Silibinin inhibits cell invasion through inactivation of both PI3K-Akt and MAPK signaling pathways

Silibinin: an inhibitor for a high-expressed BCL-2A1/BFL1 protein, linked with poor prognosis in breast cancer

Breast cancer (BC) accounts for 30% of all diagnosed cases of cancer in women and remains a leading cause of cancer-related deaths among women worldwide. The current study looks for a protein from the anti-apoptotic/pro-survival BCL-2 family whose overexpression reduces survivability in BC patients and a potential inhibitor for the protein. We found BCL-2A1/BFL1 protein with high expression linked to low survivability in BC. The protein shows prognosis in 8 out of 29 categories, whereas no other family member manifests this property. Out of 7379 compounds, three small molecules (CHEMBL9509, CHEMBL2104550 and CHEMBL3545011) form an H-bond with BCL-2A1/BFL1 protein's unique residue Cys55. Of the three small molecules, we found CHEMBL9509 (Silibinin) to be a potent inhibitor. The compound forms a stable H-bond with the residue Cys55 with the lowest binding energy compared to the other two compounds. It remains stable in the BH3 binding region for more than 100 ns, whereas the other two detach from the region. Additionally, the compound is found to be better than Venetoclax and Nematoclax. We firmly believe in the compound CHEMBL9509 potency to halt BC's progression by inhibiting the BCL-2A1/BFL1 protein, increasing patients' survivability.Communicated by Ramaswamy H. Sarma.

In Vitro/In Vivo Hepatoprotective and Antioxidant Effects of Defatted Extract and a Phenolic Fraction Obtained from Phlomis Tuberosa

An in vitro/in vivo hepatotoxicity and hepatoprotection evaluation of a defatted extract and a phenolic fraction from Phlomis tuberosa, administered alone and in a carbon tetrachloride (CCl₄)-induced metabolic bioactivation model, was performed. The extract and the phenolic fraction were analysed by high performance liquid chromatography (HPLC) to determine the total flavonoid content, to identify flavonoids and to quantify verbascoside. In addition, total polyphenolics in the samples were expressed as gallic acid equivalents. Applied alone, the extract and the fraction (5, 10 and 50 µg/mL) did not show a statistically significant hepatotoxic effect on isolated rat hepatocytes in vitro. In a CCl₄-induced hepatotoxicity model, the samples exhibited a concentration-dependent, statistically significant hepatoprotective effect, which was most pronounced at 50 µg/mL for both. The phenolic fraction exhibited a more pronounced hepatoprotective effect compared to the extract. Data from the in vitro study on the effects of the extract were also confirmed in the in vivo experiment conducted in a CCl₄-induced hepatotoxicity model in rats. A histopathological study showed that the animals treated with CCl₄ and the extract had an unaltered histoarchitecture of the liver. The effects of the extract were the same as those of silymarin.

Biochemical features and therapeutic potential of α-Mangostin: Mechanism of action, medicinal values, and health benefits

α-Mangostin (α-MG) is a natural xanthone obtained from the pericarps of mangosteen. It exhibits excellent potential, including anti-cancer, neuroprotective, antimicrobial, antioxidant, and anti-inflammatory properties, and induces apoptosis. α-MG controls cell proliferation by modulating signaling molecules, thus implicated in cancer therapy. It possesses incredible pharmacological features and modulates crucial cellular and molecular factors. Due to its lesser water solubility and pitiable target selectivity, α-MG has limited clinical application. As a known antioxidant, α-MG has gained significant attention from the scientific community, increasing interest in extensive technical and biomedical applications. Nanoparticle-based drug delivery systems were designed to improve the pharmacological features and efficiency of α-MG. This review is focused on recent developments on the therapeutic potential of α-MG in managing cancer and neurological diseases, with a special focus on its mechanism of action. In addition, we highlighted biochemical and pharmacological features, metabolism, functions, anti-inflammatory, antioxidant effects and pre-clinical applications of α-MG.

Fungal antitumor protein D1 is internalized via endocytosis and inhibits non-small cell lung cancer proliferation through MAPK signaling pathway

Lung cancer has the highest mortality among cancer-related deaths worldwide. Among lung cancers, non-small cell lung cancer (NSCLC) is the most common histological type. In the previous research, we isolated a protein (D1) from Boletus bicolor that inhibits the proliferation of NSCLC cell lines. In this study, we elucidated the internalization mechanism and antitumor mechanism of protein D1 in A549 cells. Protein D1 has a strong inhibitory effect on A549 cells. It binds to secretory carrier membrane protein 3 on the A549 cell membrane and enters A549 cells by clathrin-mediated endocytosis. In vitro, protein D1 activates mitogen-activated protein kinase (MAPK) signaling pathway. JNK and p38MAPK are the biological targets for protein D1. In vivo, protein D1 inhibits the tumor growth of NSCLC xenografts by inducing apoptosis and inhibiting cell proliferation. Protein D1 alters the expression of genes related to apoptosis, cell cycle, and MAPK signaling pathway in tumor cells.

Neurofibromatosis: Molecular Pathogenesis and Natural Compounds as Potential Treatments

The neurofibromatosis syndromes, including NF1, NF2, and schwannomatosis, are tumor suppressor syndromes characterized by multiple nervous system tumors, particularly Schwann cell neoplasms. NF-related tumors are mainly treated by surgery, and some of them have been treated by but are refractory to conventional chemotherapy. Recent advances in molecular genetics and genomics alongside the development of multiple animal models have provided a better understanding of NF tumor biology and facilitated target identification and therapeutic evaluation. Many targeted therapies have been evaluated in preclinical models and patients with limited success. One major advance is the FDA approval of the MEK inhibitor selumetinib for the treatment of NF1-associated plexiform neurofibroma. Due to their anti-neoplastic, antioxidant, and anti-inflammatory properties, selected natural compounds could be useful as a primary therapy or as an adjuvant therapy prior to or following surgery and/or radiation for patients with tumor predisposition syndromes, as patients often take them as dietary supplements and for health enhancement purposes. Here we review the natural compounds that have been evaluated in NF models. Some have demonstrated potent anti-tumor effects and may become viable treatments in the future.

Alteration and dysfunction of ion channels/transporters in a hypoxic microenvironment results in the development and progression of gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the most common malignant cancers in the world and has only few treatment options and, concomitantly, a poor prognosis. It is generally accepted now that the tumor microenvironment, particularly that under hypoxia, plays an important role in cancer development. Hypoxia can regulate the energy metabolism and malignancy of tumor cells by inducing or altering various important factors, such as oxidative stress, reactive oxygen species (ROS), hypoxia-inducible factors (HIFs), autophagy and acidosis. In addition, altered expression and/or dysfunction of ion channels/transporters (ICTs) have been encountered in a variety of human tumors, including GC, and to play an important role in the processes of tumor cell proliferation, migration, invasion and apoptosis. Increasing evidence indicates that ICTs are at least partly involved in interactions between cancer cells and their hypoxic microenvironment. Here, we provide an overview of the different ICTs that regulate or are regulated by hypoxia in GC.

CONCLUSIONS AND PERSPECTIVES

Hypoxia is one of the major obstacles to cancer therapy. Regulating cellular responses and factors under hypoxia can inhibit GC. Similarly, altering the expression or activity of ICTs, such as the application of ion channel inhibitors, can slow down the growth and/or migration of GC cells. Since targeting the hypoxic microenvironment and/or ICTs may be a promising strategy for the treatment of GC, more attention should be paid to the interplay between ICTs and the development and progression of GC in such a microenvironment.

Evaluation of anti-cancer potency of silibinin on murine renal carcinoma RenCa cells in an animal model with an intact immune system

Silibinin is a flavonoid extract isolated from milk thistle and has been proved to be a promising chemotherapeutic drug for cancer. However, most of those studies were performed on the human cancer cells, where the effects of silibinin could only be observed on an animal model with a deficient immune system. RenCa cells were isolated from a murine spontaneous renal cell carcinoma, which resembles many features of human renal cell carcinoma, and have been used to establish animal models with a sound immune response. Herein, we investigated the anti-cancer effects of silibinin on RenCa cells, revealing that it inhibited cell viability in both dose- and time-dependent manners. Silibinin slightly triggered apoptosis and significantly induced G2-M cell cycle arrest by downregulating cyclin B1 and CDK1 and increasing expression of p21. Furthermore, silibinin significantly inhibited the growth of RenCa cell xenografts in vivo. In addition, we found that silibinin reduced programmed cell death 1 ligand 1 expression of RenCa cells in vivo and in vitro. Our findings demonstrate that silibinin can inhibit the growth of mouse tumor cells in an animal model with an intact immune system, and silibinin may decrease the immunosuppression effect of tumor cells. Our results provide new evidence for evaluation of Silibinin application in cancer therapy.

Lung Cancer Management with Silibinin: A Historical and Translational Perspective

The flavonolignan silibinin, the major bioactive component of the silymarin extract of Silybum marianum (milk thistle) seeds, is gaining traction as a novel anti-cancer therapeutic. Here, we review the historical developments that have laid the groundwork for the evaluation of silibinin as a chemopreventive and therapeutic agent in human lung cancer, including translational insights into its mechanism of action to control the aggressive behavior of lung carcinoma subtypes prone to metastasis. First, we summarize the evidence from chemically induced primary lung tumors supporting a role for silibinin in lung cancer prevention. Second, we reassess the preclinical and clinical evidence on the effectiveness of silibinin against drug resistance and brain metastasis traits of lung carcinomas. Third, we revisit the transcription factor STAT3 as a central tumor-cell intrinsic and microenvironmental target of silibinin in primary lung tumors and brain metastasis. Finally, by unraveling the selective vulnerability of silibinin-treated tumor cells to drugs using CRISPR-based chemosensitivity screenings (e.g., the hexosamine biosynthesis pathway inhibitor azaserine), we illustrate how the therapeutic use of silibinin against targetable weaknesses might be capitalized in specific lung cancer subtypes (e.g., KRAS/STK11 co-mutant tumors). Forthcoming studies should take up the challenge of developing silibinin and/or next-generation silibinin derivatives as novel lung cancer-preventive and therapeutic biomolecules.

Redox-sensitive hyaluronic acid-cholesterol nanovehicles potentiate efficient transmembrane internalization and controlled release for penetrated "full-line" inhibition of pre-metastatic initiation

Metastatic breast cancer is a major cause of cancer-related mortality worldwide. The tumor-specific penetration and triggered drug release for "full-line" inhibition of pre-metastatic initiation are of essential importance in improving mortality rates. Here, a crosslinked, redox-sensitive amphiphilic conjugate (cHLC) was constructed with a combination of features, including hyaluronic acid (HA)-mediated tumor active targeting, lipoic acid (LA) core-crosslinking based bio-stability and reducibility, and lipid raft anchoring-promoted HA-mediated endocytosis through cholesterol (CHO) modification for the penetrated co-delivery of paclitaxel (PTX) and the multi-targeted anti-metastatic agent, silibinin (SB). Resultantly, the nanodrug (cHLC/(PTX + SB)) demonstrated enhanced tumor cytoplasm-selective rapid drug delivery in a 4T1 model both in vitro and in vivo. The released SB efficiently sensitized cells to PTX treatment and inhibited the whole process of pre-metastatic initiation including epithelial-to-mesenchymal transition (EMT), local and blood vessel invasion. The exquisite design of this delivery system provides a deep insight into enhancing focus accessibility of multi-targeted drugs for an efficient inhibition of tumor metastasis.

Targeting the hallmarks of cancer: the effects of silibinin on proliferation, cell death, angiogenesis, and migration in colorectal cancer

Background

Silibinin, as a chemopreventive agent, has shown anti-cancer efficacy against different types of cancers. In the present study, we investigated the anti-cancer activities of silibinin on CT26 mouse colon cell line.

Methods

CT26 cells were treated with different concentrations of silibinin. To examine the cytotoxic effect of silibinin on proliferation, apoptosis, autophagy, angiogenesis, and migration, MTT, colony-forming assay, Annexin V/PI flow cytometry, RT-qPCR, and Scratch assay were used.

Results

Silibinin was found to significantly reduce CT26 cells survival. Furthermore, silibinin strongly induced apoptosis and autophagy by up-regulating the expression of Bax, Caspase-3, Atg5, Atg7 and BECN1 and down-regulating Bcl-2. Silibinin considerably down-regulated the expression of COX-2, HIF-1α, VEGF, Ang-2, and Ang-4 as well as the expression of MMP-2, MMP-9, CCR-2 and CXCR-4.

Conclusions

The present study revealed that silibinin shows anticancer activities by targeting proliferation, cell survival, angiogenesis, and migration of CT26 cells.

Network pharmacology-based evaluation of natural compounds with paclitaxel for the treatment of metastatic breast cancer

Metastatic breast cancer is a prevalent life-threatening disease. Paclitaxel (PTX) is widely used in metastatic breast cancer therapy, but the side effects limit its chemotherapeutic application. Multidrug strategies have recently been used to maximize potency and decrease the toxicity of a particular drug by reducing its dosage. Therefore, we have evaluated the combined anti-cancerous effect of PTX with tested natural compounds (andrographolide (AND), silibinin (SIL), mimosine (MIM) and trans-anethole (TA)) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, trypan blue dye exclusion assay, proliferating cell nuclear antigen (PCNA) staining, network pharmacology, molecular docking, molecular dynamics (MD) and in vivo chick chorioallantoic membrane (CAM) angiogenesis assay. We observed a reduction in the IC₅₀ value of PTX with tested natural compounds. Further, the network pharmacology-based analysis of compound-disease-target (C-D-T) network showed that PTX, AND, SIL, MIM and TA targeted 55, 61, 56, 31 and 18 proteins of metastatic breast cancer, respectively. Molecular docking results indicated that AND and SIL inhibited the C-D-T network's core target kinase insert domain receptor (KDR) protein more effectively than others. While MD showed that the binding of AND with KDR was stronger and more stable than others. In trypan blue dye exclusion assay and PCNA staining, AND and SIL along with PTX were found to be more effective than PTX alone. CAM assay results suggested that AND, SIL and TA increase the anti-angiogenic potential of PTX. Thus, natural compounds can be used to improve the anti-cancer potential of PTX.

Phytochemicals in cancer and their effect on the PI3K/AKT-mediated cellular signalling

Protein kinases belong to the largest family of enzymes controlling every aspect of cellular activity including gene expression, cell division, differentiation and metabolism. They are part of major intracellular signalling pathways. Hence, it is not surprising that they are involved in the development of major diseases such as cardiovascular disorders, diabetes, dementia and, most importantly, cancer when they undergo mutations, modifications and unbalanced expression. This review will explore the possibility to draw a connection between the application of natural phytochemicals and the treatment of cancer. We have chosen to focus on the PI3K/AKT cellular signalling pathway which has been shown to be a major target by natural compounds in cell cultures and animal models.

Perspectives and controversies regarding the use of natural products for the treatment of lung cancer

Lung cancer is the leading cause of cancer‐related mortality both in men and women and accounts for 18.4% of all cancer‐related deaths. Although advanced therapy methods have been developed, the prognosis of lung cancer patients remains extremely poor. Over the past few decades, clinicians and researchers have found that chemical compounds extracted from natural products may be useful for treating lung cancer. Drug formulations derived from natural compounds, such as paclitaxel, doxorubicin, and camptothecin, have been successfully used as chemotherapeutics for lung cancer. In recent years, hundreds of new natural compounds that can be used to treat lung cancer have been found through basic and sub‐clinical research. However, there has not been a corresponding increase in the number of drugs that have been used in a clinical setting. The probable reasons may include low solubility, limited absorption, unfavorable metabolism, and severe side effects. In this review, we present a summary of the natural compounds that have been proven to be effective for the treatment of lung cancer, as well as an understanding of the mechanisms underlying their pharmacological effects. We have also highlighted current controversies and have attempted to provide solutions for the clinical translation of these compounds.

Transcriptome profiling reveals Silibinin dose-dependent response network in non-small lung cancer cells

Silibinin (SIL), a natural flavonolignan from the milk thistle (Silybum marianum), is known to exhibit remarkable hepatoprotective, antineoplastic and EMT inhibiting effects in different cancer cells by targeting multiple molecular targets and pathways. However, the predominant majority of previous studies investigated effects of this phytocompound in a one particular cell line. Here, we carry out a systematic analysis of dose-dependent viability response to SIL in five non-small cell lung cancer (NSCLC) lines that gradually differ with respect to their intrinsic EMT stage. By correlating gene expression profiles of NSCLC cell lines with the pattern of their SIL IC50 response, a group of cell cycle, survival and stress responsive genes, including some prominent targets of STAT3 (BIRC5, FOXM1, BRCA1), was identified. The relevancy of these computationally selected genes to SIL viability response of NSCLC cells was confirmed by the transient knockdown test. In contrast to other EMT-inhibiting compounds, no correlation between the SIL IC50 and the intrinsic EMT stage of NSCLC cells was observed. Our experimental results show that SIL viability response of differently constituted NSCLC cells is linked to a subnetwork of tightly interconnected genes whose transcriptomic pattern can be used as a benchmark for assessment of individual SIL sensitivity instead of the conventional EMT signature. Insights gained in this study pave the way for optimization of customized adjuvant therapy of malignancies using Silibinin.

An Update on the Role of Dietary Phytochemicals in Human Skin Cancer: New Insights into Molecular Mechanisms

Human skin is continuously subjected to environmental stresses, as well as extrinsic and intrinsic noxious agents. Although skin adopts various molecular mechanisms to maintain homeostasis, excessive and repeated stresses can overwhelm these systems, leading to serious cutaneous damage, including both melanoma and non-melanoma skin cancers. Phytochemicals present in the diet possess the desirable effects of protecting the skin from damaging free radicals as well as other benefits. Dietary phytochemicals appear to be effective in preventing skin cancer and are inexpensive, widely available, and well tolerated. Multiple in vitro and in vivo studies have demonstrated the significant anti-inflammatory, antioxidant, and anti-angiogenic characteristics of dietary phytochemicals against skin malignancy. Moreover, dietary phytochemicals affect multiple important cellular processes including cell cycle, angiogenesis, and metastasis to control skin cancer progression. Herein, we discuss the advantages of key dietary phytochemicals in whole fruits and vegetables, their bioavailability, and underlying molecular mechanisms for preventing skin cancer. Current challenges and future prospects for research are also reviewed. To date, most of the chemoprevention investigations have been conducted preclinically, and additional clinical trials are required to conform and validate the preclinical results in humans.

Anticancer Activities of Meroterpenoids Isolated from the Brown Alga Cystoseira usneoides against the Human Colon Cancer Cells HT-29

Colorectal cancer (CRC) is one of the most common types of cancers and a leading cause of cancer death worldwide. The current treatment for CRC mainly involves surgery, radiotherapy, and chemotherapy. However, due to the side effects and the emergence of drug resistance, the search for new anticancer agents, pharmacologically safe and effective, is needed. In the present study, we have investigated the anticancer effects of eight algal meroterpenoids (AMTs, 1-8) isolated from the brown seaweed Cystoseira usneoides and their underlying mechanisms of action using HT-29, a highly metastatic human colon cancer cell line. All the tested meroterpenoids inhibited the growth of HT-29 malignant cells and were less toxic towards non-cancer colon cells, with the AMTs 1 and 5 exhibiting selectivity indexes of 5.26 and 5.23, respectively. Treatment of HT-29 cells with the AMTs 1, 2, 3, 4, 5, and 7 induced cell cycle arrest in G2/M phase and, in some instances, apoptosis (compounds 2, 3, and 5). Compounds 1-8 also exhibited significant inhibitory effects on the migration and/or invasion of colon cancer cells. Mechanistic analysis demonstrated that the AMTs 1, 2, 5, 6, 7, and 8 reduced phosphorylation levels of extracellular signal-regulated kinase (ERK) and the AMTs 2, 3, 4, 5, 7, and 8 decreased phosphorylation of c-JUN N-terminal kinase (JNK). Moreover, the AMTs 1, 2, 3, 4, 7, and 8 inhibited phosphorylation levels of protein kinase B (AKT) in colon carcinoma cells. These results provide new insights into the mechanisms and functions of the meroterpenoids of C. usneoides, which exhibit an anticancer effect on HT-29 colon cancer cells by inducing cell cycle arrest and apoptosis via the downregulation of ERK/JNK/AKT signaling pathways.

Potential Applications of NRF2 Modulators in Cancer Therapy

The nuclear factor erythroid 2-related factor 2 (NRF2)-Kelch-like ECH-associated protein 1 (KEAP1) regulatory pathway plays an essential role in protecting cells and tissues from oxidative, electrophilic, and xenobiotic stress. By controlling the transactivation of over 500 cytoprotective genes, the NRF2 transcription factor has been implicated in the physiopathology of several human diseases, including cancer. In this respect, accumulating evidence indicates that NRF2 can act as a double-edged sword, being able to mediate tumor suppressive or pro-oncogenic functions, depending on the specific biological context of its activation. Thus, a better understanding of the mechanisms that control NRF2 functions and the most appropriate context of its activation is a prerequisite for the development of effective therapeutic strategies based on NRF2 modulation. In line of principle, the controlled activation of NRF2 might reduce the risk of cancer initiation and development in normal cells by scavenging reactive-oxygen species (ROS) and by preventing genomic instability through decreased DNA damage. In contrast however, already transformed cells with constitutive or prolonged activation of NRF2 signaling might represent a major clinical hurdle and exhibit an aggressive phenotype characterized by therapy resistance and unfavorable prognosis, requiring the use of NRF2 inhibitors. In this review, we will focus on the dual roles of the NRF2-KEAP1 pathway in cancer promotion and inhibition, describing the mechanisms of its activation and potential therapeutic strategies based on the use of context-specific modulation of NRF2.

Suppression of FADS1 induces ROS generation, cell cycle arrest, and apoptosis in melanocytes: implications for vitiligo

Vitiligo is a potentially serious condition characterized by loss of melanin and death of melanocytes. To identify potential therapeutic targets for vitiligo, we conducted a microarray analysis of three human vitiligo specimens and paired adjacent normal tissues. Because we found that the fatty acid desaturase 1 (FADS1) gene was downregulated in vitiligo specimens, we carried out experiments to assess its role in melanocyte replication and survival. RT-qPCR was used to verify that FADS1 expression was lower in vitiligo-affected tissues and vitiligo melanocyte PIG3V cells than in matched controls or normal human epidermal PIG1 melanocytes. In addition, CCK-8, immunofluorescence, western blot and flow cytometry assay were used to detect the proliferation and apoptosis in PIG1 cells respectively. Overexpression of FADS1 promoted proliferation of PIG3V melanocytes, while FADS1 silencing inhibited proliferation and induced cell death in PIG1 melanocytes. Increased ROS generation; induction of mitochondrial-mediated apoptosis via upregulation of Bax and active caspases 3 and 9 and downregulation of Bcl-2; and cell cycle arrest via downregulation of c-Myc and Cyclin D1 and upregulation of p21 were all enhanced after FADS1 silencing in PIG1 melanocytes. These findings implicate FADS1 downregulation in the pathogenesis of vitiligo and may open new avenues for its treatment.

Phenotypic Screen Identifies JAK2 as a Major Regulator of FAT10 Expression

FAT10 is a ubiquitin-like protein suggested to target proteins for proteasomal degradation. It is highly upregulated upon pro-inflammatory cytokines, namely, TNFα, IFNγ, and IL6, and was found to be highly expressed in various epithelial cancers. Evidence suggests that FAT10 is involved in cancer development and may have a pro-tumorigenic role. However, its biological role is still unclear, as well as its biochemical and cellular regulation. To identify pathways underlying FAT10 expression in the context of pro-inflammatory stimulation, which characterizes the cancerous environment, we implemented a phenotypic transcriptional reporter screen with a library of annotated compounds. We identified AZ960, a potent JAK2 inhibitor, which significantly downregulates FAT10 under pro-inflammatory cytokines induction, in an NFκB-independent manner. We validated JAK2 as a major regulator of FAT10 expression via knockdown, and we suggest that the transcriptional effects are mediated through pSTAT1/3/5. Overall, we have elucidated a pathway regulating FAT10 transcription and discovered a tool compound to chemically downregulate FAT10 expression, and to further study its biology.

Annexin A3 depletion overcomes resistance to oxaliplatin in colorectal cancer via the MAPK signaling pathway

Colorectal cancer (CRC) is a common disease with high mortality and morbidity. Annexin A3 (ANXA3) belongs to the structurally homologous family of Ca²⁺ and phospholipid-binding proteins. This study aimed to investigate the effects and potential mechanisms of ANXA3 on oxaliplatin (Ox) resistance in CRC. We generated two human CRC cell lines (HCT116/Ox and SW480/Ox) with acquired Ox resistance and determined their resistance properties. ANXA3 expression and cell apoptosis, migration and invasion also were evaluated. We found that cell viability of HCT116/Ox and SW480/Ox was higher than that in parental cells in the presence of Ox. ANXA3 was highly expressed in HCT116/Ox and SW480/Ox cells. ANXA3 downregulation diminished cell survival, migration and invasion, while increased the apoptosis of HCT116 and SW480 with or without Ox. Moreover, depletion of ANXA3 reduced cell viability and BrdU incorporation, increased cell apoptosis and c-caspase 3 expression in HCT116/Ox with or without Ox. A transwell assay determined that knockdown of ANXA3 impeded the migration and invasion of HCT116/Ox and SW480/Ox cells. Additionally, phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) decreased upon ANXA3 depletion in HCT116/Ox cells, and ANXA3 silencing suppressed Ox-induced activation of ERK and JNK signaling pathway. ANXA3 downregulation reduced Ox resistance in CRC, and treatment with the ERK inhibitor PD098059 or JNK inhibitor SP600125 contributed to this process. These results indicate that silencing ANXA3 could overcome Ox resistance in CRC via the mitogen-activated protein kinase signaling pathway.

Kaempferol suppresses cell migration through the activation of the ERK signaling pathways in ARPE-19 cells

Kaempferol is a flavonoid with anticancer and anti-metastasis activity in different cancer-cell lines. However, the underlying mechanisms by which kaempferol acts on human retinal pigment epithelial (ARPE-19) cells remain unclear. In this study, we demonstrated that kaempferol inhibited migration and invasion in ARPE-19 cells at non-toxic dosages. We discovered that kaempferol obviously reduced the enzyme activity and protein expression of matrix metalloproteinase-2 by increasing the phosphorylated levels of extracellular signal-regulated kinases 1/2 (ERK1/2) signaling pathways. Additionally, ERK1/2-specific inhibitor PD98059 significantly reversed kaempferol's inhibitory effects on migration and expression of MMP-2 in ARPE-19 cells. Overall, our results are the first to demonstrate that kaempferol is capable of inhibiting cell migration by targeting ERK1/2 signaling in human retinal pigment epithelial cells.

Zeylenone Induces Mitochondrial Apoptosis and Inhibits Migration and Invasion in Gastric Cancer

The mortality of gastric cancer (GC) is increasing due to its high rates of recurrence and metastasis. Zeylenone (Zey), a type of naturally occurring cyclohexene oxide, was demonstrated to be effective in cancer patients. The aim of this study is to explore the anti-cancer effect of Zey against gastric cancer both in vitro and in vivo, as well as the underlying mechanisms. We found that Zey inhibited gastric tumor growth, as demonstrated by in vitro gastric cancer cell lines and in a human gastric cancer xenograft mouse model. Furthermore, Zey induced substantial apoptosis through a mitochondrial apoptotic pathway, involving mitochondrial transmembrane potential loss, caspase-3 activation, anti-apoptotic protein downregulation, and pro-apoptotic protein upregulation. Notably, we revealed for the first time that Zey suppressed invasion and migration by wound healing and transwell chamber assays. Through Western blotting, we further explored the potential mechanism of Zey’s anti-cancer activity. We found that Zey downregulated the expression of matrix metalloproteinase 2/9 (MMP 2/9) and inhibited the phosphorylation of AKT and ERK. In short, Zey, which induced mitochondrial apoptosis and inhibited proliferation, migration, and invasion, may be developed as a novel drug for the treatment of gastric cancer.

Phytochemicals in Skin Cancer Prevention and Treatment: An Updated Review

Skin is the largest human organ, our protection against various environmental assaults and noxious agents. Accumulation of these stress events may lead to the formation of skin cancers, including both melanoma and non-melanoma skin cancers. Although modern targeted therapies have ameliorated the management of cutaneous malignancies, a safer, more affordable, and more effective strategy for chemoprevention and treatment is clearly needed for the improvement of skin cancer care. Phytochemicals are biologically active compounds derived from plants and herbal products. These agents appear to be beneficial in the battle against cancer as they exert anti-carcinogenic effects and are widely available, highly tolerated, and cost-effective. Evidence has indicated that the anti-carcinogenic properties of phytochemicals are due to their anti-oxidative, anti-inflammatory, anti-proliferative, and anti-angiogenic effects. In this review, we discuss the preventive potential, therapeutic effects, bioavailability, and structure–activity relationship of these selected phytochemicals for the management of skin cancers. The knowledge compiled here will provide clues for future investigations on novel oncostatic phytochemicals and additional anti-skin cancer mechanisms.

Polyphyllin G induce apoptosis and autophagy in human nasopharyngeal cancer cells by modulation of AKT and mitogen-activated protein kinase pathways in vitro and in vivo

Polyphyllin G (also call polyphyllin VII), extract from rhizomes of Paris yunnanensis Franch, has been demonstrated to have strong anticancer activities in a wide variety of human cancer cell lines. Previous studies found that Polyphyllin G induced apoptotic cell death in human hepatoblastoma cancer and lung cancer cells. However, the underlying mechanisms of autophagy in human nasopharyngeal carcinoma (NPC) remain unclear. In this study, Polyphyllin G can potently induced apoptosis dependent on the activations of caspase-8, -3, and -9 and the changes of Bcl-2, Bcl-xL and Bax protein expression in different human NPC cell lines (HONE-1 and NPC-039). The amount of both LC3-II and Beclin-1 was intriguingly increased suggest that autophagy was induced in Polyphyllin G-treated NPC cells. To further clarify whether Polyphyllin G-induced apoptosis and autophagy depended on AKT/ERK/JNK/p38 MAPK signaling pathways, cells were combined treated with AKT inhibitor (LY294002), ERK1/2 inhibitor (U0126), p38 MAPK inhibitor (SB203580), or JNK inhibitor (SP600125). These results demonstrated that Polyphyllin G induced apoptosis in NPC cells through activation of ERK, while AKT, p38 MAPK and JNK were responsible for Polyphyllin G-induced autophagy. Finally, an administration of Polyphyllin G effectively suppressed the tumor growth in the NPC carcinoma xenograft model in vivo. In conclusion, our results reveal that Polyphyllin G inhibits cell viability and induces apoptosis and autophagy in NPC cancer cells, suggesting that Polyphyllin G is an attractive candidate for tumor therapies. Polyphyllin G may promise candidate for development of antitumor drugs targeting nasopharyngeal carcinoma.

The Candidate Tumor Suppressor Gene SLC8A2 Inhibits Invasion, Angiogenesis and Growth of Glioblastoma

Glioblastoma is the most frequent and most aggressive brain tumor in adults. Solute carrier family 8 member 2 (SLC8A2) is only expressed in normal brain, but not present in other human normal tissues or in gliomas. Therefore, we hypothesized that SLC8A2 might be a glioma tumor suppressor gene and detected the role of SLC8A2 in glioblastoma and explored the underlying molecular mechanism. The glioblastoma U87MG cells stably transfected with the lentivirus plasmid containg SLC8A2 (U87MG-SLC8A2) and negative control (U87MG-NC) were constructed. In the present study, we found that the tumorigenicity of U87MG in nude mice was totally inhibited by SLC8A2. Overexpression of SLC8A2 had no effect on cell proliferation or cell cycle, but impaired the invasion and migration of U87MG cells, most likely through inactivating the extracellular signal-related kinases (ERK)1/2 signaling pathway, inhibiting the nuclear translocation and DNA binding activity of nuclear factor kappa B (NF-κB), reducing the level of matrix metalloproteinases (MMPs) and urokinase-type plasminogen activator (uPA)-its receptor (uPAR) system (ERK1/2-NF-κB-MMPs/uPA-uPAR), and altering the protein levels of epithelial to mesenchymal transitions (EMT)-associated proteins E-cardherin, vimentin and Snail. In addition, SLC8A2 inhibited the angiogenesis of U87MG cells, probably through combined inhibition of endothelium-dependent and endothelium-nondependent angiogenesis (vascular mimicry pattern). Totally, SLC8A2 serves as a tumor suppressor gene and inhibits invasion, angiogenesis and growth of glioblastoma.

Aeroallergen Der p 2 promotes motility of human non-small cell lung cancer cells via toll-like receptor-mediated up-regulation of urokinase-type plasminogen activator and integrin/focal adhesion kinase signaling

House dust mite (HDM) allergens are one of the major causes leading to respiratory hypersensitiveness and airway remodeling. Here we hypothesized that a major HDM allergen Der p 2 could increase cell motility and invasiveness of non-small cell lung cancer (NSCLC) cells. Our results showed that low dose (1 and 3 μg/mL) recombinant Der p 2 protein (DP2) enhanced the migration and invasiveness of human NSCLC cell A549, H1299 and CL1-5, but nonsignificantly altered their growth. Further investigation revealed that integrin αV level was increased and its downstream signaling including focal adhesion kinase (FAK) and paxillin were activated in A549 cells exposed to DP2. In parallel, DP2 also activated the FAK-associated signaling effectors such as Src, phosphatidyl inositol 3-kinase (PI3K), AKT, p38 mitogen-activated protein kinase (P38), extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK). Our findings also revealed that DP2 increased expression level of urokinase type plasminogen-activated kinase (uPA) and uPA receptor (uPAR), and subsequently enhanced the binding of uPAR to integrin αV. Moreover, the involvement of toll-like receptor 2/4 (TLR2/4)-triggered ERK1/2 activation in the increased expression of uPA and uPAR was also demonstrated. Collectively, these findings indicate that DP2 can enhance cell motility and invasiveness of NSCLC cells, attributing to TLR2/4-ERK1/2 activation, increased uPA and uPAR expression, enhanced binding of uPAR to integrin αV, and the consequent FAK signaling cascades. Thus, we suggest that DP2 may exacerbate NSCLC via promoting metastatic ability of carcinoma cell.

Silibinin induces hepatic stellate cell cycle arrest via enhancing p53/p27 and inhibiting Akt downstream signaling protein expression

BACKGROUND

Proliferation of hepatic stellate cells (HSCs) plays a pivotal role in the progression of liver fibrosis consequent to chronic liver injury. Silibinin, a flavonoid compound, has been shown to possess anti-fibrogenic effects in animal models of liver fibrosis. This was attributed to an inhibition of cell proliferation of activated HSCs. The present study was to gain insight into the molecular pathways involved in silibinin anti-fibrogenic effect.

METHODS

The study was conducted on LX-2 human stellate cells treated with three concentrations of silibinin (10, 50 and 100 μmol/L) for 24 and 96 hours. At the end of the treatment cell viability and proliferation were evaluated. Protein expression of p27, p21, p53, Akt and phosphorylated-Akt was evaluated by Western blotting analysis and Ki-67 protein expression was by immunocytochemistry. Sirtuin activity was evaluated by chemiluminescence based assay.

RESULTS

Silibinin inhibits LX-2 cell proliferation in dose- and time-dependent manner; we showed that silibinin upregulated the protein expressions of p27 and p53. Such regulation was correlated to an inhibition of both downstream Akt and phosphorylated-Akt protein signaling and Ki-67 protein expression. Sirtuin activity also was correlated to silibinin-inhibited proliferation of LX-2 cells.

CONCLUSION

The anti-proliferative effect of silibinin on LX-2 human stellate cells is via the inhibition of the expressions of various cell cycle targets including p27, Akt and sirtuin signaling.

Dehydroandrographolide inhibits oral cancer cell migration and invasion through NF-κB-, AP-1-, and SP-1-modulated matrix metalloproteinase-2 inhibition

BACKGROUND AND PURPOSE

Oral cancer is a type of head and neck cancer that is characterized by cancerous tissue growth in the oral cavity. Andrographolide and dehydroandrographolide (DA) are the two principal components of Andrographis paniculata (Burm.f.) Nees and are the main contributors to its therapeutic properties. However, the pharmacological activities of DA remain unclear.

EXPERIMENTAL APPROACH

In this study, we used wound closure assay and Boyden chamber assay to determine the effects of DA on oral cancer cell migration and invasion.

KEY RESULTS

DA treatment significantly inhibited the migration and invasion abilities of SCC9 cells in vitro. Gelatin zymography and Western blotting results revealed that DA inhibited MMP-2 activity and reduced its protein levels. DA inhibited the phosphorylation of ERK1/2, p38, and JNK 1/2 in SCC9 cells. According to the mRNA levels detected using real-time PCR, DA inhibited MMP-2 expression in SCC9 cells. This inhibitory effect was associated with the upregulation of the TIMP-2 and downregulation of NF-κB, AP-1, and SP-1 expression. In addition, DA suppressed carcinoma-associated epithelial-mesenchymal transition in SCC9 cells. Finally, DA administration effectively suppressed MMP-2 expression and tumor metastases in the oral carcinoma xenograft mouse model in vivo.

CONCLUSIONS & IMPLICATIONS

DA inhibits the invasion of human oral cancer cells and is a potential chemopreventive agent against oral cancer metastasis.

Anti-metastatic effect of rhodomyrtone from Rhodomyrtus tomentosa on human skin cancer cells

This study focused on the inhibitory effect of rhodomyrtone, a bioactive compound isolated from the leaves of Rhodomyrtus tomentosa (Aiton) Hassk., on cancer metastasis in epidermoid carcinoma A431 cells and on the verification of the underlying related molecular mechanisms of this event. We demonstrated that rhodomyrtone at the subcytotoxic concentration (0.5 and 1.5 µg/ml) exhibited pronounced inhibition of cancer metastasis by reducing cell migration, cell adhesive ability and cell invasion of A431 cells in a dose-dependent manner. Data demonstrated that rhodomyrtone could inhibit the focal adhesion kinase (FAK) and phosphorylation of protein kinase B (AKT), c-Raf, extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 MAPK involved in the downregulation the enzyme activities and protein expression of matrix metalloproteinase-2 (MMP-2) and MMP-9. Moreover, we found that rhodomyrtone increased the expression of TIMP-1 and TIMP-2, which are inhibitors of MMP-9 and MMP-2, respectively. Rhodomyrtone also inhibited the expression of NF-κB and phosphorylation of NF-κB in a dose-dependent manner. These results suggested that rhodomyrtone inhibited A431 cell metastasis by reducing MMP-2/9 activities and expression through inhibiting ERK1/2, p38 and FAK/Akt signaling pathways via NF-κB activities. This finding suggested that rhodomyrtone may be a novel antimetastasis agent for treatment of skin cancer cells.

Expression of MMPs is dependent on the activity of mitogen-activated protein kinase in chondrosarcoma

Matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) serve an important role in chondrosarcoma. The present study investigated whether the expression of MMPs was dependent on the activity of mitogen-activated protein kinase (MAPK) in chondrosarcoma. Surgical pathological specimens were collected to detect MMP-1, MMP-13, TIMP-1, type II collagen and phosphorylated MAPK levels in normal cartilage, enchondroma and chondrosarcoma tissues. The expression of MMP‑1, MMP‑13, TIMP‑1 and type II collagen was investigated utilizing MAPK inhibitors in chondrosarcoma cells. It was noted that the expression levels of MMP‑1, MMP‑13 and TIMP‑1 were increased in chondrosarcoma with the activity of MAPK. After chondrosarcoma cells were pretreated with MAPK inhibitors, the levels of MMP‑1, MMP‑13 and TIMP‑1 were inhibited. Furthermore, MMP‑1 and MMP‑13 are essential in regulating the degradation of type II collagen and decomposing cartilage matrix major. The high expression levels of MMP‑1 and MMP‑13 in chondrosarcoma expedite the invasion by chondrosarcoma cells and their expression can be depressed by MAPK inhibitors.

Effects of resveratrol on ARPE-19 cell proliferation and migration via regulating the expression of proliferating cell nuclear antigen, P21, P27 and p38MAPK/MMP-9

AIM

To explore whether resveratrol (Res) can inhibit human retinal pigment epithelial cell (ARPE-19 cell) proliferation and migration, and to research the molecular mechanisms.

METHODS

ARPE-19 cells were pretreated with various concentrations at 0, 50, 100, 150, 200 and 300 µmol/L of Res, and with 0 µmol/L Res as the control for 24, 48 and 72h. The cell proliferation, apoptosis and migration were measured with cell counting kit-8 (CCK-8), flow cytometry, and wound-healing and Transwell assays, respectively. The expression of proliferating cell nuclear antigen (PCNA), P21 and P27, as well as matrix metalloproteinase-9 (MMP-9) and p38 mitogen-activated protein kinases (p38MAPK) was identified by Western blot.

RESULTS

Cell proliferation was effectively inhibited by Res (P<0.05). When pretreated with Res, cells arrested in S-phase increased remarkably (P<0.05), but the apoptosis ratios showed no significant difference between the treatment and control groups (P>0.05). Cell migration was suppressed by Res both in wound-healing assay and Transwell migration assay (P<0.05). Decreases of PCNA, MMP-9 and p38MAPK, as well as increases of P21 and P27 were detected by Western blot (P<0.05).

CONCLUSION

Res can inhibit APRE-19 cell proliferation and migration in a concentration-dependent manner with up-regulation of the expression of P21 and P27, and down-regulation of PCNA, MMP-9 and p38MAPK.

Anti-metastatic activity of fangchinoline in human gastric cancer AGS cells

Fangchinoline (FCL) is an active component isolated from the traditional medicinal plant Stephania tetrandra S. Moore, and has been reported to possess anti-cancer functions in several types of cancers; however, the effect of FCL on gastric cancer metastasis and its underlying molecular mechanisms remain unknown. The current study aimed to investigate the effect of FCL on the cell migration and invasion of human metastatic gastric cancer AGS cells and its mechanisms. Our study demonstrates that FCL dosage dependently suppressed the adhesion, migration and invasion capacities of human gastric cancer AGS cells without obvious cytotoxic effects. Reverse transcription-polymerase chain reaction and western blot assays demonstrated that FCL greatly inhibited the expression of matrix metalloproteinase (MMP)-2 and MMP-9 at both the mRNA and protein levels, while it significantly increased the expression of tissue inhibitor of metalloproteinase (TIMP) 1 and TIMP2 messenger RNAs. Our results also indicated that FCL repressed the phosphorylation of AKT in gastric cancer AGS cells. In summary, FCL may exert its anti-metastatic property in human gastric cancer cells in vitro by suppression of MMP-2 and MMP-9, increase of TIMP1 and TIMP2 genes, and inhibition of AKT phosphorylation. FCL may be a drug candidate for the treatment of gastric cancer metastasis.

Polyphyllin G induces apoptosis and autophagy cell death in human oral cancer cells

BACKGROUND

Polyphyllin G (also called polyphyllin VII), extract from rhizomes of Paris yunnanensis Franch, has been shown to have strong anticancer activities in a wide variety of human cancer cell lines. However, the underlying influences of autophagy in human oral squamous cell carcinoma (OSCC) remain unclear.

METHODS

In this study, the roles of apoptosis and autophagy in polyphyllin G-induced death in human oral cancer cells were investigated. Moreover, the molecular mechanism of the anticancer effects of polyphyllin G in human oral cancer cells was investigated.

RESULTS

The results revealed that polyphyllin G significantly inhibited cell proliferation in human oral cancer cells; it dose-dependently induced apoptosis in SAS and OECM-1 cells through caspase-3, -8, and -9 activation and poly (ADP-ribose) polymerase cleavage. In addition, changes were observed in Bcl-2 and proapoptosis-related protein expression in different human oral cancer cell lines. The expression of both LC3-II and beclin-1 was markedly increased, suggesting the induction of autophagy in polyphyllin G-treated oral cells. To further clarify whether polyphyllin G-induced apoptosis and autophagy depended on Akt/extracellular signal-regulated kinases (ERK)/c-Jun N-terminal kinases (JNK)/p38 mitogen-activated protein kinases (MAPK) signaling pathways, the cells were cotreated with inhibitors. The results demonstrated polyphyllin G-induced apoptosis in oral cells through the activation of ERK, Akt, p38 MAPK, and JNK, whereas ERK and JNK accounted for polyphyllin G-induced autophagy.

CONCLUSION

This study is the first to demonstrate apoptosis and autophagy during polyphyllin G-induced cell death in human oral cancer cell lines. These results suggest that polyphyllin G is a promising candidate for developing antitumor drugs targeting human oral squamous cell carcinoma.

Siegesbeckia orientalis Extract Inhibits TGFβ1-Induced Migration and Invasion of Endometrial Cancer Cells

Type II endometrial carcinoma typically exhibits aggressive metastasis and results in a poor prognosis. Siegesbeckia orientalis Linne is a traditional Chinese medicinal herb with several medicinal benefits, including the cytotoxicity against various cancers. This study investigates the inhibitory effects of S. orientalis ethanol extract (SOE) on the migration and invasion of endometrial cancer cells, which were stimulated by transforming growth factor β (TGFβ). The inhibitory effects were evaluated by determining wound healing and performing the Boyden chamber assay. This study reveals that SOE can inhibit TGFβ1-induced cell wound healing, cell migration, and cell invasion in a dose-dependent manner in RL95-2 and HEC-1A endometrial cancer cells. SOE also reversed the TGFβ1-induced epithelial-mesenchymal transition, including the loss of the cell-cell junction and the lamellipodia-like structures. Western blot analysis revealed that SOE inhibited the phosphorylation of ERK1/2, JNK1/2, and Akt, as well as the expression of MMP-9, MMP-2, and u-PA in RL95-2 cells dose-dependently. The results of this investigation suggest that SOE is a potential anti-metastatic agent against human endometrial tumors.

Dehydroandrographolide, an iNOS inhibitor, extracted from Andrographis paniculata (Burm.f.) Nees, induces autophagy in human oral cancer cells

Autophagy, which is constitutively executed at the basal level in all cells, promotes cellular homeostasis by regulating the turnover of organelles and proteins. Andrographolide and dehydroandrographolide (DA) are the two principle components of Andrographis paniculata (Burm.f.) Nees. and are the main contributors to its therapeutic properties. However, the pharmacological activities of dehydroandrographolide (DA) remain unclear. In this study, DA induces oral cancer cell death by activating autophagy. Treatment with autophagy inhibitors inhibited DA-induced human oral cancer cell death. In addition, DA increased LC3-II expression and reduced p53 expression in a time- and concentration-dependent manner. Furthermore, DA induced autophagy and decreased cell viability through modulation of p53 expression. DA-induced autophagy was triggered by an activation of JNK1/2 and an inhibition of Akt and p38. In conclusion, this study demonstrated that DA induced autophagy in human oral cancer cells by modulating p53 expression, activating JNK1/2, and inhibiting Akt and p38. Finally, an administration of DA effectively suppressed the tumor formation in the oral carcinoma xenograft model in vivo. This is the first study to reveal the novel function of DA in activating autophagy, suggesting that DA could serve as a new and potential chemopreventive agent for treating human oral cancer.

Suppression of ERK1/2 and hypoxia pathways by four Phyllanthus species inhibits metastasis of human breast cancer cells

Chemotherapies remain far from ideal due to drug resistance; therefore, novel chemotherapeutic agents with higher effectiveness are crucial. The extracts of four Phyllanthus species, namely Phyllanthus niruri, Phyllanthus urinaria, Phyllanthus watsonii, and Phyllanthus amarus, were shown to induce apoptosis and inhibit metastasis of breast carcinoma cells (MCF-7). The main objective of this study was to determine the pathways utilized by these four Phyllanthus species to exert anti-metastatic activities. A cancer 10-pathway reporter was used to investigate the pathways affected by the four Phyllanthus species. Results indicated that these Phyllanthus species suppressed breast carcinoma metastasis and proliferation by suppressing matrix metalloprotein 2 and 9 expression via inhibition of the extracellular signal-related kinase (ERK) pathway. Additionally, inhibition of hypoxia-inducible factor 1-α in the hypoxia pathway caused reduced vascular endothelial growth factor and inducible nitric oxide synthase expression, resulting in anti-angiogenic effects and eventually anti-metastasis. Two-dimensional gel electrophoresis identified numerous proteins suppressed by these Phyllanthus species, including invasion proteins, anti-apoptotic protein, protein-synthesis proteins, angiogenic and mobility proteins, and various glycolytic enzymes. Our results indicated that ERK and hypoxia pathways are the most likely targets of the four Phyllanthus species for the inhibition of MCF-7 metastasis.

Mesenchymal-epithelial signalling in tumour microenvironment: role of high-mobility group Box 1

Glucose deprivation, hypoxia and acidosis are characteristic features of the central core of most solid tumours. Myofibroblasts are stromal cells present in many such solid tumours, including those of the colon, and are known to be involved in all stages of tumour progression. HMGB1 is a nuclear protein with an important role in nucleosome stabilisation and gene transcription; it is also released from immune cells and is involved in the inflammatory process. We report that the microenvironmental condition of glucose deprivation is responsible for the active release of HMGB1 from various types of cancer cell lines (HT-29, MCF-7 and A549) under normoxic conditions. Recombinant HMGB1 (10 ng/ml) triggered proliferation in myofibroblast cells via activation of PI3K and MEK1/2. Conditioned medium collected from glucose-deprived HT-29 colon cancer cells stimulated the migration and invasion of colonic myofibroblasts, and these processes were significantly inhibited by immunoneutralising antibodies to HMGB1, RAGE and TLR4, together with specific inhibitors of PI3K and MEK1/2. Our data suggest that HMGB1 released from cancer cells under glucose deprivation is involved in stimulating colonic myofibroblast migration and invasion and that this occurs through the activation of RAGE and TLR4, resulting in the activation of the MAPK and PI3K signalling pathways. Thus, HMGB1 might be released by cancer cells in areas of low glucose in solid tumours with the resulting activation of myofibroblasts and is a potential therapeutic target to inhibit solid tumour growth.

Dioscorea nipponica Attenuates Migration and Invasion by Inhibition of Urokinase-Type Plasminogen Activator through Involving PI3K/Akt and Transcriptional Inhibition of NF-κB and SP-1 in Hepatocellular Carcinoma

High mortality and morbidity rates for hepatocellular carcinoma (HCC) in Taiwan primarily result from uncontrolled tumor metastasis. In our previous studies, we have reported that Dioscorea nipponica Makino extract (DNE) has anti-metastasis effects on human oral cancer cells. However, the effect of DNE on hepatoma metastasis have not been thoroughly investigated and remains poorly understood. To determine the effects of DNE on the migration and invasion in HCC cells we used a wound healing model, Boyden chamber assays, gelatin/casein zymography and Western blotting. Transcriptional levels of matrix metalloproteinase-9 (MMP-9) and urokinase-type plasminogen activator (u-PA) were detected by real-time PCR and promoter assays. In this study, DNE treatment significantly inhibited the migration/invasion capacities of Huh7 cell lines. The results of gelatin/casein zymography and Western blotting revealed that the activities and protein levels of the MMP-9 and u-PA were inhibited by DNE. Tests of the mRNA levels, real-time PCR, and promoter assays evaluated the inhibitory effects of DNE on u-PA expression in human hepatoma cells. A chromatin immunoprecipitation (ChIP) assay showed not only that DNE inhibits u-PA expression, but also the inhibitory effects were associated with the down-regulation of the transcription factors of NF-[Formula: see text]B and SP-1 signaling pathways. Western blot analysis also showed that DNE inhibits PI3K and phosphorylation of Akt. In conclusion, these results show that u-PA expression may be a potent therapeutic target in the DNE-mediated suppression of HCC invasion/migration. DNE may have potential use as a chemo-preventive agent against liver cancer metastasis.

The Inhibitory Effect of Abietic Acid on Melanoma Cancer Metastasis and Invasiveness In Vitro and In Vivo

Melanoma cell metastasis is the primary cause of patient death. Thus, various treatment strategies have been developed to prevent metastasis. Abietic acid (AA) is an organic compound commonly found in trees. This study is aimed to investigate the antimetastatic activity of AA in B16F10-xenografted C57BL/6 mice and assess the anticancer activity of AA in combination with Taxol in melanoma cells. AA effectively reduced the formation of lung metastases by approximately 92.8%. AA treatment inhibited migratory potential ([Formula: see text]), invasion ([Formula: see text]), and motility ([Formula: see text]) of highly metastatic B16F10 melanoma cells in vitro. Zymography revealed that AA reduced the proteinase activities of matrix metalloproteinase-2 and urokinase-type plasminogen activator. Molecular analyses showed that AA reduced Akt phosphorylation and activating protein-1 DNA-binding activity by Western blot and electrophoretic mobility shift assay (EMSA), respectively. In summary, AA effectively inhibited B16F10 lung metastasis, and 50[Formula: see text][Formula: see text]M AA did not affect the viability of B16F10 cells. AA improved the efficacy of Taxol and demonstrated strong anticancer activity on melanoma cells. These results suggested that AA could be used as an antimetastatic agent or as an adjuvant for anticancer therapy.

Silymarin and Its Role in Chronic Diseases

Silymarin is the active constituent of Silybum marianum (milk thistle) which is a C-25 containing flavonolignan. Milk thistle has a lot of traditional values, being used as a vegetable, as salad, as bitter tonic, and as galactogogue in nursing mothers and in various ailments such as liver complications, depression, dyspepsia, spleenic congestions, varicose veins, diabetes, amenorrhea, uterine hemorrhage, and menstrual problems. In this present chapter, a comprehensive attempt has been made to discuss the potential of silymarin in chronic disorders. An insight into modulation of cellular signaling by silymarin and its implication in various disorders such as liver disorders, inflammatory disorders, cancer, neurological disorders, skin diseases, and hypercholesterolemia is being provided.

Naringin suppresses cell metastasis and the expression of matrix metalloproteinases (MMP-2 and MMP-9) via the inhibition of ERK-P38-JNK signaling pathway in human glioblastoma

Naringin (4',5,7-trihydroxyflavanone 7-rhamnoglucoside), a natural flavonoid, has pharmacological properties. In the present study, we investigated the anti-metastatic activity of naringin and its molecular mechanism(s) of action in human glioblastoma cells. Naringin exhibits inhibitory effects on the invasion and adhesion of U87 cells in a concentration-dependent manner by Matrigel Transwell and cell adhesion assays. Naringin also inhibited the migration of U87 cells in a concentration-dependent manner by wound-healing assay. Additional experiments showed that naringin treatment reduced the enzymatic activities and protein levels of matrix metalloproteinase (MMP)-2 and MMP-9 using a gelatin zymography assay and western blot analyses. Furthermore, naringin was able to reduce the protein phosphorylation of extracellular signal-regulated kinase ERK, p38 mitogen-activated protein kinase and c-Jun N-terminal kinase by western blotting. Collectively, our data showed that naringin attenuated the MAPK signaling pathways including ERK, JNK and p38 and resulted in the downregulation of the expression and enzymatic activities of MMP-2, MMP-9, contributing to the inhibition of metastasis in U87 cells. These findings proved that naringin may offer further application as an antimetastatic agent.

Chloride intracellular channel 1 regulates migration and invasion in gastric cancer by triggering the ROS-mediated p38 MAPK signaling pathway

Chloride intracellular channel 1 (CLIC1) has been demonstrated to be overexpressed in gastric cancer, and elevated CLIC1 expression levels are markedly associated with the processes of tumor cell migration and invasion. However, the regulatory mechanism and signaling pathway underlying these processes have remained to be elucidated. The present study examined the impact of N-acetyl cysteine (NAC), indanyloxyacetic acid (IAA)-94 and SB203580, inhibitors of reactive oxygen species (ROS), as well as CLIC1 and p38 mitogen-activated protein kinase (MAPK) on the migration and invasion of SGC-7901 gastric cancer cells in a hypoxia-reoxygenation (H-R) microenvironment. The results demonstrated that intracellular ROS and CLIC1 levels were increased under H-R conditions, and that functional inhibition of CLIC1 significantly decreased the H-R-elevated ROS generation and p-p38 MAPK levels in SGC-7901 cells, as well as inhibited the migration and invasion of SGC-7901 cells. In addition, the expression levels of MMP-2 and MMP-9 were inhibited by NAC, IAA-94 and SB203580. These results indicated that CLIC1 regulates gastric cancer-cell migration and invasion via the ROS-mediated p38 MAPK signaling pathway.

Silibinin-induced glioma cell apoptosis by PI3K-mediated but Akt-independent downregulation of FoxM1 expression

The oncogenic transcription factor Forkhead box M1 (FoxM1) is overexpressed in many human tumors, including glioma. As a critical regulator of the cell cycle and apoptosis-related genes, FoxM1 is a potential therapeutic target against human malignant glioma. Silibinin, a flavonoid isolated from Silybum marianum, dose-dependently reduced glioma cell proliferation, promoted apoptosis, and downregulated FoxM1 expression. Knockdown of FoxM1 by small hairpin RNA (shRNA) transfection also promoted glioma cell apoptosis and augmented the antiproliferative and pro-apoptotic properties of silibinin. Moreover, silibinin increased caspase-3 activation, upregulated pro-apoptotic Bax, and suppressed anti-apoptotic Bcl-2 expression, effects enhanced by FoxM1 knockdown. Silibinin treatment suppressed U87 cell PI3K phospho-activation, and simultaneous silibinin exposure, FoxM1 knockdown, and PI3K inhibition additively increased U87 cell apoptosis. Furthermore, PI3K inhibition reduced FoxM1 expression. Akt activity was also suppressed by FoxM1 downregulation but Akt inhibition did not alter FoxM1 expression. Thus, silibinin likely inhibited glioma cell proliferation and induced apoptosis through inactivation of PI3K and FoxM1, leading to activation of the mitochondrial apoptotic pathway. FoxM1 may be a novel target for chemotherapy against human glioma.