Molecular mechanisms of curcumins suppressing effects on tumorigenesis, angiogenesis and metastasis, focusing on NF-κB pathway

Inhibition of NF-κB signaling unveils novel strategies to overcome drug resistance in cancers

Drug resistance in cancer remains a major challenge in oncology, impeding the effectiveness of various treatment modalities. The nuclear factor-kappa B (NF-κB) signaling pathway has emerged as a critical player in the development of drug resistance in cancer cells. This comprehensive review explores the intricate relationship between NF-κB and drug resistance in cancer. We delve into the molecular mechanisms through which NF-κB activation contributes to resistance against chemotherapeutic agents, targeted therapies, and immunotherapies. Additionally, we discuss potential strategies to overcome this resistance by targeting NF-κB signaling, such as small molecule inhibitors and combination therapies. Understanding the multifaceted interactions between NF-κB and drug resistance is crucial for the development of more effective cancer treatment strategies. By dissecting the complex signaling network of NF-κB, we hope to shed light on novel therapeutic approaches that can enhance treatment outcomes, ultimately improving the prognosis for cancer patients. This review aims to provide a comprehensive overview of the current state of knowledge on NF-κB and its role in drug resistance, offering insights that may guide future research and therapeutic interventions in the fight against cancer.

Cancer Metabolism as a Therapeutic Target and Review of Interventions

Cancer is amenable to low-cost treatments, given that it has a significant metabolic component, which can be affected through diet and lifestyle change at minimal cost. The Warburg hypothesis states that cancer cells have an altered cell metabolism towards anaerobic glycolysis. Given this metabolic reprogramming in cancer cells, it is possible to target cancers metabolically by depriving them of glucose. In addition to dietary and lifestyle modifications which work on tumors metabolically, there are a panoply of nutritional supplements and repurposed drugs associated with cancer prevention and better treatment outcomes. These interventions and their evidentiary basis are covered in the latter half of this review to guide future cancer treatment.

Application of Polyphenols and Flavonoids in Oncological Therapy

The use of naturally derived drugs in anti-cancer therapies has grown exponentially in recent years. Among natural compounds, polyphenols have shown potential therapeutic applications in treatment due to their protective functions in plants, their use as food additives, and their excellent antioxidant properties, resulting in beneficial effects on human health. Building more efficient cancer therapies with fewer side effects on human health can be achieved by combining natural compounds with conventional drugs, which are typically more aggressive than natural chemicals with polyphenols. This article reviews a wide variety of studies where polyphenolic compounds can play a key role as anticancer drugs, alone or in combination with other drugs. Moreover, the future directions of applications of various polyphenols in cancer therapy are shown.

Antiskin Aging Effects of Indole Alkaloid N-Glycoside from Ginkgo Fruit (Ginkgo biloba fruit) on TNF-α-Exposed Human Dermal Fibroblasts

Human skin aging has internal and external factors, both of which are characterized by TNF-α overproduction. Therefore, we aimed to identify a natural product that suppresses the damage that occurs in cutaneous dermal fibroblasts exposed to TNF-α. The protective effects of the indole alkaloid N-glycoside, ginkgoside B dimethyl ester (GBDE), isolated from ginkgo fruit (Ginkgo biloba fruit) were evaluated in TNF-α stimulated human dermal fibroblasts (HDFs). GBDE inhibited TNF-α-induced MMP-1 expression to 2.2 ± 0.1-fold (p < 0.01) and reversed the decrease in collagen levels to 0.4 ± 0.00-fold (p < 0.01) at 50 μM. The effect of GBDE was due to the suppression of the phospolylaton of MAPKs (ERK, 0.47 ± 0.05; JNK, 1.21 ± 0.07; p38, 0.77 ± 0.07-folds, p < 0.001) and Akt (0.14 ± 0.03-fold, p < 0.001) compared to the TNF-α group. GBDE also reduced the expression of COX-2 to 2.06 ± 0.12-fold (p < 0.001) and increased the expression of HO-1 to 10.64 ± 0.2-fold (p < 0.001). In addition, GBDE inhibited the expression of the pro-inflammatory cytokines (IL-8, 2.2 ± 0.0; IL-1β, 1.6 ± 0.0; IL-6, 2.0 ± 0.10-folds, p < 0.05). These results provide experimental evidence that GBDE can protect against skin damage, including aging.

Emerging roles of TRIM27 in cancer and other human diseases

As a member of the TRIM protein family, TRIM27 is a RING-mediated E3 ubiquitin ligase that can mark other proteins for degradation. Its ubiquitination targets include PTEN, IκBα and p53, which allows it to regulate many signaling pathways to exert its functions under both physiological and pathological conditions, such as cell proliferation, differentiation and apoptosis. During the past decades, TRIM27 was reported to be involved in many diseases, including cancer, lupus nephritis, ischemia-reperfusion injury and Parkinson’s disease. Although the research interest in TRIM27 is increasing, there are few reviews about the diverse roles of this protein. Here, we systematically review the roles of TRIM27 in cancer and other human diseases. Firstly, we introduce the biological functions of TRIM27. Next, we focus on the roles of TRIM27 in cancer, including ovarian cancer, breast cancer and lung cancer. At the same time, we also describe the roles of TRIM27 in other human diseases, such as lupus nephritis, ischemia-reperfusion injury and Parkinson’s disease. Finally, we discuss the future directions of TRIM27 research, especially its potential roles in tumor immunity.

Antitumor Potential of Immunomodulatory Natural Products

Cancer is one of the leading causes of death globally. Anticancer drugs aim to block tumor growth by killing cancerous cells in order to prevent tumor progression and metastasis. Efficient anticancer drugs should also minimize general toxicity towards organs and healthy cells. Tumor growth can also be successfully restrained by targeting and modulating immune response. Cancer immunotherapy is assuming a growing relevance in the fight against cancer and has recently aroused much interest for its wider safety and the capability to complement conventional chemotherapeutic approaches. Natural products are a traditional source of molecules with relevant potential in the pharmacological field. The huge structural diversity of metabolites with low molecular weight (small molecules) from terrestrial and marine organisms has provided lead compounds for the discovery of many modern anticancer drugs. Many natural products combine chemo-protective and immunomodulant activity, thus offering the potential to be used alone or in association with conventional cancer therapy. In this review, we report the natural products known to possess antitumor properties by interaction with immune system, as well as discuss the possible immunomodulatory mechanisms of these molecules.

Dihydroartemisinin Inhibits Laser-Induced Choroidal Neovascularization in a Mouse Model of Neovascular AMD

Purpose: Choroidal neovascularization (CNV) is the main pathogenic process and a leading cause of severe vision loss in neovascular age-related macular degeneration (AMD). We investigated the antiangiogenic efficacy of dihydroartemisinin (DHA) in an experimental laser-induced CNV mouse model.

Methods: After fluorescein angiography confirmed that CNV was induced by laser photocoagulation in C57BL/6J mice, DHA or vehicle was given by intragastric administration once a day. On day 6 and day 12, fluorescein angiography, optic coherence tomography, and flat-mounting analysis were performed to grade CNV leakage, measure CNV thickness and evaluate CNV areas, respectively. Immunofluorescence staining and Western blot analysis were performed to evaluate the expression of NF-κB, VEGF, and VEGFR2. To confirm the safety of intragastric DHA application, changes in retinal morphology and neural cell apoptosis were tested by histopathological examination and TUNEL assay, and retinal function was determined by electroretinogram (ERG).

Results: Intragastric administration of DHA significantly suppressed CNV leakage and CNV formation in both thickness and area. Immunofluorescence showed that DHA suppressed VEGFR2 and NF-κB p65 expression in laser-induced lesions. Compared to the normal group, the protein expression of VEGF, VGFER2, NF-κB p65, and NF-κB1 p50 increased significantly in the vehicle group after laser photocoagulation, while it was profoundly inhibited by DHA treatment. In addition, histopathological examination, TUNEL analysis, and ERG test showed no obvious evidence of retinal toxicity caused by DHA.

Conclusion: Systemic administration of DHA can effectively inhibit laser-induced CNV formation in mice, which might be due to the suppression of the classic NF-κB signaling pathway and downregulation of VEGFR2 and VEGF expression. The current results suggest that DHA could be a natural potential alternative therapeutic strategy for neovascular AMD.

N6-Methyladenosine Writer Gene ZC3H13 Predicts Immune Phenotype and Therapeutic Opportunities in Kidney Renal Clear Cell Carcinoma

Background

Although the RNA modification N6-methyladenosine ZC3H13 has been found to play vital regulatory roles in many types of cancers, its role in predicting the tumor immune microenvironment (TME) and response to immune checkpoint blockade (ICB) in kidney renal clear cell carcinoma (KIRC) remains unclear.

Methods

We comprehensively analyzed the expression, prognostic significance and immunological role of ZC3H13 in pan-cancers and systematically correlated ZC3H13 with TME cell-infiltration, ICB response and targeted therapy in KIRC. The data were collected from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), Genotype-Tissue Expression (GTEx), Broad Institute Cancer Cell Line Encyclopedia (CCLE) and DrugBank database. Also, we performed RNA sequencing (RNA-seq) of 46 renal cell carcinoma tissues and 11 adjacent normal tissues to validate our result. All analyses were implemented using R software, version 3.6.3.

Results

ZC3H13 was significantly differentially expressed in most tumors. However, its expression profiles and prognostic significance were consistent only in KIRC, regardless of overall survival, progression-free survival and cancer-specific survival. Additionally, ZC3H13 expression was correlated with clinicopathological factors in KIRC. Furthermore, we found that ZC3H13 might shape a noninflamed phenotype and could predict a lower response to ICB in KIRC. These results could be validated in our own RNA-seq data. Tumor mutation burden (TMB) was significantly higher in the low ZC3H13 group. Finally, we found that ZC3H13 could predict the sensitivity of targeted therapy for KIRC.

Conclusions

ZC3H13 might shape a noninflamed phenotype in KIRC. Moreover, ZC3H13 could predict the prognosis and clinical response of ICB and the sensitivity to targeted therapies in KIRC.

An m6A-Related Prognostic Biomarker Associated With the Hepatocellular Carcinoma Immune Microenvironment

Background: N6-methyladenosine (m6A) is related to the progression of multiple cancers. However, the underlying influences of m6A-associated genes on the tumor immune microenvironment in hepatocellular carcinoma (HCC) remain poorly understood. Therefore, we sought to construct a survival prediction model using m6A-associated genes to clarify the molecular and immune characteristics of HCC.

Methods: HCC case data were downloaded from The Cancer Genome Atlas (TCGA). Then, by applying consensus clustering, we identified two distinct HCC clusters. Next, four m6A-related genes were identified to construct a prognostic model, which we validated with Gene Expression Omnibus (GEO) and International Cancer Genome Consortium (ICGC) datasets. Additionally, the molecular and immune characteristics in different subgroups were analyzed.

Results: m6A RNA methylation regulators were differentially expressed between HCC and normal samples and linked with immune checkpoint expression. Using consensus clustering, we divided HCC samples into two subtypes with distinct clinical features. Cluster 2 was associated with unfavorable prognosis, higher immune checkpoint expression and immune cell infiltration levels. In addition, the immune and carcinogenic signaling pathways were enriched in cluster 2. Furthermore, we constructed a risk model using four m6A-associated genes. Patients with different risk scores had distinct survival times, expression levels of immunotherapy biomarkers, TP53 mutation rates, and sensitivities to chemotherapy and targeted therapy. Similarly, the model exhibited an identical impact on overall survival in the validation cohorts.

Conclusion: The constructed m6A-based signature may be promising as a biomarker for prognostics and to distinguish immune characteristics in HCC.

Effect of miR-196a inhibition on esophageal cancer growth in vitro

Esophageal cancer has recent shown a higher incidence but lower 5-year survival rate after normal clinical treatment in China. The aim of this study was to observe whether the inhibition of miR-196a affects esophageal cancer cell growth by modulating the nuclear factor-κB target gene and to detect the possible cooperative therapeutic effects on esophageal cancer by knocking down miR-196a expression combined with the specific inhibitor of nuclear factor-κB target genes. Thus, anti-miR-196a or sotrastaurin, a protein kinase C (PKC) inhibitor, were used to alter PKC expression. We found that miR-196a knockdown or PKC inhibition by sotrastaurin changed PKC expression which then reduced esophageal cancer cell proliferation and downregulated proliferating cell nuclear antigen expression via the classical B-cell receptor-PKC nuclear factor-κB pathway but not the alternative pathway; in addition, miR-196a inhibition can increase the caspase level and induce esophageal cancer cell apoptosis. Our current results provided the evidence that miR-196a was related to the classical nuclear factor-κB pathway, and these new findings proved the potential therapeutic effect of miR-196a in targeted therapy for clinical esophageal cancer patients.

Ubiquitination in rheumatoid arthritis

Rheumatoid arthritis is a chronic, inflammatory joint disease leading to inflammation of synovial membrane that lines the joints. This inflammation further progresses and results in destruction of joints and surrounding cartilages. The underlying factors can be oxidative stress, pro-inflammatory mediators, imbalance and attenuation between various enzymes and proteins (like nuclear factor erythroid 2 related factor 2/Nrf2 and ubiquitin). Protein degradation pathways comprises of lysosomal, proteasomal pathway, and autophagosome (that are carried out in mammalian cells) are regulated through ubiquitin. Ubiquitin proteasomal system is dominating pathway for carrying out non-lysosomal proteolysis of intracellularly proteins. Fundamental processes including cell cycle progression, process of division, apoptosis, modulation of immune responses and cell trafficking are regulated by process of ubiquitination. Ubiquitin proteasomal pathway (UPP) includes ubiquitin moieties which are covalently attached to proteins and guides them proteasome for degradation. Misfolded, oxidized and damaged proteins which are responsible for critical processes, are major targets of degradation process. Any alteration in this system leads to dysregulated cellular homeostasis; progressively leading to numerous diseases including rheumatoid arthritis. Factors including TAK1, TRAF6 undergo are required for the progression of disease and thus contributes towards pathology of inflammatory disorders such as rheumatoid arthritis. This review will include all linked aspects which contribute its major role in rheumatoid arthritis.

Curcumin inhibits migration and invasion of non-small cell lung cancer cells through up-regulation of miR-206 and suppression of PI3K/AKT/mTOR signaling pathway

Curcumin has been proved to inhibit cell proliferation and induce cell apoptosis in non-small cell lung cancer (NSCLC). However, little is known about antimetastatic effects and molecular mechanisms of curcumin in NSCLC. In this study, we investigated the involvement of miR-206 in curcumin's anti-invasion and anti-migration in NSCLC. Cell proliferation was determined by MTT assay. Cell migration and invasion were analyzed by wound healing assay and transwell assay. MiRNA-206 expression was detected by real-time PCR. Western blot was used to detect the protein expression of PI3K/AKT/mTOR signaling pathway. Curcumin significantly inhibited migration and invasion in A549 cells, accompanied by significantly elevated miR-206 expression. Overexpression of miR-206 could inhibit migration and invasion of A549 cells, but it could also significantly decrease the phosphorylation levels of mTOR and AKT. The inhibition of miR-206 promoted cell migration, invasion and increased the phosphorylation level of mTOR and AKT. Furthermore, miR-206 mimics improved the inhibitory effects of curcumin on cell migration, invasion and the phosphorylation level of mTOR and AKT in A549 cells. On the contrary, MiR-206 inhibitors reversed the inhibitory effects of curcumin on cell migration, invasion and the phosphorylation level of mTOR and AKT. In conclusion, curcumin inhibited cell invasion and migration in NSCLC by elevating the expression of miR-206 which further suppressed the activation of the PI3K/AKT/mTOR pathway.

MicroRNA-410-3p modulates chondrocyte apoptosis and inflammation by targeting high mobility group box 1 (HMGB1) in an osteoarthritis mouse model

Background

Osteoarthritis (OA) is the most prevalent type of arthritis, which commonly involves inflammation in the articular cartilage in OA pathogenesis. MicroRNAs (miRNAs) play essential roles in the regulation and pathophysiology of various diseases including OA. MiR-410-3p has been demonstrated to mediate inflammatory pathways, however, the regulatory functions of miR-410-3p in OA remain largely unknown.

Methods

The regulations of miR-410-3p were investigated in OA. Mouse primary chondrocytes and mouse in vivo models were used. The expression levels of miR-410-3p and HMGB1 were measured by qPCR. The transcription activity of NF-κB was assessed by luciferase reporter assay. MTT assay was performed to assess cellular proliferation. Cell apoptosis was evaluated with the Fluorescein Isothiocyanate (FITC) Annexin V assay. Expression levels of proteins were determined by Western blot.

Results

The results demonstrated that miR-410-3p was markedly downregulated in articular cartilage tissues as well as in lipopolysaccharide (LPS)-treated chondrocytes in OA mice. In addition, upregulation of miR-410-3p markedly inhibited LPS-induced apoptosis of chondrocytes. The results also demonstrated that the high mobility group box 1 (HMGB1) was a target of miR-410-3p. LPS-induced upregulated expression of HMGB1 significantly suppressed expression of miR-410-3p. Furthermore, upregulation of miR-410-3p markedly inhibited HMGB1 expression, the nuclear factor (NF)-kB activity and pro-inflammatory cytokines production. Taken together, the results suggested that miR-410-3p targeted HMGB1 and modulated chondrocytes apoptosis and inflammation through the NF-κB signaling pathway.

Conclusions

These findings provide insights into the potential of miR-410-3p/ HMGB1 as therapeutic targets for OA treatment.

The in vivo preventive and therapeutic properties of curcumin in bile reflux-related oncogenesis of the hypopharynx

Bile at strongly acidic pH exerts a carcinogenic effect on the hypopharynx, based upon recent pre‐clinical studies that support its role as an independent risk factor. We recently demonstrated in vitro that curcumin can prevent oncogenic profile of bile in human hypopharyngeal cells, by inhibiting NF‐κB. We hypothesize that topically applied curcumin to the hypopharynx can similarly block early oncogenic molecular events of bile, by inhibiting NF‐κB and consequently altering the expression of genes with oncogenic function. Using Mus musculus (C57Bl/6J), we topically applied curcumin (250 μmol/L; three times per day; 10 days) to the hypopharynx, 15 minutes before, 15 minutes after or in combination with bile acids (pH 3.0). Immunohistochemical analysis and qPCR revealed that topically applied curcumin either before, after or in combination with acidic bile exposure significantly suppressed its induced NF‐κB activation in regenerating epithelial cells, and overexpression of Rela, Bcl2, Egfr, Stat3, Wnt5a, Tnf, Il6, Ptgs2. Akt1 was particularly inhibited by curcumin when applied simultaneously with bile. We provide novel evidence into the preventive and therapeutic properties of topically applied curcumin in acidic bile‐induced early oncogenic molecular events in hypopharyngeal mucosa, by inhibiting NF‐κB, and shaping future translational development of effective targeted therapies using topical non‐pharmacologic inhibitors of NF‐κB.

Comprehensive Analysis of the PD-L1 and Immune Infiltrates of m6A RNA Methylation Regulators in Head and Neck Squamous Cell Carcinoma

Because most studies have focused on the intrinsic carcinogenic pathways of tumors, the underlying role of N6-methyladenosine (m⁶A) methylation in tumor immune microenvironment (TIME) remains elusive. Herein, we systematically explored the correlations of prominent m⁶A regulators with PD-L1 and immune infiltrates in 769 head and neck squamous cell carcinomas (HNSCCs; The Cancer Genome Atlas [TCGA] cohort, n = 499; GSE65858 cohort, n = 270). The PD-L1 expression evidently associated with m⁶A regulators. Two molecular subtypes (cluster1/2) were identified by consensus clustering for 15 m⁶A regulators. The cluster2 preferentially associated with favorable prognosis, upregulated PD-L1 expression, higher immunoscore, and distinct immune cell infiltration. The hallmarks of G2M checkpoint, mTORC1 signaling, and PI3K/AKT/mTOR signaling were remarkably enriched in the cluster1. A prognostic risk score was constructed using seven m⁶A regulator-associated signatures that represented an independent prognosis factor for HNSCC. Patients with low-risk score exhibited higher immunoscore and upregulated PD-L1 expression than patients with high-risk score. Consistently, m⁶A regulators showed the same influence on immune modulation and survival in external GSE65858 cohort. Further analysis revealed that m⁶A regulator-based signatures were implicated in TIME and their copy-number alterations dynamically affected the abundance of tumor-infiltrating immune cells. Collectively, our study elucidated the important role of m⁶A methylation in TIME of HNSCC. The proposed m⁶A regulator-based signatures might serve as crucial mediators of TIME in HNSCC, representing promising therapeutic targets in improving immunotherapeutic efficacy.

5,6,7,4'-Tetramethoxyflavanone protects against neuronal degeneration induced by dexamethasone by attenuating amyloidogenesis in mice

Long-term exposure to high glucocorticoid levels induces memory impairment and neurodegeneration in Alzheimer's disease (AD) by increasing the expression of amyloid β and tau hyperphosphorylation (pTau). Previous studies showed beneficial effects of flavonoids in neurodegenerative models. 5,6,7,4'-tetramethoxyflavanone (TMF) is one of the active ingredients in Chromolaena odorata (L.), which R. M. King and H. Rob discovered in Thailand. This study focused on the effects of TMF on dexamethasone (DEX)-induced neurodegeneration, amyloidogenesis, pTau expression, neuron synaptic function, and cognitive impairment and the potential mechanisms involved. Mice were intraperitoneally administered DEX for 28 days before being treated with TMF for 30 days. The mice were randomly divided into six groups (twelve mice per group): control; TMF administration (40 mg/kg); pioglitazone administration (20 mg/kg); DEX administration (60 mg/kg); DEX administration plus TMF; and DEX administration plus pioglitazone. Behavioral tests showed that TMF significantly attenuated the memory impairment triggered by DEX. Consistently, TMF reduced DEX-induced amyloid beta production by reducing the expression of beta-site APP cleaving enzyme 1 (BACE1) and presenilin 1 (PS1), whereas it increased the gene expression of a disintegrin and metalloprotease 10 (ADAM10). TMF treatment also decreased pTau expression, inhibited phosphonuclear factor-kappa B (pNF-kB) and inhibited glycogen synthase kinase 3 (GSK-3) activity by increasing GSK3 phosphorylation (pGSK3). In addition, TMF also improved synaptic function by increasing the expression of synaptophysin (Syn) and postsynaptic density protein 95 (PSD95) while decreasing acetylcholine esterase activity. Conclusively, TMF provided neuroprotection against DEX-induced neurodegeneration. These findings suggest that TMF might have potential as a therapeutic drug for AD.

Use of Curcumin in Achieving Clinical and Endoscopic Remission in Ulcerative Colitis: A Systematic Review and Meta-analysis

BACKGROUND

Ulcerative Colitis (UC) is characterized by chronic inflammation of the mucosal layers of the colon. Treatment of refractory UC is challenging and has a huge healthcare burden. Although there have been advancements in immunomodulatory therapies, these require a step-up financially, and these medications are also associated with significant adverse events. Curcumin, an active ingredient of turmeric, has been studied in the past and found to be useful in the treatment of UC when used as an adjuvant along with mesalamine. We did a systematic review and meta-analysis to explore the role curcumin plays in clinical and endoscopic remission in patients with UC.

MATERIALS AND METHODS

A comprehensive literature review was conducted by first searching the MEDLINE, Pubmed, and Embase databases through December 2017 to identify all studies that compared the use of curcumin when used along with mesalamine with placebo for clinical and endoscopic improvement and remission.

RESULTS

Three randomized controlled trials including 142 patients were included in the study. Use of curcumin along with mesalamine was associated with increased odds of clinical remission (pooled odds ratio of 6.78, 95% CI: 2.39-19.23, P = 0.042). Clinical improvement, endoscopic remission and improvement rate also trended higher in the curcumin group compared to placebo.

CONCLUSIONS

This study demonstrates higher clinical remission rates when curcumin was used in combination with mesalamine to achieve remission in patients with UC. Curcumin, due to its cost effectiveness and safer side effect profile, can decrease the healthcare burden and morbidity associated with this relapsing and remitting disease.

Co-delivery of curcumin and doxorubicin in PEGylated liposomes favored the antineoplastic C26 murine colon carcinoma microenvironment

Our recent studies have demonstrated that the antitumor efficacy of doxorubicin (DOX), administered in long-circulating liposomes (LCL), could be considerably improved after its co-encapsulation with curcumin (CURC). Thus, the question addressed within this article is whether LCL-CURC-DOX can be exploited more efficiently than liposomal DOX for future colorectal cancer therapy. Therefore, we investigated the physicochemical and biological properties of LCL-CURC-DOX and the mechanisms of its antitumor activity in C26 murine colon carcinoma in vivo. Our results proved that the developed nanoformulation based on the co-encapsulation of CURC and DOX met the requirements of a modern drug delivery system for future cancer therapy, demonstrating enhanced antitumor activity on C26 colon carcinoma in vivo. The antitumor efficacy of LCL-CURC-DOX relied on suppressive effects on main protumor processes such as angiogenesis, inflammation, oxidative stress, invasion and resistance to apoptosis, and on the dysregulation of Th1/Th2 cell axis which favored the antineoplastic phenotype of cells in tumor microenvironment (TME). The development of multitargeted strategies aiming at stimulating antitumor effects within the tumor milieu and counteracting the escape mechanisms of cancer cells would be beneficial in the management of colon cancer in the future.

Suppressed expression of Cbl-b by NF-κB mediates icotinib resistance in EGFR-mutant non-small-cell lung cancer

Although epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) could greatly improve the prognosis of NSCLC patients harboring activating EGFR mutations, drug resistance still remains a major obstacle to successful treatment. Our previous study found that the EGFR-TKI icotinib could upregulate the expression of Casitas-B-lineage lymphoma protein-B (Cbl-b), an E3 ubiquitin ligase. In the present study, we aimed to clarify the potential role of Cbl-b in the resistance to icotinib, and the underlying mechanisms using EGFR-mutant cell lines. We found that icotinib inhibited the proliferation of mutant-EGFR NSCLC cells (PC9 and HCC827), and upregulated the expression of Cbl-b at both the protein and mRNA levels. Cbl-b knockdown decreased the sensitivity of PC9 and HCC827 cells to icotinib, and partially restored icotinib-inhibited AKT activation in PC9 cells. On the contrary, Cbl-b overexpression could partly reverse the drug resistance in PC9 icotinib-resistant cells (PC9/IcoR). Moreover, overexpressing p65, the main member of transcription factor NF-κB family, reversed the icotinib-mediated upregulation of Cbl-b. Collectively, these data suggest that icotinib could upregulate Cbl-b mediated by NF-κB inhibition, and Cbl-b contribute to the icotinib sensitivity in EGFR-mutant NSCLC cells. This study highlights that low expression of Cbl-b might be the key obstacles in the efficacy of icotinib therapy.

Role of Thrombospondin-1 and Nuclear Factor-κB Signaling Pathways in Antiangiogenesis of Infantile Hemangioma

BACKGROUND

Propranolol is the first-line drug for treatment of infantile hemangioma. However, its mechanism of action remains unclear. Nuclear factor-κB is highly expressed in tumors, directly or indirectly promoting angiogenesis. Thrombospondin-1 is the most important antiangiogenesis protein in vivo. These proteins mediate signaling pathways, probably playing an important role in hemangioma treatment. This study explored the synergistic regulation of thrombospondin-1 and nuclear factor-κB signaling pathways in the treatment of hemangioma with propranolol.

METHODS

The hemangioma-derived endothelial cells were sorted out from the specimens of proliferative hemangioma by flow cytometry. Furthermore, a BALB/c nude mouse hemangioma model was established. Viability and proliferation of hemangioma-derived endothelial cells and the role of thrombospondin-1 and nuclear factor-κB signaling pathways were observed after propranolol administration in vitro and in vivo.

RESULTS

The expression of thrombospondin-1 and its receptor CD36 in hemangioma-derived endothelial cells gradually increased with the increase in propranolol concentration, whereas the expression of nuclear factor-κBp65, phosphorylated inhibitor of κB alpha (p-IκBα), and phosphorylated inhibitor of nuclear factor-κB kinase beta (p-IκKβ) weakened gradually (p < 0.05). In vivo, the tumors shrank gradually after propranolol treatment, with an increase in thrombospondin-1 and CD36 and a decrease in nuclear factor-κBp65, p-IκBα, and p-IκKβ (p < 0.05). Glucocorticoid improved the antiangiogenesis mediated by thrombospondin-1/CD36 and inhibited the angiogenesis mediated by nuclear factor-κB/IκB (p < 0.05). Negative regulation occurred between the two signaling pathways.

CONCLUSION

The treatment of infantile hemangioma with propranolol is promising to promote thrombospondin-1-mediated antiangiogenesis and to block nuclear factor-κB-mediated angiogenesis.

A Phase 2 Study to Assess the Immunomodulatory Capacity of a Lecithin-based Delivery System of Curcumin in Endometrial Cancer

Curcumin is a botanical with anti-tumor and immunomodulatory properties. We hypothesized that curcumin supplementation might influence inflammatory biomarker levels in endometrial carcinoma (EC). In this open-label, non-randomized phase 2 study (NCT02017353), seven EC patients consumed 2 g/day Curcumin Phytosome (CP) orally for 2 weeks. Blood was taken at baseline, days 1, 7, 14, and 21. The following analytes were measured: curcuminoids and metabolites, 56 inflammatory biomarkers, COX-2, frequencies of myeloid-derived suppressor cells, dendritic cells and NK cells, expression of MHC molecules on leukocytes and monocytes and activation/memory status of T cells. Patients completed quality of life (QoL) questionnaires at baseline and end of treatment. Curcumin metabolites were detectable in plasma upon CP intake. CP downregulated MHC expression levels on leukocytes (P = 0.0313), the frequency of monocytes (P = 0.0114) and ICOS expression by CD8⁺ T cells (P = 0.0002). However, CP upregulated CD69 levels on CD16⁻ NK cells (P = 0.0313). No differences were observed regarding inflammatory biomarkers, frequencies of other immune cell types, T cell activation and COX-2 expression. A non-significant trend to improved QoL was observed. Overall, CP-induced immunomodulatory effects in EC were modest without significant QoL changes. Given the small population and the observed variability in inter-patient biomarker levels, more research is necessary to explore whether benefits of CP can be obtained in EC by different supplementation regimens.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier NCT02017353; www.clinicaltrialsregister.eu, identifier 2013-001737-40.

Recruited bone marrow derived cells, local stromal cells and IL-17 at the front line of resistance development to anti-VEGF targeted therapies

Although anti-angiogenic agents targeting VEGF have shown affordable beneficial outcomes in several human cancer types, in most pre-clinical and clinical studies, these effects are transient and followed by rapid relapse and tumor regrowth. Recently, it has been suggested that recruited bone marrow derived cells (BMDCs) to the tumor-microenvironment together with stromal cells play an important role in development of resistance to anti-VEGF therapies. Additionally, acquired resistance to anti-VEGF therapies has shown to be mediated partly through overexpression of different pro-angiogenic cytokines and growth factors including G-CSF, IL-6, IL-8, VEGF and FGF by these cells. Alongside, IL-17, a pro-inflammatory cytokine, mostly secreted by infiltrated CD4⁺ T helper cells, has shown to mediate resistance to anti-VEGF therapies, through recruiting BMDCs and modulating stromal cells activities including endothelial cells, tumor associated macrophages and cancer associated fibroblasts. Here, we examined the role of BMDCs, tumor stromal cells, IL-17 and their negotiation in development of resistance to anti-VEGF targeted therapies.

A pentacyclic triterpene derivative possessing polyhydroxyl ring A suppresses growth of HeLa cells by reactive oxygen species-dependent NF-κB pathway

Pentacyclic triterpene derivatives possessing polyhydroxyl ring A exhibit many important pharmacological activities. (1β, 2α, 3β, 19β, 23)-1,2,3,19,23-pentahydroxyolean-12-en-28-oic acid (5), a new bioactive phytochemical with tetra-hydroxyl ring A isolated from Euphorbia sieboldiana in our laboratory, showed potential inhibition effects against several cancer cells previously. This study was performed to investigate the underlying mechanisms of action for its antitumor activity. The results showed that compound 5 inhibited dose-/time-dependently cell growth with low toxicity to normal cells and induced apoptosis in cervical cancer cells. Also, compound 5 inhibited the growth and proliferation of HeLa cells and resulted in G1 phase arrest. Furthermore, exposure of cells to compound 5 caused inactivation of the TNF-α-TAK1-IKK-NF-κB axis and inhibition of TNF-α-stimulated NF-κB activity, followed by down-regulation of NF-κB target genes involved in cell apoptosis (Bcl-2) and in the cell cycle and growth (Cyclin D, c-Myc). Additionally, compound 5 significantly suppressed the migration of HeLa cells. In addition, exposure of HeLa cells to compound 5 decreased the activity of NF-κB through the generation of reactive oxygen species (ROS). Collectively, these results suggested that compound 5 exerted potent anticancer effects on HeLa cells in vitro through targeting the ROS-dependent NF-κB signaling cascade and this compound may be a promising anticancer agent for cancer treatment.

Anti-angiogenic effects of Qingdu granule on breast cancer through inhibiting NFAT signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Qingdu granule (QDG), a traditional Chinese herbal prescription, had anti-tumor effect on breast cancer. However the underlying mechanism of QDG was unclear.

THE AIM OF THIS STUDY

The present study aimed to investigate whether QDG could inhibit angiogenesis of breast cancer via acting on nuclear factor of activated T-cells (NFAT) signaling pathway. This was implicated in human umbilical vein endothelial cells (HUVECs) in vitro and breast cancer xenograft model in vivo.

MATERIALS AND METHODS

The VEGF₁₆₅ (15.58 ng/mL) induced human umbilical vein endothelial cells (HUVECs) were treated with serum samples containing tamoxifen (TAM), tacrolimus (FK506), or QDG with three dosages. The migration and canalization capacities of HUVECs were evaluated by transwell migration and tube formation assay. In 72 h-cultured HUVECs, The gene expression, protein amount, and nuclear translocation of NFATc3 were measured. The anti-tumor and anti-angiogenic effects of QDG in vivo were investigated in breast cancer xenograft model. The serum VEGF levels, microvessel density, and protein expressions (immunohistochemistry and western blot) of VEGF, VEGFR2 and NFATc3 were detected.

RESULTS

The results showed that, QDG significantly inhibited HUVEC migration and tube formation. It downregulated NFATc3 gene expression, decreased NFATc3 protein amount, and reduced the ratio of NFATc3 nuclear translocation in HUVECs. In breast cancer xenograft model, QDG treatment significantly suppressed tumor growth, inhibited VEGF release, and decreased microvessel density. QDG reduced protein expressions of VEGF, VEGFR2 and NFATc3.

CONCLUSION

The results suggested that QDG showed anti-angiogenic effects of breast cancer both in vitro and in vivo. The mechanism might be partially associated with inhibiting NFAT signaling pathway.

The Curcumin Analog CH-5 Exerts Anticancer Effects in Human Osteosarcoma Cells via Modulation of Transcription Factors p53/Sp1

Curcumin is a potential anticancer drug with poor bioavailability, which limits its clinical use as a therapeutic agent. The aim of this study was a preliminary evaluation of the curcumin analogue CH-5 as a cytotoxic agent in human osteosarcoma cell lines U2OS, MG-63, and Saos-2. CH-5 inhibited cell viability at lower concentrations than curcumin, leading to the induction of apoptosis. The cellular levels of the transcription factors p53 and Sp1 affect the expression of cellular pathways that lead to apoptosis. CH-5 increased p53 protein levels in U2OS cells and reduced Sp1 levels, with a consequent effect on the expression of their target genes DNA methyltransferase 1 (DNMT1) and growth arrest and DNA damage-inducible 45 alpha gene (Gadd45a). CH-5 repressed DNMT1 and increased Gadd45a mRNA expression, which was dependent on p53, as this effect was only observed in the colorectal cancer cell line HCT116 with active p53, but not in the isogenic p53-deficient HCT116 cells. CH-5 also reduced the protein levels of DNMT1, which led to the upregulation of Gadd45a. These results suggest that CH-5 has potentially higher anticancer activity than curcumin, which is associated with the expression of apoptosis-associated genes regulated by the transcription factors Sp1 and p53. Future work on CH-5 will define the therapeutic potential of this compound in vivo.

Curcumin prevents the bile reflux-induced NF-κB-related mRNA oncogenic phenotype, in human hypopharyngeal cells

The presence of bile is not an uncommon finding in acidic oesophageal and extra‐oesophageal refluxate, possibly affecting the hypopharyngeal mucosa and leading to neoplastic events. We recently demonstrated that acidic bile (pH ≤ 4.0) can induce NF‐κB activation and oncogenic mRNA phenotype in normal hypopharyngeal cells and generate premalignant changes in treated hypopharyngeal mucosa. We hypothesize that curcumin, a dietary inhibitor of NF‐κB, may effectively inhibit the acidic bile‐induced cancer‐related mRNA phenotype, in treated human hypopharyngeal primary cells (HHPC), supporting its potential preventive use in vivo. Luciferase assay, immunofluorescence, Western blot, qPCR and PCR microarray analysis were used to explore the effect of curcumin in HHPC exposed to bile (400 μmol/L) at acidic and neutral pH. Curcumin successfully inhibited the acidic bile‐induced NF‐κB signalling pathway (25% of analysed genes), and overexpression of NF‐κB transcriptional factors, c‐REL, RELA(p65), anti‐apoptotic bcl‐2, oncogenic TNF‐α, EGFR, STAT3, WNT5A, ΔNp63 and cancer‐related IL‐6. Curcumin effectively reduced bile‐induced bcl‐2 overexpression at both acidic and neutral pH. Our novel findings suggest that, similar to pharmacologic NF‐κB inhibitor, BAY 11‐7082, curcumin can suppress acidic bile‐induced oncogenic mRNA phenotype in hypopharyngeal cells, encouraging its future in vivo pre‐clinical and clinical explorations in prevention of bile reflux‐related pre‐neoplastic events mediated by NF‐κB.

Gallic acid inhibits the release of ADAMTS4 in nucleus pulposus cells by inhibiting p65 phosphorylation and acetylation of the NF-κB signaling pathway

This study investigated the inhibitory effect of gallic acid (GA) on the release of A Disintegrin and Metalloproteinase with Thrombospondin motifs 4 (ADAMTS4) through the regulation of the NF-κB signaling pathway, which is closely related to the matrix metalloproteinases in nucleus pulposus cells. Different concentrations of GA were added to TNF-α-induced human nucleus pulposus cells (hNPCs) and intervertebral disc degeneration rat model. ADAMTS-4 expression increased both in the TNF-α-induced nucleus pulposus cells and intervertebral disc degeneration rat model. By contrast, the release of ADAMTS-4 was reduced, and the TNF-α-induced apoptosis of nucleus pulposus cells was significantly inhibited after addition of GA at different concentrations. Further study found that the levels of phosphorylated p65 (p-p65) was increased and the classical NF-κB signal pathway was activated after the nucleus pulposus cells were stimulated by TNF-α. Meanwhile, GA suppressed the p65 phosphorylation and inceased p65 deacetylation levels. As a consequence, GA can decrease the expression of ADAMTS-4 in nucleus pulposus cells by regulating the phosphorylation and acetylation of p65 in NF-κB signaling pathways.

Targeting High Expressed α5β1 Integrin in Liver Metastatic Lesions To Resist Metastasis of Colorectal Cancer by RPM Peptide-Modified Chitosan-Stearic Micelles

Liver metastasis is a leading death cause in colorectal cancer. The pathological differences between orthotopic tumors and metastatic lesions increased the therapeutic difficulty of metastasis. Herein, the α₅β₁ integrin receptor expression on metastatic cells was first measured, the result showed that metastatic cells expressed the α₅β₁ integrin higher than that of the original cells from orthotopic tumors. Afterward, RPM peptide-modified chitosan-stearic (RPM-CSOSA) was designed based on α₅β₁ integrin expression. The cytotoxicity and resistance to migration and the invasion ability of the targeting drug delivery system loading doxorubicin (DOX) and curcumin (CUR) were evaluated in vitro. The metastatic inhibition of the targeting drug delivery system was also investigated in HT29 liver metastatic models. The modified RPM peptide could increase the cellular internalization of CSOSA micelles in metastatic tumor cells and endothelial cells mediated by α₅β₁ integrin. The synergistic effects of RPM-CSOSA/DOX and RPM-CSOSA/CUR could obviously inhibit migratory and invasive abilities of HT29 cells and endothelial cells. Moreover, the RPM-CSOSA/DOX&RPM-CSOSA/CUR could obviously decrease the number of metastatic sites by 86.96%, while CSOSA/DOX&CSOSA/CUR decreased liver metastasis by 66.58% compared with that in the saline group. In conclusion, the RPM peptide-modified drug delivery system may provide insights into targeting the metastatic cells overexpressing the α₅β₁ integrin, and it has the potential to inhibit liver metastasis of colorectal cancer.

Suppression of chronic inflammation with engineered nanomaterials delivering nuclear factor κB transcription factor decoy oligodeoxynucleotides

As a prototypical pro-inflammatory transcription factor, constitutive activation of NF-κB signaling pathway has been reported in several chronic inflammatory disorders including inflammatory bowel disease, cystic fibrosis, rheumatoid arthritis and cancer. Application of decoy oligodeoxynucleotides (ODNs) against NF-κB, as an effective molecular therapy approach, has brought about several promising outcomes in treatment of chronic inflammatory disorders. However, systematic administration of these genetic constructs is mostly hampered due to their instability, rapid degradation by nucleases and poor cellular uptake. Both chemical modification and application of delivery systems have shown to effectively overcome some of these limitations. Among different administered delivery systems, nanomaterials have gained much attention for delivering NF-κB decoy ODNs owing to their high loading capacity, targeted delivery and ease of synthesis. In this review, we highlight some of the most recently developed nanomaterial-based delivery systems for overcoming limitations associated with clinical application of these genetic constructs.

Combination curcumin and (-)-epigallocatechin-3-gallate inhibits colorectal carcinoma microenvironment-induced angiogenesis by JAK/STAT3/IL-8 pathway

Tumor microenvironment has a crucial role in cancer development and progression, whereas the mechanism of how it regulates angiogenesis is unclear. In this study, we simulated the colorectal carcinoma microenvironment by conditioned medium (CM) of colorectal carcinoma cell lines (SW620, HT-29, HCT116) supernatant or colorectal carcinoma tissue homogenate supernatant to induce normal endothelial cells (NECs). We found that colorectal carcinoma CM promoted tumor angiogenesis by coercing NECs toward tumor endothelial cells (TECs) with the activation of the JAK/STAT3 signaling pathway. Antibody array analysis showed HT-29 supernatant contained numerous angiogenesis-related proteins, especially IL-8. Interestingly, the production of IL-8 in NECs induced by HT-29 CM was also increased. We also verified the crucial role of IL-8 in promoting the CM-induced angiogenesis, as IL-8 repression by neutralizing antibody abolished the transition of NECs toward TECs. Curcumin and (-)-epigallocatechin-3-gallate (EGCG) are broadly investigated in cancer chemoprevention. However, poor bioavailability hurdles their application alone, and the mechanism of their anti-angiogenesis still need to be illuminated. Here, we found that curcumin combination with EGCG attenuated the tumor CM-induced transition of NECs toward TECs by inhibiting JAK/STAT3 signaling pathway. Furthermore, the combination of curcumin and EGCG markedly reduced tumor growth and angiogenesis in the colorectal carcinoma PDX mouse model, and the combined anti-angiogenic effect was better than that of curcumin or EGCG alone. Taken together, our findings provide a new mechanism of tumor angiogenesis, and the combination of curcumin and EGCG represents a potential anti-angiogenic therapeutic method for colorectal carcinoma.

Protective effects of flavonoids against Alzheimer's disease-related neural dysfunctions

Senile ages of human life is mostly associated with developmental of several neurological complicated conditions including decreased cognition and reasoning, increased memory loss and impaired language performance. Alzheimer's disease (AD) is the most prevalent neural disorder associated with dementia, consisting of about 70% of dementia reported cases. Failure of currently approved chemical anti-AD therapeutic agents has once again brought up the idea of administering naturally occurring compounds as effective alternative and/or complementary regimens in AD treatment. Polyphenol structured neuroprotecting agents are group of biologically active compounds abundantly found in plants with significant protecting effects against neural injuries and degeneration. As a subclass of this family, Flavonoids are potent anti-oxidant, anti-inflammatory and signalling pathways modulatory agents. Phosphatidylinositol 3-kinase (PI3K)/AKT and mitogen activated protein kinase (MAPK) pathways are both affected by Flavonoids. Regulation of pro-survival transcription factors and induction of specific genes expression in hippocampus are other important anti AD therapeutic activities of Flavonoids. These agents are also capable of inhibiting specific enzymes involved in phosphorylation of tau proteins including β-secretases, cyclin dependent kinase 5 and glycogen synthase. Other significant anti AD effects of Flavonoids include neural rehabilitation and lost cognitive performance recovery. In this review, first we briefly describe the pathophysiology and important pathways involved in pathology of AD and then describe the most important mechanisms through which Flavonoids demonstrate their significant neuroprotective effects in AD therapy.

Stimuli-Responsive Mesoporous Silica NPs as Non-viral Dual siRNA/Chemotherapy Carriers for Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) is the most aggressive and lethal subtype of breast cancer. It is associated with a very poor prognosis and intrinsically resistant to several conventional and targeted chemotherapy agents and has a 5-year survival rate of less than 25%. Because the treatment options for TNBC are very limited and not efficient enough for achieving minimum desired goals, shifting toward a new generation of anti-cancer agents appears to be very critical. Among recent alternative approaches being proposed, small interfering RNA (siRNA) gene therapy can potently suppress Bcl-2 proto-oncogene and p-glycoprotein gene expression, the most important chemotherapy resistance inducers in TNBC. When resensitized, primarily ineffective chemotherapy drugs turn back into valuable sources for further intensive chemotherapy. Regrettably, siRNA's poor stability, rapid clearance in the circulatory system, and poor cellular uptake mostly hampers the beneficial outcomes of siRNA therapy. Considering these drawbacks, dual siRNA/chemotherapy drug encapsulation in targeted delivery vehicles, especially mesoporous silica nanoparticles (MSNs) appears to be the most reasonable solution. The literature is full of reports of successful treatments of multi-drug-resistant cancer cells by administration of dual drug/siRNA-loaded MSNs. Here we tried to answer the question of whether application of a similar approach with identical delivery devices in TNBC is rational.

Curcumin Anti-Apoptotic Action in a Model of Intestinal Epithelial Inflammatory Damage

The purpose of this study is to determine if a preventive treatment with curcumin can protect intestinal epithelial cells from inflammatory damage induced by IFNγ. To achieve this goal we have used a human intestinal epithelial cell line (HT29) treated with IFNγ to undergo apoptotic changes that can reproduce the damage of intestinal epithelia exposed to inflammatory cytokines. In this model, we measured the effect of curcumin (curcuminoid from Curcuma Longa) added as a pre-treatment at different time intervals before stimulation with IFNγ. Curcumin administration to HT29 culture before the inflammatory stimulus IFNγ reduced the cell apoptosis rate. This effect gradually declined with the reduction of the curcumin pre-incubation time. This anti-apoptotic action by curcumin pre-treatment was paralleled by a reduction of secreted IL7 in the HT29 culture media, while there was no relevant change in the other cytokine levels. Even though curcumin pre-administration did not impact the activation of the NF-κB pathway, a slight effect on the phosphorylation of proteins in this inflammatory signaling pathway was observed. In conclusion, curcumin pre-treatment can protect intestinal cells from inflammatory damage. These results can be the basis for studying the preventive role of curcumin in inflammatory bowel diseases.

Nutritional control of IL-23/Th17-mediated autoimmune disease through HO-1/STAT3 activation

The nutritional curcumin (CUR) is beneficial in cell-mediated autoimmune diseases. The molecular mechanisms underlying this food-mediated silencing of inflammatory immune responses are poorly understood. By investigating antigen-specific immune responses we found that dietary CUR impairs the differentiation of Th1/Th17 cells in vivo during encephalomyelitis and instead promoted Th2 cells. In contrast, feeding CUR had no inhibitory effect on ovalbumin-induced airway inflammation. Mechanistically, we found that CUR induces an anti-inflammatory phenotype in dendritic cells (DC) with enhanced STAT3 phosphorylation and suppressed expression of Il12b and Il23a. On the molecular level CUR readily induced NRF2-sensitive heme oxygenase 1 (HO-1) mRNA and protein in LPS-activated DC. HO-1 enhanced STAT3 phosphorylation, which enriched to Il12b and Il23a loci and negatively regulated their transcription. These findings demonstrate the underlying mechanism through which a nutritional can interfere with the immune response. CUR silences IL-23/Th17-mediated pathology by enhancing HO-1/STAT3 interaction in DC.

Naturally occurring compounds acting as potent anti-metastatic agents and their suppressing effects on Hedgehog and WNT/β-catenin signalling pathways

Despite numerous remarkable achievements in the field of anti-cancer therapy, tumour relapse and metastasis still remain major obstacles in improvement of overall cancer survival, which may be at least partially owing to epithelial-mesenchymal transition (EMT). Multiple signalling pathways have been identified in EMT; however, it appears that the role of the Hedgehog and WNT/β-catenin pathways are more prominent than others. These are well-known preserved intracellular regulatory pathways of different cellular functions including proliferation, survival, adhesion and differentiation. Over the last few decades, several naturally occurring compounds have been identified to significantly obstruct several intermediates in Hedgehog and WNT/β-catenin signalling, eventually resulting in suppression of signal transduction. This article highlights the current state of knowledge associated with Hedgehog and WNT/β-catenin, their involvement in metastasis through EMT processes and introduction of the most potent naturally occurring agents with capability of suppressing them, eventually overcoming tumour relapse, invasion and metastasis.

Curcumin inhibits angiogenesis by up-regulation of microRNA-1275 and microRNA-1246: a promising therapy for treatment of corneal neovascularization

OBJECTIVE

Curcumin (capable of inhibiting angiogenic growth of human umbilical vein endothelial cells [HUVECs]), can be employed in vitro as a model of pathogenesis of corneal neovascularization (CRNV). The aim of this study was to explore regulatory mechanisms of microRNA (miR) levels after curcumin treatment.

MATERIALS AND METHODS

Expression profiles of miRs in curcumin-treated HUVECs were investigated by miR microassay. Specific mimics and inhibitors of miR-1275 or miR-1246 were transfected into HUVECs. Then, their target genes, vascular endothelial growth factor B (VEGFB) and nuclear transcription factor kappa B acting protein (NKAP) were detected by quantitative real-time PCR, Western blotting assay or immunofluorescence assay. Cell proliferation and cell cycle parameters were measured with the help of CCK-8 assay and flow cytometry.

RESULTS

MiR-1275 and miR-1246 expression levels were up-regulated by curcumin. Administration of the specific mimics and inhibitors of the two miRs led to significant changes in expression of VEGFB and NKAP as well as the indicators related to angiogenesis. Anti-angiogenic effect of curcumin depended on expression patterns of the two miRs in that inhibition of either miR interfered with the effect of curcumin. Furthermore, overexpression of NKAP interrupted effects of curcumin on the cells.

CONCLUSION

Collectively, our findings demonstrate that curcumin inhibited HUVEC proliferation by up-regulation of miR-1275 and miR-1246.