Sustained ERK activation-mediated proliferation inhibition of farrerol on human gastric carcinoma cell line by G0/G1-phase cell-cycle arrest

Flavonoids and Gastric Cancer Therapy: From Signaling Pathway to Therapeutic Significance

Gastric cancer (GC) is a prevalent gastrointestinal tumor characterized by high mortality and recurrence rates. Current treatments often have limitations, prompting researchers to explore novel anti-tumor substances and develop new drugs. Flavonoids, natural compounds with diverse biological activities, are gaining increasing attention in this regard. We searched from PubMed, Web of Science, SpringerLink and other databases to find the relevant literature in the last two decades. Using "gastric cancer", "stomach cancers", "flavonoid", "bioflavonoid", "2-Phenyl-Chromene" as keywords, were searched, then analyzed and summarized the mechanism of flavonoids in the treatment of GC. It was revealed that the anti-tumor mechanism of flavonoids involves inhibiting tumor growth, proliferation, invasion, and metastasis, as well as inducing cell death through various processes such as apoptosis, autophagy, ferroptosis, and pyroptosis. Additionally, combining flavonoids with other chemotherapeutic agents like 5-FU and platinum compounds can potentially reduce chemoresistance. Flavonoids have also demonstrated enhanced biological activity when used in combination with other natural products. Consequently, this review proposes innovative perspectives for the development of flavonoids as new anti-GC agents.

Farrerol Inhibits Vascular Smooth Muscle Cell Proliferation and Protects Them From Oxidative Injury via Bidirectional Modulation of the PI3K/Akt/mTOR Signaling Pathway

The inhibition of intimal hyperplasia (IH) is an effective strategy to improve the long-term outcome of endovascular therapy and prevent restenosis. Farrerol, a naturally occurring dihydroflavone with a variety of bioactivities, exerts inhibitory effects against balloon injury-induced IH in rats. In the present study, bioinformatics analysis, in combination with in vitro experimental validation, was performed to elucidate the underlying inhibitory mechanisms. The protein–protein interaction (PPI) network was assessed to identify farrerol-related protein targets in the context of IH, based on which biological functions and pathway enrichment were analyzed. The proliferation and cell cycle distribution of vascular smooth muscle cells (VSMCs) were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2 H-tetrazolium bromide and 5-ethynyl-2-deoxyuridine incorporation assays and flow cytometric analysis, respectively. The level of pro-inflammatory cytokines in the cell culture medium was estimated using an enzyme-linked immunosorbent assay (ELISA). Protein expression in A7r5 cells was determined by western blotting. Forty-six IH-related targets of farrerol were identified, and the PI3K/Akt/mTOR pathway was highly enriched among the 43 predicted pathways ( P < .05). In serum (10% fetal bovine serum)-induced A7r5 cells, farrerol inhibited proliferation through non-cytotoxic effects, induced cell cycle arrest in the G0/G1 phase , and suppressed the activation of the PI3K/Akt/mTOR pathway. In H2O2 (300 µM)-induced A7r5 cells, farrerol reduced the release of IL-1 β and TNF- α and reversed the suppressive effect on the PI3K/Akt/mTOR pathway in response to H2O2 stimulation. In conclusion, farrerol inhibits the proliferation of VSMCs and protects VSMCs from oxidative injury via the bidirectional modulation of the PI3K/Akt/mTOR signaling pathway, which might contribute to the suppression of neointima formation.

Molecular mechanisms underlying the action of carcinogens in gastric cancer with a glimpse into targeted therapy

BACKGROUND

Gastric cancer imposes a substantial global health burden despite its overall incidence decrease. A broad spectrum of inherited, environmental and infectious factors contributes to the development of gastric cancer. A profound understanding of the molecular underpinnings of gastric cancer has lagged compared to several other tumors with similar incidence and morbidity rates, owing to our limited knowledge of the role of carcinogens in this malignancy. The International Agency for Research on Cancer (IARC) has classified gastric carcinogenic agents into four groups based on scientific evidence from human and experimental animal studies. This review aims to explore the potential comprehensive molecular and biological impacts of carcinogens on gastric cancer development and their interactions and interferences with various cellular signaling pathways.

CONCLUSIONS

In this review, we highlight recent clinical trial data reported in the literature dealing with different ways to target various carcinogens in gastric cancer. Moreover, we touch upon other multidisciplinary therapeutic approaches such as surgery, adjuvant and neoadjuvant chemotherapy. Rational clinical trials focusing on identifying suitable patient populations are imperative to the success of single-agent therapeutics. Novel insights regarding signaling pathways that regulate gastric cancer can potentially improve treatment responses to targeted therapy alone or in combination with other/conventional treatments. Preventive strategies such as control of H. pylori infection through eradication or immunization as well as dietary habit and lifestyle changes may reduce the incidence of this multifactorial disease, especially in high prevalence areas. Further in-depth understanding of the molecular mechanisms involved in the role of carcinogenic agents in gastric cancer development may offer valuable information and update state-of-the-art resources for physicians and researchers to explore novel ways to combat this disease, from bench to bedside. A schematic outlining of the interaction between gastric carcinogenic agents and intracellular pathways in gastric cancer H. pylori stimulates multiple intracellular pathways, including PI3K/AKT, NF-κB, Wnt, Shh, Ras/Raf, c-MET, and JAK/STAT, leading to epithelial cell proliferation and differentiation, apoptosis, survival, motility, and inflammatory cytokine release. EBV can stimulate intracellular pathways such as the PI3K/Akt, RAS/RAF, JAK/STAT, Notch, TGF-β, and NF-κB, leading to cell survival and motility, proliferation, invasion, metastasis, and the transcription of anti-apoptotic genes and pro-inflammatory cytokines. Nicotine and alcohol can lead to angiogenesis, metastasis, survival, proliferation, pro-inflammatory, migration, and chemotactic by stimulating various intracellular signaling pathways such as PI3K/AKT, NF-κB, Ras/Raf, ROS, and JAK/STAT. Processed meat contains numerous carcinogenic compounds that affect multiple intracellular pathways such as sGC/cGMP, p38 MAPK, ERK, and PI3K/AKT, leading to anti-apoptosis, angiogenesis, metastasis, inflammatory responses, proliferation, and invasion. Lead compounds may interact with multiple signaling pathways such as PI3K/AKT, NF-κB, Ras/Raf, DNA methylation-dependent, and epigenetic-dependent, leading to tumorigenesis, carcinogenesis, malignancy, angiogenesis, DNA hypermethylation, cell survival, and cell proliferation. Stimulating signaling pathways such as PI3K/Akt, RAS/RAF, JAK/STAT, WNT, TGF-β, EGF, FGFR2, and E-cadherin through UV ionizing radiation leads to cell survival, proliferation, and immortalization in gastric cancer. The consequence of PI3K/AKT, NF-κB, Ras/Raf, ROS, JAK/STAT, and WNT signaling stimulation by the carcinogenic component of Pickled vegetables and salted fish is the Warburg effect, tumorigenesis, angiogenesis, proliferation, inflammatory response, and migration.

The pharmacological properties and corresponding mechanisms of farrerol: a comprehensive review

CONTEXT

Farrerol, a typical natural flavanone isolated from the traditional Chinese herb 'Man-shan-hong' [Rhododendron dauricum L. (Ericaceae)] with phlegm-reducing and cough-relieving properties, is widely used in China for treating bronchitis and asthma.

OBJECTIVE

To present the anti-inflammatory, antioxidant, vasoactive, antitumor, and antimicrobial effects of farrerol and its underlying molecular mechanisms.

METHODS

The literature was reviewed by searching PubMed, Medline, Web of Knowledge, Scopus, and Google Scholar databases between 2011 and May 2021. The following key words were used: 'farrerol,' 'flavanone,' 'anti-inflammatory,' 'antioxidant,' 'vasoactive,' 'antitumor,' 'antimicrobial,' and 'molecular mechanisms'.

RESULTS

Farrerol showed anti-inflammatory effects mainly mediated via the inhibition of interleukin (IL)-6/8, IL-1β, tumour necrosis factor(TNF)-α, NF-κB, NO, COX-2, JNK1/2, AKT, PI3K, ERK1/2, p38, Keap-1, and TGF-1β. Farrerol exhibited antioxidant effects by decreasing JNK, MDA, ROS, NOX4, Bax/Bcl-2, caspase-3, p-p38 MAPK, and GSK-3β levels and enhancing Nrf2, GSH, SOD, GSH-Px, HO-1, NQO1, and p-ERK levels. The vasoactive effects of farrerol were also shown by the reduced α-SMA, NAD(P)H, p-ERK, p-Akt, mTOR, Jak2, Stat3, Bcl-2, and p38 levels, but increased OPN, occludin, ZO-1, eNOS, CaM, IP3R, and PLC levels. The antitumor effects of farrerol were evident from the reduced Bcl-2, Slug, Zeb-1, and vimentin levels but increased p27, ERK1/2, p38, caspase-9, Bax, and E-cadherin levels. Farrerol reduced α-toxin levels and increased NO production and NF-κB activity to impart antibacterial activity.

CONCLUSIONS

This review article provides a theoretical basis for further studies on farrerol, with a view to develop and utilise farrerol for treating of vascular-related diseases in the future.

Farrerol exhibits inhibitory effects on lung adenocarcinoma cells by activating the mitochondrial apoptotic pathway

Farrerol is an herbal compound extracted from rhododendron. Here, our study is to investigate biological effects of farrerol on lung adenocarcinoma (LAC) cells. Human LAC cell lines and xenograft mouse model were utilized to define the effects of farrerol on tumor growth. Our findings indicated that farrerol significantly reduced LAC cell viability as well as the colony-forming capacity. Flow cytometry analysis demonstrated that farrerol contributed to cell apoptosis and G0/G1 phase cell cycle arrest. Mechanistically, farrerol treatment upregulated proapoptotic molecules (Bak, Bid, cleaved caspase-3 and cleaved caspase-9) and senescence markers (p16 and p2), but downregulated antiapoptosis genes (Bcl-2 and Bcl-XL) and cell cycle-associated genes (CyclinD1 and CDK4); meanwhile, the phosphorylation of retinoblastoma (Rb) protein was attenuated upon pretreatment of LAC cells with farrerol in comparison to untreated control. Further studies indicated that farrerol elevated reactive oxygen species levels, activating mitochondrial apoptotic pathway and causing cell apoptosis. However, exposure to farrerol did not result in significant apoptosis in normal lung epithelial cells, suggesting a tumor-specific effect of farrerol on LAC cells. In animal model, farrerol showed a significant inhibitory effect on LAC xenograft tumor growth. And gene expressions in tumor tissues, as mentioned above, were in line with the in vitro results. Taken together, these results suggested that farrerol caused LAC cell apoptosis by activating mitochondrial apoptotic pathway, whereas farrerol treatment had no notable effect on normal lung epithelial cells. Farrerol might be an effective therapeutic drug for LAC.

Farrerol suppresses the progression of laryngeal squamous cell carcinoma via the mitochondria-mediated pathway

PURPOSE

In the context of well-known inhibitory effects of Farrerol on the invasion of lung squamous cell carcinoma cells, the unexplored effect and regulatory mechanism of Farrerol on laryngeal squamous cell carcinoma (LSCC) emerged as the target in this study.

METHODS

After treatment with Farrerol alone, or together with MitoTempo, the viability, apoptosis, cell cycle distribution, migration, and invasion of LSCC cells were measured using MTT, flow cytometry, wound-healing, and transwell assays, respectively. Meanwhile, the levels of cytochrome C (Cyt C), Cleaved caspase-3/9, Cyclin D1, E-cadherin, N-cadherin, and Vimentin in LSCC cells were evaluated by Western blot; the reactive oxygen species (ROS) formation intensity and the disruption of mitochondrial membrane potential (MMP) of LSCC cells were assessed using flow cytometry; and the effect of Farrerol on xenograft tumor formation was evaluated in animal experiment.

RESULTS

Farrerol (10, 20, 50 μM) inhibited the viability, proliferation, cell cycle progression, migration and invasion, but promoted apoptosis, ROS formation intensity and disruption of MMP of LSCC cells. Moreover, Farrerol up-regulated Cyt C (in the cytoplasm), Cleaved caspase-3/9 and E-cadherin levels, but down-regulated Cyclin D1, N-cadherin and Vimentin levels in LSCC cells. Additionally, we uncovered that MitoTempo reversed the promoting effects of Farrerol on ROS formation intensity, apoptosis, and Cyt C and Cleaved caspase-3/9 levels in LSCC cells, while improving the disruption of MMP in Farrerol-treated LSCC cells. Also, Farrerol lessened the volume and weight of mice tumors.

CONCLUSIONS

Farrerol suppressed the migration, invasion, and induced the apoptosis of LSCC cells via the mitochondria-mediated pathway.

ERK: A Double-Edged Sword in Cancer. ERK-Dependent Apoptosis as a Potential Therapeutic Strategy for Cancer

The RAF/MEK/ERK signaling pathway regulates diverse cellular processes as exemplified by cell proliferation, differentiation, motility, and survival. Activation of ERK1/2 generally promotes cell proliferation, and its deregulated activity is a hallmark of many cancers. Therefore, components and regulators of the ERK pathway are considered potential therapeutic targets for cancer, and inhibitors of this pathway, including some MEK and BRAF inhibitors, are already being used in the clinic. Notably, ERK1/2 kinases also have pro-apoptotic functions under certain conditions and enhanced ERK1/2 signaling can cause tumor cell death. Although the repertoire of the compounds which mediate ERK activation and apoptosis is expanding, and various anti-cancer compounds induce ERK activation while exerting their anti-proliferative effects, the mechanisms underlying ERK1/2-mediated cell death are still vague. Recent studies highlight the importance of dual-specificity phosphatases (DUSPs) in determining the pro- versus anti-apoptotic function of ERK in cancer. In this review, we will summarize the recent major findings in understanding the role of ERK in apoptosis, focusing on the major compounds mediating ERK-dependent apoptosis. Studies that further define the molecular targets of these compounds relevant to cell death will be essential to harnessing these compounds for developing effective cancer treatments.

Farrerol Induces Cancer Cell Death via ERK Activation in SKOV3 Cells and Attenuates TNF-α-Mediated Lipolysis

Farrerol (FA) is a flavanone isolated from the Chinese herbal medicine “Man-shan-hong” (Rhododendron dauricum L.). In the present study, FA decreased the viability of SKOV3 cells in a dose- and time-dependent manner, and it induced G2/M cell cycle arrest and cell apoptosis. Cell cycle distribution analysis via flow cytometry showed that FA decreased G1 populations and increased G2/M populations in SKOV3 cells. Additionally, Western blotting confirmed an increase in the expression level of proteins involved in the cell cycle, e.g., CDK and cyclins. FA-induced apoptosis in SKOV3 cells was also investigated using a TUNEL assay, and increased expression levels of proapoptotic factors, including Caspase-3 and poly ADP ribose polymerase (PARP), through the Extracellular signal-regulated kinase (ERK)/MAPK pathway were investigated. Proinflammatory cytokines (e.g., IL-6, TNF-α, and IL-1) have been identified as a driver of the pathological mechanisms underlying involuntary weight loss and impaired physical function, i.e., cachexia, during cancer; in the present study, we showed that farrerol attenuates TNF-α-induced lipolysis and increases adipogenic differentiation in 3T3-L1 cells. Thus, farrerol could potentially be used as an anticancer agent or anticachetic drug.

Farrerol maintains the contractile phenotype of VSMCs via inactivating the extracellular signal-regulated protein kinase 1/2 and p38 mitogen-activated protein kinase signaling

Farrerol, a dihydroflavone isolated from Rhododendron dauricum L., can inhibit vascular smooth muscle cell (VSMC) proliferation and exert a protective effect on H₂O₂-induced vascular endothelial cells injury. In this study, we investigated the effects of farrerol on VSMC phenotypic modulation and balloon injury-induced vascular neointimal formation and explored the underlying mechanisms. Serum-starved rat thoracic aorta SMCs (RASMCs) were first pretreated with farrerol (3, 10, and 30 μM, respectively), U0126 (a MEK kinase inhibitor), and SB203580 (a p38 kinase inhibitor), and followed by treatment with serum (10% FBS). The expression of several VSMC-specific markers, including α-SMA, SM22α, and OPN, were analyzed by western blot. Phosphorylation of extracellular signal-regulated protein kinase 1/2 (ERK 1/2) and p38 mitogen-activated protein kinase (MAPK) was also investigated. Farrerol inhibited the serum-induced transition of RASMCs from the contractile to the synthetic phenotype, and this was associated with a decrease in α-SMA and SM22α expression, and an increase in OPN expression. Farrerol also inhibited serum-induced phosphorylation of ERK1/2 and p38MAPK in RASMCs. Moreover, U0126 and SB203580 both inhibited the serum-induced phenotypic transition of RASMCs. These findings indicate that farrerol can maintain the contractile phenotype of VSMCs partly via inactivating the ERK1/2 and p38 MAPK signaling pathways. Using a rat model of carotid artery balloon injury, inhibition of VSMC phenotypic transition and suppression of neointimal formation were confirmed in vivo following the perivascular application of farrerol. Our results suggested that farrerol could be a promising lead compound for the treatment of vascular proliferative diseases.

Targeting ERK-Hippo Interplay in Cancer Therapy

Extracellular signal-regulated kinase (ERK) is a part of the mitogen-activated protein kinase (MAPK) signaling pathway which allows the transduction of various cellular signals to final effectors and regulation of elementary cellular processes. Deregulation of the MAPK signaling occurs under many pathological conditions including neurodegenerative disorders, metabolic syndromes and cancers. Targeted inhibition of individual kinases of the MAPK signaling pathway using synthetic compounds represents a promising way to effective anti-cancer therapy. Cross-talk of the MAPK signaling pathway with other proteins and signaling pathways have a crucial impact on clinical outcomes of targeted therapies and plays important role during development of drug resistance in cancers. We discuss cross-talk of the MAPK/ERK signaling pathway with other signaling pathways, in particular interplay with the Hippo/MST pathway. We demonstrate the mechanism of cell death induction shared between MAPK/ERK and Hippo/MST signaling pathways and discuss the potential of combination targeting of these pathways in the development of more effective anti-cancer therapies.

Homeobox B5 suppression attenuates proliferation and elevates apoptosis in hepatoma cell lines through ERK/MDM2 signalling

Homeobox B5 (HOXB5), a member of the HOX gene family, is an important gene in tumourigenesis. However, its role in hepatocellular carcinoma (HCC) cell proliferation and apoptosis remains unclear. In this study, we investigated the role and regulation mechanism of HOXB5 in HCC cell lines Hep3B and LM6. The data indicated high expression of HOXB5 in HCC tissues and cell lines. In HCC cells, inhibition of HOXB5 by transfection with HOXB5 siRNA significantly constrained cell viability, and Bcl-2 levels, and it increased cell apoptosis, cytochrome c levels, BAX levels, and caspase-3 activity. On the contrary, HOXB5 overexpression increased proliferation and Bcl-2 levels but inhibited BAX levels and caspase-3 activity in these cells. HOXB5 downregulation attenuated activation of extracellular signal-regulated kinase (ERK) and expression of the murine double minute 2 (MDM2) oncogene. Incubation with the ERK activator, phorbol 12-myristate 13-acetate (40 μmol/L), for 12 hours reversed the effects of HOXB5 inhibition on MDM2 expression, cell proliferation, and apoptosis in HCC cells. Overall, this study demonstrated that HOXB5 inhibition regulated MDM2 expression by controlling ERK activation and that it modulated proliferation and apoptosis in HCC cells.

Farrerol Directly Targets GSK-3β to Activate Nrf2-ARE Pathway and Protect EA.hy926 Cells against Oxidative Stress-Induced Injuries

Oxidative stress-mediated endothelial injury is considered to be involved in the pathogenesis of various cardiovascular diseases. Farrerol, a typical natural flavanone from the medicinal plant Rhododendron dauricum L., has been reported to show protective effects against oxidative stress-induced endothelial injuries in our previous study. However, its action molecular mechanisms and targets are still unclear. In the present study, we determined whether farrerol can interact with glycogen synthase kinase 3β- (GSK-3β-) nuclear factor erythroid 2-related factor 2- (Nrf2-) antioxidant response element (ARE) signaling, which is critical in defense against oxidative stress. Our results demonstrated that farrerol could specifically target Nrf2 negative regulator GSK-3β and inhibit its kinase activity. Mechanistic studies proved that farrerol could induce an inhibitory phosphorylation of GSK-3β at Ser9 without affecting the expression level of total GSK-3β protein and promote the nuclear translocation of Nrf2 as well as the mRNA and protein expression of its downstream target genes heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1) in EA.hy926 cells. Further studies performed with GSK-3β siRNA and specific inhibitor lithium chloride (LiCl) confirmed that GSK-3β inhibition was involved in farrerol-mediated endothelial protection and Nrf2 signaling activation. Moreover, molecular docking and molecular dynamics studies revealed that farrerol could bind to the ATP pocket of GSK-3β, which is consistent with the ATP-competitive kinetic behavior. Collectively, our results firstly demonstrate that farrerol could attenuate endothelial oxidative stress by specifically targeting GSK-3β and further activating the Nrf2-ARE signaling pathway.

Placenta-specific 9, a putative secretory protein, induces G2/M arrest and inhibits the proliferation of human embryonic hepatic cells

Background: Placenta-specific 9 (Plac9) is a putative secreted protein that was first discovered in the context of embryogenesis. The expression pattern of Plac9 during embryogenesis, together with the results of recent reports, suggest that Plac9 may play a role in the liver development. The present study was conducted to investigate the secretory characteristics of Plac9 and its potential role in liver cell physiology. Methods: Immunofluorescence was employed to identify the subcellular distribution of Plac9. Cellular proliferative activity was analyzed by MTT assay and cell colony formation. The cell cycle distribution of Plac9 was analyzed by flow cytometry, and a functional analysis was performed using L02 cells following their stable infection with a lentivirus over-expressing Plac9. Results:Plac9 is a novel protein that is localized to the cytoplasm and may be secreted through the classic endoplasmic reticulum-Golgi route. The overexpression of Plac9 inhibits cell growth and induces G2/M phase arrest. Conclusion: Our findings reveal a novel role for Plac9 in regulating cell growth.

Farrerol overcomes the invasiveness of lung squamous cell carcinoma cells by regulating the expression of inducers of epithelial mesenchymal transition

In recent years Epithelial Mesenchymal Transition (EMT) has been proposed as a mechanism indispensable to acquisition of metastatic properties by tumor cells. In this study we tested the ability of Farrerol, a Chinese herb-derived compound to ablate the EMT in human lung squamous cell carcinoma cells. Human lung squamous cell carcinoma cells, Calu-1 were treated with various concentrations of Farrerol for 24 h to examine its effect on their viability by the MTT assay. Only those concentrations which showed least effect on the viability of Calu-1 cells were further used to evaluate the expression of epithelial and mesenchymal markers by western blotting. Furthermore the effect of such concentrations on the migration and invasion of Calu-1 cells was determined by wound healing and transwell invasion assays respectively. The results demonstrated that Farrerol treatment led to the downregulation of Slug and Zeb-1, transcriptional regulators of EMT with the concomitant increase and decrease in the expression of E-cadherin and vimentin respectively. These data were further supported by migration and invasion assays which demonstrated that Farrerol treatment caused inhibited the migration and invasion of Calu-1 lung squamous cell carcinoma cells. Taken together, our results indicate that Farrerol suppresses lung squamous cell carcinoma cell metastatic potential by modulating the expression of EMT proteins.

H2S-releasing nanoemulsions: a new formulation to inhibit tumor cells proliferation and improve tissue repair

The improvement of solubility and/or dissolution rate of poorly soluble natural compounds is an ideal strategy to make them optimal candidates as new potential drugs. Accordingly, the allyl sulfur compounds and omega-3 fatty acids are natural hydrophobic compounds that exhibit two important combined properties: cardiovascular protection and antitumor activity. Here, we have synthesized and characterized a novel formulation of diallyl disulfide (DADS) and α-linolenic acid (ALA) as protein-nanoemulsions (BAD-NEs), using ultrasounds. BAD-NEs are stable over time at room temperature and show antioxidant and radical scavenging property. These NEs are also optimal H2S slow-release donors and show a significant anti-proliferative effect on different human cancer cell lines: MCF-7 breast cancer and HuT 78 T-cell lymphoma cells. BAD-NEs are able to regulate the ERK1/2 pathway, inducing apoptosis and cell cycle arrest at the G0/G1 phase. We have also investigated their effect on cell proliferation of human adult stem/progenitor cells. Interestingly, BAD-NEs are able to improve the Lin- Sca1+ human cardiac progenitor cells (hCPC) proliferation. This stem cell growth stimulation is combined with the expression and activation of proteins involved in tissue-repair, such as P-AKT, α-sma and connexin 43. Altogether, our results suggest that these antioxidant nanoemulsions might have potential application in selective cancer therapy and for promoting the muscle tissue repair.

Ferrerol overcomes the invasiveness of lung squamous cell carcinoma cells by regulating the expression of inducers of Epithelial Mesenchymal Transition

In recent years Epithelial Mesenchymal Transition (EMT) has been proposed as a mechanism indispensable to acquisition of metastatic properties by tumor cells. In this study we tested the ability of Ferrerol, a Chinese herb-derived compound to ablate the EMT in human lung squamous cell carcinoma cells. Human lung squamous cell carcinoma cells, Calu-1 were treated with various concentrations of Ferrerol for 24 h to examine its effect on their viability by the MTT assay. Only those concentrations which showed least effect on the viability of Calu-1 cells were further used to evaluate the expression of epithelial and mesenchymal markers by western blotting. Furthermore the effect of such concentrations on the migration and invasion of Calu-1 cells was determined by wound healing and transwell invasion assays respectively. The results demonstrated that Ferrerol treatment led to the downregulation of Slug and Zeb-1, transcriptional regulators of EMT with the concomitant increase and decrease in the expression of E-cadherin and vimentin respectively. These data were further supported by migration and invasion assays which demonstrated that Ferrerol treatment caused inhibited the migration and invasion of Calu-1 lung squamous cell carcinoma cells. Taken together, our results indicate that Ferrerol suppresses lung squamous cell carcinoma cell metastatic potential by modulating the expression of EMT proteins.

Sulforaphane induces p53‑deficient SW480 cell apoptosis via the ROS‑MAPK signaling pathway

Sulforaphane (SFN) has been revealed to inhibit the growth and induce apoptosis of cancer cells. However, the detailed anticancer effects of SFN on p53‑deficient colon cancer cells has yet to be clearly elucidated. The present study employed p53‑deficient SW480 cells to establish an SFN‑induced in vitro model of apoptosis. The critical events leading to apoptosis were then evaluated in SFN‑treated p53‑deficient SW480 cells, by performing an MTT assay, flow cytometry, western blotting and ELISA. The results demonstrated that SFN at concentrations of 5, 10, 15 and 20 µM induced mitochondria‑associated cell apoptosis, which was further confirmed by disruption of the mitochondrial membrane potential, an increase in the Bax/Bcl‑2 ratio, as well as activation of caspase‑3, ‑7 and ‑9. In addition, SFN‑induced apoptosis was associated with an increase in the generation of reactive oxygen species (ROS), and the activation of extracellular signal‑regulated kinases (Erk) and p38 mitogen‑activated protein kinases. However, SFN did not induce expression of the p53 family member, p73. SFN‑induced apoptosis was subsequently confirmed to be ROS‑dependent and associated with Erk/p38, as the specific inhibitors for ROS, phosphorylated (p)‑Erk and p‑p38, completely or partially attenuated the SFN‑induced reduction in SW480 cell viability. In addition, the results demonstrated that even at the lowest concentrations (5 µM), SFN increased the sensitivity of p53‑proficient HCT‑116 cells to cisplatin. In conclusion, the results suggest that SFN may induce apoptosis in p53‑deficient SW480 cells via p53/p73‑independent and ROS‑Erk/p38‑dependent signaling pathways.

Inhibitory effects of delphinidin on the proliferation of ovarian cancer cells via PI3K/AKT and ERK 1/2 MAPK signal transduction

Delphinidin is a member of the anthocyanidin family and is a natural pigment in red cabbage, berries, sweet potatoes and grapes. It possesses nutraceutical properties against various chronic diseases and types of cancer. However, little is known about its preventative effects on epithelial ovarian cancer, a disease that is associated with a low survival rate, a poor prognosis and a high rate of recurrence. The results of the present study demonstrated that the proliferation of SKOV3 cells decreased in a dose-dependent manner in response to treatment with delphinidin, and the phosphorylation of carcinogenic protein kinases associated with the progression of epithelial ovarian cancer was affected by delphinidin treatment. The levels of phosphorylated protein kinase B (AKT), ribosomal protein S6 kinase β-1 (P70S6K), ribosomal protein S (S6), extracellular signal-regulated kinase (ERK)1/2 and p38 were suppressed by increasing concentrations of delphinidin. Furthermore, the combination of certain pharmacological inhibitors, including phosphoinositide 3-kinase (PI3K; LY294002), ERK1/2 (U0126) and delphinidin significantly reduced the proliferation of SKOV3 cells and the phosphorylation of each of those target proteins. In addition, delphinidin treatment exerted anti-proliferative effects on paclitaxel-resistant SKOV3 cells, compared with treatment with paclitaxel alone. These results indicate that delphinidin inhibits the proliferation of SKOV3 cells through inactivation of PI3K/AKT and ERK1/2 mitogen-activated protein kinase signaling cascades, and that this cell signaling pathway may be a pivotal therapeutic target for the prevention of epithelial ovarian cancer, including paclitaxel-resistant ovarian cancer.