Is MAC the knife that cuts cytochrome c from mitochondria during apoptosis?

Design and anticancer behaviour of cationic/neutral half-sandwich iridium(III) imidazole-phenanthroline/phenanthrene complexes

Considerable attention has been devoted to the exploration of organometallic iridium(III) (IrIII) complexes for their potential as metallic anticancer drugs. In this study, twelve half-sandwich IrIII imidazole-phenanthroline/phenanthrene complexes were prepared and characterized. Complexes exhibited promising in-vitro anti-proliferative activity, and some are obviously superior to cisplatin towards A549 cells. These complexes possessed suitable fluorescence, and a non-energy-dependent uptake pathway was identified, subsequently leading to their accumulation in the lysosome and the lysosomal damage. Additionally, complexes could inhibit the cell cycle (G1-phase) and catalyze intracellular NADH oxidation, thus substantiating the elevation of intracellular reactive oxygen species (ROS) level, which confirming the oxidative mechanism. Western blotting further confirmed that complexes could induce A549 cell apoptosis through the lysosomal-mitochondrial anticancer pathway, which was inconsistent with cisplatin. In summary, these complexes offer fresh concepts for the development of organometallic non‑platinum anticancer drugs.

The anticancer application of half-sandwich iridium(III) ferrocene-thiosemicarbazide Schiff base complexes

Ferrocenyl derivatives and organometallic iridium(III) complexes have been prospective substitutes for platinum-based anticancer drugs. Eight half-sandwich iridium(III) ferrocene-thiosemicarbazide (Fc-TSC) Schiff base anticancer complexes were prepared in this study. These complexes displayed a dimeric structure and exhibited a particular fluorescence due to the "enol" orientation of the TSC pro-ligand. An energy-dependent pathway of the uptake mechanism was ascertained, which ended in the lysosome and led to lysosome damage and apoptosis. Flow cytometry confirmed that the complexes could block the cell cycle (G1 phase) and improve the levels of intracellular reactive oxygen species, indicating an anticancer mechanism of oxidation. Then, a lysosomal-mitochondrial anticancer pathway was verified through western blotting. In vivo toxicity assays confirmed that these complexes showed better anti-migration ability and less toxicity in comparison to cisplatin. Thus, these complexes provide a new strategy for the design of non-platinum organometallic anticancer drugs.

Senolytic and senomorphic interventions to defy senescence-associated mitochondrial dysfunction

The accumulation of senescent cells in the aging individual is associated with an increase in the occurrence of age-associated pathologies that contribute to poor health, frailty, and mortality. The number and type of senescent cells is viewed as a contributor to the body's senescence burden. Cellular models of senescence are based on induction of senescence in cultured cells in the laboratory. One type of senescence is triggered by mitochondrial dysfunction. There are several indications that mitochondria defects contribute to body aging. Senotherapeutics, targeting senescent cells, have been shown to induce their lysis by means of senolytics, or repress expression of their secretome, by means of senomorphics, senostatics or gerosuppressors. An outline of the mechanism of action of various senotherapeutics targeting mitochondria and senescence-associated mitochondria dysfunction will be here addressed. The combination of geroprotective interventions together with senotherapeutics will help to strengthen mitochondrial energy metabolism, biogenesis and turnover, and lengthen the mitochondria healthspan, minimizing one of several molecular pathways contributing to the aging phenotype.

Cytotoxicity of the methanol extracts and compounds of Brucea antidysenterica (Simaroubaceae) towards multifactorial drug-resistant human cancer cell lines

BACKGROUND

Cancer remains a global health concern and constitutes an important barrier to increasing life expectancy. Malignant cells rapidly develop drug resistance leading to many clinical therapeutic failures. The importance of medicinal plants as an alternative to classical drug discovery to fight cancer is well known. Brucea antidysenterica is an African medicinal plant traditionally used to treat cancer, dysentery, malaria, diarrhea, stomach aches, helminthic infections, fever, and asthma. The present work was designed to identify the cytotoxic constituents of Brucea antidysenterica on a broad range of cancer cell lines and to demonstrate the mode of induction of apoptosis of the most active samples.

METHODS

Seven phytochemicals were isolated from the leaves (BAL) and stem (BAS) extract of Brucea antidysenterica by column chromatography and structurally elucidated using spectroscopic techniques. The antiproliferative effects of the crude extracts and compounds against 9 human cancer cell lines were evaluated by the resazurin reduction assay (RRA). The activity in cell lines was assessed by the Caspase-Glo assay. The cell cycle distribution, apoptosis via propidium iodide (PI) staining, mitochondrial membrane potential (MMP) through 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) staining, and the reactive oxygen species (ROS) via 2´,7´-dichlorodihydrofluoresceine diacetate (H2DCFH-DA) staining, were investigated by flow cytometry.

RESULTS

Phytochemical studies of the botanicals (BAL and BAS) led to the isolation of seven compounds. BAL and its constituents 3, (3-(3-Methyl-1-oxo-2-butenyl))1H indole (1) and hydnocarpin (2), as well as the reference compound, doxorubicin, had antiproliferative activity against 9 cancer cell lines. The IC₅₀ values varied from 17.42 µg/mL (against CCRF-CEM leukemia cells) to 38.70 µg/mL (against HCT116 p53^-/- colon adenocarcinoma cells) for BAL, from 19.11 µM (against CCRF-CEM cells) to 47.50 µM (against MDA-MB-231-BCRP adenocarcinoma cells) for compound 1, and from 4.07 µM (against MDA-MB-231-pcDNA cells) to 11.44 µM (against HCT116 p53^+/+ cells) for compound 2. Interestingly, hypersensitivity of resistant cancer cells to compound 2 was also observed. BAL and hydnocarpin induced apoptosis in CCRF-CEM cells mediated by caspase activation, the alteration of MMP, and increased ROS levels.

CONCLUSION

BAL and its constituents, mostly compound 2, are potential antiproliferative products from Brucea antidysenterica. Other studies will be necessary in the perspective of the discovery of new antiproliferative agents to fight against resistance to anticancer drugs.

M, K M, Dey T, Zargar MI, Singh J. Recent advance of herbal medicines in cancer- a molecular approach

Bioactive compounds are crucial for an extensive range of therapeutic uses, and some exhibit anticancer activity. Scientists advocate that phytochemicals modulate autophagy and apoptosis, involved in the underlying pathobiology of cancer development and regulation. The pharmacological aiming of the autophagy-apoptosis signaling pathway using phytocompounds hence offers an auspicious method that is complementary to conventional cancer chemotherapy. The current review aims to explore the molecular level of the autophagic-apoptotic pathway to know its implication in the pathobiology of cancer and explore the essential cellular process as a druggable anticancer target and therapeutic emergence of naturally derived phytocompound-based anticancer agents. The data in the review were collected from scientific databases such as Google search, Web of Science, PubMed, Scopus, Medline, and Clinical Trials. With a broad outlook, we investigated their cutting-edge scientifically revealed and/or searched pharmacologic effects, a novel mechanism of action, and molecular signaling pathway of phytochemicals in cancer therapy. In this review, the evidence is focused on molecular pharmacology, specifically caspase, Nrf2, NF-kB, autophagic-apoptotic pathway, and several mechanisms to understand their role in cancer biology.

Taurine Ameliorates Iron Overload-Induced Hepatocyte Injury via the Bcl-2/VDAC1-Mediated Mitochondrial Apoptosis Pathway

Iron overload can induce reactive oxygen species (ROS) burst and liver damage. Taurine can reduce ROS production and ameliorate liver injury caused by iron overload; however, the underlying molecular mechanism remains elusive. Herein, L02 cells treated with 120 μM iron dextran for 48 h showed marked oxidative stress damage and significantly increased apoptosis. Taurine protected hepatocytes by stabilizing mitochondrial membranes and resisting oxidative stress damage caused by iron overload. However, transfection with siRNA Bcl-2 virus abrogated the observed protective effects. Following treatment with taurine, B cell lymphoma-2 (Bcl-2) could inhibit the opening of the mitochondrial permeability transition pore (mPTP), subsequently stabilizing the mitochondrial membrane potential by interacting with voltage-dependent anion channel 1 (VDAC1) of mPTP. The present study is the first to clarify the mechanism underlying taurine-afforded hepatocyte protection against iron overload-induced oxidative stress via Bcl-2-mediated inhibition of mPTP opening and the antiapoptotic pathway.

Bioactivity of fractions and constituents of Piper capense fruits towards a broad panel of cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Piper capense is a medicinal spice whose fruits are traditionally used as aqueous decoction to heal several ailments such as trypanosomiasis, helminthic infections, and cancer.

AIM OF THE STUDY

(1) To perform phytochemical investigation of the methanol extract of Piper capense; (2) to evaluate the cytotoxicity of botanicals (PCF, fractions PCFa-e), isolated phytochemicals on a broad panel of animal and human cancer cell lines; (3) to evaluate the induction of apoptosis of the most active samples.

MATERIAL AND METHODS

Resazurin reduction assay (RRA) was used to determine the cytotoxicity of the studied samples. Cell cycle distribution (PI staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP; JC-1) and reactive oxygen species (ROS; H₂DCFH-DA) were measured by flow cytometry. Column chromatography (CC) was used for the purification of PCF, whilst nuclear magnetic resonance (NMR) spectroscopic and mass spectrometric (MS) analyses were applied for structural elucidation.

RESULTS

The phytochemical investigation of PCF led to the isolation of 11 compounds: licarin B (1), licarin A (2), 7-(1,3-benzodioxol-5-yl)-7,8-dihydro-8-methyl-5-(2-propenyl)-furo[3,2-e]-1,3-benzodioxole (3), nitidine isocyanate (4), 5-hydroxy-7,4'-dimethoxyflavone (5), cardamomin (6), sitosterol (7) and stigmasterol (8), β-sitosterol 3-O-β-_D-glucopyranoside (9), oleanolic acid (10) and lupeol (11). Fraction PCFb, compound 2 and doxorubicin (as positive control drug) revealed cytotoxic effects towards the 18 tested cancer cell lines. The IC₅₀ values ranged from 6.1 μg/mL (against CCRF-CEM cells) to 44.2 μg/mL (against BRAF-V600E homozygous mutant melanoma cells) for PSCb; from 4.3 μM (against CCRF-CEM cells) to 21.8 μM (against HCT116 p53^-/-) for compound 2 and from 0.02 μM (against CCRF-CEM cells) to 123.0 μM (against CEM/ADR5000 cells) for doxorubicin. PCFb and compound 2 induced apoptosis in CCRF-CEM cells mediated by activation of caspase 3/7, 8 and 9, MMP alteration and increased ROS production.

CONCLUSION

Piper capense is a source of potent cytotoxic botanicals and phytochemicals that could help to fight various types of cancer including multidrug resistance phenotypes. PCFb and compound 2 should further be explored to develop new drugs to fight malignancies.

N-acetylglycoside of oleanolic acid (aridanin) displays promising cytotoxicity towards human and animal cancer cells, inducing apoptotic, ferroptotic and necroptotic cell death

BACKGROUND

The discovery of novel phytochemicals represents a reasonable approach to fight malignancies, especially those which are resistant to standard chemotherapy.

PURPOSE

We evaluated the cytotoxic potential of a naturally occurring N-acetylglycoside of oleanolic acid, aridanin, on 18 cancer cell lines, including sensitive and drug-resistant phenotypes mediated by P-glycoprotein, BCRP, p53 knockout, deletion-mutated EGFR, or BRAF mutations. Furthermore, metastasizing B16/F10 cells, HepG2 hepatocarcinoma and normal AML12 hepatocytes were investigated. The mechanisms of aridanin-induced cell death was further investigated.

METHODS

The resazurin reduction assay (RRA) was applied to evaluate the cytotoxicity, autophagy, ferroptotic and necroptotic cell death. CCRF-CEM leukemia cells were used for all mechanistic studies. A caspase-Glo assay was applied to evaluate the caspase activities. Flow cytometry was applied for the analyses of cell cycle (PI staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP; JC-1) and reactive oxygen species (ROS; H2DCFH-DA).

RESULTS

Aridanin and doxorubicin (positive control) inhibited the proliferation of all cancer cell lines tested. The IC50 values for aridanin varied from 3.18 µM (CCRF-CEM cells) to 9.56 µM (HepG2 cells). Aridanin had considerably lower IC50 values than that of doxorubicin against multidrug-resistant CEM/ADR5000 cells and melanoma cell lines (MaMel-80a, Mel-2a, MV3, and SKMel-505). Aridanin induced apoptosis in CCRF-CEM cells through increase of ROS levels and MMP breakdown, and to a lesser extent via caspases activation. Aridanin also induced ferroptotic and necroptotic cell death.

CONCLUSION

The present study opens good perpectives for the use of this phytochemical as an anticancer drug to combat multi-facorial resistance to established chemotherapeutics.

Ischemia and Reperfusion Injury in Kidney Transplantation: Relevant Mechanisms in Injury and Repair

Ischemia and reperfusion injury (IRI) is a complex pathophysiological phenomenon, inevitable in kidney transplantation and one of the most important mechanisms for non- or delayed function immediately after transplantation. Long term, it is associated with acute rejection and chronic graft dysfunction due to interstitial fibrosis and tubular atrophy. Recently, more insight has been gained in the underlying molecular pathways and signalling cascades involved, which opens the door to new therapeutic opportunities aiming to reduce IRI and improve graft survival. This review systemically discusses the specific molecular pathways involved in the pathophysiology of IRI and highlights new therapeutic strategies targeting these pathways.

Mitochondrial DNA targeting and impairment by a dinuclear Ir–Pt complex that overcomes cisplatin resistance

A dinuclear complex [(ppy)Ir(tpy)PtCl]²⁺ (Ir–Pt) can exhibit strong antitumor activity towards cisplatin-resistant cancer cells and induce cell necrosis via mtDNA damage and mitochondrial dysfunction.

Physiological Responses of Pacific White Shrimp Litopenaeus vannamei to Temperature Fluctuation in Low-Salinity Water

Temperature is a significant environmental factor in aquaculture. To investigate the physiological responses during temperature fluctuation (28~13°C), experimental shrimps (Litopenaeus vannamei) were treated with gradual cooling from acclimation temperature (AT, 28°C) to 13°C with a cooling rate of 7.5°C/day and rose back to 28°C at the same rate after 13°C for 24 h. Hepatopancreas histological changes, plasma metabolites concentrations, relative mRNA expression of unfolded protein response (UPR) pathway and apoptosis in hepatopancreas and hemocyte were investigated. The results showed that with the decline of temperature, the number and volume of the secretory cells in hepatopancreas increased significantly, the tubule lumen appeared dilatated, and the epithelial cell layer became thinner. The contents of glucose (Glu) significantly decreased to the minimum value of 13°C for 24 h. The contents of triglyceride (TG), total cholesterol (TC), and total protein (TP) increased and reached the peak of 13°C for 24 h. Alkaline phosphatase (ALP) and alanine aminotransferase (ALT) activities in plasma reached the lowest and highest value in 13°C, respectively. The expressions of all genes related to UPR and apoptosis in the hepatopancreas and hemocytes were significantly changed during the cooling process and reached the highest level of 13 and 13°C for 24 h, respectively. During re-warming stage, the histopathological symptoms got remission and each of the plasma metabolite concentrations and gene expressions returned to AT levels. These results revealed that pacific white shrimp can adapt to a certain level of temperature fluctuation by self-regulation.

Investigating the physiological responses of Pacific white shrimp Litopenaeus vannamei to acute cold-stress

Background

Litopenaeus vannamei is one of the most important aquaculture shrimps in the world and low temperatures present a serious challenge to its survival, growth, and distribution.

Methods

To investigate their physiological responses during acute cold-stress, L. vannamei were treated under acute cooling conditions from 28 to 13 °C with a cooling rate of 2.5 °C/2 h and were maintained at 13 °C for 12 h. Plasma metabolite concentrations, histological changes, and relative gene expression related to the unfolded protein response (UPR) pathway and apoptosis in the hepatopancreas and the hemocytes of L. vannamei were investigated.

Results

The results revealed that the concentrations of triglycerides, total cholesterol, and total protein in plasma reached their peaks at 23 °C, and then decreased to their minimum values at 13 °C for 12 h. The activity of alkaline phosphatase in the plasma decreased to its lowest level while the activity of alanine aminotransferase increased to its highest level at 13 °C for 12 h. The hepatic tubules became necrotic and the basement membranes were ruptured at 13 °C for 12 h. The gene expression related to UPR and apoptosis in the hepatopancreas and hemocytes was significantly altered by the decrease in the temperature.

Discussion

The results revealed that acute cold-stress caused histological damage in the hepatopancreas of L. vannamei, reducing its immunity. The three UPR pathways were involved in the process of acute cold-stress and the response of activating transcription factor 6 to UPR may be faster and more directthan the IRE1 and PERK pathways.

Cytotoxicity of the crude extract and constituents of the bark of Fagara tessmannii towards multi-factorial drug resistant cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Fagara tessmannii Engl. is an African medicinal plant used in Cameroonian traditional medicine to treat various types of cancers.

AIM OF THE STUDY

This work was designed to determine the cytotoxicity of the crude extract (FTB), fractions (FTBa-d) and compounds isolated from the bark of Fagara tessmannii, namely lupeol (1), fagaramide (2), zanthoxyline (3), hesperidin (4), nitidine chloride (5), fagaridine chloride (6), and β-sitosterol-3-O-β-_D-glucopyranoside (7). The study was extended to the mode of induction of apoptosis by FTB, compounds 5 and 6.

MATERIALS AND METHODS

The resazurin reduction assay was used to evaluate the cytotoxicity of samples. The cell cycle, apoptosis, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) were measured by flow cytometry. Column chromatography was used for the purification of FTB. Meanwhile, nuclear magnetic resonance (NMR) spectroscopic analysis was applied for structural elucidation.

RESULTS

The crude extract, fractions FTBa, FTBc, FTBd as well as compounds 5 and 6 revealed cytotoxicity towards the 9 tested cancer cell lines. The IC₅₀ values ranged from 17.34 µg/mL (towards U87MG.ΔEGFR glioblastoma cells) to 40.68 µg/mL (against CCRF-CEM leukemia cells) for FTB, from 16.78 µg/mL (towards U87. MGΔEGFR cells) to 37.42 µg/mL (against CEM/ADR5000 leukemia cells) for FTBa, from 19.47 µg/mL (towards U87. MG glioblastoma cells) to 41.62 µg/mL (against CCRF-CEM cells) for FTBc, from 14.17 µg/mL (against HCT116p53^-/- colon adenocarcinoma cells) to 22.28 µg/mL (towards CEM-ADR5000 cells) for FTBd, from 1.75 µM (against CCRF-CEM cells) to 23.52 µM (against U87. MGΔEGFR cells) for compound 5, from 1.69 µM (against CCRF-CEM cells) to 22.06 µM (against HepG2 hepatocarcinoma cells) for compound 6 and from 0.02 µM (against CCRF-CEM cells) to 122.96 µM (against CEM/ADR5000 cells) for doxorubicin. FTB induced apoptosis in CCRF-CEM cells mediated by enhanced ROS production. Compound 5 induced apoptosis through caspases activation and increase ROS production. Meanwhile, 6 induced apoptosis mediated by caspases activation, MMP alteration and enhanced ROS production.

CONCLUSION

Fagara tessmannii as well as its constituents 5 and 6 revealed considerable cytotoxicity and may be suitable candidates deserving to be further explored to develop new anticancer drugs to combat sensitive and resistant phenotypes.

Cytotoxicity of isoflavones and biflavonoids from Ormocarpum kirkii towards multi-factorial drug resistant cancer

BACKGROUND

While incidences of cancer are continuously increasing, drug resistance of malignant cells is observed towards almost all pharmaceuticals. Several isoflavonoids and flavonoids are known for their cytotoxicity towards various cancer cells.

PURPOSE

The aim of this study was to determine the cytotoxicity of isoflavones: osajin (1), 5,7-dihydroxy-4'-methoxy-6,8-diprenylisoflavone (2) and biflavonoids: chamaejasmin (3), 7,7″-di-O-methylchamaejasmin (4) and campylospermone A (5), a dimeric chromene [diphysin(6)] and an ester of ferullic acid with long alkyl chain [erythrinasinate (7)] isolated from the stem bark and roots of the Kenyan medicinal plant, Ormocarpum kirkii. The mode of action of compounds 2 and 4 was further investigated.

METHODS

The cytotoxicity of compounds was determined based on the resazurin reduction assay. Caspases activation was evaluated using the caspase-Glo assay. Flow cytometry was used to analyze the cell cycle (propodium iodide (PI) staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP) (JC-1) and reactive oxygen species (ROS) (H₂DCFH-DA). CCRF-CEM leukemia cells were used as model cells for mechanistic studies.

RESULTS

Compounds 1, 2 and 4 displayed IC₅₀ values below 20 µM towards CCRF-CEM and CEM/ADR5000 leukemia cells, and were further tested towards a panel of 7 carcinoma cells. The IC₅₀ values of the compounds against carcinoma cells varied from 16.90 µM (in resistant U87MG.ΔEGFR glioblastoma cells) to 48.67 µM (against HepG2 hepatocarcinoma cells) for 1, from 7.85 µM (in U87MG.ΔEGFR cells) to 14.44 µM (in resistant MDA-MB231/BCRP breast adenocarcinoma cells) for 2, from 4.96 µM (towards U87MG.ΔEGFRcells) to 7.76 µM (against MDA-MB231/BCRP cells) for 4, and from 0.07 µM (against MDA-MB231 cells) to 2.15 µM (against HepG2 cells) for doxorubicin. Compounds 2 and 4 induced apoptosis in CCRF-CEM cells mediated by MMP alteration and increased ROS production.

CONCLUSION

The present report indicates that isoflavones and biflavonoids from Ormocarpum kirkii are cytotoxic compounds with the potential of being exploited in cancer chemotherapy. Compounds 2 and 4 deserve further studies to develop new anticancer drugs to fight sensitive and resistant cancer cell lines.

Network Pharmacology-Based Study on the Mechanism of Bushen-Jianpi Decoction in Liver Cancer Treatment

To investigate the mechanism of a Bushen-Jianpi decoction (BSJPD) in liver cancer (LC) treatment, we analyzed clinical therapy data, conducted network pharmacology analysis, and performed pharmacological experimental verification in vitro and in vivo. The univariate analysis of clinical therapy showed that the BSJPD was protective factor (p < 0.05). The network pharmacology analysis showed that 9 compounds were important nodes of BSJPD-LC therapy network. In experimental verification, the rate of apoptosis increased in the liver tumors of mice treated with the BSJPD (p < 0.05); drug serum with 20 % BSJPD inhibited cell viability (p < 0.05) and reduced the expression of PI3K, the Bcl-xL/BAD ratio, and the levels of p53 and p-Akt in HepG2 cells. Moreover, licochalcone A, alisol B, and hederagenin inhibited cell viability (p < 0.05), induced cell apoptosis (p < 0.01), reduced p-Akt levels, and increased cleaved-CASP3 (p < 0.05) and p53 expression levels in HepG2 cells. These data suggest that the BSJPD prolongs the survival of LC patients and induces apoptosis and that it may be associated with the regulation of PI3K, Akt, p53, CASP3, and Bcl-xL/BAD expression.

The protective effects of the native flavanone flavanomarein on neuronal cells damaged by 6-OHDA

BACKGROUND

Flavanomarein is the main component of Coreopsis tinctoria Nutt. (C. tinctoria), which is a globally well-known flower tea that has a distinct flavor and many beneficial health effects, such as antioxidant activities. We aimed to explore the effect of flavanomarein on a 6-hydroxydopamine (6-OHDA)-lesioned cell model of oxidative stress.

METHODS

In this study, we used 6-OHDA-lesioned PC12 cells and primary cortical neurons to investigate the protective effects of flavanomarein and its potential mechanism.

RESULTS

The results indicated that pretreatment with flavanomarein (25, 50, or 100 µM for 24 h) significantly increased the cell viability, reduced the lactate dehydrogenase (LDH) release and improved the mitochondrial membrane potential (∆Ψm) and mitochondrial impairment. Additionally, flavanomarein markedly reduced the gene expression of tumor necrosis factor (TNF)-α and protein kinase C ζ (PKC-ζ), the nuclear translocation of p65, and the levels of p-AMPK-α and acetyl-p53. Flavanomarein also elevated the gene expression of P85α, PKC-β1, and Bcl-2, the protein expression of Sirt1 and ICAD, and the phosphorylation level of AKT.

CONCLUSIONS

Together, these results suggest that flavanomarein protects PC12 cells and primary cortical neurons from 6-OHDA-induced neurotoxicity by upregulating the PI3K/AKT signaling pathway and attenuating the nuclear factor kappa B (NF-κB) signaling pathway. Therefore, our study provides evidence that may aid in the development of a potential compound against 6-OHDA toxicity.

The Link Between Inflammaging and Degenerative Joint Diseases

Aging is an inevitable process in the human body that is associated with a multitude of systemic and localized changes. All these conditions have a common pathogenic mechanism characterized by the presence of a low-grade proinflammatory status. Inflammaging refers to all the processes that contribute to the occurrence of various diseases associated with aging such as frailty, atherosclerosis, Alzheimer’s disease, sarcopenia, type 2 diabetes, or osteoarthritis. Inflammaging is systemic, chronic, and asymptomatic. Osteoarthritis and many age-related degenerative joint diseases are correlated with aging mechanisms such as the presence of an inflammatory microenvironment and the impaired link between inflammasomes and autophagy. There is a close relationship between chondrocyte activity and local articular environment changes due to cell senescence, followed by secretion of inflammatory mediators. In addition, systemic inflammaging can lead to cartilage destruction, pain, disability, and an impaired quality of life. The purpose of this review is to summarize the main mechanisms implicated in inflammaging and the connection it has with degenerative joint diseases.

Heteroplasmy Shifting as Therapy for Mitochondrial Disorders

Mitochondrial disease can arise due to pathogenic sequence variants in the mitochondrial DNA (mtDNA) that prevent cells from meeting their energy demands. Mitochondrial diseases are often fatal and currently there are no treatments directed towards the underlying cause of disease. Pathogenic variants in mtDNA often exist in a state of heteroplasmy, with coexistence of pathogenic and wild type mtDNA. The load of heteroplasmy, defined as the relative amount of pathogenic mtDNA to wild type mtDNA, corresponds to timing and symptom severity. Thus, changing the heteroplasmy load may lead to a shift in disease onset and symptom severity. Here we review techniques aimed at preventing inheritance of pathogenic mtDNA via mitochondrial replacement therapy (MRT) and strategies geared toward shifting of heteroplasmy in individuals with active mitochondrial disease. MRT strategies seek to create embryos with the nuclear genetic makeup of the intended parents and wild type mtDNA from a donor in order to avoid known maternal pathogenic variants. Heteroplasmy shift approaches in patients are of two categories: nuclease dependent and nuclease independent strategies. Despite initial success in mouse models and patient cells, these techniques have not reached clinical use. Translational attempts in this area are urgently needed to improve therapies for a currently untreatable set of disorders.

Cardamonin Induces Cell Cycle Arrest, Apoptosis and Alters Apoptosis Associated Gene Expression in WEHI-3 Mouse Leukemia Cells

Cardamonin, the chalcone class, is one of the natural components from the spicy herbaceous plant (Alpinia conchigera Griff) and has anticancer activities in many human cancer cell lines. There is, however, no information to show that cardamonin induces cell apoptosis and alters apoptosis associated gene expressions in mouse leukemia cells. Thus, we investigated the effects of cardamonin on the apoptotic cell death and associated gene expression in mouse leukemia WEHI-3 cells in vitro. Results indicated that cardamonin decreased total viable cell number via induced cell morphological changes and apoptotic cell death in WEHI-3 cells that were assay by contrast-phase microscopy and flow cytometry examinations, respectively. The flow cytometry assay indicated that cardamonin increased reactive oxygen species (ROS) and Ca[Formula: see text] production, decreased the levels of mitochondrial membrane potential ([Formula: see text] and increased caspase-3, -8 and -9 activities in WEHI-3 cells. Western blotting was performed to analyze expression of relevant pro- and anti-apoptotic proteins and results showed that cardamonin decreased anti-apoptotic protein of Bcl-2 but increased pro-apoptotic protein of Bax in WEHI-3 cells. Furthermore, cardamonin increased cytochrome c, AIF and Endo G release, increased GRP78, caspase-12 that were associated with ER stress and increased Fas, Fas-Ligand and FADD expression. Furthermore, cardamonin increased the gene expressions of DAP (death-associated protein), TMBIM4 transmembrane (BAX inhibitor motif containing 4), ATG5 (autophagy related 5) but decreased the gene expression of DDIT3 (DNA-damage inducible transcript 3), DDIT4 (DNA-damage-inducible transcript 4), BAG6 (BCL2-associated athanogene 6), BCL2L13 [BCL2-like 13 (apoptosis facilitator)] and BRAT1 (BRCA1-associated ATM activator 1) that are associated with apoptosis pathways. Based on those findings, we may suggest cardamonin induced apoptotic cell death through Fas and Fas-Ligand-, caspase- and mitochondria-dependently pathways and also affects the apoptotic gene expression in WEHI-3 cells in vitro.

Effect of Taraxacum officinale extract on PI3K/Akt pathway in DMBA-induced breast cancer in albino rats

Background: Breast cancer is one of the most prevalent types of cancer and a leading cause of death in women. Materials and methods: An experimental model of breast cancer was induced in female albino rats using single intragastric dose of 7, 12 dimethylbenz (α) anthracene (DMBA) in sesame oil (50 mg/kg b.wt). Four months after DMBA administration, incidence of breast cancer was confirmed by measuring cancer antigen 15-3 (CA15-3) serum levels. Taraxacum officinale ssp. officinale root extract (TOE) was administered in a dose of 500 mg/kg by oral gavage for 4 weeks after breast cancer incidence. Level of CA15-3 as one of the best known breast tumor markers was elevated in all positive breast cancer rats. The genetic effects of TOE on Pdk1–Akt1–Pik3r1–Map3k1–Erbb2–PIk3ca using semi-quantitative RT-PCR analysis were evaluated. In parallel, histopathological changes and immunohistochemical expression of Bcl2 in mammary gland tissues were examined. Results: Level of CA15-3 was normalized in DMBA group administered TOE for 4 weeks. Administration of DMBA increased expression of Pdk1, Akt1, Pik3r1, Map3k1, Erbb2 and PIk3ca. Treatment with TOE normalized the up-regulated mRNA for all examined genes except Pik3ra that was up-regulated. Mammary gland tissues of DMBA group showed excessive proliferation of lining epithelium of acini and ductules with hyperchromatic nuclei with excessive immunostaining of Bcl2 in the proliferated epithelium that was ameliorated by TOE administration. In conclusion, TOE regulated PI3K and Akt pathways involved in suppression of breast cancer growth and proliferation. TOE is effective as anticancer herbal agent.

MicroRNA-503 regulates hypoxia-induced cardiomyocytes apoptosis through PI3K/Akt pathway by targeting IGF-1R

Coronary heart disease is the second highest specific cause of death. H9c2 cardiomyocytes were subjected to hypoxia (1% O₂) for 0, 6, 12, 24 and 48 h. Cell apoptosis and the activity of caspase3/7 was detected using ELISA; western blot was applied to determine the cleaved-caspase3 (c-caspase3), cleaved-PARP (c-PARP) and cytochrome C (Cyto C) expression after the inhibitor negative control (in-NC), miR-503 inhibitor, mimic negative control (mi-NC) and miR-503 mimic were transfected into cells for 48 h. Moreover, flow cytometry was applied to evaluate mitochondrial membrane potential. In addition, luciferase reporter gene assay was used for detection the relationship between miR-503 and insulin-like growth-factor-1 receptor (IGF-1R). Real-time PCR showed microRNA-503 (miR-503) was elevated in a time-dependent manner under hypoxia. MiR-503 inhibition prevented cell apoptosis and reduced caspase3/7 activity and the expression of c-caspase3 and c-PARP, prevented mitochondrial membrane potential collapse and reduced the cyto C level in cytosol. While, miR-503 overexpression showed a pro-apoptotic role and resulted in mitochondrial membrane potential loss. MiR-503 directly targets IGF-1R in H9c2 cardiomyocytes. The depletion of IGF-1R using a specific IGF-1R siRNA (siIGF-1R) abolished anti-apoptotic function of miR-503 inhibitor, and LY294002 showed a similar trend. In summary, miR-503 promoted cell apoptosis, caused mitochondrial membrane potential collapse and the emancipation of cyto C from mitochondrial through PI3K/Akt pathway via targeting IGF-1R in H9c2 cardiomyocytes.

Long noncoding RNA Z38 promotes cell proliferation and metastasis and inhibits cell apoptosis in human gastric cancer

Gastric cancer is one of the leading causes of cancer-associated mortality and has a high tendency to metastasize, making it a priority to develop novel diagnostic and treatment methods at the early stages. The present study investigated the role of a newly-discovered long non-coding RNA, Z38, in gastric cancer cell proliferation, metastasis and apoptosis. It was observed that Z38 was upregulated in tissues from patients with gastric cancer as well as in cultured gastric cancer cells. Knockdown of Z38 decreased the cell proliferative rate, as evidenced by colony formation assays and cell proliferation assays. In addition, Transwell assays and wound-healing assays demonstrated that depletion of Z38 significantly inhibited cell migration and invasion in AGS and MKN74 cells. Furthermore, a cell apoptosis assay and measurement of relative activities of related caspases revealed that depletion of Z38 increased cell apoptosis by promoting the activities of caspase-3 and caspase-9, but not that of caspase-8. Finally, western blot analysis further demonstrated the role of Z38 in the apoptosis of AGS and MKN74 cells. These results suggested that Z38 promotes cell proliferation and metastasis, and inhibits cell apoptosis in gastric cancer. Z38 may represent a novel therapeutic target for the treatment of gastric cancer in clinic.

Oncosis-inducing cyclometalated iridium(iii) complexes

Oncosis is a non-apoptotic form of programmed cell death (PCD), which differs from apoptosis in both morphological changes and inner pathways, and might hold the key to defeating a major obstacle in cancer therapy - drug-resistance, which is often a result of the intrinsic apoptosis resistance of tumours. However, despite the fact that the term "oncosis" was coined and used much earlier than apoptosis, little effort has been made to discover new drugs which can initiate this form of cell death, in comparison to drugs inducing apoptosis or any other type of PCD. So herein, we present the synthesis of a series of mitochondria-targeting cyclometalated Ir(iii) complexes, which activated the oncosis-specific protein porimin and calpain in cisplatin-resistant cell line A549R, and determined their cytotoxicity against a wide range of drug-resistant cancer types. To the best of our knowledge, these complexes are the very first metallo-components to induce oncosis in drug-resistant cancer cells.

A naturally occuring triterpene saponin ardisiacrispin B displayed cytotoxic effects in multi-factorial drug resistant cancer cells via ferroptotic and apoptotic cell death

INTRODUCTION

Multidrug resistance of cancer cells constitutes a serious problem in chemotherapy and a challenging issue in the discovery of new cytotoxic drugs. Many saponins are known to display anti-cancer effects. In this study, the cytotoxicity and the modes of action of a naturally occuring oleanane-type tritepene saponin, ardisiacrispin B isolated from the fruit of Ardisia kivuensis Taton (Myrsinaceae) was evaluated on a panel of 9 cancer cell lines including various sensitive and drug-resistant phenotypes.

METHODS

Resazurin reduction assay was used to evaluate cytotoxicity and ferroptotic cell death of samples; caspase-Glo assay was used to detect the activation of caspases in CCRF-CEM leukemia cells. Flow cytometry was used for cell cycle analysis and detection of apoptotic cells by annexin V/PI staining, analysis of mitochondrial membrane potential (MMP) and measurement of reactive oxygen species (ROS).

RESULTS

Ardisiacrispin B displayed significant cytotoxic effects in the 9 tested cancer cell lines with IC₅₀ values below 10 µM. The IC₅₀ values ranges were 1.20 µM (towards leukemia CCRF-CEM cells) to 6.76 µM [against heptocarcinoma HepG2 cells] for ardisiacrispin B and 0.02 µM (against CCRF-CEM cells) to 122.96 µM (against resistant CEM/ADR5000 leukemia cells) for doxorubicin. Collateral sensitivity of resistant HCT116p53^-/- colon adenocarcinoma cells to ardisiacripsin B was observed. Ardisiacrispin B induced apoptosis in CCRF-CEM cells via activation of inititator caspases 8 and 9 and effector caspase 3/7, alteration of MMP and increase in ROS production. Ferroptosis also contributed to the cytotoxicity of ardisiacrispin B.

CONCLUSIONS

The studied oleanane-type triterpene saponin is a good cytotoxic molecule that deserve more detailed exploration in the future, to develop novel cytotoxic drugs to combat both sensitive and drug-resistant cancers.

Actein inhibits cell proliferation and migration and promotes cell apoptosis in human non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) is the leading cause of death in smokers and the most common cause for cancer mortality in both males and females in the United States. Predisposition of this malignancy to distant metastasis leads to poor prognosis; therefore, it is urgent to discover novel therapeutic agents for metastatic NSCLC. The present study aimed to investigate the effects of actein treatment on NSCLC cell growth and migration. Cell viability assays demonstrated that administration of actein markedly inhibited NSCLC cell proliferation in a dose- and time-dependent manner. Transwell assays demonstrated that actein treatment suppressed cell migration and invasion in two NSCLC cell lines, A549 and 95D. Furthermore, treatment with actein remarkably increased the activities of caspase-3 and -9 in NSCLC cells. The protein expression levels of cytoplasmic BCL2 apoptosis regulator (Bcl-2) and BCL2 associated X (Bax) were markedly decreased, while the protein expression levels of mitochondrial Bax, caspase-3, -9 and cytochrome c were upregulated following actein treatment, as evidenced by western blot analysis. The present results demonstrated that actein inhibited cell proliferation and metastasis and promoted cell apoptosis in NSCLC cells, which indicated that actein administration might serve as a potential therapeutic strategy for the treatment of NSCLC in the clinic.

Protective effect of DHEA on hydrogen peroxide-induced oxidative damage and apoptosis in primary rat Leydig cells

Dehydroepiandrosterone (DHEA) is widely used as a nutritional supplement due to its putative anti-aging properties. However, the effect of DHEA in Leydig cells, a major target cell of DHEA biotransformation in male, are not clear. The present study aimed to investigate the preventative effect of DHEA on oxidative damage and apoptosis after H₂O₂ treatment in Leydig cells. The results showed that DHEA treatment attenuated the reduction of cell viability induced by H₂O₂. No differences were observed on the superoxide anion (O₂^-) content, while DHEA treatment decreased reactive oxygen species (ROS) and hydroxyl radical (OH) content in H₂O₂-treated Leydig cells. Pre-treatment with DHEA increased peroxidase (POD) activity and decreased glutathione peroxidase (GSH-Px) activity in H₂O₂-treated Leydig cell. DHEA treatment attenuated DNA damage as indicated by the decreasing of tail moment, comet length and olive tail moment. Total apoptosis ratio and early apoptosis ratio were significantly decreased in H₂O₂-treated Leydig cell that were pre-treatment with DHEA. DHEA treatment decreased Bax, capase-9 and capase-3 mRNA levels in H₂O₂-treated Leydig cells. Our results demonstrated that pre-treatment with DHEA prevented the Leydig cells oxidative damage caused by H₂O₂ through increasing POD activity, which resulted in inhibition of OH generation. Meanwhile, pre-treatment with DHEA inhibited H₂O₂-induced Leydig cells early apoptosis which mainly by reducing the pro-apoptotic protein Bax and caspases-9, caspases-3 mRNA levels. This information is important to understand the molecular mechanism of anti-ageing effect and potential application in treatment of oxidative stress induced related diseases of DHEA.

Effect of dietary zinc on morphological characteristics and apoptosis related gene expression in the small intestine of Bama miniature pigs

To investigate the effects of dietary zinc (Zn) on small intestinal mucosal epithelium, 6-month-old male Bama miniature pigs were randomly allocated into three groups and treated with three levels of Zn (Control, T1, and T2 diet supplemented with 0, 50, and 1500mg/kg Zn, respectively, as zinc sulfate) for 38days. The samples of small intestine tissues, serum, and feces were collected. The results showed that Zn concentrations of small intestine in the T2 group were higher than those in the control and T1 groups (p<0.05). In the T2 group, the pharmacological dose of dietary Zn treatment caused marked damage to the small intestinal epithelium. The expression of Bax, cleaved caspase-3, and caspase-8 were increased in the duodenum and the jejunum of the T2 group (p<0.05). The mRNA transcript levels of BAX, CYCS and CASP3 genes were upregulated in the duodenum and the jejunum of the T2 group. We concluded that a diet with a pharmacological dose of Zn increased the accumulation of Zn and the expression of Bax, cleaved caspase-3, and caspase-8, which might activate the apoptosis and lead to the marked injury of porcine small intestinal epithelium.

Siamese crocodile bile induces apoptosis in NCI-H1299 human non-small cell lung cancer cells via a mitochondria-mediated intrinsic pathway and inhibits tumorigenesis

Non-small-cell lung cancer (NSCLC) is a widespread and particularly aggressive form of cancer. Patients with NSCLC and early metastases typically have poor prognosis, highlighting the critical need for additional drugs to improve disease outcome following surgical resection. The present study aimed to determine if Siamese crocodile bile (SCB) had an anti‑cancer effect on NCI‑H1299 human NSCLC cells. The inhibitory mechanism of SCB was examined in cell culture and nude mice. In vitro experimental results revealed that SCB inhibited the proliferation and colony‑forming ability of NCI‑H1299 cells by arresting cell cycle and inducing apoptosis. The loss of the mitochondrial membrane potential and the release of cytochrome c indicated that SCB treatment may lead to mitochondrial dysfunction in NCI‑H1299 cells. At the molecular level, SCB altered the ratio of protein expression of Bax/Bcl‑2 and activated associated caspases, suggesting that intrinsic pathway involvement in the SCB‑induced apoptosis of NCI‑H1299 cells. In the in vivo experiments, intraperitoneal injection of SCB for 4 weeks inhibited xenograft tumor growth by 46.8% without observable toxicity in nude mice. Immunohistochemistry analysis of proliferating cell nuclear antigen and vascular endothelial growth factor also revealed that SCB inhibited cell proliferation and metastasis in NSCLC xenograft tumors. Overall, SCB exerted an anti-cancer effect on NCI‑H1299 human NSCLC cells in vitro and in vivo and may have therapeutic potential for the treatment of human NSCLC.

Toxicity assessment of carbon black waste: A by-product from oil refineries

In Singapore, approximately 30t/day of carbon-based solid waste are produced from petrochemical processes. This carbon black waste has been shown to possess physical properties that are characteristic of a good adsorbent such as high external surface area. Therefore, there is a growing interest to reutilize and process this carbon black waste into secondary materials such as adsorbents. However, the carbon black waste obtained from petrochemical industries may contain heavy metals that are hazardous to human health and the environment, hence restricting its full potential for re-utilization. Therefore, it is important to examine the possible toxicity effects and toxicity mechanism of carbon black waste on human health. In this study, inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis showed that the heavy metals, vanadium (V), molybdenum (Mo) and nickel (Ni), were present in the carbon black waste in high concentrations. Three human cell lines (HepG2 cells, MRC-5 cells and MDA-MB-231 cells) were used to investigate the toxicity of carbon black waste extract in a variety of in vitro assays. Results from MTS assays indicated that carbon black waste extract decreased the viability of all three cell lines in a dose and time-dependent manner. Observations from confocal microscopy further confirmed this phenomenon. Flow cytometry assay also showed that carbon black waste extract induced apoptosis of human cell lines, and the level of apoptosis increased with increasing waste concentration. Results from reactive oxygen species (ROS) assay indicated that carbon black waste extract induced oxidative stress by increasing intracellular ROS generation in these three human cell lines. Moreover, induction of oxidative damage in these cells was also observed through the alteration of glutathione (GSH) and superoxide dismutase (SOD) activities. Last but not least, by treating the cells with V-spiked solution of concentration equivalent to that found in the carbon black waste extract, V was identified as the main culprit for the high toxicity of carbon black waste extract. These findings could potentially provide insight into the hazards of carbon black waste extract and its toxicity mechanism on human cell lines.

Overproduction of reactive oxygen species - obligatory or not for induction of apoptosis by anticancer drugs

Many studies demonstrate that conventional anticancer drugs elevate intracellular level of reactive oxygen species (ROS) and alter redox-homeostasis of cancer cells. It is widely accepted that anticancer effect of these chemotherapeutics is due to induction of oxidative stress and ROS-mediated apoptosis in cancer. On the other hand, the harmful side effects of conventional anticancer chemotherapy are also due to increased production of ROS and disruption of redox-homeostasis of normal cells and tissues. This article describes the mechanisms for triggering and modulation of apoptosis through ROS-dependent and ROS-independent pathways. We try to answer the question: "Is it possible to induce highly specific apoptosis only in cancer cells, without overproduction of ROS, as well as without harmful effects on normal cells and tissues?" The review also suggests a new therapeutic strategy for selective killing of cancer cells, without significant impact on viability of normal cells and tissues, by combining anticancer drugs with redox-modulators, affecting specific signaling pathways and avoiding oxidative stress.

Knockdown of Long Noncoding RNA NR_026689 Inhibits Proliferation and Invasion and Increases Apoptosis in Ovarian Carcinoma HO-8910PM Cells

Ovarian cancer is one of the leading causes of gynecological cancer-related deaths worldwide. We investigated the role of a newly discovered long noncoding RNA, NR_026689, in cell proliferation, metastasis, and apoptosis in ovarian cancer cells. Our results showed that NR_026689 was overexpressed in both clinical ovarian cancer patients and cultured ovarian cancer cells. Knockdown of NR_026689 in HO-8910PM cells significantly decreased the cell proliferative rate and the ability to form colonies. Transwell assays revealed that depletion of NR_026689 suppressed cell migration ability by 68% and cell invasive capacity by 71% in HO-8910PM cells. Moreover, specific shRNAs against NR_026689 notably promoted cell apoptosis in HO-8910PM cells by upregulating the expression of proapoptotic proteins, including caspase 3, caspase 9, cytochrome C, and PARP. Our study suggests an oncogenic potential of NR_026689 in ovarian cancer and might provide novel clues for the diagnosis and treatment of ovarian cancer in the clinic.

Bax and Bak expression in cervical smears of women with low-and high-risk HPV types: A study of 120 cases

BACKGROUND

Human papillomavirus (HPV) is known to be involved in the carcinogenesis of squamous cells in uterine cervix cancer, mostly by binding and inactivating the p53 and pRb tumor suppressor genes. Lately, evidence has emerged suggesting that HPV oncoproteins may interact with proteins involved in cellular apoptosis as well.

AIM

This study aimed to investigate the expression of proapoptotic proteins Bax and Bak in women with low-risk and high-risk HPV types as opposed to HPV-negative women, and in women with normal pap smear compared to women with abnormal Papanicolau test (Pap) smear.

MATERIALS AND METHODS

A total of 120 liquid-based cervical samples were subtyped for HPV types with microarray hybridization and then stained and evaluated immunocytochemically for Bax and Bak expression. Statistical analysis was performed on the Bax and Bak scores (percentage of positive cells × staining intensity), the overall percentage of positive cells, and the most prevalent staining intensity group found in each sample.

RESULTS

A weak association between negative Bax staining and cytologically normal Pap smears was discovered, whereas cytologically abnormal samples tended to stain weakly or moderately positive. No other statistically significant difference was found in the other analyzed parameters.

CONCLUSION

Cytologically normal pap smears seem to have a slight tendency to stain negative for Bax as opposed to cytologically abnormal pap smears. Although the association is weak, it is an indication that there might be a connection between the expression of Bax and the development of cervical intraepithelial dysplasia, which warrants further investigation in larger-scale studies.

A sandwich ELISA for the conformation-specific quantification of the activated form of human Bax

Bcl-2 family proteins are critical regulators of mitochondrial outer membrane permeabilization (MOMP), which represents the point of no return of apoptotic cell death. The exposure of the Bax N-terminus at the mitochondria reflects Bax activation; and this activated configuration of the Bax protein is associated with MOMP. N-terminal exposure can be detected using specific monoclonal and/or polyclonal antibodies, and the onset of activated Bax has extensively been used as an early marker of apoptosis. The protocols of immunoprecipitation and/or immunocytochemistry commonly used to detect activated Bax are long and tedious, and allow semiquantification of the antigen at best. The sandwich ELISA protocol we developed has a 5 ng/mL detection limit and is highly specific for the activated conformation of Bax. This ELISA allows a rapid quantification of activated human Bax in whole cells and isolated mitochondria protein extracts. These properties grant this assay the potential to further clarify the prognostic and diagnostic value of activated Bax in disorders associated with deregulated apoptotic pathways such as degenerative diseases or cancer.

Cinnamomum cassia Suppresses Caspase-9 through Stimulation of AKT1 in MCF-7 Cells but Not in MDA-MB-231 Cells

Background

Cinnamomum cassia bark is a popular culinary spice used for flavoring and in traditional medicine. C. cassia extract (CE) induces apoptosis in many cell lines. In the present study, particular differences in the mechanism of the anti-proliferative property of C. cassia on two breast cancer cell lines, MCF-7 and MDA-MB-231, were elucidated.

Methodology/Principal Findings

The hexane extract of C. cassia demonstrated high anti-proliferative activity against MCF-7 and MDA-MB-231 cells (IC₅₀, 34±3.52 and 32.42 ±0.37 μg/ml, respectively). Oxidative stress due to disruption of antioxidant enzyme (SOD, GPx and CAT) activity is suggested as the probable cause for apoptosis initiation. Though the main apoptosis pathway in both cell lines was found to be through caspase-8 activation, caspase-9 was also activated in MDA-MB-231 cells but suppressed in MCF-7 cells. Gene expression studies revealed that AKT1, the caspase-9 suppressor, was up-regulated in MCF-7 cells while down-regulated in MDA-MB-231 cells. Although, AKT1 protein expression in both cell lines was down-regulated, a steady increase in MCF-7 cells was observed after a sharp decrease of suppression of AKT1. Trans-cinnamaldehyde and coumarin were isolated and identified and found to be mainly responsible for the observed anti-proliferative activity of CE (Cinnamomum cassia).

Conclusion

Activation of caspase-8 is reported for the first time to be involved as the main apoptosis pathway in breast cancer cell lines upon treatment with C. cassia. The double effects of C. cassia on AKT1 gene expression in MCF-7 cells is reported for the first time in this study.

Mechanistic insights into the oncolytic activity of vesicular stomatitis virus in cancer immunotherapy

Immunotherapy and oncolytic virotherapy have both shown anticancer efficacy in the clinic as monotherapies but the greatest promise lies in therapies that combine these approaches. Vesicular stomatitis virus is a prominent oncolytic virus with several features that promise synergy between oncolytic virotherapy and immunotherapy. This review will address the cytotoxicity of vesicular stomatitis virus in transformed cells and what this means for antitumor immunity and the virus’ immunogenicity, as well as how it facilitates the breaking of tolerance within the tumor, and finally, we will outline how these features can be incorporated into the rational design of new treatment strategies in combination with immunotherapy.

DNA-Hybrid-Gated Photothermal Mesoporous Silica Nanoparticles for NIR-Responsive and Aptamer-Targeted Drug Delivery

Near-infrared light is an attractive stimulus due to its noninvasive and deep tissue penetration. Particularly, NIR light is utilized for cancer thermotherapy and on-demand release of drugs by the disruption of the delivery carriers. Here we have prepared a novel NIR-responsive DNA-hybrid-gated nanocarrier based on mesoporous silica-coated Cu1.8S nanoparticles. Cu1.8S nanoparticles, possessing high photothermal conversion efficiency under a 980 nm laser, were chosen as photothermal agents. The mesoporous silica structure could be used for drug storage/delivery and modified with aptamer-modified GC-rich DNA-helix as gatekeepers, drug vectors, and targeting ligand. Simultaneously, the as-produced photothermal effect caused denaturation of DNA double strands, which triggered the drug release of the DNA-helix-loaded hydrophilic drug doxorubicin and mesopore-loaded hydrophobic drug curcumin, resulting in a synergistic therapeutic effect. The Cu1.8S@mSiO2 nanocomposites endocytosed by cancer cells through the aptamer-mediated mode are able to generate rational release of doxorubicin/curcumin under NIR irradiation, strongly enhancing the synergistic growth-inhibitory effect of curcumin against doxorubicin in MCF-7 cells, which is associated with a strong mitochondrial-mediated cell apoptosis progression. The underlying mechanism of apoptosis showed a strong synergistic inhibitory effect both on the expression of Bcl-2, Bcl-xL, Mcl-1, and upregulated caspase 3/9 activity and on the expression level of Bak and Bax. Therefore, Cu1.8S@mSiO2 with efficient synergistic therapeutic efficiency is a potential multifunctional cancer therapy nanoplatform.

Chamaejasmin B exerts anti-MDR effect in vitro and in vivo via initiating mitochondria-dependant intrinsic apoptosis pathway

Multidrug resistance (MDR) is the main obstacle limiting the efficacy of cancer chemotherapy. Looking for novel anti-MDR agents is an important way to conquer cancer drug resistance. We recently established that chamaejasmin B (CHB), a natural biflavone from Stellera chamaejasme L., is the major active component. However, its anti-MDR activity is still unknown. This study investigated the anti-MDR effect of CHB and the underlying mechanisms. First, it was found that CHB inhibited the growth of both sensitive and resistant cell lines in vitro, and the average resistant factor (RF) of CHB was only 1.26. Furthermore, CHB also displayed favorable anti-MDR activity in KB and KBV200 cancer cells xenograft mice. Subsequent study showed that CHB induced G0/G1 cell cycle arrest as well as apoptosis both in KB and in resistant KBV200 cancer cells. Further studies showed that CHB had no influence on the level of Fas/FasL and activation of procaspase 8. However, CHB-induced apoptosis was dependent on the activation of caspase 9 and caspase 3. Moreover, CHB treatment resulted in the elevation of the Bax/Bcl-2 ratio, attenuation of mitochondrial membrane potential (ΔΨ_m), and release of cytochrome c and apoptosis-inducing factor from mitochondria into cytoplasm both in KB and KBV200 cells. In conclusion, CHB exhibited good anti-MDR activity in vitro and in vivo, and the underlying mechanisms may be related to the activation of mitochondrial-dependant intrinsic apoptosis pathway. These findings provide a new leading compound for MDR therapy and supply a new evidence for the potential of CHB to be employed in clinical trial of MDR therapy in cancers.

The emerging neuroprotective role of mitochondrial uncoupling protein-2 in traumatic brain injury

Traumatic brain injury (TBI) is a multifaceted disease with intrinsically complex heterogeneity and remains a significant clinical challenge to manage. TBI model systems have demonstrated many mechanisms that contribute to brain parenchymal cell death, including glutamate and calcium toxicity, oxidative stress, inflammation, and mitochondrial dysfunction. Mitochondria are critically regulated by uncoupling proteins (UCP), which allow protons to leak back into the matrix and thus reduce the mitochondrial membrane potential by dissipating the proton motive force. This uncoupling of oxidative phosphorylation from adenosine triphosphate (ATP) synthesis is potentially critical for protection against cellular injury as a result of TBI and stroke. A greater understanding of the underlying mechanism or mechanisms by which uncoupling protein-2 (UCP2) functions to maintain or optimize mitochondrial function, and the conditions which precipitate the failure of these mechanisms, would inform future research and treatment strategies. We posit that UCP2-mediated function underlies the physiological response to neuronal stress associated with traumatic and ischemic injury and that clinical development of UCP2-targeted treatment would significantly impact these patient populations. With a focus on clinical relevance in TBI, we synthesize current knowledge concerning UCP2 and its potential neuroprotective role and apply this body of knowledge to current and potential treatment modalities.

The novel protective role of P27 in MLN4924-treated gastric cancer cells

The tumor-suppressor gene cyclin-dependent kinase inhibitor 1B (P27) is downregulated in gastric cancer cells mainly through proteolytic degradation mediated by the SKP-Cullin1-F-Box (SCF) complex. But the correlation between its downregulation and gastric cancer prognosis still remains indefinite. MLN4924, an anti-tumor agent, which suppresses the SCF complex by inhibiting Cullin1 neddylation, emerges as a promising tool to elucidate its functions in gastric cancer cells. In this study, MLN4924 induced significant growth inhibition of gastric cancer cells in a dose-dependent manner, along with the simultaneous accumulation of P27 and cell cycle abnormalities such as G2/M arrest. Importantly, we found that P27 silencing in MLN4924-treated cells resulted in an enhancement of growth inhibition both in vitro and in vivo. Mechanism analysis revealed the antagonism effects of antioxidants to this excess apoptosis, suggesting reactive oxygen species (ROS) overproduction especially in the mitochondria was the principal cause of the augmentation. Moreover, the robust ROS attacked the mitochondria to initiate collapse of the mitochondrial membrane permeability and the exportation of apoptosis-inducing factor (AIF), IAP-binding mitochondrial protein (SMAC/DIABLO) and cytochrome c. Finally, we also found that P27 knockdown affected the expression profile of several critical BH3 family members to amplify the mitochondrial dysfunction and apoptosis. In summary, our findings unveiled a protective role of P27 by maintaining mitochondrial membrane permeability in MLN4924-treated gastric cancer cells, and therefore highlighted the potential combination of MLN4924 with P27 inhibition to improve its therapeutic efficacy.

Mitochondrial Ion Channels in Cancer Transformation

Cancer transformation involves reprograming of mitochondrial function to avert cell death mechanisms, monopolize energy metabolism, accelerate mitotic proliferation, and promote metastasis. Mitochondrial ion channels have emerged as promising therapeutic targets because of their connection to metabolic and apoptotic functions. This mini review discusses how mitochondrial channels may be associated with cancer transformation and expands on the possible involvement of mitochondrial protein import complexes in pathophysiological process.

African flora has the potential to fight multidrug resistance of cancer

Background. Continuous efforts from scientists of diverse fields are necessary not only to better understand the mechanism by which multidrug-resistant (MDR) cancer cells occur, but also to boost the discovery of new cytotoxic compounds to fight MDR phenotypes. Objectives. The present review reports on the contribution of African flora in the discovery of potential cytotoxic phytochemicals against MDR cancer cells. Methodology. Scientific databases such as PubMed, ScienceDirect, Scopus, Google Scholar, and Web of Knowledge were used to retrieve publications related to African plants, isolated compounds, and drug resistant cancer cells. The data were analyzed to highlight cytotoxicity and the modes of actions of extracts and compounds of the most prominent African plants. Also, thresholds and cutoff points for the cytotoxicity and modes of action of phytochemicals have been provided. Results. Most published data related to the antiproliferative potential of African medicinal plants were from Cameroon, Egypt, Nigeria, or Madagascar. The cytotoxicity of phenolic compounds isolated in African plants was generally much better documented than that of terpenoids and alkaloids. Conclusion. African flora represents an enormous resource for novel cytotoxic compounds. To unravel the full potential, efforts should be strengthened throughout the continent, to meet the challenge of a successful fight against MDR cancers.

Ceramide-induced apoptosis in renal tubular cells: a role of mitochondria and sphingosine-1-phoshate

Ceramide is synthesized upon stimuli, and induces apoptosis in renal tubular cells (RTCs). Sphingosine-1 phosphate (S1P) functions as a survival factor. Thus, the balance of ceramide/S1P determines ceramide-induced apoptosis. Mitochondria play a key role for ceramide-induced apoptosis by altered mitochondrial outer membrane permeability (MOMP). Ceramide enhances oligomerization of pro-apoptotic Bcl-2 family proteins, ceramide channel, and reduces anti-apoptotic Bcl-2 proteins in the MOM. This process alters MOMP, resulting in generation of reactive oxygen species (ROS), cytochrome C release into the cytosol, caspase activation, and apoptosis. Ceramide regulates apoptosis through mitogen-activated protein kinases (MAPKs)-dependent and -independent pathways. Conversely, MAPKs alter ceramide generation by regulating the enzymes involving ceramide metabolism, affecting ceramide-induced apoptosis. Crosstalk between Bcl-2 family proteins, ROS, and many signaling pathways regulates ceramide-induced apoptosis. Growth factors rescue ceramide-induced apoptosis by regulating the enzymes involving ceramide metabolism, S1P, and signaling pathways including MAPKs. This article reviews evidence supporting a role of ceramide for apoptosis and discusses a role of mitochondria, including MOMP, Bcl-2 family proteins, ROS, and signaling pathways, and crosstalk between these factors in the regulation of ceramide-induced apoptosis of RTCs. A balancing role between ceramide and S1P and the strategy for preventing ceramide-induced apoptosis by growth factors are also discussed.

Paroxetine ameliorates changes in hippocampal energy metabolism in chronic mild stress-exposed rats

The molecular mechanisms underlying stress-induced depression have not been fully outlined. Hence, the current study aimed at testing the link between behavioral changes in chronic mild stress (CMS) model and changes in hippocampal energy metabolism and the role of paroxetine (PAROX) in ameliorating these changes. Male Wistar rats were divided into three groups: vehicle control, CMS-exposed rats, and CMS-exposed rats receiving PAROX (10 mg/kg/day intraperitoneally). Sucrose preference, open-field, and forced swimming tests were carried out. Corticosterone (CORT) was measured in serum, while adenosine triphosphate and its metabolites, cytosolic cytochrome-c (Cyt-c), caspase-3 (Casp-3), as well as nitric oxide metabolites (NOx) were measured in hippocampal tissue homogenates. CMS-exposed rats showed a decrease in sucrose preference as well as body weight compared to control, which was reversed by PAROX. The latter further ameliorated the CMS-induced elevation of CORT in serum (91.71±1.77 ng/mL vs 124.5±4.44 ng/mL, P<0.001) as well as the changes in adenos-ine triphosphate/adenosine diphosphate (3.76±0.02 nmol/mg protein vs 1.07±0.01 nmol/mg protein, P<0.001). Furthermore, PAROX reduced the expression of Cyt-c and Casp-3, as well as restoring NOx levels. This study highlights the role of PAROX in reversing depressive behavior associated with stress-induced apoptosis and changes in hippocampal energy metabolism in the CMS model of depression.

Cytotoxicity and modes of action of 4'-hydroxy-2',6'-dimethoxychalcone and other flavonoids toward drug-sensitive and multidrug-resistant cancer cell lines

INTRODUCTION

Resistance of cancer to chemotherapy is a main cause in treatment failure. Naturally occurring chalcones possess a wide range of biological activities including anti-cancer effects. In this work, we evaluated the antiproliferative activity of three chalcones [4'-hydroxy-2',6'-dimethoxychalcone (1), cardamomin (2), 2',4'-dihydroxy-3',6'-dimethoxychalcone (3)], and four flavanones [(S)-(-)-pinostrobin (4), (S)-(-)-onysilin (5) and alpinetin (6)] toward nine cancer cell lines amongst which were multidrug resistant (MDR) types.

METHODS

The resazurin reduction assay was used to detect the antiproliferative activity of the studied samples whilst flow cytometry for the mechanistic studies of the most active molecule (1).

RESULTS

IC50 values in a range of 2.54 μM against CEM/ADR5000 leukemia cells to 58.63 μM toward hepatocarcinoma HepG2 cells were obtained with 1. The lowest IC50 values of 8.59 μM for 2 and 10.67 μM for 3 were found against CCRF-CEM cells leukemia cells, whilst the corresponding values were above 80 μM for 4 and 6. P-glycoprotein-expressing and multidrug-resistant CEM/ADR5000 cells were much more sensitive toward compound 1 than toward doxorubicin and low cross-resistance or even collateral sensitivity was observed in other drug-resistent cell lines to this compound. Normal liver AML12 cells were more resistant to the studied compounds than HepG2 liver cancer cells, indicating tumor specificity at least to some extent. Compound 1 arrested the cell cycle between Go/G1 phase, strongly induced apoptosis via disrupted mitochondrial membrane potential (MMP) and increased production of reactive oxygen species (ROS) in the studied leukemia cell line.

CONCLUSIONS

Chalcone 1 was the best tested cytotoxic molecule and further studies will be performed in order to envisage its possible use in the fight against multifactorial resistant cancer cells.