state of knowledge on eNAMPT biology, proposed roles in disease pathogenesis, and its potential as a disease biomarker. We also briefly discuss the emerging therapeutic approaches for eNAMPT inhibition.

Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) neutralization counteracts T cell immune evasion in breast cancer

BACKGROUND

Nicotinamide phosphoribosyltransferase (NAMPT) is a key intracellular enzyme that participates in nicotinamide adenine dinucleotide (NAD) homeostasis as well as a released cytokine (eNAMPT) that is elevated in inflammatory conditions and in cancer. In patients with breast cancer, circulating eNAMPT is elevated and its plasma levels correlate with prognosis and staging. In light of this, we investigated the contribution of eNAMPT in triple negative mammary carcinoma progression by investigating the effect of its neutralization via a specific neutralizing monoclonal antibody (C269).

METHODS

We used female BALB/c mice injected with 4T1 clone 5 cells and female C57BL6 injected with EO771 cells, evaluating tumoral size, spleen weight and number of metastases. We injected two times a week the anti-eNAMPT neutralizing antibody and we sacrificed the mice after 28 days. Harvested tumors were analyzed by histopathology, flow cytometry, western blot, immunohistochemistry, immunofluorescence and RNA sequencing to define tumor characteristics (isolating tumor infiltrating lymphocytes and tumoral cells) and to investigate the molecular mechanisms behind the observed phenotype. Moreover, we dissected the functional relationship between T cells and tumoral cells using three-dimensional (3D) co-cultures.

RESULTS

The neutralization of eNAMPT with C269 led to decreased tumor size and reduced number of lung metastases. RNA sequencing and functional assays showed that eNAMPT controlled T-cell response via the programmed death-ligand 1/programmed cell death protein 1 (PD-L1/PD-1) axis and its neutralization led to a restoration of antitumoral immune responses. In particular, eNAMPT neutralization was able to activate CD8+IFNγ+GrzB+ T cells, reducing the immunosuppressive phenotype of T regulatory cells.

CONCLUSIONS

These studies indicate for the first time eNAMPT as a novel immunotherapeutic target for triple negative breast cancer.

The differential role of resistin on invasive liver cancer cells

OBJECTIVES

To determine whether inhibition of kinase signaling will suppress resistin-induced liver cancer progression. Resistin is located in monocytes and macrophages of adipose tissue. This adipocytokine is an important link between obesity, inflammation, insulin resistance, and cancer risk. Pathways that resistin is known to be involved include but are not limited to mitogen-activated protein kinases (MAPKs) and extracellular signal-regulated kinases (ERK). The ERK pathway promotes cellular proliferation, migration, survival of cancer cells, and tumor progression. The Akt pathway is known to be up-regulated in many cancers including liver cancer.

METHODS

Using an in vitro model, HepG2 and SNU-449 liver cancer cells were exposed to resistin ± ERK, Akt, or both inhibitors. The following physiological parameters were assessed: cellular proliferation, ROS, lipogenesis, invasion, MMP, and lactate dehydrogenase activity.

RESULTS

The inhibition of kinase signaling suppressed resistin-induced invasion and lactate dehydrogenase in both cell lines. In addition, in SNU-449 cells, resistin increased proliferation, ROS, and MMP-9 activity. Inhibition of PI3K and ERK decreased phosphorylated Akt and ERK, and pyruvate dehydrogenase.

CONCLUSIONS

In this study, we describe the effect of Akt and ERK inhibitors to determine if inhibition suppresses resistin-induced liver cancer progression. Resistin promotes cellular proliferation, ROS, MMP, invasion and LDH activity in SNU-449 liver cancer cells which is differentially mediated by Akt and ERK signaling pathways.

Adjuvant therapy with Huatan Sanjie Granules improves the prognosis of patients with primary liver cancer: a cohort study and the investigation of its mechanism of action based on network pharmacology

Objective: Nowadays, primary liver carcinoma (PLC) is one of the major contributors to the global cancer burden, and China has the highest morbidity and mortality rates in the world. As a well-known Chinese herbal medicine (CHM) prescription, Huatan Sanjie Granules (HSG) has been used clinically for many years to treat PLC with remarkable efficacy, but the underlying mechanism of action remains unclear. Methods: A clinical cohort study was conducted to observe the overall survival of PLC patients with vs. without oral administration of HSG. Meanwhile, the BATMAN-TCM database was used to retrieve the potential active ingredients in the six herbs of HSG and their corresponding drug targets. PLC-related targets were then screened through the Gene Expression Omnibus (GEO) database. The protein-protein interaction (PPI) network of targets of HSG against PLC was constructed using Cytoscape software. The cell function assays were further carried out for verification. Results: The results of the cohort study showed that the median survival time of PLC patients exposed to HSG was 269 days, which was 23 days longer than that of the control group (HR, 0.62; 95% CI, 0.38-0.99; p = 0.047). In particular, the median survival time of Barcelona Clinic Liver Cancer stage C patients was 411 days in the exposure group, which was 137 days longer than that in the control group (HR, 0.59; 95% CI, 0.35-0.96; p = 0.036). Meanwhile, the enrichment analysis result for the obtained PPI network consisting of 362 potential core therapeutic targets suggest that HSG may inhibit the growth of liver cancer (LC) cells by blocking the PI3K-Akt/MAPK signaling pathways. Furthermore, the above prediction results were verified by a series of in vitro assays. Specifically, we found that the expressions TP53 and YWHA2, the targets of the hepatitis B virus signaling pathway, were significantly affected by HSG. Conclusion: HSG shows promising therapeutic efficacy in the adjuvant treatment of PLC.

Visfatin-induced upregulation of lipogenesis via EGFR/AKT/GSK3β pathway promotes breast cancer cell growth

Breast cancer (BC) incidence and associated mortality have increased in tandem with the growth in obesity among the females worldwide. An adipokine, visfatin, has been shown to potentially impact glucose, lipid, and protein metabolism, and promote cancer growth however, the mechanism underlying the effect of visfatin on lipid metabolism dysregulation contributing to BC cell survival, proliferation, and metastasis has not been elucidated. Herein, we have investigated the role of visfatin on the induction of Sterol regulatory element binding protein (SREBP-1) and its upstream and downstream mediators in MCF-7 breast cancer cells. The survival and proliferation was investigated using MTT and Trypan blue assays, cytosolic lipid accumulation was observed using Nile red staining, mRNA and protein expressions were examined using RT-qPCR and western blotting, respectively, and cell cycle analysis was performed using fluorescence-activated cell sorting. Our results indicate that visfatin increased the survival and proliferation of MCF-7 cells in a time- and dose-dependent manner and augmented lipid buildup via activation of SREBP-1 and its associated downstream lipid synthesizing enzymes, at both mRNA and protein levels in MCF-7 cells. Inhibiting SREBP-1 using fatostatin or silencing with siRNA abrogated excessive lipid deposition by suppressing the expression of genes related to lipid synthesis pathway. Further, in-silico study showed high affinity binding of visfatin with epidermal growth factor receptor (EGFR), which was confirmed in an in-vitro study where visfatin increased the phosphorylation of EGFR at tyrosine residue and activated its downstream proteins via phosphorylation of AKT and GSK3β in MCF-7 cells. Inhibition of GSK3β by phosphorylation led to increased activity of SREBP-1 and associated downstream proteins. In summary, SREBP-1 may be a critical player in visfatin-induced lipid synthesis and accumulation in BC cells via activation of EGFR/AKT/GSK3β pathway leading to increased cell survival and proliferation of BC cells.

NAD+ biosynthesis metabolism predicts prognosis and indicates immune microenvironment for breast cancer

The growing evidence implies that tumor cells need to increase NAD+ levels by upregulating NAD+ biosynthesis to satisfy their growth demand. NAD+ biosynthesis metabolism is implicated in tumor progression. Breast cancer (BC) is the most common malignant malignancy in the world. Nevertheless, the prognostic significance of NAD+ biosynthesis and its relationship with the tumor immune microenvironment in breast cancer still need further investigation. In this study, we obtained the mRNA expression data and clinical information of BC samples from public databases and calculated the level of NAD+ biosynthesis activity by single-sample gene set enrichment analysis (ssGSEA). We then explored the relationship between the NAD+ biosynthesis score, infiltrating immune cells, prognosis significance, immunogenicity and immune checkpoint molecules. The results demonstrated that patients with high NAD+ biosynthetic score displayed poor prognosis, high immune infiltration, high immunogenicity, elevated PD-L1 expression, and might more benefit from immunotherapy. Taken together, our studies not only deepened the understanding of NAD+ biosynthesis metabolism of breast cancer but also provided new insights into personalized treatment strategies and immunological therapies to improve the outcomes of breast cancer patients.

Visfatin induces ovarian cancer resistance to anoikis by regulating mitochondrial activity

PURPOSE

Ovarian cancer is characterized by recurrent peritoneal and distant metastasis. To survive in a non-adherent state, floating ovarian cancer spheroids develop mechanisms to resist anoikis. Moreover, ascitic fluid from ovarian cancer patients contains high levels of visfatin with anti-apoptotic properties. However, the mechanism by which visfatin induces anoikis resistance in ovarian cancer spheroids remains unknown. Here, we aimed to assess wheather visfatin which possess anti-apoptotic properties can induce resistance of anoikis in ovarian cancer spheroids.

METHODS

Visfatin synthesis were examined using a commercial human visfatin ELISA Kit. Spheroid were exposed to visfatin and cell viability and caspase 3/7 activity were measured using CellTiter-Glo 3D cell viability assay and Caspase-Glo® 3/7 Assay System. mRNA and protein expression were analyzed by Real-time PCR and Western Blot analysis, respectively. Analysis of mitochondrial activity was estimated by JC-1 staining.

RESULTS

First, our results suggested higher expression and secretion of visfatin by epithelial than by granulosa ovarian cells, and in non-cancer tissues versus cancer tissues. Interestingly, visfatin increased the proliferation/apoptosis ratio in ovarian cancer spheroids. Specifically, both the intrinsic and extrinsic pathways of anoikis were regulated by visfatin. Moreover, the effect of the visfatin inhibitor (FK866) was opposite to that of visfatin. Furthermore, both NAMPT and FK866 affected mitochondrial activity in ovarian cancer cells.

CONCLUSION

In conclusion, visfatin acts as an anti-apoptotic factor by regulating mitochondrial activity, leading to anoikis resistance in ovarian cancer spheroids. The finding suggest visfatin as a potential novel therapeutic target for the treatment of ovarian carcinoma with peritoneal dissemination.

Serum nicotinamide phosphoribosyltransferase as a novel biomarker for non-traumatic osteonecrosis of the femoral head

OBJECTIVE

The aim of this study was to investigate the potential role of serum nicotinamide phosphoribosyltransferase (NAMPT) in non-traumatic osteonecrosis of femoral head (NONFH).

METHODS

A total of 113 NONFH patients and 81 healthy individuals were included in this study. The NAMPT levels in serum were measured by a commercial enzyme-linked immunosorbent assay kit. Radiographic progression was determined using Association Research Circulation Osseous (ARCO) classification system. Clinical severity was assessed by Harris hip score (HHS) and visual analogue scale (VAS). Correlations between serum NAMPT and radiographic progression as well as clinical severity were evaluated statistically. Receiver operating characteristic (ROC) curves were performed to evaluate the diagnostic values of NAMPT in NONFH potential and disease severity.

RESULTS

The serum NAMPT levels in NONFH patients were significantly lower than that in healthy controls. There were no significant differences among alcohol-induced group, steroids-induced group, and idiopathic group. NONFH patients with ARCO stage 4 had significant lower serum NAMPT levels in comparisons with ARCO stage 3 and 2, respectively. Lower serum NAMPT levels were also observed in bilateral NONFH cases compared with cases with unilateral NONFH. In addition, serum NAMPT was negatively correlated with ARCO stages and VAS scores, and positively correlated with HHS. ROC curve analysis indicated that serum NAMPT may serve as a novel biomarker for diagnosing early NONFH and for monitoring disease severity.

CONCLUSIONS

Our results suggest that serum NAMPT may serve as a novel biomarker for NONFH potential and disease severity.

Comparison of visfatin levels in patients with breast cancer and endometrial cancer with healthy individuals: A systematic review and meta-analysis

Background and aims

Endometrial cancer (EC) and breast cancer (BC) are prevalent in women. Visfatin is an adipokine that, in addition to being involved in metabolism and inflammation, may also be interested in carcinogenesis. Visfatin measurement in cancer patients has shown that visfatin levels in cancer patients differed from those in healthy subjects. Various studies have shown that the level of visfatin is increased in people within EC and BC, and this difference has a significant relationship with prognosis.

Methods

A comprehensive search of related articles from PubMed, Scopus, Web of Science, and the Google Scholar database was done by November 2021. Eligible articles measured visfatin levels in patients with breast cancer and EC. After selecting the eligible studies, the data were extracted and analyzed using the random effect method.

Results

Given the effect size and the confidence interval obtained, the total level of visfatin in cancer patients was different from that in healthy individuals, and this difference was statistically significant. However, the difference in visfatin levels in patients with breast cancer was much more significant than in patients with EC compared to the control group.

Conclusions

Due to the significant increase in visfatin levels in these patients, visfatin may be a potential prognostic factor in breast and ECs. Visfatin levels in cancer patients differed from those in healthy subjects, and this difference was also statistically significant (p-values = 0.00). Visfatin levels also differed between breast cancer patients and healthy individuals, which was statistically significant (p-values = 0.00). The difference in visfatin levels between patients with EC and healthy subjects was statistically significant (p-values = 0.047).

Adipokines as Regulators of Autophagy in Obesity-Linked Cancer

Excess body weight and obesity have become significant risk factors for cancer development. During obesity, adipose tissue alters its biological function, deregulating the secretion of bioactive factors such as hormones, cytokines, and adipokines that promote an inflammatory microenvironment conducive to carcinogenesis and tumor progression. Adipokines regulate tumor processes such as apoptosis, proliferation, migration, angiogenesis, and invasion. Additionally, it has been found that they can modulate autophagy, a process implicated in tumor suppression in healthy tissue and cancer progression in established tumors. Since the tumor-promoting role of autophagy has been well described, the process has been suggested as a therapeutic target in cancer. However, the effects of targeting autophagy might depend on the tumor type and microenvironmental conditions, where circulating adipokines could influence the role of autophagy in cancer. Here, we review recent evidence related to the role of adipokines in cancer cell autophagy in an effort to understand the tumor response in the context of obesity under the assumption of an autophagy-targeting treatment.

Adipose tissue-to-breast cancer crosstalk: Comprehensive insights

The review focuses on mechanistic evidence for the link between obesity and breast cancer. According to the IARC study, there is sufficient evidence that obesity is closely related to a variety of cancers. Among them, breast cancer is particularly disturbed by adipose tissue due to the unique histological structure of the breast. The review introduces the relationship between obesity and breast cancer from two aspects, including factors that promote tumorigenesis or metastasis. We summarize alterations in adipokines and metabolic pathways that contribute to breast cancer development. Breast cancer metastasis is closely related to obesity-induced pro-inflammatory microenvironment, adipose stem cells, and miRNAs. Based on the mechanism by which obesity causes breast cancer, we list possible therapeutic directions, including reducing the risk of breast cancer and inhibiting the progression of breast cancer. We also discussed the risk of autologous breast remodeling and fat transplantation. Finally, the causes of the obesity paradox and the function of enhancing immunity are discussed. Evaluating the balance between obesity-induced inflammation and enhanced immunity warrants further study.

Review of various NAMPT inhibitors for the treatment of cancer

Nicotinamide phosphoribosyltransferase (NAMPT) is a rate-limiting enzyme in the NAD salvage pathway of mammalian cells and is overexpressed in numerous types of cancers. These include breast cancer, ovarian cancer, prostate cancer, gastric cancer, colorectal cancer, glioma, and b-cell lymphoma. NAMPT is also known to impact the NAD and NADPH pool. Research has demonstrated that NAMPT can be inhibited. NAMPT inhibitors are diverse anticancer medicines with significant anti-tumor efficacy in ex vivo tumor models. A few notable NAMPT specific inhibitors which have been produced include FK866, CHS828, and OT-82. Despite encouraging preclinical evidence of the potential utility of NAMPT inhibitors in cancer models, early clinical trials have yielded only modest results, necessitating the adaptation of additional tactics to boost efficacy. This paper examines a number of cancer treatment methods which target NAMPT, including the usage of individual inhibitors, pharmacological combinations, dual inhibitors, and ADCs, all of which have demonstrated promising experimental or clinical results. We intend to contribute further ideas regarding the usage and development of NAMPT inhibitors in clinical therapy to advance the field of research on this intriguing target.

Altered Adipokine Expression in Tumor Microenvironment Promotes Development of Triple Negative Breast Cancer

Obesity is a remarkably important factor for breast carcinogenesis and aggressiveness. The implication of increased BMI in triple negative breast cancer (TNBC) development is also well established. A malignancy-promoting role of the adipose tissue has been supposed, where the adipocytes that constitute the majority of stromal cells release pro-inflammatory cytokines and growth factors. Alterations in adipokines and their receptors play significant roles in breast cancer initiation, progression, metastasis, and drug response. Classic adipokines, such as leptin, adiponectin, and resistin, have been extensively studied in breast cancer and connected with breast cancer risk and progression. Notably, new molecules are constantly being discovered and the list is continuously growing. Additionally, substantial progress has been made concerning their differential expression in association with clinical and pathological parameters of tumors and the prognostic and predictive value of their dysregulation in breast cancer carcinogenesis. However, evidence regarding the mechanisms by which adipose tissue is involved in the development of TNBC is lacking. In the present article we comment on current data on the suggested involvement of these mediators in breast cancer development and progression, with particular emphasis on TNBC, to draw attention to the design of novel targeted therapies and biomarkers.

Cellular and molecular insights into the roles of visfatin in breast cancer cells plasticity programs

Obesity has reached a pandemic proportion and is responsible for the augmentation of multimorbidity including certain cancers. With the rise in obesity amongst the female population globally, a concomitant increase in breast cancer (BC) incidence and related mortality has been observed. In the present review, we have elucidated the cellular and molecular insight into the visfatin-mediated cellular plasticity programs such as Epithelial to mesenchymal transition (EMT) and Endothelial to mesenchymal transition (EndoMT), and stemness-associated changes in BC cells. EMT and EndoMT are responsible for inducing metastasis in cancer cells and conferring chemotherapy resistance, immune escape, and infinite growth potential. Visfatin, an obesity-associated adipokine implicated in metabolic syndrome, has emerged as a central player in BC pathogenesis. Several studies have indicated the presence of visfatin in the tumor microenvironment (TME) where it augments EMT and EndoMT of BC cells. Further, Visfatin also modulates the TME by acting on the tumor stroma cells such as adipocytes, infiltrated immune cells, and adipose-associated stem cells that secrete factors such as cytokines, and extracellular vesicles responsible for augmenting cellular plasticity program. Visfatin induced altered metabolism of the cancer cells and molecular determinants such as non-coding RNAs involved in EMT and EndoMT have been discussed. We have also highlighted specific therapeutic targets that can be exploited for the development of effective BC treatment. Taken together, these advanced understandings of cellular and molecular insight into the visfatin-mediated cellular plasticity programs may stimulate the development of better approaches for the prevention and therapy of BC, especially in obese patients.

Updated Functional Roles of NAMPT in Carcinogenesis and Therapeutic Niches

Simple Summary

The advantages and applications of using the non-invasive way to detect serum biomarkers for assessing cancer diagnosis and prognosis have been explored. Nicotinamide phosphoribosyltransferase (NAMPT), also designated as pre-B-cell colony-enhancing factor (PBEF) or visfatin, is a secreted adipokine known to modulate tumor malignancies. Its significance in predicting cancer patient’s survival outcome further renders the implementation of NAMPT in clinical practice. In this review, recent discoveries of NAMPT in cancer studies were focused and integrated. We aim to provide updates for researchers who are proposing relevant objectives.

Abstract

Nicotinamide phosphoribosyltransferase (NAMPT) is notable for its regulatory roles in tumor development and progression. Emerging evidence regarding NAMPT somatic mutations in cancer patients, NAMPT expressional signatures in normal tissues and cancers, and the prognostic significance of NAMPT in many cancer types has attracted attention, and NAMPT is considered a potential biomarker of cancer. Recent discoveries have demonstrated the indirect association and direct biological functions of NAMPT in modulating cancer metastasis, proliferation, angiogenesis, cancer stemness, and chemoresistance to anticancer drugs. These findings warrant further investigation of the underlying mechanisms to provide knowledge for developing novel cancer therapeutics. In this review article, we explore recent research developments involving the oncogenic activities of NAMPT by summarizing current knowledge regarding NAMPT somatic mutations, clinical trials, transcriptome data, and clinical information and discoveries related to the NAMPT-induced signaling pathway in modulating hallmarks of cancer. Furthermore, the comprehensive representation of NAMPT RNA expression in a pancancer panel as well as in specific normal cell types at single-cell level are demonstrated. The results suggest potential sites and cell types that could facilitate NAMPT-related tumorigenesis. With this review, we aim to shed light on the regulatory roles of NAMPT in tumor development and progression, and provide information to guide future research directions in this field.

QPRT Acts as an Independent Prognostic Factor in Invasive Breast Cancer

Background. Quinolinic acid phosphoribosyltransferase (QPRT) is a rate-limiting enzyme that encodes the uronic acid pathway, which is involved in cell cycle progression and cancer cell metabolism. Some studies have demonstrated the progrowth effect of QPRT on breast cancer (BRCA) tumour cells, but its mechanism of action requires further exploration. Methods. We investigated the expression of QPRT and the prognosis of patients with different tumours by performing a pan-cancer analysis of QPRT. Prognostic values for overall survival (OS) were determined using uni- and multivariate Cox proportional hazard analyses. The prognostic survival of patients with a different pathological staging of BRCA and with QPRT high and low expression was also analysed. We also explored the relevant pathways by which QPRT affected BRCA tumorigenesis by gene set enrichment analysis (GSEA) and western blotting. The impact of QPRT on the PI3K/Akt pathway was also evaluated. Results. Pan-cancer analysis revealed significant QPRT expression in pan-cancer and correlated with prognosis in most tumour patients. QPRT was also highly expressed in BRCA when patients had poor prognoses, and its expression was associated with different pathological BRCA subtypes. GSEA revealed an association between BRCA progression and the cell cycle and the phosphatidylinositol 3-kinase (PI3K)/Akt signalling pathway, and this association was confirmed by western blotting. Conclusion. QPRT is highly expressed in breast cancer and particularly in HER2 breast cancer. Upregulated QPRT expression is an independent predictor of breast cancer prognosis and promotes breast cancer progression by activating the PI3K/Akt signalling pathway.

Inhibition of PI3K/Akt and ERK signaling decreases visfatin-induced invasion in liver cancer cells

OBJECTIVES

Visfatin is found in adipose tissue and is referred to as nicotinamide phosphoribosyltransferase (Nampt). Visfatin has anti-apoptotic, proliferative, and metastatic properties and may mediate its effects via ERK and PI3K/Akt signaling. Studies have yet to determine whether inhibition of kinase signaling will suppress visfatin-induced liver cancer. The purpose of this study was to determine which signaling pathways visfatin may promote liver cancer progression.

METHODS

HepG2 and SNU-449 liver cancer cells were exposed to visfatin with or without ERK or PI3K/Akt inhibitor, or both inhibitors combined. These processes that were assessed: proliferation, reactive oxygen species (ROS), lipogenesis, invasion, and matrix metalloproteinase (MMP).

RESULTS

Inhibition of PI3K/Akt and combination of inhibitors suppressed visfatin-induced viability. ERK inhibition in HepG2 cells decreased visfatin-induced proliferation. ERK inhibitor alone or in combination with PI3K inhibitors effectively suppressed MMP-9 secretion and invasion in liver cancer cells. PI3K and ERK inhibition and PI3K inhibition alone blocked visfatin's ROS production in SNU-449 cells. These results corresponded with a decrease in phosphorylated Akt and ERK, β-catenin, and fatty acid synthase.

CONCLUSIONS

Akt and ERK inhibition differentially regulated physiological changes in liver cancer cells. Inhibition of Akt and ERK signaling pathways suppressed visfatin-induced invasion, viability, MMP-9 activation, and ROS production.

Current Landscape: The Mechanism and Therapeutic Impact of Obesity for Breast Cancer

Obesity is defined as a chronic disease induced by an imbalance of energy homeostasis. Obesity is a widespread health problem with increasing prevalence worldwide. Breast cancer (BC) has already been the most common cancer and one of the leading causes of cancer death in women worldwide. Nowadays, the impact of the rising prevalence of obesity has been recognized as a nonnegligible issue for BC development, outcome, and management. Adipokines, insulin and insulin-like growth factor, sex hormone and the chronic inflammation state play critical roles in the vicious crosstalk between obesity and BC. Furthermore, obesity can affect the efficacy and side effects of multiple therapies such as surgery, radiotherapy, chemotherapy, endocrine therapy, immunotherapy and weight management of BC. In this review, we focus on the current landscape of the mechanisms of obesity in fueling BC and the impact of obesity on diverse therapeutic interventions. An in-depth exploration of the underlying mechanisms linking obesity and BC will improve the efficiency of the existing treatments and even provide novel treatment strategies for BC treatment.

MiR-613 Promotes Cell Death in Breast Cancer Cells by Downregulation of Nicotinamide Phosphoribosyltransferase and Reduction of NAD

NAD is mainly biosynthesized by the enzymatic action of nicotinamide phosphoribosyltransferase (NAMPT) through the salvage pathway. NAD is indispensable for the proper function and metabolism of all living cells, including cancer cells. Our previous researches revealed that inhibition of NAMPT by miRNA (miR) could suppress NAD levels and thereby hinder the growth and promotion of breast cancer (BC). Therefore, the current study was undertaken to investigate the inhibitory effects of miR-613 on NAMPT and BC cells' survival. Bioinformatics analysis and luciferase reporter assay confirmed that NAMPT 3'-untranslated region is a direct target for miR-613. The expression of miR-613 was noticed to be significantly decreased in both clinical tissue samples and BC cells by real-time PCR. Following transfection with miR-613 mimic, the expression of miR-613 was elevated in the BC cells leading to inhibition of NAMPT expression at both mRNA and protein level as measured by real-time PCR and western blotting, respectively. Inhibition of NAMPT led to a remarkable reduction in the concentration of NAD in the BC cells. The transfection also declined cell viability roughly 40% in MD Anderson-Metastatic Breast-231 (MDA-MB-231) cells. Consistently, the apoptosis rate was remarkably increased, around 65% in these cells as assayed by labeling the cells with Annexin V-fluorescein isothiocyanate (FITC) and Propidium Iodide. Targeting the NAMPT-mediated NAD salvage pathway by miR-613 is a novel approach for managing BC, which is worth further investigation.

The synergistic protection of EGCG and quercetin against streptozotocin (STZ)-induced NIT-1 pancreatic β cell damage via upregulation of BCL-2 expression by miR-16-5p

EGCG and quercetin are flavonoids which usually co-exist in edible plants and they exhibit anti-diabetes effects. This study aimed to explore the mechanisms by which quercetin and EGCG synergistically protected pancreatic β-cells from streptozotocin-induced apoptosis. EGCG, quercetin, and their combinations (both 15 μM) all reversed STZ-induced cells damage and enhanced glucose-stimulated insulin secretion, with the combination being more effective than a single compound. At the molecular level, the EGCG-quercetin combination upregulated BCL-2 expression and caused a greater reduction in miR-16-5p level than EGCG alone or quercetin alone. Overexpression of miR-16-5p could offset the down-regulated apoptotic genes caused by the synergistic action of the combination. These findings suggest that EGCG and quercetin exert synergistic anti-diabetes effect, possibly via decreasing the expression of miR-16-5p that targets directly BCL-2. This is the first report on a miRNA-based mechanism underlying the synergistic protective effect of EGCG and quercetin against pancreatic cell damage.

MicroRNA-1: Diverse role of a small player in multiple cancers

The process of cancer initiation and development is a dynamic and complex mechanism involving multiple genetic and non-genetic variations. With the development of high throughput techniques like next-generation sequencing, the field of cancer biology extended beyond the protein-coding genes. It brought the functional role of noncoding RNAs into cancer-associated pathways. MicroRNAs (miRNAs) are one such class of noncoding RNAs regulating different cancer development aspects, including progression and metastasis. MicroRNA-1 (miR-1) is a highly conserved miRNA with a functional role in developing skeletal muscle precursor cells and cardiomyocytes and acts as a consistent tumor suppressor gene. In humans, two discrete genes, MIR-1-1 located on 20q13.333 and MIR-1-2 located on 18q11.2 loci encode for a single mature miR-1. Downregulation of miR-1 has been demonstrated in multiple cancers, including lung, breast, liver, prostate, colorectal, pancreatic, medulloblastoma, and gastric cancer. A vast number of studies have shown that miR-1 affects the hallmarks of cancer like proliferation, invasion and metastasis, apoptosis, angiogenesis, chemosensitization, and immune modulation. The potential therapeutic applications of miR-1 in multiple cancer pathways provide a novel platform for developing anticancer therapies. This review focuses on the different antitumorigenic and therapeutic aspects of miR-1, including how it regulates tumor development and associated immunomodulatory functions.

Dezocine, An Opioid Analgesic, Exerts Antitumor Effects in Triple-Negative Breast Cancer by Targeting Nicotinamide Phosphoribosyltransferase

Opioids are a potential adjuvant treatment for certain cancers; while they are primarily used to relieve chronic pain, these drugs may also affect cancer progression and recurrence. Dezocine is one opioid commonly used in China, but its effects on cancer cells are unknown. Here, we demonstrated the inhibitory effect of dezocine on triple-negative breast cancer (TNBC) cells, and determined the underlying molecular mechanism. We found that dezocine suppressed cell proliferation, migration and invasion, and induced apoptosis in TNBC cells. Xenograft models demonstrated the inhibitory effects of dezocine treatment on TNBC tumor growth in vivo. The anticancer effects of dezocine were independent of opioid receptors, which are not highly expressed by normal breast or breast cancer tissues. A pull-down assay and LC-MS/MS analysis indicated that dezocine directly targets NAMPT: computer modeling verified that the free energy of dezocine kinetically bound into the pocket of NAMPT was −17.4 kcal/mol. Consequently, dezocine treatment inhibited NAMPT enzyme activity, resulting in cellular NAD abolishment. We confirmed the dezocine-induced inhibition of cell proliferation by both NAMPT knockdown and upon treatment with the inhibitor FK866. Our results suggest that both dezocine and NAMPT might represent novel therapeutic targets for TNBC.

Visfatin facilitates gastric cancer malignancy by targeting snai1 via the NF-κB signaling

BACKGROUND

Visfatin acts as an oncogenic factor in numerous tumors through a variety of cellular processes. Visfatin has been revealed to promote cell migration and invasion in gastric cancer (GC). Snai1 is a well-known regulator of EMT process in cancers. However, the relationship between visfatin and snai1 in GC remains unclear. The current study aimed to explore the role of visfatin in GC.

METHODS

The RT-qPCR and western blot analysis were used to measure RNA and protein levels, respectively. The cell migration and invasion were tested by Trans-well assays and western blot analysis.

RESULTS

Visfatin showed upregulation in GC cells. Additionally, Visfatin with increasing concentration facilitated epithelial-mesenchymal transition (EMT) process by increasing E-cadherin and reducing N-cadherin and Vimentin protein levels in GC cells. Moreover, endogenous overexpression and knockdown of visfatin promoted and inhibited migratory and invasive abilities of GC cells, respectively. Then, we found that snai1 protein level was positively regulated by visfatin in GC cells. In addition, visfatin activated the NF-κB signaling to modulate snai1 protein expression. Furthermore, the silencing of snai1 counteracted the promotive impact of visfatin on cell migration, invasion and EMT process in GC.

CONCLUSION

Visfatin facilitates cell migration, invasion and EMT process by targeting snai1 via the NF-κB signaling, which provides a potential insight for the treatment of GC.

Inhibition of visfatin by FK866 mitigates pathogenesis of cystic ovary in letrozole-induced hyperandrogenised mice

Polycystic ovary syndrome is a common reproductive disorder in the female of reproductive age, which is characterized by hyperandrogenism, insulin resistance, cystic ovary and infertility. The level of pro-inflammatory adipokine, visfatin is elevated in PCOS conditions in human and animal. In this study, letrozole induced hyperandrogenised PCOS mice model have been used to unravel the effects of visfatin inhibition. The results showed that letrozole induced hyperandrogenisation significantly (p < 0.05) elevates ovarian visfatin concentration from 66.03 ± 1.77 to 112.08 ± 3.7 ng/ml, and visfatin expression to 2.5 fold (p < 0.05) compared to control. Visfatin inhibition in PCOS by FK866 has significantly (p < 0.05) suppressed the secretion of androgens, androstenedione (from 0.329 ± 0.07 to 0.097 ± 0.01 ng/ml) and testosterone levels (from 0.045 ± 0.003 to 0.014 ± 0.0009 ng/ml). Ovarian histology showed that visfatin inhibition suppressed cyst formation and promotes corpus luteum formation. Visfatin inhibition has suppressed apoptosis and increases the expression of BCL2 along with increase in the proliferation (GCNA expression elevated). Visfatin inhibition has increased ovarian glucose content (from 167.05 ± 8.5 to 210 ± 7 mg/dl), along with increase in ovarian GLUT8 expression. In vitro study has also supported the in vivo findings where FK866 treatment significantly (p < 0.05) suppressed testosterone (control-3.84 ± 0.44 ng/ml, 1 nM FK866-2.02 ± 0.048 ng/ml, 10 nM FK866-1.74 ± 0.20 ng/ml) and androstenedione (control-4.68 ± 0.91 ng/ml, 1 nM FK866-3.38 ± 0.27 ng/ml, 10 nM FK866-4.55 ± 0.83 ng/ml) production from PCOS ovary. In conclusion, this is first report, which showed that visfatin inhibition by FK866 in hyperandrogenised mice ameliorates pathogenesis of PCOS. Thus, it may be suggested that visfatin inhibition could have a therapeutic potential in PCOS management along with other intervention.

Visfatin protein may be responsible for suppression of proliferation and apoptosis in the infantile mice ovary

Visfatin is an important adipokines, which are expressed in different tissues including ovary of mammals. The postnatal ovary in rodents undergoes dramatic changes of intra-ovarian factors in relation to proliferation and apoptosis. There are studies which showed that gonadal visfatin changes in postnatal life. However, role of visfatin in the early postnatal period i.e. infantile period has not been studied. Therefore, the present study was aimed to explore the role of visfatin in the early postnatal ovarian functions. Furthermore, to explore the role of visfatin, the endogenous visfatin was inhibited from PND14-PND21 by FK866 with dose of 1.5 mg/kg. Our results showed gain in body weight and ovarian weight after visfatin inhibition. The inhibition of visfatin increased the ovarian proliferation (increase in PCNA, GCNA expression and BrdU incorporation) and apoptosis (increase in BAX and active caspase3 expression). Moreover, visfatin inhibition decreased the expression of antiapoptotic/survival protein, BCL2 in the ovary. These findings suggest that visfatin in the infantile ovary may suppress the proliferation and apoptosis by up-regulating BCL2 expression. An interesting finding has been observed that circulating estrogen and progesterone remain unaffected, although visfatin inhibition up-regulated ER-β and down-regulated ER-α. It may also be suggested that visfatin could regulates proliferation and apoptosis via modulating estrogen signaling. In conclusion, visfatin inhibits the proliferation and apoptosis without modulating the ovarian steroid biosynthesis and visfatin mediated BCL2 expression could also be mechanism to preserve the good quality follicle in early postnatal period.

A Negative Feedback Loop Between NAMPT and TGF-β Signaling Pathway in Colorectal Cancer Cells

BACKGROUND

Nicotinamide phosphoribosyltransferase (NAMPT) and the transforming growth factor-β (TGF-β) signaling pathway play important roles in colorectal tumorigenesis and progress. However, the underlying regulatory mechanisms between NAMPT and TGF-β signaling in colorectal cancer (CRC) remain poorly understood.

METHODS

Public data were extracted from the Oncomine database and the PrognoScan database to investigate the mRNA expression and the prognostic value of NAMPT, respectively, in CRC. Western blot tests were performed to detect Smad2, Smad3, p-Smad2, p-Smad3, Smad4 expression in CRC cells transfected with human NAMPT-siRNA or NAMPT-overexpressing plasmid. TGF-β1 concentrations in culture supernatants were assayed using ELISA kits. The effect of TGF-β1 on NAMPT expression was evaluated by quantitative real-time PCR and Western blot. The dual-luciferase reporter assay was employed to confirm the binding of miR-1-3p to NAMPT 3'-UTR. Subsequently, NAMPT levels in HCT116 cells transfected with the mimics and inhibitors of miR-1-3p were detected by quantitative real-time PCR and Western blot.

RESULTS

NAMPT was overexpressed in human CRC and was correlated with short overall survival. NAMPT increased the protein expression levels of components in the TGF-β signaling pathway including Smad2, Smad3, and Smad4. Moreover, NAMPT promoted TGF-β1 secretion. Intriguingly, the TGF-β1 treatment down-regulated NAMPT expression at mRNA and protein levels in CRC cells which were partly through the up-regulation of miR-1-3p that directly bound to the NAMPT 3'-UTR. These outcomes demonstrated that NAMPT was a downstream target of miR-1-3p and there was a negative association between NAMPT and miR-1-3p in CRC.

CONCLUSION

There is a negative feedback loop between NAMPT and the TGF-β signaling pathway in CRC cells, providing new insight into the mechanism underlying the regulatory pathways in CRC.

Adipocytokines visfatin and resistin in breast cancer: Clinical relevance, biological mechanisms, and therapeutic potential

Obesity is one of the major modifiable risk factors in breast cancer, with obese adipose tissue showing a pathological role in breast cancer development and malignancy via the release of secretory factors, such as proinflammatory cytokines and adipocytokines. The current article focuses on visfatin and resistin, two such adipocytokines that have emerged over the last two decades as leading breast cancer promoting factors in obesity. The clinical association of circulating visfatin and resistin with breast cancer and their biological mechanisms are reviewed, in addition to their role in the context of tumor-stromal interactions in the breast cancer microenvironment. Recent findings have unraveled several mediators of visfatin and resistin that are involved in the crosstalk between breast cancer cells and adipose tissue in the breast tumor microenvironment, including growth differentiation factor 15 (GDF15), interleukin 6 (IL-6), and toll-like receptor 4 (TLR4). Finally, current therapeutics targeting visfatin and resistin and their respective pathways are discussed, including future therapeutic strategies such as new drug design or neutralizing peptides that target extracellular visfatin or resistin. These hold promise in the development of novel breast cancer therapies and are of increasing relevance as the prevalence of obesity-related breast cancer increases worldwide.

Inhibition of visfatin/NAMPT affects ovarian proliferation, apoptosis, and steroidogenesis in pre-pubertal mice ovary

Pubertal ovarian function might be dependent on the factors present in the pre-pubertal stages. Visfatin regulates ovarian steroidogenesis in adult. To date, no study has investigated the role of visfatin either in pre-pubertal or pubertal mice ovary. Thus, we investigated the role of visfatin in pre-pubertal mice ovary in relation to steroidogenesis and proliferation and apoptosis in vitro by inhibiting the endogenous visfatin by a specific inhibitor, FK866. Inhibition of visfatin increased the estrogen secretion and also up-regulated the expression of CYP11A1, 17βHSD and CYP19A1 in mice ovary. Furthermore, active caspase3 was up-regulated along with the down-regulation of BAX and BCL2 in the pre-pubertal ovary after visfatin inhibition. The expression of GCNA, PCNA, and BrdU labeling was also decreased by FK866 treatment. These results suggest that visfatin inhibits steroidogenesis, increases proliferation, and suppresses apoptosis in the pre-pubertal mice ovary. So, visfatin is a new regulator of ovary function in pre-pubertal mice.

Significance of Some Non-Invasive Biomarkers in the Early Diagnosis and Staging of Egyptian Breast Cancer Patients

Introduction:

Breast cancer is one of the most relevant malignancies among women. Early diagnosis and accurate staging of breast cancer is important for the selection of an appropriate therapeutic strategy and achieving a better outcome.

Aim:

This study aimed to explore the significance of some non-invasive biomarkers in the early diagnosis and staging of Egyptian breast cancer patients.

Subjects and Methods:

A total of 135 female patients with physically and pathologically confirmed breast cancer and 40 unrelated controls as well as 40 patients with benign breast mass were enrolled in this study. The malignant breast cancer group was further divided into four groups according to tumor size. Serum levels of carcinoembryonic antigen-related cell adhesion molecule-1 (CEACAM1), resistin and visfatin were determined by enzyme immunoassay.

Results:

Elevated levels of CEACAM1, resistin and visfatin were observed in breast cancer patients when compared with normal control and benign groups. The cutoff values, sensitivities and specificities of these biomarkers were appropriate for the discrimination of breast cancer from controls. Additionally, the serum levels of visfatin increased positively with tumor size and consequently with breast cancer stages.

Conclusion:

CEACAM1, resistin and visfatin are valuable in early diagnosis of breast cancer, with visfatin being preferentially used in staging.

Bone Marrow Adipocytes, Adipocytokines, and Breast Cancer Cells: Novel Implications in Bone Metastasis of Breast Cancer

Accumulating discoveries highlight the importance of interaction between marrow stromal cells and cancer cells for bone metastasis. Bone is the most common metastatic site of breast cancer and bone marrow adipocytes (BMAs) are the most abundant component of the bone marrow microenvironment. BMAs are unique in their origin and location, and recently they are found to serve as an endocrine organ that secretes adipokines, cytokines, chemokines, and growth factors. It is reasonable to speculate that BMAs contribute to the modification of bone metastatic microenvironment and affecting metastatic breast cancer cells in the bone marrow. Indeed, BMAs may participate in bone metastasis of breast cancer through regulation of recruitment, invasion, survival, colonization, proliferation, angiogenesis, and immune modulation by their production of various adipocytokines. In this review, we provide an overview of research progress, focusing on adipocytokines secreted by BMAs and their potential roles for bone metastasis of breast cancer, and investigating the mechanisms mediating the interaction between BMAs and metastatic breast cancer cells. Based on current findings, BMAs may function as a pivotal modulator of bone metastasis of breast cancer, therefore targeting BMAs combined with conventional treatment programs might present a promising therapeutic option.

The up-regulation of markers of adipose tissue fibrosis by visfatin in pre-adipocytes as well as obese children and adolescents

Adipocytes are surrounded by a three-dimensional network of extracellular matrix (ECM) proteins. Aberrant ECM accumulation and remodeling leads to adipose tissue fibrosis. Visfatin is one of the adipocytokines that is increased in obesity and is implicated in insulin resistance. The objective of this study was to investigate the effect of visfatin on major components of ECM remodeling. In this study, plasma levels of both endotrophin and visfatin in obese children and adolescents were significantly higher than those in control subjects and they showed a positive correlation with each other. Treatment of 3T3-L1 pre-adipocytes with visfatin caused significant up-regulation of Osteopontin (Opn), Collagen type VI (Col6), matrix metalloproteinases MMP-2 and MMP-9. By using inhibitors of major signaling pathways it was shown that visfatin exerted its effect on Col6a3 gene expression through PI3K, JNK, and NF-кB pathways, while induced Opn gene expression via PI3K, JNK, MAPK/ERK, and NOTCH1. Our conclusion is that, the relationship between visfatin, endotrophin and insulin resistance parameters in obesity as well as increased expression of ECM proteins by visfatin suggests adipose tissue fibrosis as a mechanism for devastating effects of visfatin in obesity.

The Importance of Breast Adipose Tissue in Breast Cancer

Adipose tissue is a complex endocrine organ, with a role in obesity and cancer. Adipose tissue is generally linked to excessive body fat, and it is well known that the female breast is rich in adipose tissue. Hence, one can wonder: what is the role of adipose tissue in the breast and why is it required? Adipose tissue as an organ consists of adipocytes, an extracellular matrix (ECM) and immune cells, with a significant role in the dynamics of breast changes throughout the life span of a female breast from puberty, pregnancy, lactation and involution. In this review, we will discuss the importance of breast adipose tissue in breast development and its involvement in breast changes happening during pregnancy, lactation and involution. We will focus on understanding the biology of breast adipose tissue, with an overview on its involvement in the various steps of breast cancer development and progression. The interaction between the breast adipose tissue surrounding cancer cells and vice-versa modifies the tumor microenvironment in favor of cancer. Understanding this mutual interaction and the role of breast adipose tissue in the tumor microenvironment could potentially raise the possibility of overcoming breast adipose tissue mediated resistance to therapies and finding novel candidates to target breast cancer.

Nicotinamide Phosphoribosyltransferase Knockdown Leads to Lipid Accumulation in HepG2 Cells through The SIRT1-AMPK Pathway

OBJECTIVE

Nicotinamide phosphoribosyltransferase (NAMPT), which is responsible for biosynthesis of nicotinamide adenine dinucleotide (NAD), has a regulatory role in cellular metabolism and thus, might be implicated in non-alcoholic fatty liver disease (NAFLD). This study aimed to show how NAMPT down-regulation in liver cells influences lipid metabolism and sirtiun 1 (SIRT1), as the main NAD-dependent deacetylase enzyme.

MATERIALS AND METHODS

In this experimental study, HepG2 cells were transfected with NAMPT siRNA and hepatic triglyceride (TG) content and SIRT1 deacetylase activity were measured by colorimetric and fluorometric methods, respectively. Gene expression of fatty acid synthase (FAS) and sterol regulatory element-binding protein-1c (SREBP- 1c) was evaluated by real-time polymerase chain reaction (PCR). Total protein level and the phosphorylated form of acetyl-CoA carboxylase (ACC) and AMP-activated protein kinase (AMPK) were also investigated by western blotting.

RESULTS

Knockdown of NAMPT significantly promoted the accumulation of TG in HepG2 cells, accompanied by a remarkable decline in SIRT1 deacetylase activity. A significant rise in the gene expression of two key lipogenic factors, FAS and SREBP-1c was also observed. These effects were also accompanied by decreased phosphorylation of ACC and AMPK. On the other hand, treatment of transfected cells with either NAD, as the SIRT1 substrate or resveratrol, as the SIRT1 activator reversed the outcomes.

CONCLUSION

These results demonstrated a protective role for NAMPT against NAFLD and its involvement in the regulation of de novo lipogenesis through the SIRT1/AMPK pathway.

Neuroprotective effects of FK866 against traumatic brain injury: Involvement of p38/ERK pathway

OBJECTIVE

FK866 is an inhibitor of nicotinamide phosphoribosyltransferase (NAMPT), which exhibits neuroprotective effects in ischemic brain injury. However, in traumatic brain injury (TBI), the role and mechanism of FK866 remain unclear. The present research was aimed to investigate whether FK866 could attenuate TBI and clarified the underlying mechanisms.

METHODS

A controlled cortical impact model was established, and FK866 at a dose of 5 mg/kg was administered intraperitoneally at 1 h and 6 h, then twice per day post-TBI until sacrifice. Brain water content, Evans blue dye extravasation, modified neurological severity scores (mNSS), Morris water maze test, enzyme-linked immunosorbent assay (ELISA), immunofluorescence staining, and western blot were performed.

RESULTS

The results demonstrated that FK866 significantly mitigated the brain edema, blood-brain barrier (BBB) disruption, and ameliorated the neurological function post-TBI. Moreover, FK866 decreased the number of Iba-1-positive cells, GFAP-positive astrocytes, and AQP4-positive cells. FK866 reduced the protein levels of proinflammatory cytokines and inhibited NF-κB from translocation to the nucleus. FK866 upregulated the expression of Bcl-2, diminished the expression of Bax and caspase 3, and the number of apoptotic cells. Moreover, p38 MAPK and ERK activation were significantly inhibited by FK866.

INTERPRETATION

FK866 attenuated TBI-induced neuroinflammation and apoptosis, at least in part, through p38/ERK MAPKs signaling pathway.

High level of visfatin and the activation of Akt and ERK1/2 signaling pathways are associated with endometrium malignant transformation in polycystic ovary syndrome

This study aimed to assess the clinicopathological significance of serum levels and endometrium tissue expression of visfatin in polycystic ovary syndrome (PCOS) patients. A total of 80 PCOS patients and 80 matching controls were included in this study. We analyzed the relationship between the expression of visfatin in endometrium and clinicopathological characteristics in PCOS patients. The correlation between the expression of visfatin and p-Akt, Akt, p-ERK1/2, and ERK1/2 in PCOS tissues was evaluated as well. Visfatin expression in PCOS endometrial tissues were significantly higher than those in controls (p = .001). The expression of phosphorylation of Akt and ERK1/2 were significantly higher in PCOS endometrium tissues compared to controls (p < .05). Moreover, a high expression of tissue visfatin in PCOS tissues was positively correlated with the expression of p-Akt (p = .015), and p-ERK1/2 (p = .013). Western blotting revealed that protein expression of visfatin in PCOS patients with endometrial hyperplasia and cancer was higher than that in patients with normal endometrium tissues, and the difference was statistically significant (p = .027). The expression of p-Akt (p = .018) and p-ERK1/2 (p = .035) in PCOS patients with endometrial hyperplasia and cancer was significantly higher than that in patients with normal endometrium tissues. Visfatin may be a potential biomarker for endometrial malignant transformation in PCOS patients.

Beyond Energy Metabolism: Exploiting the Additional Roles of NAMPT for Cancer Therapy

Tumor cells have increased requirements for NAD⁺. Thus, many cancers exhibit an increased reliance on NAD⁺ production pathways. This dependence may be exploited therapeutically through pharmacological targeting of NAMPT, the rate-limiting enzyme in the NAD⁺ salvage pathway. Despite promising preclinical data using NAMPT inhibitors in cancer models, early NAMPT inhibitors showed limited efficacy in several early phase clinical trials, necessitating the identification of strategies, such as drug combinations, to enhance their efficacy. While the effect of NAMPT inhibitors on impairment of energy metabolism in cancer cells has been well-described, more recent insights have uncovered a number of additional targetable cellular processes that are impacted by inhibition of NAMPT. These include sirtuin function, DNA repair machinery, redox homeostasis, molecular signaling, cellular stemness, and immune processes. This review highlights the recent findings describing the effects of NAMPT inhibitors on the non-metabolic functions of malignant cells, with a focus on how this information can be leveraged clinically. Combining NAMPT inhibitors with other therapies that target NAD⁺-dependent processes or selecting tumors with specific vulnerabilities that can be co-targeted with NAMPT inhibitors may represent opportunities to exploit the multiple functions of this enzyme for greater therapeutic benefit.

Corneal Denervation Causes Epithelial Apoptosis Through Inhibiting NAD+ Biosynthesis

Purpose

To determine if trigeminal innervations of the corneal epithelium maintains its integrity and homeostasis through controlling the nicotinamide adenine dinucleotide (NAD) content of this tissue.

Methods

Corneal denervation of C57BL/6 mice was induced by squeezing the nerve bundles that derive from the trigeminal ganglion and was confirmed by whole-mount corneal nerve staining and the sensation test. The apoptosis of the corneal epithelium was examined by TUNEL assay and annexin V/propidium iodide staining. NAD biosynthesis-related enzymes were analyzed by quantitative PCR, immunofluorescence staining, and Western blotting. FK866, an inhibitor of nicotinamide phosphoribosyltransferase (NAMPT), exogenous nicotinamide mononucleotide (NMN), and NAD+ were used to evaluate the effect of NAD+ on the apoptosis of cultured corneal epithelial cells and epithelial detachment in denervated mice. Protein expression that related to apoptosis and phosphorylation were analyzed by Western blotting.

Results

The denervated mice showed spontaneous corneal epithelial detachment and cell apoptosis accompanied with impaired epithelial NAD+ contents due to low levels of NAMPT. Similarly, inhibition of NAMPT recapitulated epithelial detachment as in denervated mice and induced apoptosis in cultured corneal epithelial cells. The replenishment of NMN or NAD+ partially slowed down corneal nerve fiber degeneration, reduced the epithelial defect in denervated mice, and improved apoptosis induction in FK866-treated cells by restoring the activation levels of SIRT1, AKT, and CREB.

Conclusions

Corneal denervation lowered epithelial NAD+ contents through reducing the expression of NAMPT and caused cell apoptosis and epithelial defects, suggesting that corneal innervations contribute to epithelial homeostasis by regulating NAD+ biosynthesis.

Dietary Antioxidant Trans-Cinnamaldehyde Reduced Visfatin-Induced Breast Cancer Progression: In Vivo and In Vitro Study

Excessive growth of cancer cells is the main cause of cancer mortality. Therefore, discovering how to inhibit cancer growth is an important research topic. Recently, the newly discovered adipokine, known as nicotinamide phosphoribosyl transferase (NAMPT, visfatin), which has been associated with metabolic syndrome and obesity, has also been found to be a major cause of cancer proliferation. Therefore, inhibition of NAMPT and reduction of Nicotinamide adenine dinucleotide (NAD) synthesis is one strategy for cancer therapy. Cinnamaldehyde (CA), as an antioxidant and anticancer natural compound, may have the ability to inhibit visfatin. The breast cancer cell line and xenograft animal models were treated under different dosages of visfatin combined with CA and FK866 (a visfatin inhibitor) to test for cell toxicity, as well as inhibition of tumor-related proliferation of protein expression. In the breast cancer cell and the xenograft animal model, visfatin significantly increased proliferation-related protein expression, but combination with CA or FK866 significantly reduced visfatin-induced carcinogenic effects. For the first time, a natural compound inhibiting extracellular and intracellular NAMPT has been demonstrated. We hope that, in the future, this can be used as a potential anticancer compound and provide further directions for research.

NAMPT regulates PKM2 nuclear location through 14-3-3ζ: Conferring resistance to tamoxifen in breast cancer

The resistance against tamoxifen therapy has become one of the major obstacles in the clinical treatment of breast cancer. Nicotinamide phosphoribosyltransferase (NAMPT) is an essential enzyme catalyzing nicotinamide adenine dinucleotide biosynthesis and is important for tumor metabolism. The study here sought to explore the effect of NAMPT on breast cancer survival with tamoxifen conditioning. We found that NAMPT was highly expressed in breast cancer cells compared with normal mammary epithelial cells. Inhibition of NAMPT by FK866 inhibited cell viability and aggravated apoptosis in cancer cells treated with 4-hydroxytamoxifen. NAMPT overexpression upregulated 14-3-3ζ expression. Knockdown of 14-3-3ζ reduced cell survival and promoted apoptosis. Activation of Akt signaling, rather than ERK1/2 pathway, is responsible for 14-3-3ζ regulation by NAMPT overexpression. Furthermore, NAMPT overexpression led to PKM2 accumulation in the cell nucleus and could be dampened by 14-3-3ζ inhibition. In addition, NAMPT overexpression promoted xenografted tumor growth and apoptosis in nude mice, while 14-3-3ζ inhibition attenuated its effect. Collectively, our data demonstrate that NAMPT contributes to tamoxifen resistance through regulation of 14-3-3ζ expression and PKM2 translocation.

The Role of Adipokines in Breast Cancer: Current Evidence and Perspectives

PURPOSE

The current review shows evidence for the role of adipokines in breast cancer (BC) pathogenesis summarizing the mechanisms underlying the association between adipokines and breast malignancy. Special emphasis is given also on intriguing insights into the relationship between obesity and BC as well as on the role of novel adipokines in BC development.

RECENT FINDINGS

Recent evidence has underscored the role of the triad of obesity, insulin resistance, and adipokines in postmenopausal BC. Adipokines exert independent and joint effects on activation of major intracellular signal networks implicated in BC cell proliferation, growth, survival, invasion, and metastasis, particularly in the context of obesity, considered a systemic endocrine dysfunction characterized by chronic inflammation. To date, more than 10 adipokines have been linked to BC, and this catalog is continuously increasing. The majority of circulating adipokines, such as leptin, resistin, visfatin, apelin, lipocalin 2, osteopontin, and oncostatin M, is elevated in BC, while some adipokines such as adiponectin and irisin (adipo-myokine) are generally decreased in BC and considered protective against breast carcinogenesis. Further evidence from basic and translational research is necessary to delineate the ontological role of adipokines and their interplay in BC pathogenesis. More large-scale clinical and longitudinal studies are awaited to assess their clinical utility in BC prognosis and follow-up. Finally, novel more effective and safer adipokine-centered therapeutic strategies could pave the way for targeted oncotherapy.

Suppression of nicotinamide phosphoribosyltransferase expression by miR-154 reduces the viability of breast cancer cells and increases their susceptibility to doxorubicin

BACKGROUND

Nicotinamide phosphoribosyltransferase (NAMPT) enzyme acts as the major enzyme in the nicotinamide adenine dinucleotide (NAD) synthesis salvage pathway. Deregulation of NAD could be associated with progression of several cancers such as breast cancer. Here, the consequence of NAMPT inhibition by miR-154 was investigated on breast cancer cells.

METHODS

MDA-MB-231 and MCF-7 cancer cell lines were transfected with the mimic and inhibitors of miR-154-5p and their corresponding negative controls. Consequently, levels of NAMPT and NAD were assayed employing qRT-PCR, Western blotting and enzymatic method, respectively. Subsequently, flow cytometry and colorimetric methods were performed to evaluate apoptosis and cell viability. Bioinformatics analyses as well as luciferase assay were done to investigate whether the 3'-UTR of NAMPT is directly targeted by miR-154.

RESULTS

According to the obtained results, NAMPT was recognized as a target for binding of miR-154 and the levels of this miRNA was inversely associated with both mRNA and protein levels of NAMPT in breast cancer cell lines. Functionally, miR-154 inhibited the NAD salvage pathway leading to a remarkable decrease in cell viability and increased rate of cell death. When breast cancer cells were simultaneously treated with doxorubicin and miR-154 mimic, cell viability was considerably reduced compared to treatment with doxorubicin alone in both cell lines.

CONCLUSIONS

It was concluded that the inhibition of NAD production by miR-154 might be introduced as an appropriate therapeutic approach in order to improve breast cancer outcome either alone or in combination with other conventional chemotherapeutic agents.