Breaking down Leukemia Walls: Heteronemin, a Sesterterpene Derivative, Induces Apoptosis in Leukemia Molt4 Cells through Oxidative Stress, Mitochondrial Dysfunction and Induction of Talin Expression

Heteronemin promotes iron-dependent cell death in pancreatic cancer

The marine environment has been recognized as a prolific source of potent bioactive compounds with significant anticancer properties. Among these, heteronemin, a sesterterpenoid-type natural product, has shown promise. This study delves into the potential of heteronemin as a ferroptotic agent against pancreatic cancer, using the Panc-1 cell line as a model. The cytotoxic potential of heteronemin was assessed using cell viability assays. Furthermore, its effect on lipid peroxidation was determined spectrophotometrically, while the changes it induced in autophagy- and ferritin-related protein expressions were evaluated using immunoblotting techniques. Various cell-based tests were employed to scrutinize its anticancer efficacy. Heteronemin displayed a notable cytotoxic effect, reducing cell viability by 50% at a concentration of 55 nM. This cytotoxicity was discernibly linked to ferroptosis, as evidenced by the reversal of cell death upon treatment with the ferroptosis inhibitor, ferrostatin-1. Heteronemin treatment led to a marked increase in ferroptosis markers and malondialdehyde (MDA) levels. Conversely, the expression of glutathione peroxidase-4 (GPX4), a key anti-ferroptotic protein, was suppressed. Furthermore, significant modulations in the expression of ferritinophagy- and iron-related proteins such as Atg5, Atg7, FTL, STEAP3, and DMT-1 were evident post-treatment (p < 0.05). This study underscores the potential of heteronemin as a ferroptosis inducer in pancreatic cancer cells. Given its robust cytotoxicity, heteronemin emerges as a promising lead compound for further exploration in cancer therapeutics.

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.

Terpenes extracted from marine sponges with antioxidant activity: a systematic review

Marine biodiversity has emerged as a very promising resource of bioactive compounds and secondary metabolites from different sea organisms. The sponge's secondary metabolites demonstrated various bioactivities and potential pharmacological properties. This systematic review of the literature focuses on the advances achieved in the antioxidant potential of marine sponges in vitro. The review was performed in accordance with PRISMA guidelines. The main inclusion criterion for analysis was articles with identification of compounds from terpene classes that demonstrate antioxidant activity in vitro. Searching in three different databases, two hundred articles were selected. After screening abstracts, titles and evaluating for eligibility of manuscripts 14 articles were included. The most performed analyzes to detect antioxidant activity were scavenging activity 2,2-diphenyl-1-picrylhydrazyl (DPPH) and measurement of intracellular reactive oxygen species (ROS). It was possible to identify 17 compounds of the terpene class with pronounced antioxidant activity in vitro. Scientific evidence of the studies included in this review was accessed by the GRADE analysis. Terpenes play an important ecological role, moreover these molecules have a pharmaceutical and industrial application.

Potential candidates from marine and terrestrial resources targeting mitochondrial inhibition: Insights from the molecular approach

Mitochondria are the target sites for multiple disease manifestations, for which it is appealing to researchers' attention for advanced pharmacological interventions. Mitochondrial inhibitors from natural sources are of therapeutic interest due to their promising benefits on physiological complications. Mitochondrial complexes I, II, III, IV, and V are the most common sites for the induction of inhibition by drug candidates, henceforth alleviating the manifestations, prevalence, as well as severity of diseases. Though there are few therapeutic options currently available on the market. However, it is crucial to develop new candidates from natural resources, as mitochondria-targeting abnormalities are rising to a greater extent. Marine and terrestrial sources possess plenty of bioactive compounds that are appeared to be effective in this regard. Ample research investigations have been performed to appraise the potentiality of these compounds in terms of mitochondrial disorders. So, this review outlines the role of terrestrial and marine-derived compounds in mitochondrial inhibition as well as their clinical status too. Additionally, mitochondrial regulation and, therefore, the significance of mitochondrial inhibition by terrestrial and marine-derived compounds in drug discovery are also discussed.

Heteronemin and Tetrac Induce Anti-Proliferation by Blocking EGFR-Mediated Signaling in Colorectal Cancer Cells

Overexpressed EGFR and mutant K-Ras play vital roles in therapeutic resistance in colorectal cancer patients. To search for an effective therapeutic protocol is an urgent task. A secondary metabolite in the sponge Hippospongia sp., Heteronemin, has been shown to induce anti-proliferation in several types of cancers. A thyroxine-deaminated analogue, tetrac, binds to integrin αvβ3 to induce anti-proliferation in different cancers. Heteronemin- and in combination with tetrac-induced antiproliferative effects were evaluated. Tetrac enhanced heteronemin-induced anti-proliferation in HT-29 cells (KRAS WT CRC) and HCT-116 cells (KRAS MT CRC). Heteronemin and tetrac arrested cell cycle in different phases. Combined treatment increased the cell accumulation in sub-G1 and S phases. The combined treatment also induced the inactivation of EGFR signaling and downregulated the phosphorylated ERK1/2 protein in both cell lines. Heteronemin and the combination showed the downregulation of the phosphorylated and total PI3K protein in HT-29 cells (KRAS WT CRC). Results by NanoString technology and RT-qPCR revealed that heteronemin and combined treatment suppressed the expression of EGFR and downstream genes in HCT-116 cells (KRAS MT CRC). Heteronemin or combined treatment downregulated genes associated with cancer progression and decreased cell motility. Heteronemin or the combined treatment suppressed PD-L1 expression in both cancer cell lines. However, only tetrac and the combined treatment inhibited PD-L1 protein accumulation in HT-29 cells (KRAS WT CRC) and HCT-116 cells (KRAS MT CRC), respectively. In summary, heteronemin induced anti-proliferation in colorectal cancer cells by blocking the EGFR-dependent signal transduction pathway. The combined treatment further enhanced the anti-proliferative effect via PD-L1 suppression. It can be an alternative strategy to suppress mutant KRAS resistance for anti-EGFR therapy.

The power of heteronemin in cancers

Heteronemin (Haimian jing) is a sesterterpenoid-type natural marine product that is isolated from sponges and has anticancer properties. It inhibits cancer cell proliferation via different mechanisms, such as reactive oxygen species (ROS) production, cell cycle arrest, apoptosis as well as proliferative gene changes in various types of cancers. Recently, the novel structure and bioactivity evaluation of heteronemin has received extensive attention. Hormones control physiological activities regularly, however, they may also affect several abnormalities such as cancer. L-Thyroxine (T₄), steroid hormones, and epidermal growth factor (EGF) up-regulate the accumulation of checkpoint programmed death-ligand 1 (PD-L1) and promote inflammation in cancer cells. Heteronemin suppresses PD-L1 expression and reduces the PD-L1-induced proliferative effect. In the current review, we evaluated research and evidence regarding the antitumor effects of heteronemin and the antagonizing effects of non-peptide hormones and growth factors on heteronemin-induced anti-cancer properties and utilized computational molecular modeling to explain how these ligands interacted with the integrin αvβ3 receptors. On the other hand, thyroid hormone deaminated analogue, tetraiodothyroacetic acid (tetrac), modulates signal pathways and inhibits cancer growth and metastasis. The combination of heteronemin and tetrac derivatives has been demonstrated to compensate for anti-proliferation in cancer cells under different circumstances. Overall, this review outlines the potential of heteronemin in managing different types of cancers that may lead to its clinical development as an anticancer agent.

Heteronemin and tetrac derivatives suppress non-small cell lung cancer growth via ERK1/2 inhibition

The most common cancer, lung cancer, causes deaths worldwide. Most lung cancer patients have non-small cell lung carcinomas (NSCLCs) with a poor prognosis. The chemotherapies frequently cause resistance therefore search for new effective drugs for NSCLC patients is an urgent and essential issue. Deaminated thyroxine, tetraiodothyroacetic acid (tetrac), and its nano-analogue (NDAT) exhibit antiproliferative properties in several types of cancers. On the other hand, the most abundant secondary metabolite in the sponge Hippospongia sp., heteronemin, shows effective cytotoxic activity against different types of cancer cells. In the current study, we investigated the anticancer effects of heteronemin against two NSCLC cell lines, A549 and H1299 cells in vitro. Combined treatment with heteronemin and tetrac derivatives synergistically inhibited cancer cell growth and significantly modulated the ERK1/2 and STAT3 pathways in A549 cells but only ERK1/2 in H1299 cells. The combination treatments induce apoptosis via the caspases pathway in A549 cells but promote cell cycle arrest via CCND1 and PCNA inhibition in H1299 cells. In summary, these results suggest that combined treatment with heteronemin and tetrac derivatives could suppress signal transduction pathways essential for NSCLC cell growth. The synergetic effects can be used potentially as a therapeutic procedure for NSCLC patients.

Potential Approaches Versus Approved or Developing Chronic Myeloid Leukemia Therapy

Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of patients with chronic myeloid leukemia (CML). However, continued use of these inhibitors has contributed to the increase in clinical resistance and the persistence of resistant leukemic stem cells (LSCs). So, there is an urgent need to introduce additional targeted and selective therapies to eradicate quiescent LSCs, and to avoid the relapse and disease progression. Here, we focused on emerging BCR-ABL targeted and non-BCR-ABL targeted drugs employed in clinical trials and on alternative CML treatments, including antioxidants, oncolytic virus, engineered exosomes, and natural products obtained from marine organisms that could pave the way for new therapeutic approaches for CML patients.

Heteronemin Suppresses Lymphangiogenesis through ARF-1 and MMP-9/VE-Cadherin/Vimentin

Lymphatic metastasis is a biological procedure associated with the pathogenesis of several diseases, especially in tumor metastasis. Therefore, regulation of lymphangiogenesis has become a promising strategy for cancer therapy. In this study, we aimed to investigate the anti-lymphangiogenic effect of heteronemin (SP-1) isolated from the sponge Hyrtios sp. in vitro and in vivo. Human lymphatic endothelial cells (LECs) were utilized to evaluate the anti-lymphangiogenic effect of SP-1 in vitro. Molecular docking, western blotting, flow-cytometry, MTT and ELISA were performed to investigate the mechanism of action. For in vivo approaches, the transgenic (fli1:EGFP; gata1:DsRed) zebrafish and mouse ear sponges were used. Molecular docking studies showed that SP-1 is a potent vascular endothelial growth factor receptor 3 (VEGFR-3)-binding compound. Treatment of LEC with SP-1 reduced the phosphorylation of VEGFR-3. SP-1 suppressed the development of the thoracic duct in zebrafish and mouse lymphangiogenesis ear sponges in vivo. Mechanistically, SP-1 induced the cell cycle arrest of LECs in the G0/G1 phase and reduced the downstream of VEGFR-3, such as phosphorylated MEK/ERK and NF-κB. In addition, SP-1 inhibited LECs' tubulogenesis and migration through the ARF-1 and MMP-9/VE-cadherin/vimentin. Overall, anti-lymphangiogenic properties of SP-1 occur by downregulating the VEGFR-3 cascade, ARF-1 and MMP-9/VE-cadherin/vimentin. Collectively, these results proposed that SP-1 might be a potential candidate for the treatment of lymphangiogenesis-associated diseases.

Natural Products from Tongan Marine Organisms

The islands of the South Pacific Ocean have been in the limelight for natural product biodiscovery, due to their unique and pristine tropical waters and environment. The Kingdom of Tonga is an archipelago in the central Indo-Pacific Ocean, consisting of 176 islands, 36 of which are inhabited, flourishing with a rich diversity of flora and fauna. Many unique natural products with interesting bioactivities have been reported from Indo-Pacific marine sponges and other invertebrate phyla; however, there have not been any reviews published to date specifically regarding natural products from Tongan marine organisms. This review covers both known and new/novel Marine Natural Products (MNPs) and their biological activities reported from organisms collected within Tongan territorial waters up to December 2020, and includes 109 MNPs in total, the majority from the phylum Porifera. The significant biological activity of these metabolites was dominated by cytotoxicity and, by reviewing these natural products, it is apparent that the bulk of the new and interesting biologically active compounds were from organisms collected from one particular island, emphasizing the geographic variability in the chemistry between these organisms collected at different locations.

Effect of Estrogen on Heteronemin-Induced Anti-proliferative Effect in Breast Cancer Cells With Different Estrogen Receptor Status

Estrogen (E₂) has multiple functions in breast cancers including stimulating cancer growth and interfering with chemotherapeutic efficacy. Heteronemin, a marine sesterterpenoid-type natural product, has cytotoxicity on cancer cells. Breast cancer cell lines, MCF-7 and MDA-MB-231, were used for investigating mechanisms involved in inhibitory effect of E₂ on heteronemin-induced anti-proliferation in breast cancer cells with different estrogen receptor (ER) status. Cytotoxicity was detected by cell proliferation assay and flow cytometry, gene expressions were determined by qPCR, mechanisms were investigated by Western blot and Mitochondrial ROS assay. Heteronemin exhibited potent cytotoxic effects against both ER-positive and ER-negative breast cancer cells. E₂ stimulated cell growth in ER-positive breast cancer cells. Heteronemin induced anti-proliferation via suppressing activation of ERK1/2 and STAT3. Heteronemin suppressed E₂-induced proliferation in both breast cancer cells although some gene expressions and anti-proliferative effects were inhibited in the presence of E₂ in MCF-7 and MDA-MB-231 cells with a higher concentration of heteronemin. Heteromenin decreased the Bcl-2/Bax ratio to inhibit proliferation in MDA-MB-231 but not in MCF-7 cells. Both heteronemin and E₂ increased mitochondrial reactive oxygen species but combined treatment reversed superoxide dismutase (SOD)s accumulation in MCF-7 cells. Heteronemin caused G₀/G₁ phase arrest and reduced the percentage of cells in the S phase to suppress cancer cell growth. In conclusion, Heteronemin suppressed both ER-positive and ER-negative breast cancer cell proliferation. Interactions between E₂ and heteronemin in signal transduction, gene expressions, and biological activities provide insights into the complex pathways by which anti-proliferation is induced by heteronemin in E₂-replete environments.

Oxidative stress in leukemia and antioxidant treatment

Oxidative stress is caused by the imbalance between the generation of free radicals/reactive oxygen species (ROS) and the antioxidant defense systems, which can activate various transcription factors and affect their transcriptional pathways. Oxidative stress plays an important role in the occurrence and development of leukemia and is closely related to the treatment and prognosis of leukemia. The standard chemotherapy strategies for the pre-treatment of leukemia have many drawbacks. Hence, the usage of antioxidants and oxidants in the treatment of leukemia is being explored and has been preliminarily applied. This article reviews the research progress of oxidative stress and leukemia. In addition, the application of antioxidants treatment in leukemia has been summarized.

Promising Activities of Marine Natural Products against Hematopoietic Malignancies

According to the WHO classification of tumors, more than 150 typologies of hematopoietic and lymphoid tumors exist, and most of them remain incurable diseases that require innovative approaches to improve therapeutic outcome and avoid side effects. Marine organisms represent a reservoir of novel bioactive metabolites, but they are still less studied compared to their terrestrial counterparts. This review is focused on marine natural products with anticancer activity against hematological tumors, highlighting recent advances and possible perspectives. Until now, there are five commercially available marine-derived compounds for the treatment of various hematopoietic cancers (e.g., leukemia and lymphoma), two molecules in clinical trials, and series of compounds and/or extracts from marine micro- and macroorganisms which have shown promising properties. In addition, the mechanisms of action of several active compounds and extracts are still unknown and require further study. The continuous upgrading of omics technologies has also allowed identifying enzymes with possible bioactivity (e.g., l-asparaginase is currently used for the treatment of leukemia) or the enzymes involved in the synthesis of bioactive secondary metabolites which can be the target of heterologous expression and genetic engineering.

A Marine Terpenoid, Heteronemin, Induces Both the Apoptosis and Ferroptosis of Hepatocellular Carcinoma Cells and Involves the ROS and MAPK Pathways

Hepatocellular carcinoma (HCC) is a leading cause of death, resulting in over 700 thousand deaths annually worldwide. Chemotherapy is the primary therapeutic strategy for patients with late-stage HCC. Heteronemin is a marine natural product isolated from Hippospongia sp. that has been found to protect against carcinogenesis in cholangiocarcinoma, prostate cancer, and acute myeloid leukemia. In this study, heteronemin was found to inhibit the proliferation of the HCC cell lines HA22T and HA59T and induce apoptosis via the caspase pathway. Heteronemin treatment also induced the formation of reactive oxygen species (ROS), which are associated with heteronemin-induced cell death, and to trigger ROS removal by mitochondrial SOD2 rather than cytosolic SOD1. The mitogen-activated protein kinase (MAPK) signaling pathway was associated with ROS-induced cell death, and heteronemin downregulated the expression of ERK, a MAPK that is associated with cell proliferation. Inhibitors of JNK and p38, which are MAPKs associated with apoptosis, restored heteronemin-induced cell death. In addition, heteronemin treatment reduced the expression of GPX4, a protein that inhibits ferroptosis, which is a novel form of nonapoptotic programmed cell death. Ferroptosis inhibitor treatment also restored heteronemin-induced cell death. Thus, with appropriate structural modification, heteronemin can act as a potent therapeutic against HCC.

Natural Products Targeting the Mitochondria in Cancers

There are abundant sources of anticancer drugs in nature that have a broad prospect in anticancer drug discovery. Natural compounds, with biological activities extracted from plants and marine and microbial metabolites, have significant antitumor effects, but their mechanisms are various. In addition to providing energy to cells, mitochondria are involved in processes, such as cell differentiation, cell signaling, and cell apoptosis, and they have the ability to regulate cell growth and cell cycle. Summing up recent data on how natural products regulate mitochondria is valuable for the development of anticancer drugs. This review focuses on natural products that have shown antitumor effects via regulating mitochondria. The search was done in PubMed, Web of Science, and Google Scholar databases, over a 5-year period, between 2015 and 2020, with a keyword search that focused on natural products, natural compounds, phytomedicine, Chinese medicine, antitumor, and mitochondria. Many natural products have been studied to have antitumor effects on different cells and can be further processed into useful drugs to treat cancer. In the process of searching for valuable new drugs, natural products such as terpenoids, flavonoids, saponins, alkaloids, coumarins, and quinones cover the broad space.

13-Acetoxysarcocrassolide Exhibits Cytotoxic Activity Against Oral Cancer Cells Through the Interruption of the Keap1/Nrf2/p62/SQSTM1 Pathway: The Need to Move Beyond Classical Concepts

13-Acetoxysarcocrassolide (13-AC), a marine cytotoxic product isolated from the alcyonacean coral Lobophytum crassum, exhibited potent antitumor and immunostimulant effects as reported in previous studies. However, the 13-AC antitumor mechanism of action against oral cancer cells remains unclear. The activity of 13-AC against Ca9-22 cancer cells was determined using MTT assay, flow cytometric analysis, immunofluorescence, immunoprecipitation, Western blotting, and siRNA. 13-AC induced apoptosis in oral cancer cells Ca9-22 through the disruption of mitochondrial membrane potential (MMP) and the stimulation of reactive oxygen species (ROS) generation. It increased the expression of apoptosis- and DNA damage-related proteins in a concentration- and time-dependent manner. It exerted potent antitumor effect against oral cancer cells, as demonstrated by the in vivo xenograft animal model. It significantly reduced the tumor volume (55.29%) and tumor weight (90.33%). The pretreatment of Ca9-22 cells with N-acetylcysteine (NAC) inhibited ROS production resulting in the attenuation of the cytotoxic activity of 13-AC. The induction of the Keap1-Nrf2 pathway and the promotion of p62/SQSTM1 were observed in Ca9-22 cells treated with 13-AC. The knockdown of p62 expression by siRNA transfection significantly attenuated the effect of 13-AC on the inhibition of cell viability. Our results indicate that 13-AC exerted its cytotoxic activity through the promotion of ROS generation and the suppression of the antioxidant enzyme activity. The apoptotic effect of 13-AC was found to be mediated through the interruption of the Keap1/Nrf2/p62/SQSTM1 pathway, suggesting its potential future application as an anticancer agent.

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.

Low Concentration of Withaferin a Inhibits Oxidative Stress-Mediated Migration and Invasion in Oral Cancer Cells

Withaferin A (WFA) has been reported to inhibit cancer cell proliferation based on high cytotoxic concentrations. However, the low cytotoxic effect of WFA in regulating cancer cell migration is rarely investigated. The purpose of this study is to investigate the changes in migration and mechanisms of oral cancer Ca9-22 cells after low concentrations of WFA treatment. WFA under 0.5 μM at 24 h treatment shows no cytotoxicity to oral cancer Ca9-22 cells (~95% viability). Under this condition, WFA triggers reactive oxygen species (ROS) production and inhibits 2D (wound healing) and 3D cell migration (transwell) and Matrigel invasion. Mechanically, WFA inhibits matrix metalloproteinase (MMP)-2 and MMP-9 activities but induces mRNA expression for a group of antioxidant genes, such as nuclear factor, erythroid 2-like 2 (NFE2L2), heme oxygenase 1 (HMOX1), glutathione-disulfide reductase (GSR), and NAD(P)H quinone dehydrogenase 1 (NQO1)) in Ca9-22 cells. Moreover, WFA induces mild phosphorylation of the mitogen-activated protein kinase (MAPK) family, including extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 expression. All WFA-induced changes were suppressed by the presence of ROS scavenger N-acetylcysteine (NAC). Therefore, these results suggest that low concentration of WFA retains potent ROS-mediated anti-migration and -invasion abilities for oral cancer cells.

Marine Natural Products with High Anticancer Activities

This review covers recent literature from 2012-2019 concerning 170 marine natural products and their semisynthetic analogues with strong anticancer biological activities. Reports that shed light on cellular and molecular mechanisms and biological functions of these compounds, thus advancing the understanding in cancer biology are also included. Biosynthetic studies and total syntheses, which have provided access to derivatives and have contributed to the proper structure or stereochemistry elucidation or revision are mentioned. The natural compounds isolated from marine organisms are divided into nine groups, namely: alkaloids, sterols and steroids, glycosides, terpenes and terpenoids, macrolides, polypeptides, quinones, phenols and polyphenols, and miscellaneous products. An emphasis is placed on several drugs originating from marine natural products that have already been marketed or are currently in clinical trials.

Sulfonyl chromen-4-ones (CHW09) shows an additive effect to inhibit cell growth of X-ray irradiated oral cancer cells, involving apoptosis and ROS generation

Purpose: This study evaluates the growth inhibiting potential of our previously described sulfonyl chromen-4-ones (CHW09) compound in X-ray irradiated oral cancer cells. Materials and methods: The growth inhibiting effect and mechanism of combined CHW09/X-ray treatment was examined by analyzing cell viability, cell cycle, apoptosis, reactive oxygen species (ROS), and DNA damage. Results: Individual treatments of CHW09 (10 μg/mL) and X-ray irradiation (12 Gy) slightly decreased cell viability of oral cancer Ca9-22 (87.25% and 86.54%) and CAL 27 (80.00% and 74.01%) cells and normal oral HGF-1 cells (92.76% and 87.56%) at 24 h-MTS assay, respectively. In a combined treatment (CHW09/X-ray), the cell viability in Ca9-22 and CAL 27 cells was significantly decreased to 73.48% and 59.07%, whereas HGF-1 cells maintained 84.97% viability in 24 h-MTS assay. For CAL 27 cells, both 72 h-MTS assay and clonogenic assay showed that CHW09/X-ray resulted in more growth inhibition than other treatments. Intracellular ROS levels of CHW09/X-ray were higher than for CHW09, X-ray and control. CHW09/X-ray and X-ray alone had higher G2/M arrest than the control and CHW09 alone. Moreover, flow cytometry and western blotting showed that CHW09/X-ray treatment caused higher apoptosis levels. Levels of H2A histone family member X (γH2AX)-based DNA damage and 8-oxo-2'-deoxyguanosine (8-oxodG)-oxidative DNA damage of CHW09/X-ray were higher than for CHW09, X-ray and control. Conclusion: CHW09/X-ray treatment had additive growth inhibiting effects against X-ray irradiated oral cancer cells, partly attributing to apoptosis and ROS generation.

BA6 Induces Apoptosis via Stimulation of Reactive Oxygen Species and Inhibition of Oxidative Phosphorylation in Human Lung Cancer Cells

Lung cancer is the leading cause of cancer deaths in the world, with a five-year survival rate of less than 30%. Clinically effective chemotherapeutic treatments at the initial stage may eventually face the dilemma of no drug being effective due to drug resistance; therefore, finding new effective drugs for lung cancer treatment is a necessary and important issue. Compounds capable of further increasing the oxidative stress of cancer cells are considered to have anticancer potential because they possessed the ability to induce apoptosis. This study mainly investigated the effects of BA6 (heteronemin), the marine sponge sesterterpene, on lung cancer cell apoptosis, via modulation of mitochondrial reactive oxygen species (mtROS) and oxidative phosphorylation (OXPHOS). BA6 has cellular cytotoxic activities against a variety of cancer cell lines, but it has no effect on nontumor cells. The BA6-treated lung cancer cells show a significant increase in both cellular ROS and mtROS, which in turn caused the loss of mitochondrial membrane potential (MMP). The increase of oxidative stress in lung cancer cells treated with BA6 was accompanied by a decrease in the expression of antioxidant enzymes Cu/Zn SOD, MnSOD, and catalase. In addition, OXPHOS performed in the mitochondria and glycolysis in the cytoplasm were inhibited, which subsequently reduced downstream ATP production. Pretreatment with mitochondria-targeted antioxidant MitoTEMPO reduced BA6-induced apoptosis through the mitochondria-dependent apoptotic pathway, which was accompanied by increased cell viability, decreased mtROS, enhanced MMP, and suppressed expression of cleaved caspase-3 and caspase-9 proteins. In conclusion, the results of this study clarify the mechanism of BA6-induced apoptosis in lung cancer cells via the mitochondrial apoptotic pathway, suggesting that it is a potentially innovative alternative to the treatment of human lung cancer.

The Antioxidant from Ethanolic Extract of Rosa cymosa Fruits Activates Phosphatase and Tensin Homolog In Vitro and In Vivo: A New Insight on Its Antileukemic Effect

Rosa cymosa Tratt is a Chinese herbal remedy that is used in the treatment of diarrhea, burns, rheumatoid arthritis, and hemorrhage. Despite its use in Asian folk medicine, there are limited reports on the biological activity of R. cymosa fruits. This study focused on the investigation of the antitumor effect of the antioxidative ethanolic extract of R. cymosa fruits (RCE) along with its underlying mechanism of action. RCE showed a potent cytotoxic effect against Sup-T1 and Molt-4 lymphoblastic leukemia cells. In the xenograft animal model, the tumor size was significantly reduced to about 59.42% in the RCE-treated group in comparison with the control group. The use of RCE (37.5, 75, or 150 μg/mL) triggered apoptosis by 26.52–83.49%, disrupted mitochondrial membrane potential (MMP) by 10.44–58.60%, and promoted calcium release by 1.29-, 1.44-, and 1.71-fold compared with the control group. The extract induced redox oxygen species (ROS) generation through the elimination of Nrf2/Keap1/P62-mediated oxidative stress response. The loss of phosphatase and tensin homolog (PTEN) activation by RCE impaired PI3K/Akt/Foxo and Jak/Stat activation pathways, which contributed to tumorigenesis. These multiple targets of R. cymosa against hematologic cancer cells suggested its potential application as an antileukemic dietary supplement.

Antrodia cinnamomea, a Treasured Medicinal Mushroom, Induces Growth Arrest in Breast Cancer Cells, T47D Cells: New Mechanisms Emerge

Reported cases of breast cancer have skyrocketed in the last decades with recent advances in examination techniques. Brest cancer has become the second leading cause of mortality among women worldwide, urging the scientific community to develop or find new drugs from natural sources with potent activity and a reasonable safety profile to tackle this ailment. Antrodia cinnamomea (AC) is a treasured medicinal fungus which has attracted attention due to its potent hepatoprotective and cytotoxic activities. We evaluated the antiproliferative activity of the ethanol extract of artificially cultured AC (EEAC) on breast cancer cells (T47D cells) in vivo and in vitro. Ethanol extract of artificially cultured AC inhibited T47D cells' proliferation mediated by cell cycle arrest at G1 phase as well induced autophagy. Immunoblotting assay confirmed that EEAC not only decreased the expression of the cell-cycle-related proteins but also increased the expression of transcription factor FOXO1, autophagic marker LC3 II, and p62. Ethanol extract of artificially cultured AC mediated endoplasmic reticulum stress by promoting the expression of IRE1 (inositol-requiring enzyme 1α), GRP78/Bip (glucose regulating protein 78), and CHOP (C/EBP homologous protein). Apart from previous studies, HDACs (histone deacetylases) activity was inhibited as demonstrated by a cell-free system, immunoblotting, and immunofluorescence assays following EEAC treatment. The in vivo studies demonstrated that EEAC decreased tumor volume and inhibited tumor growth without any significant side effects. High performance liquid chromatography profile demonstrated similar triterpenoids compared to the profile of wild AC ethanol extract. The multiple targets of EEAC on breast cancer cells suggested that this extract may be developed as a potential dietary supplement targeting this debilitating disease.

Heteronemin Induces Anti-Proliferation in Cholangiocarcinoma Cells via Inhibiting TGF-β Pathway

A marine sesterterpenoid-type natural product, heteronemin, retains anticancer effects. In the current study, we investigate the antitumor mechanism of heteronemin in cholangiocarcinoma cells and further explore its molecular targets. Initially, heteronemin exhibited potent cytotoxic effects against cholangiocarcinoma HuccT1 and SSP-25 cells. In vitro, heteronemin altered the abilities of cell adhesion and cell migration in HuccT1 and SSP-25 cell lines. It repressed messenger ribonucleic acid (mRNA) expression levels of transforming growth factor (TGF)-β, mothers against decapentaplegic homolog (SMAD) and Myc, whose protein products play important roles in regulating cell growth, angiogenesis, and metastasis. In addition, heteronemin altered several signaling pathways. The results indicate that heteronemin was able to modulate cell adhesion, the expression of extracellular matrix (ECM) receptors, the TGF-β pathway, cell motility, the membrane integration, metastasis response, matrix metalloproteinase (MMP) remodeling, the regulation of metabolism, sprouting angiogenesis, transcription factors, and vasculogenesis in cholangiocarcinoma cell lines. The results also suggest that it activated multiple signal transduction pathways to induce an anti-proliferation effect and anti-metastasis in cholangiocarcinoma. In conclusion, heteronemin may be used as a potential medicine for anticancer therapy.