Protein neddylation as a therapeutic target in pulmonary and extrapulmonary small cell carcinomas.

Small cell lung carcinoma (SCLC) is among the most lethal of all solid tumor malignancies. In an effort to identify novel therapeutic approaches for this recalcitrant cancer type, we applied genome-scale CRISPR/Cas9 inactivation screens to cell lines that we derived from a murine model of SCLC. SCLC cells were particularly sensitive to the deletion of NEDD8 and other neddylation pathway genes. Genetic suppression or pharmacological inhibition of this pathway using MLN4924 caused cell death not only in mouse SCLC cell lines but also in patient-derived xenograft (PDX) models of pulmonary and extrapulmonary small cell carcinoma treated ex vivo or in vivo. A subset of PDX models were exceptionally sensitive to neddylation inhibition. Neddylation inhibition suppressed expression of major regulators of neuroendocrine cell state such as INSM1 and ASCL1, which a subset of SCLC rely upon for cell proliferation and survival. To identify potential mechanisms of resistance to neddylation inhibition, we performed a genome-scale CRISPR/Cas9 suppressor screen. Deletion of components of the COP9 signalosome strongly mitigated the effects of neddylation inhibition in small cell carcinoma, including the ability of MLN4924 to suppress neuroendocrine transcriptional program expression. This work identifies neddylation as a regulator of neuroendocrine cell state and potential therapeutic target for small cell carcinomas.

Feasibility of pevonedistat combined with azacitidine, fludarabine, cytarabine in pediatric relapsed/refractory AML: Results from COG ADVL1712.

BACKGROUND: Outcomes for children with relapsed/refractory (R/R) acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) are poor, and new therapies are needed. Pevonedistat is an inhibitor of the NEDD-8 activating enzyme, a key regulator of the ubiquitin proteasome system that is responsible for protein turnover, with protein degradation regulating cell growth and survival. PROCEDURE: We evaluated the feasibility, toxicity, and pharmacokinetics (PK) of pevonedistat (20 mg/m2 days 1, 3, 5) in combination with azacitidine, fludarabine, cytarabine (aza-FLA) in children with R/R AML and MDS (NCT03813147). Twelve patients were enrolled, median age was 13 years (range 1-21). Median number of prior chemotherapeutic regimens was two (range one to five), and two (25%) patients had prior hematopoietic cell transplantation. Diagnoses were AML NOS (n = 10, 83%), acute monocytic leukemia (n = 1), and therapy-related AML (n = 1). RESULTS: Overall, three of 12 (25%) patients experienced DLTs. The day 1 mean ± SD (n = 12) Cmax , VSS , T1/2 , and CL were 223 ± 91 ng/mL, 104 ± 53.8 L/m2 , 4.3 ± 1.2 hours, and 23.2 ± 6.9 L/h/m2 , respectively. T1/2 , VSS , and Cmax , but not CL, were significantly different between age groups. The overall response rate was 25%, with n = 3 patients achieving a complete remission with incomplete hematologic recovery (CRi). CONCLUSIONS: Pevonedistat 20 mg/m2 combined with Aza-FLA was tolerable in children with R/R AML with similar toxicity profile to other intensive AML regimens. However, within the confines of a phase 1 study, we did not observe that the pevonedistat + Aza-FLA combination demonstrated significant anti-leukemic activity.

Neddylation inhibitor MLN4924 has anti-HBV activity via modulating the ERK-HNF1α-C/EBPα-HNF4α axis.

Hepatitis B virus (HBV) infection is a major public health problem. The high levels of HBV DNA and HBsAg are positively associated with the development of secondary liver diseases, including hepatocellular carcinoma (HCC). Current treatment with nucleos(t)ide analogues mainly reduces viral DNA, but has minimal, if any, inhibitory effect on the viral antigen. Although IFN reduces both HBV DNA and HBsAg, the serious associated side effects limit its use in clinic. Thus, there is an urgent demanding for novel anti-HBV therapy. In our study, viral parameters were determined in the supernatant of HepG2.2.15 cells, HBV-expressing Huh7 and HepG2 cells which transfected with HBV plasmids and in the serum of HBV mouse models with hydrodynamic injection of pAAV-HBV1.2 plasmid. RT-qPCR and Southern blot were performed to detect 35kb mRNA and cccDNA. RT-qPCR, Luciferase assay and Western blot were used to determine anti-HBV effects of MLN4924 and the underlying mechanisms. We found that treatment with MLN4924, the first-in-class neddylation inhibitor currently in several phase II clinical trials for anti-cancer application, effectively suppressed production of HBV DNA, HBsAg, 3.5kb HBV RNA as well as cccDNA. Mechanistically, MLN4924 blocks cullin neddylation and activates ERK to suppress the expression of several transcription factors required for HBV replication, including HNF1α, C/EBPα and HNF4α, leading to an effective blockage in the production of cccDNA and HBV antigen. Our study revealed that neddylation inhibitor MLN4924 has impressive anti-HBV activity by inhibiting HBV replication, thus providing sound rationale for future MLN4924 clinical trial as a novel anti-HBV therapy.

Phase I study assessing the mass balance, pharmacokinetics, and excretion of [14C]-pevonedistat, a NEDD8-activating enzyme inhibitor in patients with advanced solid tumors.

Pevonedistat (TAK-924/MLN4924) is an investigational small-molecule inhibitor of the NEDD8-activating enzyme that has demonstrated preclinical and clinical activity across solid tumors and hematological malignancies. Here we report the results of a phase I trial characterizing the mass balance, pharmacokinetics, and clearance pathways of [14C]-pevonedistat in patients with advanced solid tumors (NCT03057366). In part A (n = 8), patients received a single 1-h intravenous infusion of [14C]-pevonedistat 25 mg/m2. In part B (n = 7), patients received pevonedistat 25 or 20 mg/m2 on days 1, 3, and 5 in combination with, respectively, docetaxel 75 mg/m2 or carboplatin AUC5 plus paclitaxel 175 mg/m2 on day 1 every 3 weeks. Following the single dose of [14C]-pevonedistat 25 mg/m2 in part A, there was a parallel log-linear decline in plasma and whole blood pevonedistat concentration, with systemic exposure of unchanged pevonedistat representing 41% of drug-related material (i.e., unchanged pevonedistat and its metabolites). The mean terminal half-life of pevonedistat and drug-related material in plasma was 8.4 and 15.6 h, respectively. Pevonedistat distributed preferentially in whole blood with a mean whole-blood-to-plasma ratio for pevonedistat AUC∞ of 40.8. By 1 week post dose, the mean recovery of administered radioactivity was 94% (41% in urine and 53% in feces). The pevonedistat safety profile during both study parts was consistent with previous clinical experience, with no new safety signals observed. In part B, pevonedistat in combination with docetaxel or carboplatin plus paclitaxel was generally well tolerated. ClinicalTrials.gov identifier: NCT03057366 .

4-Methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP) Targets Estrogen Receptor ß, to Evoke the Resistance of Human Breast Cancer MCF-7 Cells to G-1, an Agonist for G Protein-Coupled Estrogen Receptor 1.

Bisphenol A (BPA) has been shown to induce the activation of nuclear estrogen receptor α/ß (ERα/ß) in both in vitro and in vivo settings. We originally obtained a 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP), a possible active metabolite of BPA, strongly activating the ERs-mediated transcription in MCF-7 cells with an EC50 of 2.8 nM (i.e., BPA's EC50 = 519 nM). Environmental estrogens can also target G protein-coupled estrogen receptor 1 (GPER1), a membrane-type ER. However, the effects of BPA/MBP on GPER1, have not yet been fully resolved. In this study, we used MCF-7, a ERα/ERß/GPER1-positive human breast cancer cell line, as a model to investigate the effects of the exposure to BPA or MBP. Our results revealed that at concentrations below 1 nM MBP, but not BPA, downregulates the expression of GPER1 mRNA via upregulated ERß, and the MCF-7 cells pre-treated with MBP display resistance to GPER1 agonist G-1-mediated anti-proliferative effects. Because GPER1 can act as a tumor suppressor in several types of cancer including breast cancer, the importance of MBP-mediated decrease in GPER1 expression in breast cancer cells is discussed.

Therapeutic Potential of Jasmonic Acid and Its Derivatives.

A modern method of therapeutic use of natural compounds that would protect the body are jasmonates. The main representatives of jasmonate compounds include jasmonic acid and its derivatives, mainly methyl jasmonate. Extracts from plants rich in jasmonic compounds show a broad spectrum of activity, i.e., anti-cancer, anti-inflammatory and cosmetic. Studies of the biological activity of jasmonic acid and its derivatives in mammals are based on their structural similarity to prostaglandins and the compounds can be used as natural therapeutics for inflammation. Jasmonates also constitute a potential group of anti-cancer drugs that can be used alone or in combination with other known chemotherapeutic agents. Moreover, due to their ability to stimulate exfoliation of the epidermis, remove discoloration, regulate the function of the sebaceous glands and reduce the visible signs of aging, they are considered for possible use in cosmetics and dermatology. The paper presents a review of literature data on the biological activity of jasmonates that may be helpful in treatment and prevention.

The Anti-Tumor Activity of the NEDD8 Inhibitor Pevonedistat in Neuroblastoma.

Pevonedistat is a neddylation inhibitor that blocks proteasomal degradation of cullin-RING ligase (CRL) proteins involved in the degradation of short-lived regulatory proteins, including those involved with cell-cycle regulation. We determined the sensitivity and mechanism of action of pevonedistat cytotoxicity in neuroblastoma. Pevonedistat cytotoxicity was assessed using cell viability assays and apoptosis. We examined mechanisms of action using flow cytometry, bromodeoxyuridine (BrDU) and immunoblots. Orthotopic mouse xenografts of human neuroblastoma were generated to assess in vivo anti-tumor activity. Neuroblastoma cell lines were very sensitive to pevonedistat (IC50 136-400 nM). The mechanism of pevonedistat cytotoxicity depended on p53 status. Neuroblastoma cells with mutant (p53MUT) or reduced levels of wild-type p53 (p53si-p53) underwent G2-M cell-cycle arrest with rereplication, whereas p53 wild-type (p53WT) cell lines underwent G0-G1 cell-cycle arrest and apoptosis. In orthotopic neuroblastoma models, pevonedistat decreased tumor weight independent of p53 status. Control mice had an average tumor weight of 1.6 mg + 0.8 mg versus 0.5 mg + 0.4 mg (p < 0.05) in mice treated with pevonedistat. The mechanism of action of pevonedistat in neuroblastoma cell lines in vitro appears p53 dependent. However, in vivo studies using mouse neuroblastoma orthotopic models showed a significant decrease in tumor weight following pevonedistat treatment independent of the p53 status. Novel chemotherapy agents, such as the NEDD8-activating enzyme (NAE) inhibitor pevonedistat, deserve further study in the treatment of neuroblastoma.

The Effect of Neddylation Inhibition on Inflammation-Induced MMP9 Gene Expression in Esophageal Squamous Cell Carcinoma.

Inhibition of the protein neddylation process by the small-molecule inhibitor MLN4924 has been recently indicated as a promising direction for cancer treatment. However, the knowledge of all biological consequences of MLN4924 for cancer cells is still incomplete. Here, we report that MLN4924 inhibits tumor necrosis factor-alpha (TNF-α)-induced matrix metalloproteinase 9 (MMP9)-driven cell migration. Using real-time polymerase chain reaction (PCR) and gelatin zymography, we found that MLN4924 inhibited expression and activity of MMP9 at the messenger RNA (mRNA) and protein levels in both resting cells and cells stimulated with TNF-α, and this inhibition was closely related to impaired cell migration. We also revealed that MLN4924, similar to TNF-α, induced phosphorylation of inhibitor of nuclear factor kappa B-alpha (IκB-α). However, contrary to TNF-α, MLN4924 did not induce IκB-α degradation in treated cells. In coimmunoprecipitation experiments, nuclear IκB-α which formed complexes with nuclear factor kappa B p65 subunit (NFκB/p65) was found to be highly phosphorylated at Ser32 in the cells treated with MLN4924, but not in the cells treated with TNF-α alone. Moreover, in the presence of MLN4924, nuclear NFκB/p65 complexes were found to be enriched in c-Jun and cyclin dependent kinase inhibitor 1 A (CDKN1A/p21) proteins. In these cells, NFκB/p65 was unable to bind to the MMP9 gene promoter, which was confirmed by the chromatin immunoprecipitation (ChIP) assay. Taken together, our findings identified MLN4924 as a suppressor of TNF-α-induced MMP9-driven cell migration in esophageal squamous cell carcinoma (ESCC), likely acting by affecting the nuclear ubiquitin-proteasome system that governs NFκB/p65 complex formation and its DNA binding activity in regard to the MMP9 promoter, suggesting that inhibition of neddylation might be a new therapeutic strategy to prevent invasion/metastasis in ESCC patients.

UBC12-mediated SREBP-1 neddylation worsens metastatic tumor prognosis.

Activation of sterol regulatory element-binding protein 1 (SREBP-1), a master lipogenic transcription factor, is associated with cancer metabolism and metabolic disorders. Neddylation, the process of adding NEDD8 to its substrate, contributes to diverse biological processes. Here, we identified SREBP-1 as a substrate for neddylation by UBC12 and explored its impact on tumor aggressiveness. In cell-based assays, SREBP-1 neddylation prolonged SREBP-1 stability with a decrease in ubiquitination. Consequently, NEDD8 overexpression facilitated proliferation, migration, and invasion of SK-Hep1 liver tumor cells. MLN4924 (an inhibitor of the NEDD8-activating enzyme-E1) treatment or UBC12 knockdown prevented SREBP-1 neddylation and tumor cell phenotype change. This effect was corroborated in an in vivo xenograft model. In human specimens, SREBP-1, UBC12, and NEDD8 were all upregulated in hepatocellular carcinoma (HCC) compared to nontumorous regions. Moreover, SREBP-1 levels positively correlated with UBC12. In GEO database analyses, SREBP-1 levels were greater in metastatic HCC samples accompanying UBC12 upregulation. In HCC analysis, tumoral SREBP-1 and UBC12 levels discriminated overall patient survival rates. Additionally, MLN4924 treatment destabilized SREBP-1 in MDA-MB-231 breast cancer cells and in the tumor cell xenograft. SREBP-1 and UBC12 were also highly expressed in human breast cancer tissues. Moreover, most breast cancers with lymph node metastasis displayed predominant SREBP-1 and UBC12 expressions, which compromised overall patient survival rates. In summary, SREBP-1 is neddylated by UBC12, which may contribute to HCC and breast cancer aggressiveness through SREBP-1 stabilization, and these events can be intervented by MLN4924 therapy. Our findings may also provide potential reliable prognostic markers for tumor metastasis.

Pivalopril improves anti-cancer efficiency of cDDP in breast cancer through inhibiting proliferation, angiogenesis and metastasis.

Breast cancer is the most common cancer type among female worldwide. Cisplatin (cDDP) is one of the most effective chemotherapies for the treatment of breast cancer. Nevertheless, there is an urgent requirement to reduce its systemic side effects and chemoresistance. In this present study, pivalopril (PP), a clinically used antihypertensive drug, has been verified as a chemosensitizer that extremely improves the sensitivity of breast cancer cells to cDDP. PP treatment markedly promoted the capacity of cDDP to reduce the proliferation of breast cancer cells. The combination of PP and cDDP significantly induced apoptosis and inhibited vascular endothelial growth factor (VEGF) expression in breast cancer cells, accompanied with reduced angiogenesis. Furthermore, PP plus cDDP effectively reduced the cell migration and invasion in breast cancer cells. The in vivo studies confirmed that the anti-metastatic effect of cDDP was further improved by PP, as evidenced by the markedly decreased number of metastatic nodules in lungs. Moreover, we confirmed that PP combined with cDDP cooperatively suppressed tumor growth in breast cancer xenograft mouse models without extra toxicity. Together, the present study provided the first evidence that PP greatly sensitized breast cancer cells to cDDP without additional toxicity, and the synergistic effect may be mainly through cooperatively inhibiting proliferation, angiogenesis, metastasis, and inducing apoptotic cell death.

Effect of methyl jasmonate and 3-bromopyruvate combination therapy on mice bearing the 4 T1 breast cancer cell line.

Cancer cells apply the Warburg pathway to meet their increased metabolic demands caused by their rapid growth and proliferation and also creates an acidic environment to promote cancer cell invasion. 3-bromopyruvate (3-BrP) as an anti-cancer agent disrupts glycolytic pathway. Moreover, one of the mechanism of actions of Methyl Jasmonate (MJ) is interference in glycolysis. Hence, the aim of this study was to evaluate MJ and 3-BrP interaction. MTT assay was used to determine IC50 and synergistic concentrations. Combination index was applied to evaluate the drug- drug interaction. Human tumor xenograft breast cancer mice was used to evaluate drug efficacy in vivo. Tumor size was considered as a drug efficacy criterion. In addition to drug efficacy, probable side effects of these drugs including hepatotoxicity, renal failure, immunotoxicity, and losing weight were evaluated. Serum alanine aminotransferase and aspartate aminotransferase for hepatotoxicity, serum urea and creatinine level for the possibility of renal failure and changes in body weight were measured to evaluate drug toxicity. IL10 and TGFß secretion in supernatant of isolated splenocytes from treated mice were assessed to check immunotoxicity. 3-BrP synergistically augmented the efficacy of MJ in the specific concentrations. This polytherapy was more effective than monotherapy of 3-BrP, MJ, and also surprisingly cyclophosphamide as a routine treatment for breast cancer in the tumor bearing mice. These results have been shown by decrease in tumor volume and increase of tumor growth inhibition percentage. This combination therapy didn't have any noticeable side effects on kidney, liver, and immune system and body weight.

Pevonedistat, a Neuronal Precursor Cell-Expressed Developmentally Down-Regulated Protein 8-Activating Enzyme Inhibitor, Is a Potent Inhibitor of Hepatitis B Virus.

Hepatitis B virus (HBV) infection is a major health concern worldwide. To prevent HBV-related mortality, elimination of viral proteins is considered the ultimate goal of HBV treatment; however, currently available nucleos(t)ide analogs rarely achieve this goal, as viral transcription from episomal viral covalently closed circular DNA (cccDNA) is not prevented. HBV regulatory protein X was recently found to target the protein structural maintenance of chromosomes 5/6 (Smc5/6) for ubiquitination and degradation by DDB1-CUL4-ROC1 E3 ligase, resulting in enhanced viral transcription from cccDNA. This ubiquitin-dependent proteasomal pathway requires an additional ubiquitin-like protein for activation, neuronal precursor cell-expressed developmentally down-regulated protein 8 (NEDD8). Here, we show that pevonedistat, a NEDD8-activating enzyme inhibitor, works efficiently as an antiviral agent. Pevonedistat significantly restored Smc5/6 protein levels and suppressed viral transcription and protein production in the HBV minicircle system in in vitro HBV replication models and in human primary hepatocytes infected naturally with HBV. Conclusion: These results indicate that pevonedistat is a promising compound to treat chronic HBV infection.

Successful treatment with baloxavir marboxil of a patient with peramivir-resistant influenza A/H3N2 with a dual E119D/R292K substitution after allogeneic hematopoietic cell transplantation: a case report.

BACKGROUND: Extended use of oseltamivir in an immunocompromised host could reportedly induce neuraminidase gene mutation possibly leading to oseltamivir-resistant influenza A/H3N2 virus. To our knowledge, no report is available on the clinical course of a severely immunocompromised patient with a dual E119D/R292K neuraminidase mutated-influenza A/H3N2 during the administration of peramivir. CASE PRESENTATION: A 49-year-old male patient was admitted for second allogeneic hematopoietic cell transplantation for active acute leukemia. The patient received 5 mg prednisolone and 75 mg cyclosporine and had severe lymphopenia (70/µL). At the time of hospitalization, the patient was diagnosed with upper tract influenza A virus infection, and oseltamivir treatment was initiated immediately. However, the patient was intolerant to oseltamivir. The following day, treatment was changed to peramivir. Despite a total period of neuraminidase-inhibitor administration of 16 days, the symptoms and viral shedding continued. Changing to baloxavir marboxil resolved the symptoms, and the influenza diagnostic test became negative. Subsequently, sequence analysis of the nasopharyngeal specimen revealed the dual E119D/R292K neuraminidase mutant influenza A/H3N2. CONCLUSIONS: In a highly immunocompromised host, clinicians should take care when peramivir is used for extended periods to treat influenza virus A/H3N2 infection as this could potentially leading to a dual E119D/R292K substitution in neuraminidase protein. Baloxavir marboxil may be one of the agents that can be used to treat this type of mutated influenza virus infection.

Terrein suppressed lipopolysaccharide-induced neuroinflammation through inhibition of NF-κB pathway by activating Nrf2/HO-1 signaling in BV2 and primary microglial cells.

In the course of our continuous investigation on the bioactive marine-derived fungal metabolites, terrein was isolated from marine-derived fungal strain Penicillium sp. SF-7181. Terrein inhibited the overproduction of pro-inflammatory mediators, such as nitric oxide (NO) and prostaglandin E2 (PGE2), as well as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-stimulated BV2 and primary microglial cells. This compound also repressed the LPS-induced production of pro-inflammatory cytokines, interleukin (IL)-1ß and IL-6. These inhibitory effects of terrein were associated with the inactivation of the nuclear factor kappa B (NF-κB) pathway through suppression of the translocation of p65/p50 heterodimer into the nucleus, the phosphorylation and degradation of inhibitor kappa B (IκB)-α and the DNA binding activity of the p65 subunit. In addition, terrein induced the protein expression of heme oxygenase (HO)-1 through the activation of nuclear transcription factor erythroid-2 related factor 2 (Nrf2) in BV2 and primary microglial cells. The anti-inflammatory effect of terrein was blocked by pre-treatment with a selective HO-1 inhibitor, suggesting that its anti-neuroinflammatory effect is mediated by HO-1 induction.

Jasmonates from Chinese acorns (Quercus serrata var. brevipetiolata) exert pronounced anti-neuroinflammatory activities.

Chinese oak (Quercus serrata var. brevipetiolata) belongs to the genus Quercus in Fagaceae family. Its seed, called as Chinese acorn, has been served as a traditional medicine and foodstuff in China. In this study, ten jasmonates were isolated and purified from Chinese acorn, including five new (1-5) and five known jasmonates (6-10). The new jasmonates were identified as butyl (1R,2R)-2-[(2'Z)-5'-hydroxy-penten-2'-enyl]-3-oxo-cyclopentane acetate (1), methyl {2-[4'-(ß-d-glucopyranosyloxy)-pentyl}-3-oxo-cyclopentane acetate (2), methyl {(1R,2R)-2-[(2'Z,4'R)-4'-(ß-d-glucopyransyloxy)-pent-2'-enyl]}-3-oxo-cyclopentane acetate (3), methyl {(1R,2R)-2-[(2'E,4'S)-4'-(ß-d-glucopyransyloxy)-pent-2'-enyl]}-3-oxo-cyclopentane acetate (4), and methyl {(1R,2R)-2-[(2'S,3'E)-2'-(ß-D-glucopyransyloxy)-pent-3'-enyl]}-3-oxo-cyclopentane acetate (5), respectively. The isolated jasmonates were evaluated for anti-neuroinflammatory activity, and some showed pronounced inhibitory effects on the production of nitric oxide (NO) induced by lipopolysaccharide (LPS) in BV-2 microglia cells. Some jasmonates could dose-dependently reduce the expression of LPS-induced pro-inflammatory factors (iNOS and COX-2) and could block NF-κB nuclear translocation. This study suggested that Chinese acorns could be served as a healthy product for neuroinflammatory related diseases, such as Alzheimer's disease.

The therapeutic potential of bilobalide on experimental autoimmune encephalomyelitis (EAE) mice.

Inflammatory demyelination in the central nervous system (CNS) is a hallmark of multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Besides MS disease-modifying therapy, targeting myelin sheath protection/regeneration is currently a hot spot in the treatment of MS. Here, we attempt to explore the therapeutic potential of Bilobalide (BB) for the myelin protection/regeneration in EAE model. The results showed that BB treatment effectively prevented worsening and demyelination of EAE, accompanied by the inhibition of neuroinflammation that should be closely related to T cell tolerance and M2 macrophages/microglia polarization. BB treatment substantially inhibited the infiltration of T cells and macrophages, thereby alleviating the enlargement of neuroinflammation and the apoptosis of oligodendrocytes in CNS. The accurate mechanism of BB action and the feasibility of clinical application in the prevention and treatment of demyelination remain to be further explored.

Targeting Protein Neddylation for Cancer Therapy.

Neddylation is a posttranslational modification that conjugates a ubiquitin-like protein NEDD8 to substrate proteins. The best-characterized substrates of neddylation are the cullin subunits of cullin-RING E3 ubiquitin ligase complexes (CRLs). CRLs as the largest family of E3 ubiquitin ligases control many important biological processes, including tumorigenesis, through promoting ubiquitylation and subsequent degradation of a variety of key regulatory proteins. The process of protein neddylation is overactivated in multiple types of human cancers, providing a sound rationale as an attractive anticancer therapeutic strategy, evidenced by the development of the NEDD8-activating enzyme (NAE) inhibitor MLN4924 (also known as pevonedistat). Recently, increasing evidence strongly indicates that neddylation inhibition by MLN4924 exerts anticancer effects mainly by triggering cell apoptosis, senescence, and autophagy and causing angiogenesis suppression, inflammatory responses, and chemo-/radiosensitization in a context-dependent manner. Here, we briefly summarize the latest progresses in this field, focusing on the preclinical studies to validate neddylation modification as a promising anticancer target.

Neddylation-Independent Activities of MLN4924.

MLN4924, also known as pevonedistat, is a highly selective small-molecule inhibitor of NEDD8 (neuronal precursor cell-expressed developmentally downregulated protein 8)-activating enzyme (NAE) to block the entire neddylation modification cascade, leading to inactivation of cullin-RING ligases (CRLs), since activation of CRLs requires cullin neddylation. MLN4924 showed impressive anticancer activity in many preclinical studies and is currently in several Phase I/II clinical trials for anticancer therapy as a single agent or in combination with chemotherapeutic drugs.In addition to well-characterized anti-neddylation activity, recent studies showed that MLN4924 has several neddylation-independent activities. First, MLN4924 triggers EGFR dimerization to activate EGFR and its downstream RAS/MAPK and PI3K/AKT1 signals, leading to enhanced tumor sphere formation, accelerated EGF-mediated wound healing, and inhibited ciliogenesis. Second, MLN4924 induces PKM2 tetramerization to promote glycolysis, thus affecting energy metabolism. Third, MLN4924 inhibits the interaction between ACT1 (NF-κB activator 1) and TRAF6 (tumor necrosis factor receptor-associated factor 6) and attenuates IL-17A-mediated activation of NF-κB to reduce pulmonary inflammation. Fourth, MLN4924 inhibits IRF3 binding to the IFN-ß promoter to inhibit IFN-ß production. And finally, MLN4924 activates the JNK signaling pathway to reduce c-FLIP levels, thus enhancing TRAIL-induced apoptosis. This chapter will summarize these neddylation-independent activities of MLN4924 and discuss the underlying mechanisms and potential therapeutic applications.

A Meta-Analysis Comparing the Efficacy and Safety of Peramivir with Other Neuraminidase Inhibitors for Influenza Treatment.

BACKGROUND AND OBJECTIVES: This meta-analysis compared the efficacy and safety of peramivir compared to other neuraminidase inhibitors (NAIs). Materials and Methods: Data from PubMed, Embase, and Cochrane databases and ClinicalTrials.gov were searched until January 2019. Randomized controlled trials (RCTs) and observational studies (OSs) comparing peramivir with other NAIs for treating influenza were included. The Grading of Recommendations, Assessments, Development, and Evaluations (GRADE) system was used to judge the overall certainty of evidence; the result was moderate. The primary outcome was time to alleviation of symptoms. Twelve articles involving 2681 patients were included in this meta-analysis. We used a random-effect model to pool the effect size, which is expressed as the difference in means (MD), risk ratio (RR), and 95% confidence interval (CI). Results: Overall, peramivir was superior to other NAIs (MD = -11.214 hours, 95% CI: -19.119 to -3.310). The incidence of adverse events (RR = 1.023, 95% CI: 0.717 to 1.460) and serious adverse events (RR = 1.068, 95% CI: 0.702 to 1.625) in the peramivir group was similar to those in the oseltamivir group. In addition, peramivir had higher efficacy than each NAI alone. Conclusion: In conclusion, the efficacy of peramivir might be higher than that of other NAIs, and this agent is tolerated as well as other NAIs.

Neddylation: a novel modulator of the tumor microenvironment.

Neddylation, a post-translational modification that adds an ubiquitin-like protein NEDD8 to substrate proteins, modulates many important biological processes, including tumorigenesis. The process of protein neddylation is overactivated in multiple human cancers, providing a sound rationale for its targeting as an attractive anticancer therapeutic strategy, as evidence by the development of NEDD8-activating enzyme (NAE) inhibitor MLN4924 (also known as pevonedistat). Neddylation inhibition by MLN4924 exerts significantly anticancer effects mainly by triggering cell apoptosis, senescence and autophagy. Recently, intensive evidences reveal that inhibition of neddylation pathway, in addition to acting on tumor cells, also influences the functions of multiple important components of the tumor microenvironment (TME), including immune cells, cancer-associated fibroblasts (CAFs), cancer-associated endothelial cells (CAEs) and some factors, all of which are crucial for tumorigenesis. Here, we briefly summarize the latest progresses in this field to clarify the roles of neddylation in the TME, thus highlighting the overall anticancer efficacy of neddylaton inhibition.