Compartmentalized mitochondrial ferroptosis converges with optineurin-mediated mitophagy to impact airway epithelial cell phenotypes and asthma outcomes.

A stable mitochondrial pool is crucial for healthy cell function and survival. Altered redox biology can adversely affect mitochondria through induction of a variety of cell death and survival pathways, yet the understanding of mitochondria and their dysfunction in primary human cells and in specific disease states, including asthma, is modest. Ferroptosis is traditionally considered an iron dependent, hydroperoxy-phospholipid executed process, which induces cytosolic and mitochondrial damage to drive programmed cell death. However, in this report we identify a lipoxygenase orchestrated, compartmentally-targeted ferroptosis-associated peroxidation process which occurs in a subpopulation of dysfunctional mitochondria, without promoting cell death. Rather, this mitochondrial peroxidation process tightly couples with PTEN-induced kinase (PINK)-1(PINK1)-Parkin-Optineurin mediated mitophagy in an effort to preserve the pool of functional mitochondria and prevent cell death. These combined peroxidation processes lead to altered epithelial cell phenotypes and loss of ciliated cells which associate with worsened asthma severity. Ferroptosis-targeted interventions of this process could preserve healthy mitochondria, reverse cell phenotypic changes and improve disease outcomes.

[Establishment and evaluation of early in-hospital death prediction model for patients with acute pancreatitis in intensive care unit].

OBJECTIVE: To investigate the death risk prediction factors of acute pancreatitis (AP) patients in intensive care unit (ICU), and to establish a death prediction model and evaluate its efficacy. METHODS: A retrospective cohort study was conducted using the data in the Medical Information Mart for Intensive Care-III (MIMIC-III). The clinical data of 285 AP patients admitted to the ICU in the database were collected, including age, gender, blood routine and blood biochemical indicators, comorbidities, simplified acute physiology score III (SAPS III) and hospital prognosis. By using univariate analysis, the differences in the clinical data of the patients were compared between the two groups. Binary multivariate Logistic regression analysis was used to screen out independent predictors of in-hospital death in AP patients. A death prediction model was established, and the nomogram was drawn. The receiver operator characteristic curve (ROC curve) was plotted, and the area under the ROC curve (AUC) was used to test the discrimination of the prediction model. In addition, the prediction model was compared with the SAPS III score in predicting in-hospital death. The calibration ability of the prediction model was evaluated by the Hosmer-Lemeshow goodness of fit test, and a calibration map was drawn to show the calibration degree of the prediction model. RESULTS: Among 285 patients with AP, 29 patients died in the hospital and 256 patients survived. Univariate analysis showed that the patients in the death group were older than those in the survival group (years old: 70±17 vs. 58±16), and had higher white blood cell count (WBC), total bilirubin (TBil), serum creatinine (SCr), blood urea nitrogen (BUN), red blood cell volume distribution width (RDW), proportion of congestive heart failure and SAPS III score [WBC (×109/L): 18.5 (13.9, 24.3) vs. 13.2 (9.3, 17.9), TBil (µmol/L): 29.1 (15.4, 66.7) vs. 16.2 (10.3, 29.1), SCr (µmol/L): 114.9 (88.4, 300.6) vs. 79.6 (53.0, 114.9), BUN (mmol/L): 13.9 (9.3, 17.8) vs. 6.1 (3.7, 9.6), RDW: 0.152 (0.141, 0.165) vs. 0.141 (0.134, 0.150), congestive heart failure: 34.5% vs. 14.8%, SAPS III score: 66 (52, 90) vs. 39 (30, 48), all P < 0.05]. Multivariate Logistic regression analysis showed that age [odds ratio (OR) = 1.038, 95% confidence interval (95%CI) was 1.005-1.073], WBC (OR = 1.103, 95%CI was 1.038-1.172), TBil (OR = 1.247, 95%CI was 1.066-1.459), BUN (OR = 1.034, 95%CI was 1.014-1.055) and RDW (OR = 1.344, 95%CI was 1.024-1.764) were independent risk predictors of in-hospital death in patients with AP. Logistic regression model was established: Logit(P) = 0.037×age+0.098×WBC+0.221×TBil+0.033×BUN+0.296×RDW-12.133. ROC curve analysis showed that the AUC of the Logistic regression model for predicting the in-hospital death of patients with AP was 0.870 (95%CI was 0.794-0.946), the sensitivity was 86.2%, and the specificity was 78.5%, indicating that the model had good predictive performance, and it was superior to the SAPS III score [AUC was 0.831 (95%CI was 0.754-0.907), the sensitivity was 82.8%, and the specificity was 75.4%]. A nomogram model was established based on the result of multivariate Logistic regression analysis. The calibration map showed that the calibration curve of the nomogram model was very close to the standard curve, with the goodness of fit test: χ2 = 6.986, P = 0.538, indicating that the consistency between the predicted death risk of the nomogram model and the actual occurrence risk was relatively high. CONCLUSIONS: The older the AP patient is, the higher the WBC, TBil, BUN, and RDW, and the greater the risk of hospital death. The death prediction Logistic regression model and nomogram model constructed based on the above indicators have good discrimination ability and high accuracy for high-risk patients with hospital death, which can accurately predict the probability of death in AP patients and provide a basis for prognosis judgment and clinical treatment of AP patients.

BRD4 PROTAC degrader MZ1 exhibits anti-B-cell acute lymphoblastic leukemia effects via targeting CCND3.

INTRODUCTION: B-cell acute lymphoblastic leukemia (B-ALL) is the most prevalent malignant tumor affecting children. While the majority of B-ALL patients (90%) experience successful recovery, early relapse cases of B-ALL continue to exhibit high mortality rates. MZ1, a novel inhibitor of Bromodomains and extra-terminal (BET) proteins, has demonstrated potent antitumor activity against hematological malignancies. The objective of this study was to examine the role and therapeutic potential of MZ1 in the treatment of B-ALL. METHODS: In order to ascertain the fundamental mechanism of MZ1, a sequence of in vitro assays was conducted on B-ALL cell lines, encompassing Cell Counting Kit 8 (CCK8) assay, Propidium iodide (PI) staining, and Annexin V/PI staining. Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were employed to examine protein and mRNA expression levels. Transcriptomic RNA sequencing (RNA-seq) was utilized to screen the target genes of MZ1, and lentiviral transfection was employed to establish stably-expressing/knockdown cell lines. RESULTS: MZ1 has been observed to induce the degradation of Bromodomain Containing 4 (BRD4), Bromodomain Containing 3 (BRD3), and Bromodomain Containing 2 (BRD2) in B-ALL cell strains, leading to inhibited cell growth and induction of cell apoptosis and cycle arrest in vitro. These findings suggest that MZ1 exhibits cytotoxic effects on two distinct molecular subtypes of B-ALL, namely 697 (TCF3/PBX1) and RS4;11 (MLL-AF4) B-ALL cell lines. Additionally, RNA-sequencing analysis revealed that MZ1 significantly downregulated the expression of Cyclin D3 (CCND3) gene in B-ALL cell lines, which in turn promoted cell apoptosis, blocked cell cycle, and caused cell proliferation inhibition. CONCLUSION: Our results suggest that MZ1 has potential anti-B-ALL effects and might be a novel therapeutic target.

Multi-signaling pathway activation by pH responsive manganese particles for enhanced vaccination.

As metal ions play important roles in the process of immunomodulation, immunotherapy based on metal ions has attracted tremendous interests in recent years. Here, we screened common metal ions and found that Mn2+ could enhance the immune function in vitro. A new type of nanovaccine is thus fabricated by a biomimetic approach using nanoscale coordination polymer formed by Mn2+ and 2-methylimidazole (2-MI) to encapsulate ovalbumin (OVA) protein, a model antigen, obtaining OVA@MM nanoparticles. Compared to free OVA, OVA@MM nanoparticles could more effectively induce the maturation of bone marrow-derived dendritic cells (BMDCs) and their subsequent antigen cross-presentation. The particles made of Mn2+ and 2-MI could activate immune-regulated signal pathways to enhance the immune functions of BMDCs. Such OVA@MM nanovaccine could not only provide prophylactic effect to inhibit the growth of B16-OVA tumor on immunized mice, but also significantly inhibit tumor growth in the mice with B16-OVA tumor combined with anti-programmed cell death protein 1 (anti-PD-1) antibody. Therefore, this nanovaccine platform based on Mn2+, 2-MI and antigen may provide a simple, effective and broadly applicable strategy to enhance adaptive immunity against cancer and other diseases.

Smart Nanomedicine to Enable Crossing Blood-Brain Barrier Delivery of Checkpoint Blockade Antibody for Immunotherapy of Glioma.

Immune checkpoint blockade (ICB) therapy has shown tremendous promises in the treatment of various types of tumors. However, ICB therapy with antibodies appears to be less effective for glioma, partly owing to the existence of the blood-brain barrier (BBB) that impedes the entrance of therapeutics including most proteins to the central nervous system (CNS). Herein, considering the widely existing nicotinic acetylcholine receptors (nAChRs) and choline transporters (ChTs) on the surface of BBB, a choline analogue 2-methacryloyloxyethyl phosphorylcholine (MPC) is employed to fabricate the BBB-crossing copolymer via free-radical polymerization, followed by conjugation with antiprogrammed death-ligand 1 (anti-PD-L1) via a pH-sensitive traceless linker. The obtained nanoparticles exhibit significantly improved BBB-crossing capability owing to the receptor-mediated transportation after intravenous injection in an orthotopic glioma tumor model. Within the acidic glioma microenvironment, anti-PD-L1 would be released from such pH-responsive nanoparticles, further triggering highly effective ICB therapy of glioma to significantly prolong animal survival. This work thus realizes glioma microenvironment responsive BBB-crossing delivery of ICB antibodies, promising for the next generation immunotherapy of glioma.

Real-time imaging of asthmatic epithelial cells identifies migratory deficiencies under type-2 conditions.

BACKGROUND: The epithelium is increasingly recognized as a pathologic contributor to asthma and its phenotypes. Although delayed wound closure by asthmatic epithelial cells is consistently observed, underlying mechanisms remain poorly understood, partly due to difficulties in studying dynamic physiologic processes involving polarized multilayered cell systems. Although type-2 immunity has been suggested to play a role, the mechanisms by which repair is diminished are unclear. OBJECTIVES: This study sought to develop and utilize primary multilayered polarized epithelial cell systems, derived from patients with asthma, to evaluate cell migration in response to wounding under type-2 and untreated conditions. METHODS: A novel wounding device for multilayered polarized cells, along with time-lapse live cell/real-time confocal imaging were evaluated under IL-13 and untreated conditions. The influence of inhibition of 15 lipoxygenase (15LO1), a type-2 enzyme, on the process was also addressed. Cell migration patterns were analyzed by high-dimensional frequency modulated Möbius for statistical comparisons. RESULTS: IL-13 stimulation negatively impacts wound healing by altering the total speed, directionality, and acceleration of individual cells. Inhibition 15LO1 partially improved the wound repair through improving total speed. CONCLUSIONS: Migration abnormalities contributed to markedly slower wound closure of IL-13 treated cells, which was modestly reversed by 15LO1 inhibition, suggesting its potential as an asthma therapeutic target. These novel methodologies offer new ways to dynamically study cell movements and identify contributing pathologic processes.

Machine learning implicates the IL-18 signaling axis in severe asthma.

Asthma is a common disease with profoundly variable natural history and patient morbidity. Heterogeneity has long been appreciated, and much work has focused on identifying subgroups of patients with similar pathobiological underpinnings. Previous studies of the Severe Asthma Research Program (SARP) cohort linked gene expression changes to specific clinical and physiologic characteristics. While invaluable for hypothesis generation, these data include extensive candidate gene lists that complicate target identification and validation. In this analysis, we performed unsupervised clustering of the SARP cohort using bronchial epithelial cell gene expression data, identifying a transcriptional signature for participants suffering exacerbation-prone asthma with impaired lung function. Clinically, participants in this asthma cluster exhibited a mixed inflammatory process and bore transcriptional hallmarks of NF-κB and activator protein 1 (AP-1) activation, despite high corticosteroid exposure. Using supervised machine learning, we found a set of 31 genes that classified patients with high accuracy and could reconstitute clinical and transcriptional hallmarks of our patient clustering in an external cohort. Of these genes, IL18R1 (IL-18 Receptor 1) negatively associated with lung function and was highly expressed in the most severe patient cluster. We validated IL18R1 protein expression in lung tissue and identified downstream NF-κB and AP-1 activity, supporting IL-18 signaling in severe asthma pathogenesis and highlighting this approach for gene and pathway discovery.

Furin Enzyme and pH Synergistically Triggered Aggregation of Gold Nanoparticles for Activated Photoacoustic Imaging and Photothermal Therapy of Tumors.

Specific and effective accumulation of nanoparticles within tumors is highly crucial for precise cancer diagnosis and treatment. Therefore, spatiotemporally manipulating the aggregation of small gold nanoparticles (AuNPs) in a tumor microenvironment is of great significance for enhancing the diagnostic and therapeutic efficacy of tumors. Herein, we reported a novel furin enzyme/acidic pH synergistically triggered small AuNP aggregation strategy for activating the photoacoustic (PA) imaging and photothermal (PTT) functions of AuNPs in vivo. Smart gold nanoparticles decorated with furin-cleavable RVRR (Arg-Val-Arg-Arg) peptides (Au-RRVR) were rationally designed and fabricated. Both in vitro and in vivo experiments demonstrated that such Au-RRVR nanoparticles could be simultaneously induced by furin and acidic pH to form large aggregates within tumorous tissue resulting in improved tumor accumulation and retention, which can further activate the PA and PTT effect of AuNPs for sensitive imaging and efficient therapy of tumors. Thus, we believe that this dual-stimuli-responsive aggregation system may offer a universal platform for effective cancer diagnosis and treatment.

15-Lipoxygenase 1 in nasal polyps promotes CCL26/eotaxin 3 expression through extracellular signal-regulated kinase activation.

BACKGROUND: 15-Lipoxygenase 1 (15LO1) is expressed in airway epithelial cells in patients with type 2-high asthma in association with eosinophilia. Chronic rhinosinusitis with nasal polyps (CRSwNP) is also associated with type 2 inflammation and eosinophilia. CCL26/eotaxin 3 has been reported to be regulated by 15LO1 in lower airway epithelial cells. However, its relation to 15LO1 in patients with CRSwNP or mechanisms for its activation are unclear. OBJECTIVE: We sought to evaluate 15LO1 and CCL26 expression in nasal epithelial cells (NECs) from patients with CRSwNP and healthy control subjects (HCs) and determine whether 15LO1 regulates CCL26 in NECs through extracellular signal-regulated kinase (ERK) activation. METHODS: 15LO1, CCL26, and phosphorylated ERK were evaluated in NECs from patients with CRSwNP and HCs. 15LO1/CCL26 and CCL26/cytokeratin 5 were colocalized by means of immunofluorescence. IL-13-stimulated NECs were cultured at an air-liquid interface with or without 15-lipoxygenase 1 gene (ALOX15) Dicer-substrate short interfering RNAs (DsiRNA) transfection, a specific 15LO1 enzymatic inhibitor, and 2 ERK inhibitors. Expression of 15LO1 and CCL26 mRNA and protein was analyzed by using quantitative RT-PCR, Western blotting, and ELISA. RESULTS: 15LO1 expression was increased in nasal polyp (NP) epithelial cells compared with middle turbinate epithelial cells from patients with CRSwNP and HCs. 15LO1 expression correlated with CCL26 expression and colocalized with CCL26 expression in basal cells of the middle turbinate and NPs from patients with CRSwNP. In primary NECs in vitro, IL-13 induced 15LO1 and CCL26 expression. 15LO1 knockdown and inhibition decreased IL-13-induced ERK phosphorylation and CCL26 expression. ERK inhibition (alone) similarly decreased IL-13-induced CCL26. Phosphorylated ERK expression was increased in NECs from CRSwNP subjects and positively correlated with both 15LO1 and CCL26 expression. CONCLUSIONS: 15LO1 expression is increased in NP epithelial cells and contributes to CCL26 expression through ERK activation. 15LO1 could be considered a novel therapeutic target for CRSwNP.

Sialylation of MUC4ß N-glycans by ST6GAL1 orchestrates human airway epithelial cell differentiation associated with type-2 inflammation.

Although type-2-induced (T2-induced) epithelial dysfunction is likely to profoundly alter epithelial differentiation and repair in asthma, the mechanisms for these effects are poorly understood. A role for specific mucins, heavily N-glycosylated epithelial glycoproteins, in orchestrating epithelial cell fate in response to T2 stimuli has not previously been investigated. Levels of a sialylated MUC4ß isoform were found to be increased in airway specimens from asthmatic patients in association with T2 inflammation. We hypothesized that IL-13 would increase sialylation of MUC4ß, thereby altering its function and that the ß-galactoside α-2,6-sialyltransferase 1 (ST6GAL1) would regulate the sialylation. Using human biologic specimens and cultured primary human airway epithelial cells (HAECs),we demonstrated that IL-13 increases ST6GAL1-mediated sialylation of MUC4ß and that both were increased in asthma, particularly in sputum supernatant and/or fresh isolated HAECs with elevated T2 biomarkers. ST6GAL1-induced sialylation of MUC4ß altered its lectin binding and secretion. Both ST6GAL1 and MUC4ß inhibited epithelial cell proliferation while promoting goblet cell differentiation. These in vivo and in vitro data provide strong evidence for a critical role for ST6GAL1-induced sialylation of MUC4ß in epithelial dysfunction associated with T2-high asthma, thereby identifying specific sialylation pathways as potential targets in asthma.

Dysfunctional ErbB2, an EGF receptor family member, hinders repair of airway epithelial cells from asthmatic patients.

BACKGROUND: Genetic and genomic data increasingly point to the airway epithelium as critical to asthma pathogenesis. Epithelial growth factor (EGF) family members play a fundamental role in epithelial differentiation, proliferation, and repair. Although expression of erythroblastosis oncogene B2 (ErbB2) mRNA, an EGF family receptor, was reported to be lower in asthmatic patients, little is understood about its functional role. OBJECTIVE: We sought to determine whether decreased ErbB2 activation in freshly isolated human airway epithelial cells (HAECs) from asthmatic patients associated with impaired wound closure in vitro. METHODS: An in vitro scratch-wound model of air-liquid interface cultured and freshly isolated HAECs were compared between HAECs from healthy control subjects (HCs) and asthmatic patients in relation to ErbB2. RESULTS: Freshly brushed HAECs from asthmatic patients had impaired ErbB2 activation compared with those from HCs. In an in vitro scratch-wound model, HAECs from asthmatic patients showed delayed wound closure compared with HAECs from HCs. Cell proliferation, as assessed based on [3H] thymidine incorporation after wounding, and expression or activation of ErbB2 and cyclin D1 at the leading edge of the wound were lower in HAECs from asthmatic patients and HCs. A selective ErbB2 tyrosine kinase inhibitor, mubritinib, impaired wound closure and decreased cyclin D1 expression in healthy HAECs, with less effect on cells from asthmatic patients, supporting diminished activity in asthmatic patients. CONCLUSION: These results implicate a primary defect in the ErbB2 pathway as constraining epithelial repair processes in asthmatic patients. Restoration of homeostatic ErbB2 function should be considered a novel asthma therapeutic target.

Rottlerin inhibits cell growth and invasion via down-regulation of EZH2 in prostate cancer.

Rottlerin as a natural agent, which is isolated from Mallotus philippinensis, has been identified to play a critical role in tumor inhibition. However, the molecular mechanism of rottlerin-mediated anti-tumor activity is still ambiguous. It has been reported that EZH2 exhibits oncogenic functions in a variety of human cancers. Therefore, inhibition of EZH2 could be a promising strategy for the treatment of human cancers. In this study, we aim to explore whether rottlerin could inhibit tumorigenesis via suppression of EZH2 in prostate cancer cells. Multiple approaches such as FACS, Transwell invasion assay, RT-PCR, Western blotting, and transfection were performed to determine our aim. We found that rottlerin treatment led to inhibition of cell growth, migration and invasion, but induction of apoptosis in prostate cancer cells. Importantly, we defined that rottlerin decreased the expression of EZH2 and H3K27me3 in prostate cancer cells. Moreover, overexpression of EZH2 abrogated the rottlerin-induced inhibition of cell growth, migration, and invasion in prostate cancer cells. Consistently, down-regulation of EZH2 enhanced rottlerin-triggered anti-tumor function. Collectively, our work demonstrated that rottlerin exerted its tumor suppressive function via inhibition of EZH2 expression in prostate cancer cells. Our findings indicated that rottlerin might be a potential therapeutic compound for treating patients with prostate cancer.

Inhibition of Notch-1 pathway is involved in rottlerin-induced tumor suppressive function in nasopharyngeal carcinoma cells.

Recent studies have revealed that rottlerin is a natural chemical drug to exert its anti-cancer activity. However, the molecular mechanisms of rottlerin-induced tumor suppressive function have not been fully elucidated. Notch signaling pathway has been characterized to play a crucial role in tumorigenesis. Therefore, regulation of Notch pathway could be beneficial for the treatment of human cancer. The aims of our current study were to explore whether rottlerin could suppress Notch-1 expression, which leads to inhibition of cell proliferation, migration and invasion in nasopharyngeal carcinoma cells. We performed several approaches, such as CTG, Flow cytometry, scratch healing assay, transwell and Western blotting. Our results showed that rottlerin treatment inhibited cell growth, migration and invasion, and triggered apoptosis, and arrested cell cycle to G1 phase. Moreover, the expression of Notch-1 was obvious decreased in nasopharyngeal carcinoma cells after rottlerin treatment. Importantly, overexpression of Notch-1 promoted cell growth and invasion, whereas down-regulation of Notch-1 inhibited cell growth and invasion in nasopharyngeal carcinoma cells. Notably, we found the over-expression of Notch-1 could abrogate the anti-cancer function induced by rottlerin. Strikingly, our study implied that Notch-1 could be a useful target of rottlerin for the prevention and treatment of human nasopharyngeal carcinoma.

Regulation of RIP3 by the transcription factor Sp1 and the epigenetic regulator UHRF1 modulates cancer cell necroptosis.

Receptor-interacting kinase-3 (RIP3) is a key regulator of necroptosis. It has been shown that the expression of RIP3 is silenced in most cancer cells and tissues due to genomic methylation. However, the regulatory mechanisms controlling RIP3 expression in cancer cells have not been fully elucidated. Here, we report that Sp1, a well-characterized zinc-finger transcription factor, directly regulates RIP3 expression in cancer cells. Knockdown of endogenous Sp1 significantly decreases the transcription of Rip3, thereby further inhibiting necroptosis. The re-expression of Sp1 restores the necroptotic response. In addition, knockdown of epigenetic regulator UHRF1 (ubiquitin-like, containing PHD and RING finger domains 1) in RIP3-null cancer cells reduces the methylation level of the Rip3 promoter. This effect is sufficient to trigger the expression of RIP3 in RIP3-null cancer cells. The induced expression of RIP3 by UHRF1 RNAi depends on the presence of Sp1. Remarkably, the ectopic expression of RIP3 in RIP3-null cancer cells results in a decrease in tumor growth in mice. Therefore, our findings offer insights into RIP3 expression control in cancer cells and suggest an inhibitory effect of RIP3 on tumorigenesis.

MiR-26b reverses temozolomide resistance via targeting Wee1 in glioma cells.

Emerging evidence has demonstrated that microRNAs (miRNA) play a critical role in chemotherapy-induced epithelial-mesenchymal transition (EMT) in glioma. However, the underlying mechanism of chemotherapy-triggered EMT has not been fully understood. In the current study, we determined the role of miR-26b in regulation of EMT in stable temozolomide (TMZ)-resistant (TR) glioma cells, which have displayed mesenchymal features. Our results illustrated that miR-26b was significantly downregulated in TR cells. Moreover, ectopic expression of miR-26b by its mimics reversed the phenotype of EMT in TR cells. Furthermore, we found that miR-26b governed TR-mediate EMT partly due to governing its target Wee1. Notably, overexpression of miR-26b sensitized TR cells to TMZ. These findings suggest that upregulation of miR-26b or targeting Wee1 could serve as novel approaches to reverse chemotherapy resistance in glioma.

The effects of curcumin on proliferation, apoptosis, invasion, and NEDD4 expression in pancreatic cancer.

Pancreatic cancer (PC) is one of the most fatal cancers worldwide. The incidence and death rates are still increasing for PC. Curcumin is the biologically active diarylheptanoid constituent of the spice turmeric, which exerts its anticancer properties in various human cancers including PC. In particular, accumulating evidence has proved that curcumin targets numerous therapeutically important proteins in cell signaling pathways. The neural precursor cell expressed developmentally down-regulated protein 4 (NEDD4) is an E3 HECT ubiquitin ligase and is frequently over-expressed in various cancers. It has reported that NEDD4 might facilitate tumorigenesis via targeting and degradation of multiple tumor suppressor proteins including PTEN. Hence, in the present study we explore whether curcumin inhibits NEDD4, resulting in the suppression of cell growth, migration and invasion in PC cells. We found that curcumin inhibited cell proliferation and triggered apoptosis in PC, which is associated with increased expression of PTEN and p73. These results suggested that inhibition of NEDD4 might be beneficial to the antitumor properties of curcumin on PC treatments.

Rottlerin exhibits antitumor activity via down-regulation of TAZ in non-small cell lung cancer.

Rottlerin, a polyphenolic compound derived from Mallotus philipinensis, has been reported to exhibit anti-tumor activities in a variety of human malignancies including NSCLC (non-small cell lung cancer). TAZ (transcriptional co-activator with PDZ-binding motif), one of the key activators in Hippo pathway, has been characterized as an oncoprotein. Therefore, inhibition of TAZ could be useful for the treatment of human cancers. In the current study, we aimed to explore whether rottlerin inhibits the expression of TAZ in NSCLC, leading to its anti-cancer activity. Multiple approaches were applied for determining the mechanism of rottlerin-mediated anti-tumor function, including cell growth assay, Flow cytometry, wound healing assay, invasion assay, Western blotting, and transfection. We found that rottlerin inhibited cell growth, triggered apoptosis, arrested cell cycle, and retarded cell invasion in NSCLC cells. Moreover, our results showed that overexpression of TAZ enhanced cell growth, stimulated apoptosis, and promoted cell migration and invasion. Consistently, inhibition of TAZ exhibited anti-tumor activity in NSCLC cells. Notably, we validated that rottlerin exerted its tumor suppressive function via inactivation of TAZ in NSCLC cells. Taken together, our study indicates that inhibition of TAZ by rottlerin could be a promising strategy for the prevention and therapy of NSCLC.

Rottlerin exhibits anti-cancer effect through inactivation of S phase kinase-associated protein 2 in pancreatic cancer cells.

Rottlerin, a natural product isolated from Mallotus philippinensis, has been characterized as an effective chemoprevention agent in inhibiting tumor cell growth. Although multiple studies have revealed the role of rottlerin in tumorigenesis, the molecular mechanism of rottlerin-mediated anti-tumor activity has not been fully elucidated. It has been reported that Skp2 (S-phase kinase associated protein 2) plays an oncogenic role in human malignancies, indicating that inactivation of Skp2 could be a promising approach for the treatment of cancers. Therefore, in this study, we aim to investigate whether rottlerin exhibits its anti-tumor activities via targeting Skp2 pathway in pancreatic cancer. We found that rottlerin inhibited cell growth, induced apoptosis, arrested cell cycle, and retarded cell invasion and migration. Notably, we observed that the expression of Skp2 was significantly decreased in rottlerin-treated pancreatic cancer cells. Importantly, overexpression of Skp2 abrogated the anti-tumor function induced by rottlerin in pancreatic cancer cells. Consistently, depletion of Skp2 promoted rottlerin-mediated inhibition of cell growth and invasion. Collectively, our study demonstrated that rottlerin could suppress Skp2 expression and subsequently exert its tumor suppressive function in pancreatic cancer cells, suggesting that rottlerin might be a potential therapeutic compound for treating pancreatic cancer.

Curcumin inhibits cell growth and invasion and induces apoptosis through down-regulation of Skp2 in pancreatic cancer cells.

Natural polyphenol compound curcumin has been found to exhibit its anticancer activity in a variety of human malignancies including pancreatic cancer (PC). However, the underlying mechanism has not been fully understood. Accumulating evidence has demonstrated that Skp2 (S-phase kinase associated protein 2) plays an oncogenic role in the development and progression of human cancers. In this study, we aim to explore the molecular basis of curcumin-induced cell growth inhibition in PC cells.Multiple methods such as CTG assay, Flow cytometry, clonogenic assay, wound healing assay, Transwell invasion assay, Western blotting, and transfection were performed to validate the oncogenic role of curcumin in PC cells. We found that curcumin suppressed cell growth, clonogenic potential, migration and invasion, and induced cell apoptosis and cell cycle arrest. Moreover, we observed thatover-expression of Skp2 significantly promoted cell growth, whereas down-regulation of Skp2 with siRNAs inhibited cell growth. The molecular basis of curcumin-mediated cell growth inhibition we identified is that curcumin significantly suppressed Skp2 expression and subsequently induced p21 expression. These findings suggested thattargeting Skp2 by curcumin could be a promising therapeutic strategy for the treatment of PC patients.