Sinulariolide Suppresses Cell Migration and Invasion by Inhibiting Matrix Metalloproteinase-2/-9 and Urokinase through the PI3K/AKT/mTOR Signaling Pathway in Human Bladder Cancer Cells

Natural products and derivatives in renal, urothelial and testicular cancers: Targeting signaling pathways and therapeutic potential

BACKGROUND

Natural products have demonstrated significant potential in cancer drug discovery, particularly in renal cancer (RCa), urothelial carcinoma (UC), and testicular cancer (TC).

PURPOSE

This review aims to examine the effects of natural products on RCa, UC and TC.

STUDY DESIGN

systematic review METHODS: PubMed and Web of Science databases were retrieved to search studies about the effects of natural products and derivatives on these cancers. Relevant publications in the reference list of enrolled studies were also checked.

RESULTS

This review highlighted their diverse impacts on key aspects such as cell growth, apoptosis, metastasis, therapy response, and the immune microenvironment. Natural products not only hold promise for novel drug development but also enhance the efficacy of existing chemotherapy and immunotherapy. Importantly, we exert their effects through modulation of critical pathways and target genes, including the PI3K/AKT pathway, NF-κB pathway, STAT pathway and MAPK pathway, among others in RCa, UC, and TC.

CONCLUSION

These mechanistic insights provide valuable guidance for researchers, facilitating the selection of promising natural products for cancer management and offering potential avenues for further gene regulation studies in the context of cancer treatment.

Natural Products as Regulators against Matrix Metalloproteinases for the Treatment of Cancer

Cancers are currently the major cause of mortality in the world. According to previous studies, matrix metalloproteinases (MMPs) have an impact on tumor cell proliferation, which could lead to the onset and progression of cancers. Therefore, regulating the expression and activity of MMPs, especially MMP-2 and MMP-9, could be a promising strategy to reduce the risk of cancers. Various studies have tried to investigate and understand the pathophysiology of cancers to suggest potent treatments. In this review, we summarize how natural products from marine organisms and plants, as regulators of MMP-2 and MMP-9 expression and enzymatic activity, can operate as potent anticancer agents.

Marine-Derived Anticancer Agents Targeting Apoptotic Pathways: Exploring the Depths for Novel Cancer Therapies

Extensive research has been conducted on the isolation and study of bioactive compounds derived from marine sources. Several natural products have demonstrated potential as inducers of apoptosis and are currently under investigation in clinical trials. These marine-derived compounds selectively interact with extrinsic and intrinsic apoptotic pathways using a variety of molecular mechanisms, resulting in cell shrinkage, chromatin condensation, cytoplasmic blebs, apoptotic bodies, and phagocytosis by adjacent parenchymal cells, neoplastic cells, or macrophages. Numerous marine-derived compounds are currently undergoing rigorous examination for their potential application in cancer therapy. This review examines a total of 21 marine-derived compounds, along with their synthetic derivatives, sourced from marine organisms such as sponges, corals, tunicates, mollusks, ascidians, algae, cyanobacteria, fungi, and actinobacteria. These compounds are currently undergoing preclinical and clinical trials to evaluate their potential as apoptosis inducers for the treatment of different types of cancer. This review further examined the compound's properties and mode of action, preclinical investigations, clinical trial studies on single or combination therapy, and the prospective development of marine-derived anticancer therapies.

Deep-Sea Sponges and Corals off the Western Coast of Florida-Intracellular Mechanisms of Action of Bioactive Compounds and Technological Advances Supporting the Drug Discovery Pipeline

The majority of natural products utilized to treat a diverse array of human conditions and diseases are derived from terrestrial sources. In recent years, marine ecosystems have proven to be a valuable resource of diverse natural products that are generated to defend and support their growth. Such marine sources offer a large opportunity for the identification of novel compounds that may guide the future development of new drugs and therapies. Using the National Oceanic and Atmospheric Administration (NOAA) portal, we explore deep-sea coral and sponge species inhabiting a segment of the U.S. Exclusive Economic Zone, specifically off the western coast of Florida. This area spans ~100,000 km2, containing coral and sponge species at sea depths up to 3000 m. Utilizing PubMed, we uncovered current knowledge on and gaps across a subset of these sessile organisms with regards to their natural products and mechanisms of altering cytoskeleton, protein trafficking, and signaling pathways. Since the exploitation of such marine organisms could disrupt the marine ecosystem leading to supply issues that would limit the quantities of bioactive compounds, we surveyed methods and technological advances that are necessary for sustaining the drug discovery pipeline including in vitro aquaculture systems and preserving our natural ecological community in the future. Collectively, our efforts establish the foundation for supporting future research on the identification of marine-based natural products and their mechanism of action to develop novel drugs and therapies for improving treatment regimens of human conditions and diseases.

Preclinical Characterization of 22-(4'-Pyridinecarbonyl) Jorunnamycin A against Lung Cancer Cell Invasion and Angiogenesis via AKT/mTOR Signaling

Non-small-cell lung cancer (NSCLC), the most prevalent form of lung cancer, is associated with an unfavorable prognosis owing to its high rate of metastasis. Thus, the identification of new drugs with potent anticancer activities is essential to improve the clinical outcome of this disease. Marine organisms exhibit a diverse source of biologically active compounds with anticancer effects. The anticancer effects of jorunnamycin A (JA) derived from the Thai blue sponge (Xestospongia sp.) and 22-(4'-pyridinecarbonyl) jorunnamycin A (22-(4'-py)-JA), the semisynthetic derivative of JA, have been reported. The present study aimed to investigate the impact of 22-(4'-py)-JA on NSCLC metastasis using in vitro, in vivo, and in silico approaches. The JA derivative inhibited tumor cell invasion and tube formation in human umbilical vein endothelial cells (HUVECs). The computational analysis demonstrated strong and stable interactions between 22-(4'-py)-JA and the AKT protein. Further examinations into the molecular mechanisms revealed the suppression of AKT/mTOR/p70S6K signaling by 22-(4'-py)-JA, leading to the downregulation of matrix metalloproteinases (MMP-2 and MMP-9), hypoxia-inducible factor-1α (HIF-1α), and vascular endothelial growth factor (VEGF). Furthermore, 22-(4'-py)-JA suppressed in vivo metastasis by decreasing the number of colonies in the lung. These findings indicated the antimetastasis activity of 22-(4'-py)-JA, which might prove useful for further clinical applications.

Natural Products as New Approaches for Treating Bladder Cancer: From Traditional Medicine to Novel Drug Discovery

Bladder cancer (BC) is a heterogeneous disease that a tumor develops in the bladder lining and in some cases, the bladder muscle. Chemotherapy and immunotherapy are commonly used to treat bladder cancer. However, chemotherapy can cause burning and irritation in the bladder while BCG immunotherapy, which is the main type of intravesical immunotherapy for bladder cancer, can also cause burning in the bladder and flu-like symptoms. Thus, drugs originating from natural products have attracted much attention due to the reports that they have anti-cancer properties with low adverse effects. In this study, eighty-seven papers that dealt with natural products preventing or treating bladder cancer were reviewed. The studies were classified into the following mechanism: 71 papers on cell death, 5 papers on anti-metastasis, 3 papers on anti-angiogenesis, 1 paper on anti-resistance, and 7 papers on clinical trials. Most of the natural products that induced apoptosis up-regulated proteins such as caspase-3 and caspase-9. Regarding anti-metastasis, MMP-2 and MMP-9 are regulated frequently. Regarding anti-angiogenesis, HIF-1α and VEGF-A are down-regulated frequently. Nevertheless, the number of papers regarding anti-resistance and clinical trial are too few, so more studies are needed. In conclusion, this database will be useful for future in vivo studies of the anti-bladder cancer effect of natural products, in the process of selecting materials used for the experiment.

Stellettin B Isolated from Stelletta Sp. Reduces Migration and Invasion of Hepatocellular Carcinoma Cells through Reducing Activation of the MAPKs and FAK/PI3K/AKT/mTOR Signaling Pathways

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors, and there is currently a lack of effective treatment options to control the metastasis. This study was performed to examine the mechanisms of the migration and invasion characteristics of HCC, with the aim of reducing metastasis by inhibiting cancer cell migration and invasion. In this study, we used Stellettin B, an active compound isolated from Stelletta sponges, as the experimental drug and evaluated its inhibition effects on cell migration and invasion in human hepatoma cells (HA22T and HepG2). MTT assay, gelatin zymography, and western blotting were employed. The results showed that Stellettin B significantly inhibited the protein expressions of MMP-2, MMP-9, and uPA, while upregulating the protein expressions of TIMP-1 and TIMP-2. The expressions of p-FAK, p-PI3K, p-AKT, p-mTOR, and MAPKs (p-JNK, p-JUN, p-MAPKp38, and p-ERK) were decreased with increasing concentrations of Stellettin B. Our results suggest that Stellettin B-dependent downregulation of MMP-2 and MMP-9 activities could be mediated by FAK/PI3K/AKT/mTOR and MAPKs signaling pathways in HA22T and HepG2 cells, preventing HCC invasion and migration.

AKT inhibition sensitizes EVI1 expressing colon cancer cells to irinotecan therapy by regulating the Akt/mTOR axis

PURPOSE

Ecotropic viral integration site 1 (EVI1) is an oncogenic transcription factor that has been attributed to chemotherapy resistance in different cancers. As yet, however, its role in colon cancer drug resistance is not completely understood. Here, we set out to investigate the functional and therapeutic relevance of EVI1 in colon cancer drug resistance.

METHODS

The EVI1 gene was knocked down in colon cancer cells that were subsequently tested for susceptibility to irinotecan using in vitro assays and in vivo subcutaneous mouse colon cancer models. The effect of EVI1 knockdown on the AKT-mTOR signaling pathway was assessed using cell line models, immunohistochemistry and bioinformatics tools. The anti-proliferative activity of AKT inhibitor GSK690693 and its combination with irinotecan was tested in colon cancer cell line models (2D and 3D). Finally, the therapeutic efficacy of GSK690693 and its combination with irinotecan was evaluated in xenografted EVI1 expressing colon cancer mouse models.

RESULTS

We found that EVI1 knockdown decreased cancer stem cell-like properties and improved irinotecan responses in both cell line and subcutaneous mouse models. In addition, we found that EVI1 downregulation resulted in inhibition of AKT/mTOR signaling and RICTOR expression. Knocking down RICTOR expression increased the cytotoxic effects of irinotecan in EVI1 downregulated colon cancer cells. Co-treatment with irinotecan and ATP-competitive AKT inhibitor GSK690693 significantly reduced colon cancer cell survival and tumor progression rates.

CONCLUSION

Inhibition of the AKT signaling cascade by GSK690693 may serve as an alternative to improve the irinotecan response in EVI1-expressing colon cancer cells.

Matrix metalloproteinase contribution in management of cancer proliferation, metastasis and drug targeting

Matrix metalloproteinases (MMPs) or matrixins, are members of a zinc-dependent endopeptidase family. They cause remodeling of the extracellular matrix (ECM) leading to numerous diseases. MMPs subfamilies possess: collagenases, gelatinases, stromelysins and membrane-type MMPs (MT-MMP). They consist of several domains; pro-peptide, catalytic, linker peptide and the hemopexin (Hpx) domains. MMPs are involved in initiation, proliferation and metastasis of cancer through the breakdown of ECM physical barriers. Overexpression of MMPs is associated with poor prognosis of cancer. This review will discuss both types of MMPs and current inhibitors, which target them in different aspects, including, biosynthesis, activation, secretion and catalytic activity. Several synthetic and natural inhibitors of MMPs (MMPIs) that can bind the catalytic domain of MMPs have been designed including; peptidomimetic, non-peptidomimetic, tetracycline derivatives, off-target MMPI, natural products, microRNAs and monoclonal antibodies.

Dieckol, an Algae-Derived Phenolic Compound, Suppresses UVB-Induced Skin Damage in Human Dermal Fibroblasts and Its Underlying Mechanisms

Ultraviolet (UV) irradiation is considered to be the primary environmental factor that causes skin damage. In the present study, we investigated the protective effect of dieckol (DK), a compound isolated from the brown seaweed Ecklonia cava, against UVB-induced skin damage in human dermal fibroblasts (HDF cells). The results indicated that DK effectively inhibited the activity of collagenase. DK remarkably reduced the intracellular reactive oxygen species level and improved the viability of UVB-irradiated HDF cells. Besides, DK significantly and dose-dependently improved collagen synthesis and inhibited intracellular collagenase activity in UVB-irradiated HDF cells. In addition, DK markedly reduced the expression of proinflammatory cytokines and matrix metalloproteinases. Further analyses revealed that these processes were mediated through the regulation of nuclear factor kappa B, activator protein 1, and mitogen-activated protein kinase signaling pathways in the UVB-irradiated HDF cells. In conclusion, these results indicate that DK possesses strong in vitro photoprotective effects and therefore has the potential to be used as an ingredient in the cosmeceutical industry.

Natural Marine and Terrestrial Compounds as Modulators of Matrix Metalloproteinases-2 (MMP-2) and MMP-9 in Alzheimer's Disease

Several studies have reported neuroprotective effects by natural products. A wide range of natural compounds have been investigated, and some of these may play a beneficial role in Alzheimer's disease (AD) progression. Matrix metalloproteinases (MMPs), a family of zinc-dependent endopeptidases, have been implicated in AD. In particular, MMP-2 and MMP-9 are able to trigger several neuroinflammatory and neurodegenerative pathways. In this review, we summarize and discuss existing literature on natural marine and terrestrial compounds, as well as their ability to modulate MMP-2 and MMP-9, and we evaluate their potential as therapeutic compounds for neurodegenerative and neuroinflammatory diseases, with a focus on Alzheimer's disease.

L-type amino acid transporter 1 promotes proliferation and invasion of human chorionic trophoblast and choriocarcinoma cells through mTORC1

L-type amino acid transporter 1 (LAT1) is a neutral amino acid transporter expressed in trophoblast giant cells onembryonic day 8 in mice. LAT1 is responsible for metabolism in blastocysts and cancer cells. Despite research concerning the aberrant high expression and indispensable function of LAT1 in various cancers, little is known about the role of LAT1 in regulating the behaviors of human trophoblast cells under different physiological and pathological conditions. The HTR8-SVneo human trophoblast cell line and JEG-3 and JAR choriocarcinoma cell lines are used as models for trophoblast cell biological research. The proliferation and apoptosis of these cells were assayed using the CCK-8 assay and flow cytometry, respectively. Transwell-chambers were used to observed migration and invasion of the cells. Immunofluorescent staining, western blot, and RT-PCR assays were used to determine the possible mechanism of LAT1 on human trophoblast cell behaviors with small interfering RNA or signal agonists and antagonist treatments. LAT1 was expressed in the trophoblast and choriocarcinoma cells. LAT1 was involved in regulating behaviors of these cells, such as cell proliferation, apoptosis, migration, and invasion. Detailed results suggested that LAT1 modulated trophoblast cell functions by mediation of mTORC1 signaling pathways. Our results implicate LAT1 as a very important regulator in human trophoblast cell behaviors at the maternal-fetal interface.

Marine compounds targeting the PI3K/Akt signaling pathway in cancer therapy

Cancer is a disease characterized by overproliferation, including that due to transformation, apoptosis disorders, proliferation, invasion, angiogenesis and metastasis, and is one of the deadliest diseases. Currently, conservative chemotherapy is used for cancer treatment due to a lack of effective drugs. The PI3K/Akt signaling pathway plays a very essential role in the pathogenesis of many cancers, and abnormal activation of this pathway leads to abnormal expression of a series of downstream proteins, which ultimately results in the excessive proliferation of cancer cells. Therefore, the PI3K/Akt signaling pathway is a critical target in cancer treatment. Marine drugs have attracted much attention in recent years, and studies have found that many extracts from oceanic animals, plants and microorganisms or their metabolites exert antitumor effects, including antiproliferative effects or the induction of cell cycle arrest, apoptosis or autophagy. However, most anticancer targets and the mechanisms of marine compounds remain unclear. The great potential of the development of marine drugs provides a new direction for cancer treatment. This review focuses on marine compounds that target the PI3K/Akt signaling pathway for the prevention and treatment of cancer and provides comprehensive information for those interested in research on marine drugs.

Anti-Breast Cancer Effect of 2-Dodecyl-6-Methoxycyclohexa-2,5-Diene-1,4-Dione in vivo and in vitro Through MAPK Signaling Pathway

Background

2-Dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD) has been reported to inhibit a variety of cancer cell lines. The purpose of this study was to investigate the effects of DMDD on 4T1 breast cancer cells and the effects of DMDD on 4T1 breast cancer in mice and its molecular mechanisms.

Methods

4T1 breast cancer cells were treated with different concentrations of DMDD, and their proliferation, apoptosis, cell-cycle distribution, migration, and invasion were detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT, Acridine orange and ethidium bromide dual staining analysis (AO/EB) dual staining, flow cytometry, scratch test, and the Transwell assay. Relative quantitative real-time qPCR analysis and Western blot were applied to examine the expression levels of related genes and proteins. In animal experiments, we established a xenograft model to assess the anti-breast cancer effects of DMDD by evaluating the inhibition rate. The apoptotic activity of DMDD was evaluated by hematoxylin-eosin (HE) staining, transmission electron microscope (TEM) analysis and TdT-mediated dUTP nick end labeling (TUNEL) assays. The mRNA expression levels of MAPK pathway components were detected by relative quantitative real-time qPCR. In addition, the protein expression levels of MAPK pathway components were assessed through immunohistochemical assays and Western blotting.

Results

Experiments showed that DMDD could inhibit the proliferation, migration, invasion of 4T1 cells and induce cellular apoptosis and G1 cell cycle arrest. Moreover, DMDD down-regulated the mRNA expressions of raf1, mek1, mek2, erk1, erk2, bcl2, and up-regulated the mRNA expression of bax. DMDD reduced the protein expressions of p-raf1, p-mek, p-erk, p-p38, Bcl2, MMP2, MMP9 and increased the protein expressions of Bax and p-JNK. The results showed that DMDD can effectively reduce the tumor volume and weight of breast cancer in vivo, up-regulate the expression of IL-2, down-regulate the expression of IL-4 and IL-10, induce the apoptosis of breast cancer cells in mice, and regulate the expression of genes and proteins of the MAPK pathway.

Conclusion

Our study indicates that DMDD can inhibit proliferation, migration, and invasion and induces apoptosis and cell-cycle arrest of 4T1 breast cancer cells. Also, our findings indicate that DMDD induces the apoptosis of breast cancer cells and inhibits the growth in mice. Its mechanism may be related to the MAPK pathway.

Garcinol acts as an antineoplastic agent in human gastric cancer by inhibiting the PI3K/AKT signaling pathway

Gastric cancer (GC) is one of the most common malignancies worldwide; however, treatment options other than surgery remain limited. Neoadjuvant chemotherapy has the potential to suppress of gastric tumorigenesis. Garcinol has been reported to exert inhibitory effects on the progression of numerous carcinomas. However, its effects in GC remain unclear. Therefore, the aim of the present study was to investigate the effects of garcinol on the proliferation, invasion and apoptosis of gastric carcinoma cells and then to explore the underlying mechanisms. Garcinol significantly decreased the proliferation and invasion of GC cells and increased apoptosis in a dose-dependent manner. Additionally, the expression of AKT^p-Thr308, cyclin D1, Bcl-2, BAX, matrix metalloprotease (MMP-2) and MMP-9 in HGC-27 cells following treatment with garcinol. The results obtained in the present study suggested that garcinol may inhibit gastric tumorigenesis by suppressing the PI3K/AKT signaling pathway.

Cinobufacini Inhibits Colon Cancer Invasion and Metastasis via Suppressing Wnt/β-Catenin Signaling Pathway and EMT

Cinobufacini is a well-known Chinese medicine extracted from Venenum Bufonis, also called Chan Su. It has been used clinically for various cancers, including colon cancer. However, the function of Cinobufacini on colon cancer invasion and metastasis, and its underlying molecular mechanism, is still not clear. In this study, we investigated the function and mechanism of Cinobufacini on colon cancer invasion and metastasis both in vitro and in vivo studies. Human colon cancer cells were cultured. CCK assay was used to detect the effect of Cinobufacini on colon cancer cells proliferation. The invasion and migration abilities were observed by transwell assays, and the expression of invasion and migration related genes MMP2, MMP9, and epithelial-to-mesenchymal transition (EMT) relate genes were observed by Western blot assays. An orthotopic xenograft model in nude mice was established using colon cancer HCT116 cells, and the function of Cinobufacini on colon cancer invasion and metastasis were observed in vivo. We found Cinobufacini significantly inhibited colon cancer cell proliferation in a dose/time-dependent manner; the invasion and migration abilities of colon cancer were decreased after treated with Cinobufacini. The metastasis and EMT related genes MMP9, MMP2, N-cadherin and Snail were obviously down-regulated, while the expression of E-cadherin was up-regulated after treatment with Cinobufacini. The Wnt/β-catenin signaling pathway related genes were observed using WB,and results show that the expression of β-catenin, wnt3a, c-myc, cyclin D1, and MMP7 were all down-regulated after being treated with cinobufacini, while the expression of APC was up-regulated. In vivo studies of the volume and weight of orthotopic xenograft tumors showed significantly shrinkage in the Cinobufacini group compared to the control group. The enterocoelia and liver metastasis tumors were significantly decreased, and the expression of MMP9, MMP2, and β-catenin were also down-regulated, while E-cadherin was up-regulated in vivo after the treatment with Cinobufacini. Our data proves that Cinobufacini can inhibit colon cancer invasion and metastasis both in vitro and in vivo; the mechanism is related by suppressing the Wnt/β-catenin signaling pathway and then inhibiting the EMT of CRC.

Anti-cancer effects of methanol-ethyl acetate partitioned fraction from Magnolia grandiflora in human non-small cell lung cancer H1975 cells

Non-small cell lung cancer (NSCLC) constitutes nearly 85% of all cases of lung cancer. Drug resistance, dose-limiting toxicity, and metastasis in NSCLC eventually reduce the efficacy of chemotherapeutics. In this study, we have shown that the methanol-ethyl acetate partitioned fraction from Magnolia grandiflora L. seeds (MEM) exhibit potential anti-cancer activities against NSCLC H1975 cells in vivo and in vitro. MEM significantly inhibited the proliferation of H1975 cells in a concentration- and time-dependent manner. Further, MEM exhibited potent anti-tumor efficacy and low toxicity in nude mice bearing H1975 tumors. Our study also showed that MEM could induce cellular apoptosis in H1975 cells by down-regulating the protein expression levels of Akt and p-Akt-473, and by increasing the ratio of Bax/Bcl-2. Also, MEM significantly inhibited metastasis-related cell invasion and migration of H1975 cells, which associated with the down-regulation of HIF-1α, MMP-2, and MMP-9 protein expression levels. Thus, our data shows that MEM may be an effective fraction of M. grandiflora in NSCLC treatment.

Roles of the PI3K/AKT/mTOR signalling pathways in neurodegenerative diseases and tumours

The PI3 K/AKT/mTOR signalling pathway plays an important role in the regulation of signal transduction and biological processes such as cell proliferation, apoptosis, metabolism and angiogenesis. Compared with those of other signalling pathways, the components of the PI3K/AKT/mTOR signalling pathway are complicated. The regulatory mechanisms and biological functions of the PI3K/AKT/mTOR signalling pathway are important in many human diseases, including ischaemic brain injury, neurodegenerative diseases, and tumours. PI3K/AKT/mTOR signalling pathway inhibitors include single-component and dual inhibitors. Numerous PI3K inhibitors have exhibited good results in preclinical studies, and some have been clinically tested in haematologic malignancies and solid tumours. In this review, we briefly summarize the results of research on the PI3K/AKT/mTOR pathway and discuss the structural composition, activation, communication processes, regulatory mechanisms and biological functions of the PI3K/AKT/mTOR signalling pathway in the pathogenesis of neurodegenerative diseases and tumours.

Interaction of YAP1 and mTOR promotes bladder cancer progression

Yes‑associated protein 1 (YAP1) and mammalian target of rapamycin (mTOR) signaling pathways have been found to be deregulated in bladder cancer and accelerate the malignant progression of bladder cancer. However, the crosstalk between YAP1 and mTOR and its role in bladder cancer progression remains unclear. The aim of the present study was to investigate this crosstalk and the results revealed that the expression of YAP1 and mTOR was elevated in bladder cancer tissues compared with that in adjacent normal tissues. Knockdown of either mTOR or YAP1 with siRNA transfection significantly repressed the proliferation ability and induced apoptosis of HT‑1376 and J82 bladder cancer cells, particularly when YAP1 and mTOR were downregulated simultaneously. Upregulation of mTOR increased the mRNA and protein levels of YAP1 and enhanced its nuclear accumulation. In turn, YAP1 upregulation increased mTOR expression, reduced its protein degradation and increased its stability. In addition, immunofluorescence and Duolink assays demonstrated that YAP1 and mTOR were co‑localized in the nucleus. Immunoprecipitation assay demonstrated that the YAP1 protein was able to bind to the mTOR protein. Moreover, YAP1 combined with S‑phase kinase‑associated protein 2 (SKP2) and positively regulated its expression. Furthermore, the promotion of cell growth and inhibition of cell apoptosis induced by YAP1 overexpression were abolished when SKP2 was downregulated in HT‑1376 and J82 cells. Taken together, the findings of the present study indicated that the crosstalk between YAP1 and mTOR plays a pivotal role in accelerating the progression of bladder cancer, which may provide new insights into the role of the YAP1/mTOR axis in the occurrence and development of bladder cancer.

Natural products targeting the PI3K-Akt-mTOR signaling pathway in cancer: A novel therapeutic strategy

The phosphatidylinositol 3-kinase (PI3K)-Akt and the mammalian target of rapamycin (mTOR) represent two vital intracellular signaling pathways, which are associated with various aspects of cellular functions. These functions play vital roles in quiescence, survival, and growth in normal physiological circumstances as well as in various pathological disorders, including cancer. These two pathways are so intimately connected to each other that in some instances these are considered as one unique pathway crucial for cell cycle regulation. The purpose of this review is to emphasize the role of PI3K-Akt-mTOR signaling pathway in different cancer conditions and the importance of natural products targeting the PI3K-Akt-mTOR signaling pathway. This review also aims to draw the attention of scientists and researchers to the assorted beneficial effects of the numerous classes of natural products for the development of new and safe drugs for possible cancer therapy. We also summarize and critically analyze various preclinical and clinical studies on bioactive compounds and constituents, which are derived from natural products, to target the PI3K-Akt-mTOR signaling pathway for cancer prevention and intervention.

Recent insights into natural product inhibitors of matrix metalloproteinases

Members of the matrix metalloproteinase (MMP) family have biological functions that are central to human health and disease, and MMP inhibitors have been investigated for the treatment of cardiovascular disease, cancer and neurodegenerative disorders. The outcomes of initial clinical trials with the first generation of MMP inhibitors proved disappointing. However, our growing understanding of the complexities of the MMP function in disease, and an increased understanding of MMP protein architecture and control of activity now provide new opportunities and avenues to develop MMP-focused therapies. Natural products that affect MMP activities have been of strong interest as templates for drug discovery, and for their use as chemical tools to help delineate the roles of MMPs that still remain to be defined. Herein, we highlight the most recent discoveries of structurally diverse natural product inhibitors to these proteases.

Sinulariolide Inhibits Gastric Cancer Cell Migration and Invasion through Downregulation of the EMT Process and Suppression of FAK/PI3K/AKT/mTOR and MAPKs Signaling Pathways

Cancer metastasis is the main cause of death in cancer patients; however, there is currently no effective method to predict and prevent metastasis of gastric cancer. Therefore, gaining an understanding of the molecular mechanism of tumor metastasis is important for the development of new drugs and improving the survival rate of patients who suffer from gastric cancer. Sinulariolide is an active compound isolated from the cultured soft coral Sinularia flexibilis. We employed sinulariolide and gastric cancer cells in experiments such as MTT, cell migration assays, cell invasion assays, and Western blotting analysis. Analysis of cell migration and invasion capabilities showed that the inhibition effects on cell metastasis and invasion increased with sinulariolide concentration in AGS and NCI-N87 cells. Immunostaining analysis showed that sinulariolide significantly reduced the protein expressions of MMP-2, MMP-9, and uPA, but the expressions of TIMP-1 and TIMP-2 were increased, while FAK, phosphorylated PI3K, phosphorylated AKT, phosphorylated mTOR, phosphorylated JNK, phosphorylated p38MAPK, and phosphorylated ERK decreased in expression with increasing sinulariolide concentration. From the results, we inferred that sinulariolide treatment in AGS and NCI-N87 cells reduced the activities of MMP-2 and MMP-9 via the FAK/PI3K/AKT/mTOR and MAPKs signaling pathways, further inhibiting the invasion and migration of these cells. Moreover, sinulariolide altered the protein expressions of E-cadherin and N-cadherin in the cytosol and Snail in the nuclei of AGS and NCI-N87 cells, which indicated that sinulariolide can avert the EMT process. These findings suggested that sinulariolide is a potential chemotherapeutic agent for development as a new drug for the treatment of gastric cancer.

Marine Natural Products from Indonesian Waters

Natural products are primal and have been a driver in the evolution of organic chemistry and ultimately in science. The chemical structures obtained from marine organisms are diverse, reflecting biodiversity of genes, species and ecosystems. Biodiversity is an extraordinary feature of life and provides benefits to humanity while promoting the importance of environment conservation. This review covers the literature on marine natural products (MNPs) discovered in Indonesian waters published from January 1970 to December 2017, and includes 732 original MNPs, 4 structures isolated for the first time but known to be synthetic entities, 34 structural revisions, 9 artifacts, and 4 proposed MNPs. Indonesian MNPs were found in 270 papers from 94 species, 106 genera, 64 families, 32 orders, 14 classes, 10 phyla, and 5 kingdoms. The emphasis is placed on the structures of organic molecules (original and revised), relevant biological activities, structure elucidation, chemical ecology aspects, biosynthesis, and bioorganic studies. Through the synthesis of past and future data, huge and partly undescribed biodiversity of marine tropical invertebrates and their importance for crucial societal benefits should greatly be appreciated.

Chloride channel-3 is required for efficient tumour cell migration and invasion in human cervical squamous cell carcinoma

OBJECTIVE

Chloride channel-3 (ClC-3) plays significant roles in various physiological and physiopathological activities, including cell migration and invasion ability. The purpose of this study was to evaluate whether ClC-3 influences the migration and invasion of cervical squamous cell carcinoma cells and its possible mechanisms.

METHODS

Paraffin-embedded cervical tissues, including normal cervical tissues, cervical squamous cell carcinoma (SCC) and homologous paracancerous tissues, were collected. The cervical squamous cell carcinoma and matched paracarcinoma fresh tissues specimens were collected from 49 patients with SCC, and the normal cervical tissues were collected from 45 non-cervical squamous cell carcinoma patients. The human cervical squamous carcinoma cell line SiHa was cultured. ClC-3 expression was assessed by real-time RT-PCR, immunohistochemistry and Western blot, and the expression of phospho-PI3K/Akt/mTOR and matrix metalloproteinase-9 (MMP-9) was detected by Western blot. Small interfering RNA (siRNA) technology was used to knockdown ClC-3 expression. SiHa cell migration and invasion ability were measured using Transwell assays with or without Matrigel-coated membranes.

RESULTS

ClC-3 mRNA and protein expression in SCC tissues from cervical squamous cell carcinoma patients was significantly upregulated, and no significant difference was noted between the matched paracarcinoma fresh tissue from the same patients and non-cervical cancer patients. SiHa cell migration and invasion and phospho-PI3K/Akt/mTOR and MMP-9 expression were attenuated by knocking down ClC-3 expression using ClC-3 siRNA.

CONCLUSIONS

ClC-3 participates in the processes of SCC cell migration and invasion and regulates MMP-9 expression via the PI3K/Akt/mTOR signaling pathway.

MT1‑MMP promotes the proliferation and invasion of gastric carcinoma cells via regulating vimentin and E‑cadherin

The present study aimed to explore the possible effects of membrane‑type 1 matrix metalloproteinase (MT1‑MMP) on gastric carcinoma cells proliferation and invasion. Immunohistochemistry analysis was conducted to measure MT1‑MMP expression level in 15 patients with gastric carcinoma. Subsequently, recombinant short hairpin RNA (shRNA) vectors targeting MT1‑MMP were constructed to silence the expression of MT1‑MMP in gastric carcinoma cells. Then, the inhibitive efficiency was verified via reverse transcription quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis. The effects of MT1‑MMP silencing on cell proliferation and invasion were detected through Cell Counting Kit‑8 test and Transwell assays. The expression levels of vimentin and epithelial cadherin (E‑cadherin) were detected by RT‑qPCR. The immunohistochemistry analysis results revealed that MT1‑MMP expression in gastric carcinoma tissues was markedly overexpressed compared with non‑cancerous adjacent tissues. The MT1‑MMP expression level in cancer‑derived cell line AGS cells was also significantly increased compared with that in non‑cancer‑derived GES‑1 cells. In addition, the MT1‑MMP expression level in AGS cells was significantly decreased via shRNA transfection. Cell proliferation and invasion were markedly inhibited following knockdown of MT1‑MMP level in AGS cells. These inhibitory effects were associated with the decreased expression of vimentin and increased expression of E‑cadherin. MT1‑MMP was overexpressed in gastric carcinoma cells, and silencing of MT1‑MMP inhibited the proliferation and invasion of cells via regulating the expression of vimentin and E‑cadherin.

Marine natural products

Covering: January to December 2017This review covers the literature published in 2017 for marine natural products (MNPs), with 740 citations (723 for the period January to December 2017) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1490 in 477 papers for 2017), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. Geographic distributions of MNPs at a phylogenetic level are reported.

Sandensolide Induces Oxidative Stress-Mediated Apoptosis in Oral Cancer Cells and in Zebrafish Xenograft Model

Presently, natural sources and herbs are being sought for the treatment of human oral squamous cell carcinoma (OSCC) in order to alleviate the side effects of chemotherapy. This study investigates the effect of sandensolide, a cembrane isolated from Sinularia flexibilis, to inhibit human OSCC cell growth with the aim of developing a new drug for the treatment of oral cancer. In vitro cultured human OSCC models (Ca9.22, SCC9 and HSC-3 cell lines) and oral normal cells (HGF-1), as well as a zebrafish xenograft model, were used to test the cytotoxicity of sandensolide (MTT assay), as well as to perform cell cycle analysis and Western blotting. Both the in vitro bioassay and the zebrafish xenograft model demonstrated the anti-oral cancer effect of sandensolide. Moreover, sandensolide was able to significantly suppress colony formation and induce apoptosis, as well as cell cycle arrest, in OSCC by regulating multiple key proteins. Induction of reactive oxygen species (ROS) was observed in sandensolide-treated oral cancer cells. However, these apoptotic changes were rescued by NAC pretreatment. These findings contribute to the knowledge of the model of action of sandensolide, which may induce oxidative stress-mediated cell death pathways as a potential agent in oral cancer therapeutics.

Oxidative stress-modulating drugs have preferential anticancer effects - involving the regulation of apoptosis, DNA damage, endoplasmic reticulum stress, autophagy, metabolism, and migration

To achieve preferential effects against cancer cells but less damage to normal cells is one of the main challenges of cancer research. In this review, we explore the roles and relationships of oxidative stress-mediated apoptosis, DNA damage, ER stress, autophagy, metabolism, and migration of ROS-modulating anticancer drugs. Understanding preferential anticancer effects in more detail will improve chemotherapeutic approaches that are based on ROS-modulating drugs in cancer treatments.

Cembranoid-Related Metabolites and Biological Activities from the Soft Coral Sinularia flexibilis

Five new cembranoid-related diterpenoids, namely, flexibilisins D and E (1 and 2), secoflexibilisolides A and B (3 and 4), and flexibilisolide H (5), along with nine known compounds (6–14), were isolated from the soft coral Sinularia flexibilis. Their structures were established by extensive spectral analysis. Compound 3 possesses an unusual skeleton that could be biogenetically derived from cembranoids. The cytotoxicity and anti-inflammatory activities of the isolates were investigated, and the results showed that dehydrosinulariolide (7) and 11-epi-sinulariolide acetate (8) exhibited cytotoxicity toward a limited panel of cancer cell lines and 14-deoxycrassin (9) displayed anti-inflammatory activity by inhibition of superoxide anion generation and elastase release in N-formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLF/CB)-induced human neutrophils.

Isoliquiritigenin inhibits proliferation and metastasis of MKN28 gastric cancer cells by suppressing the PI3K/AKT/mTOR signaling pathway

Isoliquiritigenin (ISL) is a flavonoid extracted from licorice root, which is known to serve important antitumor roles in numerous types of cancers; however, its effect on gastric cancer remains to be elucidated. The present study aimed to explore the roles and underlying mechanisms of ISL in MKN28 gastric cancer cells. MKN28 cell proliferation was measured using the Cell Counting Kit‑8 (CCK8) assay. A Transwell assay was used to determine the effects of ISL on the migration and invasion of MKN28 cells. Apoptosis was assessed by flow cytometry, and the expression levels of apoptosis‑, autophagy‑ and signaling pathway‑related proteins were detected by western blot analysis. The results of the CCK8 assay demonstrated that ISL significantly inhibited the proliferation of MKN28 cells (P<0.05). Transwell assays demonstrated that the migration and invasion of MKN28 cells were significantly inhibited following treatment with ISL (P<0.05). Flow cytometric analysis indicated that ISL induced apoptosis of MKN28 cells. In addition, western blot analysis revealed that the ratio of microtubule‑associated proteins 1A/1B light chain 3B (LC3)II/LC3I was upregulated, as was Beclin 1 expression; however, p62 was downregulated following ISL pretreatment, thus suggesting that ISL triggered autophagy in MKN28 cells. In addition, the phosphorylation levels of protein kinase B (AKT) and mammalian target of rapamycin (mTOR) were significantly reduced following ISL treatment. These results indicated that ISL may influence apoptosis and autophagy in MKN28 cells by suppressing the phosphoinositide 3‑kinase/AKT/mTOR signaling pathway. In conclusion, the findings of the present study suggested that ISL may inhibit MKN28 cell proliferation, migration and invasion by inducing apoptosis and autophagy, implying potential as a therapeutic agent for gastric cancer.

lncRNA DLEU1 contributes to tumorigenesis and development of endometrial carcinoma by targeting mTOR

lncRNA DLEU1 as a non-coding gene, involves in the occurrence and development of multiple tumors. However, there is no related report in endometrial carcinoma. In order to focus on the role and mechanism of lncRNA DLEU1 in endometrial carcinoma, we used qRT-PCR to detect the expression of lncRNA DLEU1 and found that lncRNA DLEU1 was highly expressed in endometrial carcinoma compared to normal endometrium. Moreover, compared to Ishikawa and KLE, lncRNA DLEU1 was higher in HEC-1B. In addition, up-regulation of lncRNA DLEU1 promoted cell viability, migration, invasion, and reduced the proportion of apoptosis. Otherwise, down-regulation of lncRNA DLEU1 produced opposite results. Xenograft nude mice model assay showed that lncRNA DLEU1 can promote tumorigenesis in vivo. RiP confirmed that lncRNA DLEU1 could bind to mTOR. The rescue experiments revealed that silence of mTOR after up-regulation of lncRNA DLEU1 resulted in decrease of cell viability, migration, and invasion and increase of apoptosis. The expression changes of PI3K, AKT1, p70S6K, rpS6, GSK3β, STAT3, and Bcl-xl were consistent with lncRNA DLEU1 and mTOR in Western blot. Thus, we suggest that lncRNA DLEU1 combines with mTOR and then increases the expression of PI3K/AKT/mTOR pathway to promote endometrial carcinoma tumorigenesis and progression. The present discovery has probability to provide a biomarker and lay the foundation for targeted therapy of endometrial carcinoma.

Sinularin Selectively Kills Breast Cancer Cells Showing G2/M Arrest, Apoptosis, and Oxidative DNA Damage

The natural compound sinularin, isolated from marine soft corals, is antiproliferative against several cancers, but its possible selective killing effect has rarely been investigated. This study investigates the selective killing potential and mechanisms of sinularin-treated breast cancer cells. In 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H- tetrazolium, inner salt (MTS) assay, sinularin dose-responsively decreased the cell viability of two breast cancer (SKBR3 and MDA-MB-231) cells, but showed less effect on breast normal (M10) cells after a 24 h treatment. According to 7-aminoactinomycin D (7AAD) flow cytometry, sinularin dose-responsively induced the G2/M cycle arrest of SKBR3 cells. Sinularin dose-responsively induced apoptosis on SKBR3 cells in terms of a flow cytometry-based annexin V/7AAD assay and pancaspase activity, as well as Western blotting for cleaved forms of poly(ADP-ribose) polymerase (PARP), caspases 3, 8, and 9. These caspases and PARP activations were suppressed by N-acetylcysteine (NAC) pretreatment. Moreover, sinularin dose-responsively induced oxidative stress and DNA damage according to flow cytometry analyses of reactive oxygen species (ROS), mitochondrial membrane potential (MitoMP), mitochondrial superoxide, and 8-oxo-2'-deoxyguanosine (8-oxodG)). In conclusion, sinularin induces selective killing, G2/M arrest, apoptosis, and oxidative DNA damage of breast cancer cells.

Effects of the Combination of Gliotoxin and Adriamycin on the Adriamycin-Resistant Non-Small-Cell Lung Cancer A549 Cell Line

Acquired drug resistance constitutes an enormous hurdle in cancer treatment, and the search for effective compounds against resistant cancer is still advancing. Marine organisms are a promising natural resource for the discovery and development of anticancer agents. In this study, we examined whether gliotoxin (GTX), a secondary metabolite isolated from marine-derived Aspergillus fumigatus, inhibits the growth of adriamycin (ADR)-resistant non-small-cell lung cancer (NSCLC) cell lines A549/ADR. We investigated the effects of GTX on A549/ADR cell viability with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the induction of apoptosis in A549/ADR cells treated with GTX via fluorescence-activated cell sorting analysis, Hoechst staining, annexin V/propidium iodide staining, tetraethylbenzimidazolylcarbocyanine iodide (JC-1) staining, and western blotting. We found that GTX induced apoptosis in A549/ADR cells through the mitochondria-dependent pathway by disrupting mitochondrial membrane potential and activating p53, thereby increasing the expression levels of p21, p53 upregulated modulator of apoptosis (PUMA), Bax, cleaved poly (ADP-ribose) polymerase (PARP), and cleaved caspase-9. More importantly, we discovered that GTX works in conjunction with ADR to exert combinational effects on A549/ADR cells. In conclusion, our results suggest that GTX may have promising effects on ADR-resistant NSCLC cells by inducing mitochondria-dependent apoptosis and through the combined effects of sequential treatment with ADR.

Bufalin inhibits gastric cancer invasion and metastasis by down-regulating Wnt/ASCL2 expression

Achaete-scute-like 2 (ASCL2) is a transcription factor containing a basic helix-loop-helix (bHLH) domain and is a downstream target of Wnt signaling in intestinal stem cells. Bufalin is the primary active ingredient in Chan Su, a traditional Chinese medicine obtained from the skin and parotid venom glands of toads. The purpose of this study was to research the anti-invasion and anti-metastasis activity of bufalin in gastric cancer and to identify the potential mechanism. Bufalin inhibited gastric cancer cell invasion and metastasis, suppressed cancer cell colony formation, and inhibited the growth of subcutaneous xenografted tumors in nude mice. Furthermore, bufalin inhibited ASCL2 expression and down-regulated the expression of invasion-related genes such as MMP2, MMP9, and vimentin, thereby suppressing epithelial-mesenchymal transition (EMT) in gastric cancer. A Wnt signaling inhibitor (XAV939) down-regulated invasion and the expression of ASCL2, β-catenin, and vimentin but up-regulated E-cadherin expression. In nude mice, bufalin inhibited the tumorigenic behavior of gastric cancer cells, induced cancer cell apoptosis, and regulated invasion-related gene expression. Together, our results suggest that bufalin arrests invasion and metastasis and that its mechanism of action may involve down-regulating Wnt/ASCL2 expression.

Bioactive Steroids with Methyl Ester Group in the Side Chain from a Reef Soft Coral Sinularia brassica Cultured in a Tank

A continuing chemical investigation of the ethyl acetate (EtOAc) extract of a reef soft coral Sinularia brassica, which was cultured in a tank, afforded four new steroids with methyl ester groups, sinubrasones A–D (1–4) for the first time. In particular, 1 possesses a β-d-xylopyranose. The structures of the new compounds were elucidated on the basis of spectroscopic analyses. The cytotoxicities of compounds 1–4 against the proliferation of a limited panel of cancer cell lines were assayed. The anti-inflammatory activities of these new compounds 1–4 were also evaluated by measuring their ability to suppress superoxide anion generation and elastase release in N-formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLP/CB)-induced human neutrophils. Compounds 2 and 3 were shown to exhibit significant cytotoxicity, and compounds 3 and 4 were also found to display attracting anti-inflammatory activities.