Resveratrol inhibits LPS-induced epithelial-mesenchymal transition in mouse melanoma model

Effects of daphnetin on the mechanism of epithelial-mesenchymal transition induced by HMGB1 in human lung adenocarcinoma cells (A549 cell line)

As a cancer with the highest incidence in recent years, lung cancer is mainly composed of three diseases: non-small cell lung cancer, small cell lung cancer and neuroendocrine tumor. The morbidity and mortality of this malignant tumor are the highest in both male and female populations worldwide. In my country, lung cancer has become the most common cancer disease and the leading cause of cancer death, so it is extremely important to find lung cancer therapeutic targets. Based on previous studies, we speculated that the TLR4-Myd88-NFκB pathway may be involved in hmgb1-induced EMT in A549 cells, and daphnetin may also inhibit hmgb1-induced EMT through the TLR4-Myd88-NFκB pathway in A549 cells, but related studies have not linked it to hmgb1-induced EMT. Therefore, the innovation of this study is to test these two conjectures and analyze how daphnetin affects the epithelial-mesenchymal transition (EMT) mechanism induced by HMGB1 in human lung adenocarcinoma cells (A549 cell line), aiming at lung adenocarcinoma cells, foundation for clinical treatment. The proliferation rate and the migrating cell number presented an obvious decrease in the HMGB1+TLR4-shRNA group and the HMGB1+daphnetin group relative to the HMGB1 group (P < 0.0001). The intracellular expression of TLR4, Myd88, NFκB, vimentin and snail1 proteins were significantly decreased (P < 0.001), while that of E-cadherin presented a remarkable increase (P < 0.001) in the HMGB1+TLR4-shRNA and HMGB1+daphnetin group compared with the HMGB1 group. TLR4-MyD88-NFκB pathway is associated with HMGB1-induced EMT in A549 cells. Daphnetin had an inhibitory effect on HMGB1-induced EMT via the TLR4-Myd88-NF-κB pathway in A549 cells.

Aryl Hydrocarbon Receptor Activation in Pulmonary Alveolar Epithelial Cells Limits Inflammation and Preserves Lung Epithelial Cell Integrity

The aryl hydrocarbon receptor (AHR) is a receptor/transcription factor widely expressed in the lung. The physiological roles of AHR expressed in the alveolar epithelium remain unclear. In this study, we tested the hypothesis that alveolar epithelial AHR activity plays an important role in modulating inflammatory responses and maintaining alveolar integrity during lung injury and repair. AHR is expressed in alveolar epithelial cells (AECs) and is active. AHR activation with the endogenous AHR ligand, FICZ (5,11-dihydroindolo[3,2-b] carbazole-6-carboxaldehyde), significantly suppressed inflammatory cytokine expression in response to inflammatory stimuli in primary murine AECs and in the MLE-15 epithelial cell line. In an LPS model of acute lung injury in mice, coadministration of FICZ with LPS suppressed protein leak, reduced neutrophil accumulation in BAL fluid, and suppressed inflammatory cytokine expression in lung tissue and BAL fluid. Relevant to healing following inflammatory injury, AHR activation suppressed TGF-β-induced expression of genes associated with epithelial-mesenchymal transition. Knockdown of AHR in primary AECs with shRNA or in CRISPR-Cas-9-induced MLE-15 cells resulted in upregulation of α-smooth muscle actin (αSma), Col1a1, and Fn1 and reduced expression of epithelial genes Col4a1 and Sdc1. MLE-15 clones lacking AHR demonstrated accelerated wound closure in a scratch model. AHR activation with FICZ enhanced barrier function (transepithelial electrical resistance) in primary murine AECs and limited decline of transepithelial electrical resistance following inflammatory injury. AHR activation in AECs preserves alveolar integrity by modulating inflammatory cytokine expression while enhancing barrier function and limiting stress-induced expression of mesenchymal genes.

MyD88 signaling pathways: role in breast cancer

MyD88 plays a central role in breast cancer, exerting a multitude of effects that carry substantial implications. Elevated MyD88 expression is closely associated with aggressive tumor characteristics, suggesting its potential as a valuable prognostic marker and therapeutic target. MyD88 exerts influence over several critical aspects of breast cancer, including metastasis, recurrence, drug resistance, and the regulation of cancer stem cell properties. Furthermore, MyD88 modulates the release of inflammatory and chemotactic factors, thereby shaping the tumor's immune microenvironment. Its role in immune response modulation underscores its potential in influencing the dynamic interplay between tumors and the immune system. MyD88 primarily exerts intricate effects on tumor progression through pathways such as Phosphoinositide 3-kinases/Protein kinase B (PI3K/Akt), Toll-like Receptor/Nuclear Factor Kappa B (TLR/NF-κB), and others. Nevertheless, in-depth research is essential to unveil the precise mechanisms underlying the diverse roles of MyD88 in breast cancer. The translation of these findings into clinical applications holds great promise for advancing precision medicine approaches for breast cancer patients, ultimately enhancing prognosis and enabling the development of more effective therapeutic strategies.

Bitter Phytochemicals as Novel Candidates for Skin Disease Treatment

Skin diseases represent a global healthcare challenge due to their rising incidence and substantial socio-economic burden. While biological, immunological, and targeted therapies have brought a revolution in improving quality of life and survival rates for certain dermatological conditions, there remains a stringent demand for new remedies. Nature has long served as an inspiration for drug development. Recent studies have identified bitter taste receptors (TAS2Rs) in both skin cell lines and human skin. Additionally, bitter natural compounds have shown promising benefits in addressing skin aging, wound healing, inflammatory skin conditions, and even skin cancer. Thus, TAS2Rs may represent a promising target in all these processes. In this review, we summarize evidence supporting the presence of TAS2Rs in the skin and emphasize their potential as drug targets for addressing skin aging, wound healing, inflammatory skin conditions, and skin carcinogenesis. To our knowledge, this is a pioneering work in connecting information on TAS2Rs expression in skin and skin cells with the impact of bitter phytochemicals on various beneficial effects related to skin disorders.

Citral-Enriched Fraction of Lemon Essential Oil Mitigates LPS-Induced Hepatocyte Injuries

Lemon essential oil (LEO) is known for its aromatic and healthy properties; however, less consideration is given to the biological properties of the fractions obtained from LEO. This study aims to evaluate the ability of a citral-enriched fraction obtained from LEO (Cfr-LEO) to counteract lipopolysaccharide (LPS)-mediated inflammation, oxidative stress, and epithelial-mesenchymal transition (EMT) in healthy human hepatocytes. Human immortalized hepatocytes (THLE-2 cell line) were pretreated with Cfr-LEO and subsequently exposed to LPS at various time points. We report that the pretreatment with Cfr-LEO counteracts LPS-mediated effects by inhibiting inflammation, oxidative stress, and epithelial-mesenchymal transition in THLE-2. In particular, we found that pretreatment with Cfr-LEO reduced NF-κB activation and the subsequent proinflammatory cytokines release, ROS production, and NRF2 and p53 expression. Furthermore, the pretreatment with Cfr-LEO showed its beneficial effect in counteracting LPS-induced EMT. Taken together, these results support Cfr-LEO application in the nutraceutical research field not only for its organoleptic properties, conferred by citral enrichment, but also for its biological activity. Our study could lay the basis for the development of foods/drinks enriched with Cfr-LEO, aimed at preventing or alleviating chronic conditions associated with liver dysfunction.

Role of the Microbiota in Skin Neoplasms: New Therapeutic Horizons

The skin and the gut are regularly colonized by a variety of microorganisms capable of interacting with the immune system through their metabolites and influencing the balance between immune tolerance and inflammation. Alterations in the composition and diversity of the skin microbiota have been described in various cutaneous diseases, including skin cancer, and the actual function of the human microbiota in skin carcinogenesis, such as in progression and metastasis, is currently an active area of research. The role of Human Papilloma Virus (HPV) in the pathogenesis of squamous cell carcinoma is well consolidated, especially in chronically immunosuppressed patients. Furthermore, an imbalance between Staphylococcus spp., such as Staphylococcus epidermidis and aureus, has been found to be strongly related to the progression from actinic keratosis to squamous cell carcinoma and differently associated with various stages of the diseases in cutaneous T-cell lymphoma patients. Also, in melanoma patients, differences in microbiota have been related to dissimilar disease course and prognosis and may affect the effectiveness and tolerability of immune checkpoint inhibitors, which currently represent one of the best chances of a cure. From this point of view, acting on microbiota can be considered a possible therapeutic option for patients with advanced skin cancers, even if several issues are still open.

The Potential for Natural Products to Overcome Cancer Drug Resistance by Modulation of Epithelial-Mesenchymal Transition

The acquisition of resistance and ultimately disease relapse after initial response to chemotherapy put obstacles in the way of cancer therapy. Epithelial-mesenchymal transition (EMT) is a biologic process that epithelial cells alter to mesenchymal cells and acquire fibroblast-like properties. EMT plays a significant role in cancer metastasis, motility, and survival. Recently, emerging evidence suggested that EMT pathways are very important in making drug-resistant involved in cancer. Natural products are gradually emerging as a valuable source of safe and effective anticancer compounds. Natural products could interfere with the different processes implicated in cancer drug resistance by reversing the EMT process. In this review, we illustrate the molecular mechanisms of EMT in the emergence of cancer metastasis. We then present the role of natural compounds in the suppression of EMT pathways in different cancers to overcome cancer cell drug resistance and improve tumor chemotherapy. HighlightsDrug-resistance is one of the obstacles to cancer treatment.EMT signaling pathways have been correlated to tumor invasion, metastasis, and drug-resistance.Various studies on the relationship between EMT and resistance to chemotherapy agents were reviewed.Different anticancer natural products with EMT inhibitory properties and drug resistance reversal effects were compared.

Combined Effects of Resveratrol and Vitamin E From Peanut Seeds and Sprouts on Colorectal Cancer Cells

Resveratrol (RES) and Vitamin E (VE) are anti-cancer active ingredients with relatively high content in peanut seeds and sprouts. This study aimed to determine the synergistic inhibitory effect of RES and VE on colorectal cancer. Using 5-FU as a positive drug control, the effect of RES combined with VE on HCT-8 cells was determined, and cell viability was detected using the cell-counting kit 8 (CCK8) method. Cell morphology changes were observed using optical microscopy. Cell migration ability was evaluated by the scratch test, while cell colonies were determined by the cloning test formation ability. Apoptosis status was assessed by flow cytometry and nuclear staining by DAPI, and the expression level of apoptosis-related proteins was determined by western blotting. Compared with the single component group, the RES combined with VE group significantly inhibited the growth and proliferation of HCT-8 intestinal cancer cells in vitro. The RES combined with VE group had a greater impact on cell morphology changes and cell colony formation and significantly reduced cell migration ability and intestinal cancer cell apoptosis (p < 0.05). Additionally, combined treatment with RES and VE significantly upregulated the expression of pro-apoptotic proteins BAX, caspase-3, caspase-8, and caspase-9, and downregulated the expression of anti-apoptotic protein BCL-2, compared to the single component treatment. RES combined with VE is effective in promoting intestinal cancer cell apoptosis. This study demonstrated the significant positive synergy of RES and VE on HCT-8 cells, providing a new perspective for more effective use of RES.

Resveratrol and Its Analogs: Potent Agents to Reverse Epithelial-to-Mesenchymal Transition in Tumors

Epithelial-to-mesenchymal transition (EMT), a complicated program through which polarized epithelial cells acquire motile mesothelial traits, is regulated by tumor microenvironment. EMT is involved in tumor progression, invasion and metastasis via reconstructing the cytoskeleton and degrading the tumor basement membrane. Accumulating evidence shows that resveratrol, as a non-flavonoid polyphenol, can reverse EMT and inhibit invasion and migration of human tumors via diverse mechanisms and signaling pathways. In the present review, we will summarize the detailed mechanisms and pathways by which resveratrol and its analogs (e.g. Triacetyl resveratrol, 3,5,4'-Trimethoxystilbene) might regulate the EMT process in cancer cells to better understand their potential as novel anti-tumor agents. Resveratrol can also reverse chemoresistance via EMT inhibition and improvement of the antiproliferative effects of conventional treatments. Therefore, resveratrol and its analogs have the potential to become novel adjunctive agents to inhibit cancer metastasis, which might be partly related to their blocking of the EMT process.

Salmonella alters heparanase expression and reduces tumor metastasis

Salmonella causes salmonellosis, is a facultative anaerobe and is one of the common Gram-negative bacteria. Salmonella has anti-tumor potential and tumor-targeting activity. The heparin sulfate on cell surfaces can be cleaved by heparanase that is an endo-β-D-glucuronidase. Heparanase can destroy the extracellular matrix and is involved in tumor metastasis and angiogenic activity. Previously, Salmonella was demonstrated to inhibit tumor metastasis. It remains unclear whether Salmonella inhibits metastasis by regulating heparanase. The expression of heparanase in Salmonella-treated tumor cells was found to be decreased. Transwell and wound-healing assays demonstrated the inhibition of cell migration after Salmonella treatment. Salmonella was found to influence the levels of phosphate-protein kinase B (P-AKT) and phosphate-extracellular regulated protein kinases (P-ERK), which are involved in heparanase expression. Salmonella reduced the heparanase expression induced upregulating PERK and PAKT signaling pathways. The mice bearing an experimental metastasis tumor model was used to evaluate the anti-tumor metastatic effects of Salmonella. Compared with the control group, Salmonella significantly reduced the number of metastatic nodules and enhanced survival. The results of our study indicate that Salmonella plays a vital role in the inhibition of tumor metastasis through the downregulation of heparanase.

Salmonella reduces tumor metastasis by downregulation C-X-C chemokine receptor type 4

Tumor metastasis is the main reason for the death of most cancer patients. C-X-C chemokine receptor type 4 (CXCR4) has been demonstrated to be overexpressed in numerous types of cancer. CXCR4 selectively binds with stromal cell-derived factor 1 (SDF1), also known as C-X-C family chemokine ligand 12 (CXCL12) (CXCL12/SDF-1), which induced tumor proliferation and metastasis. Recently, the use of conventional cancer treatments had some limitation; bacteria treatment for cancer becomes a trend that overcomes these limitations. Plenty of studies show that Salmonella has anti-tumor and anti-metastatic activity. The current study aimed to investigate Salmonella suppresses CXCR4 protein expression and tumor cell migration ability in B16F10 melanoma and LL2 lung carcinoma cells. Salmonella reduced CXCR4 protein expression through downregulating Protein Kinase-B (Akt)/Mammalian Target of Rapamycin (mTOR) signaling pathway. In cells transfected with constitutively active Akt plasmids, a reverse effect of Salmonella-induced inhibition of CXCR4 was observed. Tumor cells have chemotactic response to CXCL12 in migration assay, and we found that Salmonella reduced tumor chemotactic response after CXCL12 treatment. The C57BL/6 mice were intravenously injected with B16F10 and LL2 cells pre-incubated with or without Salmonella, the tumor size and lung weight of Salmonella group had obviously decreased, indicating anti-metastatic effect that confirmed the findings from the in vitro experiments.

Melatonin prevents LPS-induced epithelial-mesenchymal transition in human alveolar epithelial cells via the GSK-3β/Nrf2 pathway

BACKGROUND

Oxidative stress plays a critical role in pulmonary fibrosis after acute lung injury (ALI), and epithelial-mesenchymal transition (EMT) events are involved in this process. The purpose of this study was to investigate the protective effects of melatonin, a natural antioxidant, on lipopolysaccharide (LPS)-induced EMT in human alveolar epithelial cells.

METHODS

Human type II alveolar epithelial cell-derived A549 cells were incubated with LPS and melatonin alone or in combination for up to 24 h. The morphological changes of the treated cells were evaluated as well as indexes of oxidative stress. EMT-related proteins and the Nrf2 signaling pathway were detected by western blot analysis and immunofluorescence staining, respectively. To further investigate the underlying mechanisms, the effects of melatonin on cells transfected Nrf2 short hairpin RNA (shRNA) and the PI3K / GSK-3β signaling pathway were evaluated.

RESULTS

Treatment with melatonin upregulated Nrf2 expression, inhibited LPS-induced cell morphological change, reversed the expressions of EMT-related proteins, and reduced reactive oxygen species (ROS) production in A549 cells, as well as the levels of malondialdehyde (MDA) and anti-oxidative enzymes. Yet, the effects of melatonin were almost completely abolished in cells transfected Nrf2 shRNA. Furthermore, the data demonstrated that melatonin could activate the PI3K/AKT signaling pathway, resulting in phosphorylation of GSK-3β (Ser9) and upregulation of the Nrf2 protein in A549 cells, which ultimately attenuated LPS-induced EMT.

CONCLUSION

The present study is the first to demonstrate that melatonin can protect human alveolar epithelial cells against oxidative stress by effectively inhibiting LPS-induced EMT, which was mostly dependent on upregulation of the Nrf2 pathway via the PI3K/GSK-3β axis. Further studies are warranted to investigate the role of melatonin for the treatment of oxidative stress-associated diseases, as well as pulmonary fibrosis after ALI.

Mangiferin inhibits lipopolysaccharide-induced epithelial-mesenchymal transition (EMT) and enhances the expression of tumor suppressor gene PER1 in non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) is often complicated by pulmonary infection, which affects treatment and prognosis. Bacterial lipopolysaccharide (LPS) is an effective stimulator of inflammatory cytokine production, and previous studies have reported that LPS promotes tumor invasion and metastasis. Mangiferin is a plant-derived C-glucosylxanthone with many biological activities, such as antioxidation and anti-inflammation. This research mainly explored the mechanism of its antitumor activities on LPS-induced A549, NCI-H460, and NCI-H520 NSCLC cells. We determined that mangiferin exhibits growth inhibiting activity against LPS-induced NSCLC cells through the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. In addition, mangiferin reversed the LPS-induced downregulation of E-cadherin (epithelial marker); conversely, it significantly inhibited the expression of raised vimentin (mesenchymal markers). Moreover, the ability of NSCLC cells to migrate, as evidenced by the wound healing and transwell migration assays, and the expression of CXCR4 increased by LPS were significantly repressed by mangiferin. In addition, mangiferin markedly mediated protein levels of PER1 and NLRP3 in LPS-induced NSCLC cells and reduced the secretion of IL-1β. These results indicate that mangiferin is not only a remarkable anti-inflammatory compound but also an antitumor agent; thus, it has the potential for being developed into anti-inflammatory and antitumor drugs in the future.

The MyD88 inhibitor TJ-M2010-2 suppresses proliferation, migration and invasion of breast cancer cells by regulating MyD88/GSK-3β and MyD88/NF-κB signalling pathways

MyD88 has been implicated in the tumourigenesis, metastasis and recurrence of breast cancer (BC). Here we utilized TJ-M2010-2 (TJ), an inhibitor of MyD88 homodimerimerization, and siMyD88 to suppress the function of MyD88 in MCF-7 and MDA-MB-231 cells. BC cells were treated in vitro and xenografted into nude mice to generate a model in vivo. TJ inhibited BC cell growth by impeding proliferation rather than by promoting apoptosis in vitro. Additionally, TJ and siMyD88 significantly attenuated cell migration and invasion, inhibited EMT-like progression and reduced cytokine (IL-6, IL-8, TGF-β1 and TNF-α) secretion induced by LPS. In vivo, TJ significantly hindered tumour growth in mice. Notably, TJ also decreased the secretion of IL-6, IL-8, TGF-β1, and TNF-α and M2 macrophage infiltration in the tumour microenvironment. The expression of MyD88, TRAF6, NF-κB p65, Snail, MMP-2, MMP-9, p-GSK-3β and p-Akt was significantly downregulated by TJ in BC cells and tumour tissues. Collectively, these results suggest that a MyD88 inhibitor (TJ) may be a promising therapeutic modality for treating BC patients.

Sodium Propionate Attenuates the Lipopolysaccharide-Induced Epithelial-Mesenchymal Transition via the PI3K/Akt/mTOR Signaling Pathway

Short-chain fatty acids (SCFAs), especially propionate, originate from the fermentation of dietary fiber in the gut and play a key role in inhibiting pulmonary inflammation. Chronic inflammation may induce an epithelial-mesenchymal transition (EMT) in alveolar epithelial cells and result in fibrotic disorders. This study was designed to investigate the beneficial effect of sodium propionate (SP) on lipopolysaccharide (LPS)-induced EMT. In cultured BEAS-2B cells, the protein expression levels of E-cadherin, α-smooth muscle actin (SMA), and vimentin were 0.66 ± 0.20, 1.44 ± 0.23, and 1.32 ± 0.21 in the LPS group vs 1.11 ± 0.36 (P < 0.05), 1.04 ± 0.30 (P < 0.05), and 0.96 ± 0.13 (P < 0.01) in the LPS + SP group (mean ± standard deviation), respectively. Meanwhile, LPS-triggered inflammatory cytokines and extracellular proteins were also reduced by SP administration in BEAS-2B cells. Moreover, SP treatment attenuated inflammation, EMT, extracellular matrix (ECM) deposition, and even fibrosis in a mouse EMT model. In terms of mechanism, LPS-treated BEAS-2B cells exhibited a higher level of phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) phosphorylation, which was interrupted by SP treatment. It is worth noting that the blockade of the PI3K/Akt/mTOR signaling cascade reduced the LPS-evoked EMT process in BEAS-2B cells. These results suggest that SP can block LPS-induced EMT via inhibition of the PI3K/Akt/mTOR signaling cascade, which provides a basis for possible clinical use of SP in airway and lung diseases.

Lipopolysaccharide (LPS) inhibits ectopic bone formation induced by bone morphogenetic protein-2 and TGF-β1 through IL-1β production

OBJECTIVES

In order to gain new insight into bacterial infection during bone-regenerative treatment using bone morphogenetic proteins (BMPs), we examined the effects of lipopolysaccharide (LPS) on ectopic bone formation induced by BMP-2 and transforming growth factor (TGF)-β1 in mice.

METHODS

We implanted collagen sponges containing BMP-2, TGF-β1, and various amounts of LPS into mouse muscle tissues. Lump-like masses in which ectopic bones developed in mice were processed for microcomputed tomography, DNA microarray, reverse-transcription PCR, and histological analyses.

RESULTS

LPS treatment caused a dose-dependent reduction in the volume of ectopic bone. The total volume of ectopic bone induced by BMP-2 + TGF-β1 treatment was reduced by more than 75% in the presence of LPS. Histological analysis of the ectopic bone tissues revealed a significant reduction in total bone volume and bone volume/total volume in response to LPS. LPS treatment significantly increased the osteoblast number and osteoid volume, while the osteoclast number did not change. Since LPS induced production of TNF-α and IL-1β in lump-like masses, we implanted collagen sponges containing BMP-2 and TGF-β1 with or without LPS into TNF-α- or IL-1α/β-deficient mice. LPS treatment reduced the volume of ectopic bones in TNF-α-deficient mice but not in IL-1α/β-deficient mice. Furthermore, collagen sponges containing IL-1β reduced ectopic bone formation by BMP-2 and TGF-β1 in wild-type mice to the same extent as LPS treatment did.

CONCLUSIONS

LPS suppresses the ectopic bone formation induced by BMP-2 and TGF-β1 through IL-1β production.

Resveratrol induces depletion of TRAF6 and suppresses prostate cancer cell proliferation and migration

Although the early diagnosis of prostate cancer (PCa) enhances life expectancy with a 5-year survival rate of 100 %, metastasized-PCa is the fundamental reason for death by PCa, hence requires an advanced and target-directed treatment strategy. Metastasis is considered to be initiated with the epithelial-mesenchymal transition (EMT) event in which tumor cells change their epithelial characteristics into mesenchymal form and exacerbates the cancer progression. Herein, we investigated the effect and mechanism of resveratrol function in PCa cell proliferation and migration and reported that TNF-receptor associated factor 6 (TRAF6), an unconventional E3 ligase, is a key mediator of resveratrol function to inhibit PCa cell growth and proliferation and targeted for lysosomal degradation by resveratrol. MTT and cell counting demonstrated that resveratrol inhibited the viability and proliferation in DU145 and PC3 cells. Resveratrol (50 μM) mediated the degradation of TRAF6 which in turn facilitated repression of the NF-κB pathway. Also, wound healing and transwell migration assays and level of EMT-related proteins showed that resveratrol used TRAF6, at least in part to inhibit cell migration. Overexpression of TRAF6 augmented EMT in PCa by upregulating the expression of transcription factor SLUG. Moreover, TRAF6 overexpression was closely associated with EMT process through the NF-κB pathway. Our exploration exhibited that resveratrol may inhibit EMT through the TRAF6/NF-κB/SLUG axis. Altogether, this study represents that TRAF6 acts as an intermediary of resveratrol action to suppress PCa cell proliferation and migration, and concerns future attention to obtain as a therapeutic target for the treatment of PCa.

Investigating the regulation mechanism of baicalin on triple negative breast cancer's biological network by a systematic biological strategy

OBJECTIVE

To investigate the regulation mechanism of baicalin on triple negative breast cancer (TNBC)'s biological network by a systematic biological strategy and cytology experiment.

METHODS

A systematic biological methodology is utilized to predict the potential targets of baicalin, collect the genes of TNBC, and analyze the TNBC and baicalin's network. After the systematic biological analysis is performed, the cytology experiment, real-time quantitative PCR (qPCR) is used to validate the key biological processes and signaling pathways.

RESULTS

After systematic biological analysis, two networks were constructed and analyzed: (1) TNBC network; (2) Baicalin-TNBC protein-protein interaction (PPI) network. Several TNBC-related, treatment-related targets, clusters, signaling pathways and biological processes were found. Cytology experiment shows that baicalin can inhibit the proliferation, migration and invasion of breast cancer MDA-MB-231 cells in vitro (P < 0.05). The results of qPCR showed that baicalin increase the expression of E-cadherin mRNA, and decrease the expression of vimentin, β-catenin, c-Myc and MMP-7 mRNA in LPS-induced breast cancer MDA-MB-231 cells (P < 0.05).

CONCLUSION

Baicalin may achieve anti-tumor effects through regulating the targets, biological processes and pathways found in this research.

The Inhibitory Effect of (-)-Epigallocatechin-3-Gallate on Breast Cancer Progression via Reducing SCUBE2 Methylation and DNMT Activity

Epigenetic modifications are important mechanisms responsible for cancer progression. Accumulating data suggest that (-)-epigallocatechin-3-gallate (EGCG), the most abundant catechin of green tea, may hamper carcinogenesis by targeting epigenetic alterations. We found that signal peptide-CUB (complement protein C1r/C1s, Uegf, and Bmp1)-EGF (epidermal growth factor) domain-containing protein 2 (SCUBE2), a tumor suppressor gene, was hypermethylated in breast tumors. However, it is unknown whether EGCG regulates SCUBE2 methylation, and the mechanisms remain undefined. This study was designed to investigate the effect of EGCG on SCUBE2 methylation in breast cancer cells. We reveal that EGCG possesses a significantly inhibitory effect on cell viability in a dose- and time-dependent manner and presents more effects than other catechins. EGCG treatment resulted in enhancement of the SCUBE2 gene, along with elevated E-cadherin and decreased vimentin expression, leading to significant suppression of cell migration and invasion. The inhibitory effect of EGCG on SCUBE2 knock-down cells was remarkably alleviated. Further study demonstrated that EGCG significantly decreased the SCUBE2 methylation status by reducing DNA methyltransferase (DNMT) expression and activity. In summary, this study reported for the first time that SCUBE2 methylation can be reversed by EGCG treatment, finally resulting in the inhibition of breast cancer progression. These results suggest the epigenetic role of EGCG and its potential implication in breast cancer therapy.

Unraveling the molecular mechanisms and the potential chemopreventive/therapeutic properties of natural compounds in melanoma

Melanoma is the most fatal form of skin cancer. Current therapeutic approaches include surgical resection, chemotherapy, targeted therapy and immunotherapy. However, these treatment strategies are associated with development of drug resistance and severe side effects. In recent years, natural compounds have also been extensively studied for their anti-melanoma effects, including tumor growth inhibition, apoptosis induction, angiogenesis and metastasis suppression and cancer stem cell elimination. Moreover, a considerable number of studies reported the synergistic activity of phytochemicals and standard anti-melanoma agents, as well as the enhanced effectiveness of their synthetic derivatives and novel formulations. However, clinical data confirming these promising effects in patients are still scanty. This review emphasizes the anti-tumor mechanisms and potential application of the most studied natural products for melanoma prevention and treatment.

Knockdown of Delta-like 3 restricts lipopolysaccharide-induced inflammation, migration and invasion of A2058 melanoma cells via blocking Twist1-mediated epithelial-mesenchymal transition

AIMS

To investigate the effects and mechanisms of DLL3 in inflammation-mediated A2058 melanoma cell invasion and metastasis.

MATERIALS AND METHODS

Melanoma A2058 cells was stimulated with lipopolysaccharide (LPS), with or without transfection of DLL3 siRNA, or DLL3 overexpression vector, or Twist1 siRNA. Cell migration and invasion were detected by wound healing and transwell invasion assay. The production of inflammatory factors TNF-α and IL-6 was measured by ELISA. The expression of Notch signaling-related molecules was detected by PCR and western blot. The protein expression of MMP1, MMP9, VEGF, DLL3, and EMT-related molecules was tested by western blot.

KEY FINDINGS

LPS treatment increased migration and invasion of A2058 cells, accompanied by increased expression of TNF-α and IL-6. DLL3 was both upregulated in the LPS- or TNF-α-stimulated A2058 cells, and DLL3 knockdown inhibited LPS-induced inflammation, migration and invasion of A2058 cells, accompanied by down-regulation of MMP1, MMP9 and VEGF. Besides, DLL3 knockdown inhibits the expression of Twist1, a key EMT regulating factor, as well as the EMT hallmarks slug, N-cadherin and vimentin. Moreover, Twist1 silence inhibited EMT, and limited LPS-induced migration and invasion of A2058 cells, with decreased expression of MMP1, MMP9 and VEGF and reduced production of TNF-α and IL-6 in LPS-stimulated A2058 cells.

SIGNIFICANCE

Knockdown of DLL3 restricts LPS-induced inflammation, migration and invasion of A2058 melanoma cells via blocking Twist1-mediated EMT. Therefore, targeting DLL3 may be a promising therapeutic strategy against inflammation-aggravated melanoma progression.

Epithelial-mesenchymal transition as a target for botanicals in cancer metastasis

BACKGROUND

The plant kingdom represents an unlimited source of phytotherapeutics with promising perspectives in the field of anticancer drug discovery.

PURPOSE

In this view, epithelial-mesenchymal transition (EMT) represents a novel and major target in anticancer therapy. Therefore, this narrative review aims to provide an updated overview on the bioactive phytochemicals with anti-EMT activity.

CONCLUSION

Among the plant products reviewed, phenylpropanoids were the most investigated at preclinical phase, thus exhibiting a promising potential as anticancer drugs, though an evidence-based clinical efficacy is still lacking.

Toll-like receptor 4 shRNA attenuates lipopolysaccharide-induced epithelial-mesenchymal transition of intrahepatic biliary epithelial cells in rats

BACKGROUND AND AIM

Intrahepatic biliary epithelial cells (IBECs) of the bile duct in liver tissue of patients with hepatolithiasis promoted the development of diseases through epithelial-mesenchymal transition (EMT). This study investigated whether lipopolysaccharide (LPS), a cell-wall constituent of gram-negative bacteria, could induce EMT of IBECs and toll-like receptor 4 (TLR4) had a regulatory role via activating the nuclear factor-κB (NF-κB)/Snail signaling pathway during this process in vivo.

METHODS

TLR4 short hairpin RNA (shRNA) adenovirus or negative control shRNA (NC shRNA) adenovirus (1 × 10⁹ plaque-forming unit (PFU), respectively) was injected into the caudal vein of rats. After 96 h, 1 mg/kg LPS was infused retrogradely into the common bile duct for 48 h per rat. The effects of TLR4 shRNA on LPS-induced EMT were determined by evaluating the histopathological changes in IBECs using hematoxylin and eosin staining and the changes in the levels of EMT markers, TLR4, NF-κB p65, pNF-κB p65, and Snail using real-time polymerase chain reaction and Western blot analysis.

RESULTS

Compared with normal saline treatment, a loss of epithelial cell markers (E-cadherin and cytokeratin 7) and a gain of mesenchymal cell markers (N-cadherin and matrix metalloproteinase 2) were revealed. The levels of TLR4, NF-κB phosphorylation, and Snail significantly increased after LPS treatment, whereas pretreatment with TLR4 shRNA inhibited the LPS-induced EMT by downregulating the NF-κB/Snail signaling pathway.

CONCLUSIONS

LPS induced the EMT of IBECs by activating TLR4. The RNAi-mediated knockdown of TLR4 suppressed EMT occurrence via downregulating the NF-κB/Snail signaling pathway, implicating TLR4 as a new target for human hepatolithiasis.

Resveratrol inhibits Erk1/2-mediated adhesion of cancer cells via activating PP2A-PTEN signaling network

Resveratrol, a natural polyphenol compound, has been shown to possess anticancer activity. However, how resveratrol inhibits cancer cell adhesion has not been fully elucidated. Here, we show that resveratrol suppressed the basal or type I insulin-like growth factor (IGF)-1-stimulated adhesion of cancer cells (Rh1, Rh30, HT29, and HeLa cells) by inhibiting the extracellular signal-regulated kinase 1/2 (Erk1/2) pathway. Inhibition of Erk1/2 with U0126, knockdown of Erk1/2, or overexpression of dominant-negative mitogen-activated protein kinase kinase 1 (MKK1) strengthened resveratrol's inhibition of the basal or IGF-1-stimulated of Erk1/2 phosphorylation and cell adhesion, whereas ectopic expression of constitutively active MKK1 attenuated the inhibitory effects of resveratrol. Further research revealed that both protein phosphatase 2A (PP2A) and phosphatase and tensin homolog (PTEN)-Akt were implicated in resveratrol-inactivated Erk1/2-dependent cell adhesion. Inhibition of PP2A with okadaic acid or overexpression of dominant-negative PP2A rendered resistance to resveratrol's suppression of the basal or IGF-1-stimulated phospho-Erk1/2 and cell adhesion, whereas expression of wild-type PP2A enhanced resveratrol's inhibitory effects. Overexpression of wild-type PTEN or dominant-negative Akt or inhibition of Akt with Akt inhibitor X strengthened resveratrol's inhibition of the basal or IGF-1-stimulated Erk1/2 phosphorylation and cell adhesion. Furthermore, inhibition of mechanistic/mammalian target of rapamycin (mTOR) with rapamycin or silencing mTOR enhanced resveratrol's inhibitory effects on the basal and IGF-1-induced inhibition of PP2A-PTEN, activation of Akt-Erk1/2, and cell adhesion. The results indicate that resveratrol inhibits Erk1/2-mediated adhesion of cancer cells via activating PP2A-PTEN signaling network. Our data highlight that resveratrol has a great potential in the prevention of cancer cell adhesion.

Downregulations of AKT/mTOR Signaling Pathway for Salmonella-Mediated Suppression of Matrix Metalloproteinases-9 Expression in Mouse Tumor Models

The roles of Matrix MetalloProteinases (MMPs), such as MMP-9, in tumor metastasis are well studied, and this in turns stimulates the development of MMP inhibitors as antitumor agents. Previously, Salmonella accumulation was observed in the metastatic nodules of the lungs after systemic administration. Salmonella significantly enhanced the survival of the pulmonary metastatic tumor-bearing mice. Based on our previous observation, we hypothesized that Salmonella could affect metastasis-related protein expression. The treatment of Salmonella clearly reduced the expression of MMP-9. Meanwhile, the MMP-9 related signaling pathways, including Phosph-Protein Kinase B (P-AKT) and Phosph-mammalian Targets Of Rapamycin (P-mTOR) were decreased after a Salmonella treatment. The Salmonella inhibited tumor cell migration by wound-healing and Transwell assay. The anti-metastatic effects of Salmonella were evaluated in mice bearing experimental metastasis tumor models. Consequently, Salmonella inhibited the expression of MMP-9 by reducing the AKT/mTOR pathway and metastatic nodules in vivo.

Potential Mechanisms of Action of Dietary Phytochemicals for Cancer Prevention by Targeting Cellular Signaling Transduction Pathways

Cancer is a severe health problem that significantly undermines life span and quality. Dietary approach helps provide preventive, nontoxic, and economical strategies against cancer. Increased intake of fruits, vegetables, and whole grains are linked to reduced risk of cancer and other chronic diseases. The anticancer activities of plant-based foods are related to the actions of phytochemicals. One potential mechanism of action of anticancer phytochemicals is that they regulate cellular signal transduction pathways and hence affects cancer cell behaviors such as proliferation, apoptosis, and invasion. Recent publications have reported phytochemicals to have anticancer activities through targeting a wide variety of cell signaling pathways at different levels, such as transcriptional or post-transcriptional regulation, protein activation and intercellular messaging. In this review, we discuss major groups of phytochemicals and their regulation on cell signaling transduction against carcinogenesis via key participators, such as Nrf2, CYP450, MAPK, Akt, JAK/STAT, Wnt/β-catenin, p53, NF-κB, and cancer-related miRNAs.

Recent progress on the effects of microRNAs and natural products on tumor epithelial-mesenchymal transition

Epithelial–mesenchymal transition (EMT) is a biological process of phenotypic transition of epithelial cells that can promote physiological development as well as tissue healing and repair. In recent years, cancer researchers have noted that EMT is closely related to the occurrence and development of tumors. When tumor cells undergo EMT, they can develop enhanced migration and local tissue invasion abilities, which can lead to metastatic growth. Nevertheless, two researches in NATURE deny its necessity in specific tumors and that is discussed in this review. The degree of EMT and the detection of EMT-associated marker molecules can also be used to judge the risk of metastasis and to evaluate patients’ prognosis. MicroRNAs (miRNAs) are noncoding small RNAs, which can inhibit gene expression and protein translation through specific binding with the 3′ untranslated region of mRNA. In this review, we summarize the miRNAs that are reported to influence EMT through transcription factors such as ZEB, SNAIL, and TWIST, as well as some natural products that regulate EMT in tumors. Moreover, mutual inhibition occurs between some transcription factors and miRNAs, and these effects appear to occur in a complex regulatory network. Thus, understanding the role of miRNAs in EMT and tumor growth may lead to new treatments for malignancies. Natural products can also be combined with conventional chemotherapy to enhance curative effects.

Protective Effects of Hydrogen-Rich Saline Against Lipopolysaccharide-Induced Alveolar Epithelial-to-Mesenchymal Transition and Pulmonary Fibrosis

BACKGROUND Fibrotic change is one of the important reasons for the poor prognosis of patients with acute respiratory distress syndrome (ARDS). The present study investigated the effects of hydrogen-rich saline, a selective hydroxyl radical scavenger, on lipopolysaccharide (LPS)-induced pulmonary fibrosis. MATERIAL AND METHODS Male ICR mice were divided randomly into 5 groups: Control, LPS-treated plus vehicle treatment, and LPS-treated plus hydrogen-rich saline (2.5, 5, or 10 ml/kg) treatment. Twenty-eight days later, fibrosis was assessed by determination of collagen deposition, hydroxyproline, and type I collagen levels. Development of epithelial-to-mesenchymal transition (EMT) was identified by examining protein expressions of E-cadherin and α-smooth muscle actin (α-SMA). Transforming growth factor (TGF)-β1 content, total antioxidant capacity (T-AOC), malondialdehyde (MDA) content, catalase (CAT), and superoxide dismutase (SOD) activity were determined. RESULTS Mice exhibited increases in collagen deposition, hydroxyproline, type I collagen contents, and TGF-β1 production in lung tissues after LPS treatment. LPS-induced lung fibrosis was associated with increased expression of α-SMA, as well as decreased expression of E-cadherin. In addition, LPS treatment increased MDA levels but decreased T-AOC, CAT, and SOD activities in lung tissues, indicating that LPS induced pulmonary oxidative stress. Hydrogen-rich saline treatment at doses of 2.5, 5, or 10 ml/kg significantly attenuated LPS-induced pulmonary fibrosis. LPS-induced loss of E-cadherin in lung tissues was largely reversed, whereas the acquisition of α-SMA was dramatically decreased by hydrogen-rich saline treatment. In addition, hydrogen-rich saline treatment significantly attenuated LPS-induced oxidative stress. CONCLUSIONS Hydrogen-rich saline may protect against LPS-induced EMT and pulmonary fibrosis through suppressing oxidative stress.

Propofol suppresses LPS-induced nuclear accumulation of HIF-1α and tumor aggressiveness in non-small cell lung cancer

Tumor hypoxia has been recognized as a characteristic of the tumor microenvironment and promotes metastasis in a variety of types of cancer. However, in lung cancer, the role of hypoxia-inducible factor 1α (HIF-1α) in modulating the cellular response to the inflammation-related microenvironment remains unclear. In the present study, enhanced expression of HIF-1α accompanied by an increased ROS level was observed in lipopolysaccharide (LPS)-stimulated non-small cell lung cancer (NSCLC) cells. In addition, propofol, a general anesthetic, was found to significantly reduce the LPS-induced upregulation of HIF-1α and ROS in a dose-dependent manner. Further study showed that propofol may antagonize the role of LPS in activating HIF-1α through attenuating the protein stability and nuclear localization of HIF-1α. Moreover, knockdown of HIF-1α attenuated expression of mesenchymal marker, vimentin, but promoted the expression of epidermal marker, E-cadherin, in the LPS-treated NSCLC cells. Notably, LPS-induced epithelial-to-mesenchymal transition (EMT) was notably suppressed by propofol treatment. Consistently, a wound healing assay revealed that propofol abrogated LPS-stimulated migration of NSCLC cells while overexpression of HIF-1α reversed the effects of propofol. Similarly, we investigated the influence of propofol on the invasive capability of NSCLC cells. Western blot and RT-PCR analyses indicated that both knockdown of HIF-1α and treatment of propofol attenuated the LPS-activated expression of MMP2 and MMP9 which are necessary for tumor invasion. However, results from the Transwell assay confirmed that propofol also suppressed cell invasion by decreasing HIF-1α expression in the LPS-treated NSCLC cells. Analysis of clinical specimens demonstrated abnormal expression of HIF-1α in NSCLC tissues and a poor prognosis in patients with elevated HIF-1α expression. Thus, the present study suggests a potential strategy for NSCLC by targeting HIF-1α.

Towards therapeutic advances in melanoma management: An overview

Melanoma is one of the most aggressive types of skin cancer with rapidly increasing incidence rate. The disease is largely considered incurable and the patients diagnosed with metastatic melanoma have a survival of not more than five years. Despite of the recent advances in anti-melanoma chemo- and immunotherapies, the available drugs are relatively toxic and responsive to only a limited subset of lesions. Currently, topical pharmacotherapy is demonstrated as an effective approach for the treatment of various skin cancers. Also, in vitro testing of melanoma cell lines and murine melanoma models has identified a number of relatively safe and effective phytochemicals. In this review, we described the use of topical pharmacotherapy for the treatment of skin cancers. Melanoma treatment by drugs targeting MAPK-pathway has also been discussed. Long non-coding RNAs and therapeutics targeting ER-associated pathways looks quite promising for the treatment of melanoma. Moreover, some natural anticancer compounds that have been reported to have anti-melanoma effects have also been described. At present a better understanding of genetics and epigenetics of initiation and progression of melanoma is needed for the identification of novel biomarkers and development of targeted therapeutics against melanoma.

Anti-metastatic potential of resveratrol and its metabolites by the inhibition of epithelial-mesenchymal transition, migration, and invasion of malignant cancer cells

BACKGROUND

Increased epithelial-mesenchymal transition (EMT) and cell migration and invasion abilities of cancer cells play important roles in the metastatic process of cancer. Resveratrol is a stilbenoid, a type of natural polyphenol found in the skin of grapes, berries, and peanuts. A number of experiments have examined resveratrol's ability to target diverse pathways associated with carcinogenesis and cancer progression.

PURPOSE

This article aims to present updated overview of the knowledge that resveratrol and its metabolites or analogs have the potential to inhibit metastasis of cancer via affecting many signaling pathways related with EMT, cancer migration, and invasion in diverse organs of the body.

CHAPTERS

This article starts with a short introduction describing diverse beneficial effects of resveratrol including cancer prevention and the aim of the present study. To address the effects of resveratrol on cancer metastasis, mechanisms of EMT, migration, invasion, and their relevance with cancer metastasis, anti-metastatic effects of resveratrol through EMT-related signaling pathways and inhibitory effects of resveratrol on migration and invasion are highlighted. In addition, anti-metastatic potential of resveratrol metabolites and analogs is addressed.

CONCLUSION

Resveratrol was demonstrated to turn back the EMT process induced by diverse signaling pathways in several cellular and animal cancer models. In addition, resveratrol can exert chemopreventive efficacies on migration and invasion of cancer cells by inhibiting the related pathways and target molecules. Although these findings display the anti-metastatic potential of resveratrol, more patient-oriented clinical studies demonstrating the marked efficacies of resveratrol in humans are still needed.

Lipopolysaccharide-induced α-catenin downregulation enhances the motility of human colorectal cancer cells in an NF-κB signaling-dependent manner

α-Catenin is an important molecule involved in the maintenance of cell-cell adhesion and a prognostic marker in cancer since its expression is essential for preventing cancer metastasis. However, the mechanism that leads to the downregulation of α-catenin in cancer progression remains unclear. The present study revealed that lipopolysaccharide (LPS)-induced NF-κB signaling activation suppressed α-catenin expression and motility in SW620 colorectal cancer (CRC) cells, using real-time polymerase chain reaction, Western blotting, and transwell migration assays. LPS treatment reduced both the mRNA and protein expression of α-catenin and thereby enhanced cell motility. Conversely, incubating cells with an NF-κB inhibitor disrupted these effects. Furthermore, the ectopic expression of p65 alone mimicked the effects of LPS stimulation. In CRC tissues, the presence of enteric bacterial LPS-related neutrophil-enriched foci was correlated with α-catenin downregulation. Collectively, these findings suggest that LPS-induced NF-κB signaling is related to α-catenin suppression and enhanced cell motility in CRC. Therefore, NF-κB is a novel potential therapeutic target for CRC metastasis.

Unraveling the Anticancer Effect of Curcumin and Resveratrol

Resveratrol and curcumin are natural products with important therapeutic properties useful to treat several human diseases, including cancer. In the last years, the number of studies describing the effect of both polyphenols against cancer has increased; however, the mechanism of action in all of those cases is not completely comprehended. The unspecific effect and the ability to interfere in assays by both polyphenols make this challenge even more difficult. Herein, we analyzed the anticancer activity of resveratrol and curcumin reported in the literature in the last 11 years, in order to unravel the molecular mechanism of action of both compounds. Molecular targets and cellular pathways will be described. Furthermore, we also discussed the ability of these natural products act as chemopreventive and its use in association with other anticancer drugs.

Use of Polyphenolic Compounds in Dermatologic Oncology

Polyphenols are a widely used class of compounds in dermatology. While phenol itself, the most basic member of the phenol family, is chemically synthesized, most polyphenolic compounds are found in plants and form part of their defense mechanism against decomposition. Polyphenolic compounds, which include phenolic acids, flavonoids, stilbenes, and lignans, play an integral role in preventing the attack on plants by bacteria and fungi, as well as serving as cross-links in plant polymers. There is also mounting evidence that polyphenolic compounds play an important role in human health as well. One of the most important benefits, which puts them in the spotlight of current studies, is their antitumor profile. Some of these polyphenolic compounds have already presented promising results in either in vitro or in vivo studies for non-melanoma skin cancer and melanoma. These compounds act on several biomolecular pathways including cell division cycle arrest, autophagy, and apoptosis. Indeed, such natural compounds may be of potential for both preventive and therapeutic fields of cancer. This review evaluates the existing scientific literature in order to provide support for new research opportunities using polyphenolic compounds in oncodermatology.

Hinokitiol Inhibits Melanogenesis via AKT/mTOR Signaling in B16F10 Mouse Melanoma Cells

H inokitiol purified from the heartwood of cupressaceous plants has had various biological functions of cell differentiation and growth. Hinokitiol has been demonstrated as having an important role in anti-inflammation and anti-bacteria effect, suggesting that it is potentially useful in therapies for hyperpigmentation. Previously, hinokitiol inhibited the production of melanin by inhibiting tyrosinase activity. The autophagic signaling pathway can induce hypopigmentation. This study is warranted to investigate the mechanism of hinokitiol-induced hypopigmentation through autophagy in B16F10 melanoma cells. The melanin contents and expression of microthphalmia associated transcription factor (MITF) and tyrosinase were inhibited by treatment with hinokitiol. Moreover, the phosphorylation of the protein express levels of phospho-protein kinase B (P-AKT) and phospho-mammalian targets of rapamycin (P-mTOR) were reduced after hinokitiol treatment. In addition, the microtubule associated protein 1 light chain 3 (LC3) -II and beclin 1 (autophagic markers) were increased after the B16F10 cell was treated with hinokitiol. Meanwhile, hinokitiol decreased cellular melanin contents in a dose-dependent manner. These findings establish that hinokitiol inhibited melanogenesis through the AKT/mTOR signaling pathway.

Role of phytochemicals in the inhibition of epithelial–mesenchymal transition in cancer metastasis

Epithelial–mesenchymal transition (EMT) development is controlled by several signaling pathways including Hedgehog, Wnt, fibroblast growth factors (FGF), hepatocyte growth factor/scatter factor (HGF),etc. Phytochemicals is very promising therapeutic candidate that inhibit the progression of EMT by inhibiting the signaling pathways.

Genomic instability in human cancer: Molecular insights and opportunities for therapeutic attack and prevention through diet and nutrition

Genomic instability can initiate cancer, augment progression, and influence the overall prognosis of the affected patient. Genomic instability arises from many different pathways, such as telomere damage, centrosome amplification, epigenetic modifications, and DNA damage from endogenous and exogenous sources, and can be perpetuating, or limiting, through the induction of mutations or aneuploidy, both enabling and catastrophic. Many cancer treatments induce DNA damage to impair cell division on a global scale but it is accepted that personalized treatments, those that are tailored to the particular patient and type of cancer, must also be developed. In this review, we detail the mechanisms from which genomic instability arises and can lead to cancer, as well as treatments and measures that prevent genomic instability or take advantage of the cellular defects caused by genomic instability. In particular, we identify and discuss five priority targets against genomic instability: (1) prevention of DNA damage; (2) enhancement of DNA repair; (3) targeting deficient DNA repair; (4) impairing centrosome clustering; and, (5) inhibition of telomerase activity. Moreover, we highlight vitamin D and B, selenium, carotenoids, PARP inhibitors, resveratrol, and isothiocyanates as priority approaches against genomic instability. The prioritized target sites and approaches were cross validated to identify potential synergistic effects on a number of important areas of cancer biology.

The impact of low-dose carcinogens and environmental disruptors on tissue invasion and metastasis

The purpose of this review is to stimulate new ideas regarding low-dose environmental mixtures and carcinogens and their potential to promote invasion and metastasis. Whereas a number of chapters in this review are devoted to the role of low-dose environmental mixtures and carcinogens in the promotion of invasion and metastasis in specific tumors such as breast and prostate, the overarching theme is the role of low-dose carcinogens in the progression of cancer stem cells. It is becoming clearer that cancer stem cells in a tumor are the ones that assume invasive properties and colonize distant organs. Therefore, low-dose contaminants that trigger epithelial-mesenchymal transition, for example, in these cells are of particular interest in this review. This we hope will lead to the collaboration between scientists who have dedicated their professional life to the study of carcinogens and those whose interests are exclusively in the arena of tissue invasion and metastasis.

Aqueous extract of Psoralea corylifolia L. inhibits lipopolysaccharide-induced endothelial-mesenchymal transition via downregulation of the NF-κB-SNAIL signaling pathway

The epithelial-mesenchymal transition (EMT) is a pivotal event in the invasion and metastasis of cancer cells. Psoralea corylifolia L. (PC) inhibits the proliferation of various cancer cells. However, its possible role in EMT has not been identified. In the present study, we examined the effects of an aqueous extract of Psoralea corylifolia L. (PCAE), a typical medicinal decoction, on the EMT. Lipopolysaccharide (LPS) induced EMT-like phenotypic changes, enhancing cell migration and invasion. However, PCAE markedly reduced the expression of the LPS-induced EMT markers, including N-cadherin and vimentin, and increased the expression of β-catenin. PCAE also inhibited cell migration and invasion in vitro. The effects of PCAE on the LPS-induced EMT were mediated by the inactivation of the NF-κB-SNAIL signaling pathway. The results provide new evidence that PCAE suppresses cancer cell invasion and migration by inhibiting EMT. Therefore, PCAE is a potentially effective dietary chemopreventive agent for malignant tumors since it inhibits metastasis.

Resveratrol Enhances Chemosensitivity in Mouse Melanoma Model Through Connexin 43 Upregulation

Although current studies indicate that resveratrol exhibits potential antitumor activities, the precise mechanisms of its beneficial effects combined with chemotherapy are not fully understood. This work is warranted to elucidate the underlying mechanism of antitumor effects by the combination therapy of resveratrol and cisplatin. The presence of functional gap junctions is highly relevant for the success of chemotherapy. Gap junctions mediate cell communication by allowing the passage of molecules from one cell to another. Connexin (Cx) 43 is ubiquitous and reduced in a variety of tumor cells. Cx43 may influence the response of tumor cells to treatments by facilitating the passage of antitumor drugs or death signals between neighboring tumor cells. Following resveratrol treatment, dose-dependent upregulation of Cx43 expressions was observed. In addition, gap junction intercellular communication was increased. To study the mechanism underlying these resveratrol-induced Cx43 expressions, we found that resveratrol induced a significant increase in mitogen-activated protein kinases (MAPK) signaling pathways. The MAPK inhibitors significantly reduced the expression of Cx43 protein after resveratrol treatment. Specific knockdown of Cx43 resulted in a reduction of cell death after resveratrol and cisplatin treatment. Our results suggest that treatment of resveratrol in tumor leads to increase Cx43 gap junction communication and enhances the combination of resveratrol and cisplatin therapeutic effects. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 877-886, 2015.

The pharmacology of resveratrol in animals and humans

In addition to thousands of research papers related to resveratrol (RSV), approximately 300 review articles have been published. Earlier research tended to focus on pharmacological activities of RSV related to cardiovascular systems, inflammation, and carcinogenesis/cancer development. More recently, the horizon has been broadened by exploring the potential effect of RSV on the aging process, diabetes, neurological dysfunction, etc. Herein, we primarily focus on the in vivo pharmacological effects of RSV reported over the past 5 years (2009-2014). In addition, recent clinical intervention studies performed with resveratrol are summarized. Some discrepancies exist between in vivo studies with animals and clinical studies, or between clinical studies, which are likely due to disparate doses of RSV, experimental settings, and subject variation. Nevertheless, many positive indications have been reported with mammals, so it is reasonable to advocate for the conduct of more definitive clinical studies. Since the safety profile is pristine, an added advantage is the use of RSV as a dietary supplement. This article is part of a Special Issue entitled: Resveratrol: Challenges in translating pre-clinical findings to improved patient outcomes.

Review of natural compounds for potential skin cancer treatment

Most anti-cancer drugs are derived from natural resources such as marine, microbial and botanical sources. Cutaneous malignant melanoma is the most aggressive form of skin cancer, with a high mortality rate. Various treatments for malignant melanoma are available, but due to the development of multi-drug resistance, current or emerging chemotherapies have a relatively low success rates. This emphasizes the importance of discovering new compounds that are both safe and effective against melanoma. In vitro testing of melanoma cell lines and murine melanoma models offers the opportunity for identifying mechanisms of action of plant derived compounds and extracts. Common anti-melanoma effects of natural compounds include potentiating apoptosis, inhibiting cell proliferation and inhibiting metastasis. There are different mechanisms and pathways responsible for anti-melanoma actions of medicinal compounds such as promotion of caspase activity, inhibition of angiogenesis and inhibition of the effects of tumor promoting proteins such as PI3-K, Bcl-2, STAT3 and MMPs. This review thus aims at providing an overview of anti-cancer compounds, derived from natural sources, that are currently used in cancer chemotherapies, or that have been reported to show anti-melanoma, or anti-skin cancer activities. Phytochemicals that are discussed in this review include flavonoids, carotenoids, terpenoids, vitamins, sulforaphane, some polyphenols and crude plant extracts.

A novel anti‑cancer effect of resveratrol: reversal of epithelial‑mesenchymal transition in prostate cancer cells

Carcinoma progression is associated with the loss of epithelial features and the acquisition of a mesenchymal phenotype, a process known as epithelial-mesenchymal transition (EMT). Resveratrol, a natural polyphenolic compound found in grapes, berries and peanuts, has a wide range of pharmacological properties, including anti-tumor metastasis properties. The underlying mechanism through which resveratrol inhibits metastasis of prostate cancer (PCa) is not yet fully understood; however, it is thought to be associated with the disruption of EMT. In the present study, lipopolysaccharide (LPS) was used to trigger EMT in PC-3 and LNCaP PCa cell lines, and the cell lines were subsequently treated with resveratrol. The results demonstrated that exposure of PC-3 and LNCaP cells to LPS resulted in morphological alterations characteristic of EMT, as well as an increase in the expression of the mesenchymal marker vimentin and a decrease in the expression of E-cadherin. In addition, LPS exposure resulted in an increase in cell motility, along with an upregulation of the transcription factor glioma-associated oncogene homolog 1 (Gli1). However, treatment with resveratrol inhibited LPS-induced morphological changes, decreased the expression of LPS-induced markers of EMT and inhibited the expression of Gli1, resulting in the inhibition of in vitro cell motility and invasiveness. These results provide a novel perspective for the anti-invasion mechanism of resveratrol, suggesting that the effect is in part due to its ability to inhibit the EMT process through the Hedgehog signaling pathway.

Salmonella induce autophagy in melanoma by the downregulation of AKT/mTOR pathway

Salmonella have been demonstrated to inhibit tumor growth. However, the mechanism of Salmonella-induced tumor cell death is less defined. Autophagy is a cellular process that mediates the degradation of long-lived proteins and unwanted organelles in the cytosol. Tumor cells frequently display lower levels of basal autophagic activity than their normal counterparts and fail to increase autophagic activity in response to stresses. Autophagy is involved in the cell defense elimination of bacteria. The signaling pathways leading to activation of Salmonella-induced autophagy in tumor cells remain to be elucidated. We used autophagy inhibitor (3-Methyladenine) and apoptosis inhibitor (Z-VAD-FMK) to demonstrate that Salmonella may induce cell death via apoptosis and autophagic pathway. Meanwhile, we suggested that Salmonella induce autophagy in a dose- and time-dependent manner. The autophagic markers were increased after tumor cell infected with Salmonella. In addition, the protein express levels of phosph-protein kinase B (P-AKT), phosph-mammalian targets of rapamycin (P-mTOR), phosph-p70 ribosomal s6 kinase (P-p70s6K) in tumor cells were decreased by western analysis after Salmonella infection. In conclusion, our results point out that Salmonella induce the autophagic signaling pathway via downregulation of AKT/mTOR pathway. Herein, our findings that Salmonella in controlling tumor growth may induce autophagic signal pathway.

An extract of Rhodobacter sphaeroides reduces cisplatin-induced nephrotoxicity in mice

Cisplatin is used as a treatment for various types of solid tumors. Renal injury severely limits the use of cisplatin. Renal cell apoptosis, oxidative stress, and inflammation contribute to cisplatin-induced nephrotoxicity. Previously, we found that an extract of Rhodobacter sphaeroides (Lycogen™) inhibited proinflammatory cytokines and the production of nitric oxide in activated macrophages in a dextran sodium sulfate (DSS)-induced colitis model. Here, we evaluated the effect of Lycogen™, a potent anti-inflammatory agent, in mice with cisplatin-induced renal injury. We found that attenuated renal injury correlated with decreased apoptosis due to a reduction in caspase-3 expression in renal cells. Oral administration of Lycogen™ significantly reduced the expression of tumor necrosis factor-α and interleukin-1β in mice with renal injury. Lycogen™ reduces renal dysfunction in mice with cisplatin-induced renal injury. The protective effects of the treatment included blockage of the cisplatin-induced elevation in serum urea nitrogen and creatinine. Meanwhile, Lycogen™ attenuated body weight loss and significantly prolonged the survival of mice with renal injury. We propose that Lycogen™ exerts anti-inflammatory activities that represent a promising strategy for the treatment of cisplatin-induced renal injury.