The end of the (cell) line: methods for the study of apoptosis in vitro

Tormentic acid derivatives: synthesis and apoptotic activity

Several derivatives of tormentic acid have been prepared and tested for their antitumor activity. The dichloroacetate 14 is an excellent antitumor active agent acting by an apoptose inducing pathway as demonstrated by OA/PI staining, DNA laddering experiments as well as by an annexin V binding assay.

Antiproliferative effects of lectins from Canavalia ensiformis and Canavalia brasiliensis in human leukemia cell lines

The antiproliferative activity of lectins Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr) were studied using human leukemia MOLT-4 and HL-60 cell lines. It was revealed that both ConA and ConBr were markedly cytotoxic to cells using MTT and NAC assays. The IC(50) values were approximately 3 and 20 μg/mL for ConA and ConBr, respectively, for both MOLT-4 and HL-60 cells. However, in normal human peripheral blood lymphocytes, the lectins were not cytotoxic, even when tested at concentrations as high as 200 μg/ml. Using comet assay, the lectins produced a rate of DNA damage exceeding 80% in MOLT-4 and HL-60 cells. Fluorescence analysis revealed the morphology characteristic of apoptosis, with low concentrations of apoptotic bodies and fragmented DNA (5 μg/ml). Flow cytometric analysis demonstrated an accumulation of cells in the sub-G1 cell cycle that is characteristic of DNA fragmentation, and a decrease in membrane integrity at high concentrations. Lastly, we evaluated the alterations in mitochondrial potential that reduced after treatment with lectins. Our results indicate that ConA and ConBr inhibited cell proliferation selectively in tumor cells and that apoptosis was the main death mechanism. Therefore, lectins can be considered a class of molecules with a high antitumor activity potential.

Cytotoxic activity and antioxidant capacity of purified lichen metabolites: an in vitro study

The purpose of this study was to investigate the effects of six lichen metabolites (diffractaic acid, lobaric acid, usnic acid, vicanicin, variolaric acid, protolichesterinic acid) on proliferation, viability and reactive oxygen species (ROS) level towards three human cancer cell lines, MCF-7 (breast adenocarcinoma), HeLa (cervix adenocarcinoma) and HCT-116 (colon carcinoma). Cells were treated with different concentrations (2.5-100 μM) of these compounds for 48 h. In this comparative study, our lichen metabolites showed various cytotoxic effects in a concentration-dependent manner, and usnic acid was the most potent cytotoxic agent, while variolaric acid did not inhibit the proliferation of any of the three cell lines used. All tested lichen compounds did not exhibit free radical scavenging activity using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The lichen metabolites did not significantly increase the intracellular ROS level and did not prevent oxidative injury induced by t-butylhydroperoxide in HeLa cells. To better clarify the mechanism(s) of cytotoxic effect induced by protolichesterinic acid in HeLa cells, we investigated apoptotic markers such as condensation and fragmentation of nuclear chromatin and activation of caspase-3, 8 and 9. Our results revealed that the antiproliferative activity of 40 μM protolichesterinic acid in HeLa cells is related to its ability to induce programmed cell death involving caspase-3, 8 and 9 activation.

In vivo antigenotoxic activity of watercress juice (Nasturtium officinale) against induced DNA damage

The present study was carried out to investigate the genotoxicity as well as possible protective activity against damage induced by cyclophosphamide (CP) of the aqueous juice of watercress (Nasturtium officinale, W.T. Aiton) in vivo. Male and female Swiss mice 7-8 weeks old (N = 48) were treated by gavage with 1 g kg(-1) body weight and 0.5 g kg(-1) body weight of watercress juice during 15 consecutive days. Genotoxicity and its possible protective effect were tested by the comet assay in peripheral blood cells and the micronucleus test in bone marrow. In addition, biopsies of the bladder, epididymis and testicles of mice were performed to extend the experimental design. Watercress juice per se did not induce genetic damage according to the comet assay and micronucleus study, exhibiting a protective activity against CP (P < 0.05 and P < 0.001, respectively). The comparative analysis of bladder histological changes obtained in the watercress plus CP group against those treated with CP alone suggests a probable protective effect. Further studies are needed in order to establish the protective role of watercress juice against DNA damage.

Prolonged feeding of terrestrial isopod (Porcellio scaber, Isopoda, Crustacea) on TiO (2) nanoparicles. Absence of toxic effect

Nanoparticles of titanium dioxide are one of most widely used nanomaterials in different products in everyday use and in industry, but very little is known about their effects on non- target cells and tissues. Terrestrial isopods were exposed to food dosed with nano-TiO₂ to give final nominal concentration 1000 and 2000 µg TiO₂/g dry weight of food. The effects of ingested nano-TiO₂ on the model invertebrate Porcellio scaber (Isopoda, Crustacea) after short-term (3 and 7 days) and prolonged (14 and 28 days) dietary exposure was assessed by conventional toxicity measures such as feeding rate, weight change and mortality. Cell membrane destabilization was also investigated. No severe toxicity effects were observed after 3, 7, 14 or 28 days of dietary exposure to nano-TiO₂, but some animals, particularly those exposed to lower concentrations of nanoparticles, had severely destabilized digestive cell membranes. It was concluded that strong destabilization of the cell membrane was sporadic, and neither concentration- nor time-related. Further research is needed to confirm this sporadic toxic effect of nanoparticles.

Genetic toxicology evaluation of essential oil of Alpinia zerumbet and its chemoprotective effects against H(2)O(2)-induced DNA damage in cultured human leukocytes

Essential oil (EO) of Alpinia zerumbet leaves, at non-toxic concentrations (50-300 μg/mL), did not induce genotoxicity in human leukocytes. However, at the highest concentration (500 μg/mL) tested caused a reduction in cell proliferation and viability, and an increase in DNA damage. Moreover, in vivo experiments showed that EO (400 mg/kg) did not exert mutagenicity on peripheral blood cells and bone marrow in mice. In DPPH test, EO showed scavenging effects against DPPH radicals, and other free radicals (determination of intracellular GSH and lipid peroxidation assays). Furthermore, EO was able to reduce the intracellular levels of ROS, and prevented leukocytes DNA against oxidative damage. The ability of EO to reduce H(2)O(2) toxicity was observed only when cells were treated with EO during and after exposure to H(2)O(2). With the co- and post-treatment procedures, EO decreased the frequency of apoptotic and micronucleated leukocytes as well DNA strand breaks. However, a synergistic effect was observed in cultures exposed to 500 μg/mL EO. In conclusion, EO at concentrations up to 300 μg/mL or doses up to 400mg/kg are not mutagenic in leukocytes and in mice, but do have antioxidative and protective effects against the cytotoxicity and clastogenesis induced by H(2)O(2).

Aqueous extracts of Lippia turbinata and Aloysia citriodora (Verbenaceae): assessment of antioxidant capacity and DNA damage

The aim of the present work was to make a contribution to the knowledge of aqueous extracts of Lippia turbinata and Aloysia citriodora (Verbenaceae; infusion and decoction) in relation with the establishment of its antioxidant activity and lack of DNA damage, for its potential use in therapeutics. The cytogenotoxic profile was evaluated through genotoxic biomarkers such as mitotic index, cellular proliferation kinetics, sister chromatid exchanges, single-cell gel electrophoresis assay, and micronucleus test in human peripheral blood lymphocyte cultures. No statistical differences were found (P > .05) between control and exposed cultures, even between both aqueous extracts. The total antioxidant capacity was shown to be higher in the decoction than in the infusion and both aqueous extracts protected against protein carbonylation and lipid peroxidation, the decoction being more efficient than the infusion (P < .005). These results suggest the safe use of these medicinal plants as chemoecologic agents in therapeutics.

Effect of ingested titanium dioxide nanoparticles on the digestive gland cell membrane of terrestrial isopods

The aim of this study was to find out whether ingested titanium dioxide nanoparticles (nano-TiO(2)) cause cell membrane damage by direct contact or by lipid peroxidation. We assessed lipid peroxidation and digestive gland cell membrane stability of animals fed on food dosed with nano-TiO(2). Conventional toxicity measures were completed to determine if cellular effects are propagated to higher levels of biological complexity. An invertebrate model organism (Porcellio scaber, Isopoda, Crustacea) was fed with food containing nanosized TiO(2) and the result confirmed that at higher exposure concentrations after 3 d exposure, nano-TiO(2) destabilized cell membranes but lipid peroxidation was not detected. Oxidative stress as evidenced by lipid peroxidation was observed at longer exposure durations and high exposure doses. These data suggest that cell membranes are destabilized by direct interactions between nanoparticles and cell membrane, not solely via oxidative stress.

Cadmium-induced oxidative stress and apoptotic changes in the testis of freshwater crab, Sinopotamon henanense

Cadmium (Cd), one of the most toxic environmental and industrial pollutants, is known to exert gonadotoxic and spermiotoxic effects. In the present study, we examined the toxic effect of Cd on the testis of freshwater crab, Sinopotamon henanense. Crabs were exposed to different Cd concentrations (from 0 to 116.00 mg·L(-1)) for 7 d. Oxidative stress and apoptotic changes in the testes were detected. The activities of SOD, GPx and CAT initially increased and subsequently decreased with increasing Cd concentrations, which was accompanied with the increase in malondialdehyde (MDA) and H(2)O(2) content in a concentration-dependent manner. Typical morphological characteristic and physiological changes of apoptosis were observed using a variety of methods (HE staining, AO/EB double fluorescent staining, Transmission Electron Microscope observation and DNA fragmentation analysis), and the activities of caspase-3 and caspase-9 were increased in a concentration-dependent manner after Cd exposure. These results led to the conclusion that Cd could induced oxidative damage as well as apoptosis in the testis, and the apoptotic processes may be mediated via mitochondria-dependent apoptosis pathway by regulating the activities of caspase-3 and caspase-9.

Preclinical study of treatment response in HCT-116 cells and xenografts with (1) H-decoupled (31) P MRS

The topoisomerase I inhibitor, irinotecan, and its active metabolite SN-38 have been shown to induce G(2) /M cell cycle arrest without significant cell death in human colon carcinoma cells (HCT-116). Subsequent treatment of these G(2) /M-arrested cells with the cyclin-dependent kinase inhibitor, flavopiridol, induced these cells to undergo apoptosis. The goal of this study was to develop a noninvasive metabolic biomarker for early tumor response and target inhibition of irinotecan followed by flavopiridol treatment in a longitudinal study. A total of eleven mice bearing HCT-116 xenografts were separated into two cohorts where one cohort was administered saline and the other treated with a sequential course of irinotecan followed by flavopiridol. Each mouse xenograft was longitudinally monitored with proton ((1) H)-decoupled phosphorus ((31) P) magnetic resonance spectroscopy (MRS) before and after treatment. A statistically significant decrease in phosphocholine (p = 0.0004) and inorganic phosphate (p = 0.0103) levels were observed in HCT-116 xenografts following treatment, which were evidenced within twenty-four hours of treatment completion. Also, a significant growth delay was found in treated xenografts. To discern the underlying mechanism for the treatment response of the xenografts, in vitro HCT-116 cell cultures were investigated with enzymatic assays, cell cycle analysis, and apoptotic assays. Flavopiridol had a direct effect on choline kinase as measured by a 67% reduction in the phosphorylation of choline to phosphocholine. Cells treated with SN-38 alone underwent 83 ± 5% G(2) /M cell cycle arrest compared to untreated cells. In cells, flavopiridol alone induced 5 ± 1% apoptosis while the sequential treatment (SN-38 then flavopiridol) resulted in 39 ± 10% apoptosis. In vivo (1) H-decoupled (31) P MRS indirectly measures choline kinase activity. The decrease in phosphocholine may be a potential indicator of early tumor response to the sequential treatment of irinotecan followed by flavopiridol in noninvasive and/or longitudinal studies.

Synthesis and biological evaluation of derivatives of 4-deoxypodophyllotoxin as antitumor agents

In an attempt to generate compounds with superior bioactivity and reduced toxicity, a series of derivatives of deoxypodophyllotoxin were synthesized by reacting 4'-demethyl-4-deoxypodophyllotoxin with substituted piperazines or their amino acid amides. The cytotoxic activity of these compounds against three human cancer cell lines was evaluated. We found that p-nitrophenylpiperazine substitution (Compound 8b) led to an increase in the potency of the compound. Compound 8b exhibited the most potent cytotoxicity against A-549, HeLa and SiHa cells (IC(50) values were 0.102, 0.180 and 0.0195 μM, respectively). In addition, flow cytometric analysis showed that 8b induced cell cycle arrest in the G1 phase accompanied by apoptosis in A-549 cells.

Mononaphthalimide spermidine conjugate induces cell proliferation inhibition and apoptosis in HeLa cells

Developing polyamine-drug conjugates that are capable of specific entry to tumor cells is attractive in improving chemotherapeutic efficacy. Currently, the exact cytotoxic mechanism of these conjugates is not well known. Here, our research revealed the effect of a mononaphthalimide-spermidine (MNISpd) conjugate on the growth and survival of HeLa cells and possible mechanisms. In characterizing the mechanism of MNISpd cytotoxicity, inhibition of proliferation is observed in the 0.5-6 μM range and there is evidence of apoptosis at equal or greater than 6 μM, but with less toxicity on HELF cell. The lower concentrations of MNISpd induced a cell cycle arrest correlated with enhanced p21 expression and decreased cdc2 but not Cdk2 expression. MNISpd-induced apoptosis was correlated with caspase-3 activation, decreased XIAP expression and a loss of mitochondrial membrane potential. Apoptosis but not cell cycle arrest was susceptible to N-acetyl-L-cysteine (NAC) treatment. It is proposed that MNISpd-induced apoptosis in HeLa cells is related to oxidative stress and that at lower exposure concentrations effects on cell proliferation predominate while at higher concentrations apoptosis develops.

Casearin X exhibits cytotoxic effects in leukemia cells triggered by apoptosis

Clerodane diterpenes have demonstrated cytotoxic, antiplasmodial and anti-ulcer properties. In the present work, we determined the cytotoxic effect of casearin L (Cas L), O (Cas O) and X (Cas X) and (-)-hardwickiic acid isolated from Casearia sylvestris leaves, and investigated the underlying mechanisms involved in in vitro cell death induced by Cas X in HL-60 leukemia cells (0.7, 1.5 and 3.0μM). Cytotoxicity tests demonstrated that Cas X was the most active compound studied, showing greater cytotoxic effects against CEM and HL-60 lines (IC(50) of 0.4μM) and human peripheral blood mononuclear cells (PBMC, IC(50) of 1.2μM). After 24h exposure, Cas X caused a decrease in 5-bromo-20-deoxyuridine (BrdU) incorporation (36.6 and 24.5% labeling at 0.7 and 1.5μM, respectively), reduction in viability, and increase in apoptotic and necrotic leukemia cells in a dose-dependent manner evidenced by the trypan blue and AO/EB (acridine orange/ethidium bromide) assays. Moreover, Cas X-treated cells exhibited nuclear fragmentation and cytoplasmic vacuolization depending on the concentration tested. These characteristics of apoptosis or secondary necrosis were confirmed by flow cytometry which revealed DNA fragmentation, phosphatidylserine externalization, activation of the effector caspases 3/7 and mitochondrial depolarization. We then found evidence that Cas X causes cell death via apoptotic pathways, corroborating the potential of casearins as compounds with promising antitumor-related properties.

Effect of ionic stress on apoptosis and the expression of TRPM2 in human olfactory neuroepithelial-derived progenitors

OBJECTIVES

Disturbed ion homeostasis and apoptosis have been implicated in the pathophysiology of bipolar disorder (BD). TRPM2, a nonselective cation channel, is involved in apoptosis and is possibly linked with BD. In this study, monensin, a sodium ionophore, was used to model the increase [Na(+)](in) and [Ca(2+)](in) seen in BD patients.

METHODS

Human olfactory neuroepithelial-derived progenitors (ONP), which possess neuronal markers, were utilized to investigate the effects of monensin on apoptosis and the response of TRPM2, and the effects of lithium on the cellular response to monensin. Monensin treatment for 6 h activated caspase-3, -7 and poly(ADP-ribose) polymerase (PARP), inducing apoptosis.

RESULTS

[Na(+)](in) increased to twice the basal level and reached steady state after 2 h of 10(-6) M monensin treatment, while [Ca(2+)](in) rose after 6 h of the treatment. Monensin treatment for 24 h decreased expression of the long form of TRPM2, and increased expression of the short form. Lithium (1 mM) pretreatment reduced the [Na(+)](in) and [Ca(2+)](in) elevation caused by monensin, down-regulated the levels of caspase-3, -7 and PARP, and reduced expression of TRPM2.

CONCLUSIONS

Our findings suggest that the elevation of [Na(+)](in) and [Ca(2+)](in) induced ONP apoptosis and altered the expression of TRPM2. Lithium pretreatment attenuated the apoptosis induced by ionic stress.

Cyclodextrin induces calcium-dependent lysosomal exocytosis

Cyclodextrins (CDs) have long been used to manipulate cellular cholesterol levels both in vitro and in vivo, but their direct effects at a cellular level are not well characterized. Recently, CDs have garnered much interest because of their ability to clear stored cholesterol from Niemann Pick Type C (NPC) cells and markedly prolong the life of NPC1 disease mice. Here, we investigate the hypothesis that treatment with 2-hydroxypropyl- β-cyclodextrin (HPB-CD) stimulates lysosomal exocytosis in a calcium-enhanced manner. We propose that this exocytosis is the mechanism by which HPB-CD ameliorates the endolysosomal cholesterol storage phenotype in NPC cells. These findings have significant implications for the use of HPB-CD in biochemical assays and data interpretation as well as for their use for the treatment for NPC and other disorders.

Effect of San-ao Decoction, a traditional Chinese prescription, on IL-4 treated normal human bronchial epithelium

ETHNOPHARMACOLOGICAL RELEVANCE

San-ao Decoction (SA) is a classical prescription, clinically employed to treat asthma in Chinese medicine.

AIM OF STUDY

The present study was designed to examine whether SA has a protective effect on normal human bronchial epithelium modeled by interleukin-4 (IL-4), in association with eotaxin-3.

MATERIALS AND METHODS

SA is made of three traditional Chinese medicines: Herba Ephedrae, Semen Armeniacae amarum and Radix Glycyrrhizae. Apoptosis was measured by fluorescence microscopy and flow cytometry with IL-4 activated NHBE. In addition, eotaxin-3 mRNA's expression was detected by RT-PCR in NHBE stimulated with IL-4.

RESULTS

Fluorescence microscopy and flow cytometry showed that IL-4-induced normal human bronchial epithelium (NHBE) apoptosis, while SA decreased the apoptosis of NHBE with IL-4 stimulation. RT-PCR showed no expression or low expression of eotaxin-3 mRNA on NHBE, IL-4 enhanced the eotaxin-3 mRNA's expression, and that could be decreased by SA.

CONCLUSIONS

The results indicate that SA can decrease NHBE's damage and inflammation through reducing eotaxin-3 mRNA expression.

Survival of human multiple myeloma cells is dependent on MUC1 C-terminal transmembrane subunit oncoprotein function

The MUC1 C-terminal transmembrane subunit (MUC1-C) oncoprotein is a direct activator of the canonical nuclear factor-kappaB (NF-kappaB) RelA/p65 pathway and is aberrantly expressed in human multiple myeloma cells. However, it is not known whether multiple myeloma cells are sensitive to the disruption of MUC1-C function for survival. The present studies demonstrate that peptide inhibitors of MUC1-C oligomerization block growth of human multiple myeloma cells in vitro. Inhibition of MUC1-C function also blocked the interaction between MUC1-C and NF-kappaB p65 and activation of the NF-kappaB pathway. In addition, inhibition of MUC1-C in multiple myeloma cells was associated with activation of the intrinsic apoptotic pathway and induction of late apoptosis/necrosis. Primary multiple myeloma cells, but not normal B-cells, were also sensitive to MUC1-C inhibition. Significantly, treatment of established U266 multiple myeloma xenografts growing in nude mice with a lead candidate MUC1-C inhibitor resulted in complete tumor regression and lack of recurrence. These findings indicate that multiple myeloma cells are dependent on intact MUC1-C function for constitutive activation of the canonical NF-kappaB pathway and for their growth and survival.

Toxicity of abamectin to the terrestrial isopod Porcellio scaber (Isopoda, Crustacea)

To determine effects of the antiparasitic veterinary drug abamectin on the isopod Porcellio scaber, animals were exposed for 21 days to Lufa 2.2 soil spiked at concentrations of 3-300 mg/kg dry soil. After exposure, abamectin residues in the isopods were analysed using a novel analytical method. Toxicity was evaluated on different levels of biological organisation: biochemical, cellular and the individual organism. Measurements included glutathione S-transferase (GST) activity and stability of cell membranes in the digestive gland, animal mass gain or loss, food consumption, behaviour and mortality. LC50 for the effect of abamectin on survival of P. scaber was 71 mg/kg dry soil. The most obvious sublethal effects were reduced food consumption and decreased body mass (NOEC 3 mg/kg dry soil). Additionally, loss of digging activity and reduced GST activity (NOEC 30 mg/kg dry soil) and cell membrane destabilization (NOEC 10 mg/kg dry soil) were recorded. Abamectin only slightly accumulated in the isopods, with bioaccumulation factors always being <0.1. Based on these results and current information on environmental levels of abamectin, it is not likely that isopods will be affected by abamectin, but further studies with exposure through faeces are recommended.

Doxorubicin can penetrate nitrile gloves and induces apoptosis in keratinocytes cell lines

Doxorubicin (DOXO) is an anthracycline antibiotic which is used in the treatment of human malignancies such as leukemia, lymphoma and a number of solid tumors, particularly breast cancer. Anthracyclines have been reported to contaminate chemotherapy workstation surfaces as well as other workplaces surfaces. The occupational exposure to these drugs could occur in hospitals, for nurses involved in anthracyclines preparation and administration, in chemical industries during the commercial formulate syntheses, and in analytical laboratories. Numerous studies investigated cutaneous effects related to DOXO administration, on the contrary few literature data are available about effects on the skin due to the direct contact with the drug. The present study investigated the DOXO permeability of three commercially available gloves' types used to protect skin in occupational contexts, as well as the effects of DOXO on human keratinocyte cell line (HaCaT). The results suggest that the DOXO permeability of gloves depends not only on glove material but also on DOXO solutions' pH, in fact nitrile gloves can be penetrated by acid solutions, while neither natural rubbers nor nitrile gloves are permeable to neutral solutions. Moreover, DOXO solutions, even at low concentration, cause apoptosis in epithelial cells, through activation of intrinsic pathway p53-independent.

Pore formation triggered by Legionella spp. is an Nlrc4 inflammasome-dependent host cell response that precedes pyroptosis

Legionella pneumophila, the etiological agent of Legionnaires disease, is known to trigger pore formation in bone marrow-derived macrophages (BMMs) by mechanisms dependent on the type IVB secretion system known as Dot/Icm. Here, we used several mutants of L. pneumophila in combination with knockout mice to assess the host and bacterial factors involved in pore formation in BMMs. We found that regardless of Dot/Icm activity, pore formation does not occur in BMMs deficient in caspase-1 and Nlrc4/Ipaf. Pore formation was temporally associated with interleukin-1beta secretion and preceded host cell lysis and pyroptosis. Pore-forming ability was dependent on bacterial Dot/Icm but independent of several effector proteins, multiplication, and de novo protein synthesis. Flagellin, which is known to trigger the Nlrc4 inflammasome, was required for pore formation as flaA mutant bacteria failed to induce cell permeabilization. Accordingly, transfection of purified flagellin was sufficient to trigger pore formation independent of infection. By using 11 different Legionella species, we found robust pore formation in response to L. micdadei, L. bozemanii, L. gratiana, L. jordanis, and L. rubrilucens, and this trait correlated with flagellin expression by these species. Together, the results suggest that pore formation is neither L. pneumophila specific nor the result of membrane damage induced by Dot/Icm activity; instead, it is a highly coordinated host cell response dependent on host Nlrc4 and caspase-1 and on bacterial flagellin and type IV secretion system.

Diagnosis of cell death by means of infrared spectroscopy

Fourier transform infrared (FTIR) spectroscopy has been established as a fast spectroscopic method for biochemical analysis of cells and tissues. In this research we aimed to investigate FTIR's utility for identifying and characterizing different modes of cell death, using leukemic cell lines as a model system. CCRF-CEM and U937 leukemia cells were treated with arabinoside and doxorubicin apoptosis inducers, as well as with potassium cyanide, saponin, freezing-thawing, and H(2)O(2) necrosis inducers. Cell death mode was determined by various gold standard biochemical methods in parallel with FTIR-microscope measurements. Both cell death modes exhibit large spectral changes in lipid absorbance during apoptosis and necrosis; however, these changes are similar and thus cannot be used to distinguish apoptosis from necrosis. In contrast to the above confounding factor, our results reveal that apoptosis and necrosis can still be distinguished by the degree of DNA opaqueness to infrared light. Moreover, these two cell death modes also can be differentiated by their infrared absorbance, which relates to the secondary structure of total cellular protein. In light of these findings, we conclude that, because of its capacity to monitor multiple biomolecular parameters, FTIR spectroscopy enables unambiguous and easy analysis of cell death modes and may be useful for biochemical and medical applications.

Hazardous potential of manufactured nanoparticles identified by in vivo assay

New products of nanotechnologies, including nanoparticles, need to be assessed according to their biological reactivity and toxic potential. Given the large number of diverse nanomaterials, a tiered approach is favoured. The aim of our work presented here is to elaborate an in vivo assay with terrestrial invertebrates (Porcellio scaber), which could serve as a first step of hazard identification of nanoparticles. We adapted the widely used acridine orange/ethidium bromide (AO/EB) assay to be applicable for cell membrane stability assessment of entire organ where the animal was exposed in vivo. The digestive glands (hepatopancreas) of terrestrial isopods were taken as a model test system. The assay was validated with Cu(NO(3))(2) and surfactants. The results showed that all tested nanoparticles, i.e. nanosized TiO(2), nanosized ZnO and fullerenes (C(60)) have cell membrane destabilization potential. As expected, C(60) is the most biologically potent. The AO/EB in vivo assay proved to be fast because response is recorded after 30 min of exposure, relatively simple because digestive glands are inspected immediately after isolation from exposed animals and promising approach because different types of nanoparticles could be tested for their biological potential. This assay provides data for the identification of hazardous potential of nanoparticles before subsequent steps in a tiered approach are decided.

MUC1 oncoprotein is a druggable target in human prostate cancer cells

Human prostate cancers are dependent on the androgen receptor for their progression. The MUC1 heterodimeric oncoprotein is aberrantly overexpressed in prostate cancers; however, it is not known if MUC1 is of functional importance to these tumors. To assess dependence on MUC1, we synthesized an inhibitor, designated GO-201, which interacts directly with the MUC1-C subunit at its oligomerization domain. Treatment of MUC1-positive DU145 and PC3 prostate cancer cells with GO-201, and not an altered version, resulted in inhibition of proliferation. GO-201 also induced necrotic cell death that was associated with increases in reactive oxygen species, loss of mitochondrial transmembrane potential, and depletion of ATP. By contrast, GO-201 had no effect against MUC1-negative LNCaP, CWR22Rv1, and MDA-PCa-2b prostate cancer cells. Significantly, GO-201 treatment of DU145 and PC3 xenografts growing in nude mice resulted in complete tumor regression and prolonged lack of recurrence. These findings indicate that certain prostate cancer cells are dependent on MUC1-C for growth and survival and that directly targeting MUC1-C results in their death in vitro and in tumor models.

Modulation of NF-kappaB-dependent gene expression by H2O2: a major role for a simple chemical process in a complex biological response

We recently observed that H2O2 regulates inflammation via upexpression of a few NF-kappaB-dependent genes, while leaving expression of most NF-kappaB-dependent genes unaltered. Here we test the hypothesis that this differential gene expression depends on the apparent affinity of kappaB sites in the gene-promoter regions toward NF-kappaB. Accordingly, cells were transfected with three reporter plasmids containing kappaB sequences with different affinities for NF-kappaB. It was observed that the lower the affinity, the higher the range of TNF-alpha concentrations where H2O2 upregulated gene expression. Mathematical models reproduced the key experimental observations indicating that H2O2 upregulation ceased when NF-kappaB fully occupied the kappaB sites. In vivo, it is predicted that genes with high-affinity sites remain insensitive to H2O2, whereas genes with lower-affinity sites are upregulated by H2O2. In conclusion, a simple chemical mechanism is at the root of a complex biologic process such as differential gene expression caused by H2O2.

Direct targeting of the mucin 1 oncoprotein blocks survival and tumorigenicity of human breast carcinoma cells

The mucin 1 (MUC1) oncoprotein is aberrantly overexpressed by approximately 90% of human breast cancers. However, there are no effective agents that directly inhibit MUC1 and induce death of breast cancer cells. We have synthesized a MUC1 inhibitor (called GO-201) that binds to the MUC1 cytoplasmic domain and blocks the formation of MUC1 oligomers in cells. GO-201, and not an altered version, attenuates targeting of MUC1 to the nucleus of human breast cancer cells, disrupts redox balance, and activates the DNA damage response. GO-201 also arrests growth and induces necrotic death. By contrast, the MUC1 inhibitor has no effect on cells null for MUC1 expression or nonmalignant mammary epithelial cells. Administration of GO-201 to nude mice bearing human breast tumor xenografts was associated with loss of tumorigenicity and extensive necrosis, which results in prolonged regression of tumor growth. These findings show that targeting the MUC1 oncoprotein is effective in inducing death of human breast cancer cells in vitro and in tumor models.

Dicamba-induced genotoxicity in Chinese hamster ovary (CHO) cells is prevented by vitamin E

In the present study the cytogenetic and genotoxic effect of benzoic herbicide dicamba and its Argentinean commercial formulation banvel (57.71% dicamba) was evaluated and whether this effect is mediated through oxidative damage or not. The protective role of vitamin E was also studied. Sister chromatid exchange (SCE) frequency, cell-cycle progression, and cell viability analyses in CHO cells were used as in vitro end-points. Treatments with the test compounds were performed either during 24h (Protocol A) or 12h (Protocol B) before harvesting. Protocol A showed that vitamin E decreased pesticide SCE induction, corrected the cell-cycle delay and partially protected cell-death only in 500 microg/ml dicamba-treated cultures. A similar trend was found in banvel-treated cultures. Protocol B revealed similar protective role of vitamin E only for dicamba-induced geno- and cytotoxicity. Based on these observations it could be suggested that dicamba injures DNA by delivering reactive oxygen species rather than by another type of mechanism/s. Although banvel mimics the effect observed by dicamba, its formulation contains other xenobiotic/s agents able to induce cellular and DNA damage by a different mechanism/s. Further investigations are needed to acquire a comprehensive knowledge of the possible mechanism/s through dicamba and banvel exert their toxic effects.

SMI of Bcl-2 TW-37 is active across a spectrum of B-cell tumors irrespective of their proliferative and differentiation status

The Bcl-2 family of proteins is critical to the life and death of malignant B-lymphocytes. Interfering with their activity using small-molecule inhibitors (SMI) is being explored as a new therapeutic strategy for treating B-cell tumors. We evaluated the efficacy of TW-37, a non-peptidic SMI of Bcl-2 against a range spectrum of human B-cell lines, fresh patient samples and animal xenograft models. Multiple cytochemical and molecular approaches such as acridine orange/ethidium bromide assay for apoptosis, co-immunoprecipitation of complexes and western blot analysis, caspase luminescent activity assay and apoptotic DNA fragmentation assay were used to demonstrate the effect of TW-37 on different B-cell lines, patient derived samples, as well as in animal xenograft models. Nanomolar concentrations of TW-37 were able to induce apoptosis in both fresh samples and established cell lines with IC50 in most cases of 165-320 nM. Apoptosis was independent of proliferative status or pathological classification of B-cell tumor. TW-37 was able to block Bim-Bcl-XL and Bim-Mcl-1 heterodimerization and induced apoptosis via activation of caspases -9, -3, PARP and DNA fragmentation. TW-37 administered to tumor-bearing SCID mice led to significant tumor growth inhibition (T/C), tumor growth delay (T-C) and Log10kill, when used at its maximum tolerated dose (40 mg/kg x 3 days) via tail vein. TW-37 failed to induce changes in the Bcl-2 proteins levels suggesting that assessment of baseline Bcl-2 family proteins can be used to predict response to the drug. These findings indicate activity of TW-37 across the spectrum of human B-cell tumors and support the concept of targeting the Bcl-2 system as a therapeutic strategy regardless of the stage of B-cell differentiation.

Apoptosis and haemorrhagic shock

Abstract

This is a review paper that provides an overview of current information on programmed cell death in haemorrhagic shock, including the identification of different molecular receptor signals. A PubMed search for all dates was undertaken using the search terms apoptosis, trauma and haemorrhagic shock. Original research, sentinel and review papers from peer-reviewed journals were included for identification of key concepts. Haemorrhagic shock remains a primary cause of death in civilian and military trauma. Apoptosis is accelerated following haemorrhagic shock. Many methods are used to detect and quantify apoptosis. Fluid resuscitation regimens vary in their effect on the extent of apoptosis. Investigators are examining the effects of haemorrhagic shock and fluid resuscitation on apoptotic signalling pathways. Molecular information is becoming available and being applied to the care of patients experiencing haemorrhagic shock, making it essential for nurses and other health care providers to consider the mechanisms and consequences of apoptosis.

Duchesnea phenolic fraction inhibits in vitro and in vivo growth of cervical cancer through induction of apoptosis and cell cycle arrest

Duchesnea indica (Andr.) Focke has been commonly used to treat cancer in Asian countries for centuries, and recently has been shown to possess anticancer properties in vitro and in vivo. But the underlying mechanism of the anticancer action is unclear, especially in in vivo studies. In this study, we investigated the anticancer effect and associated mechanisms of Duchesnea phenolic fraction (DPF) on cervical cancer in vitro and in vivo. Our results showed that DPF significantly inhibited cervical cancer cell proliferation in dose- and time-dependent manners. DPF induced apoptosis as determined by AO/EB staining, DNA fragmentation and flow cytometry. Some apoptosis correlated proteins were altered following DPF treatment. Bax was up-regulated while Bcl-2 was down-regulated, and the expression ratio of Bax/Bcl-2 was increased. These resulted in the translocation of Bax to mitochondria, the release of cytochrome c from the mitochondria to the cytosol and caspase-3 activation. Concurrently, DPF provoked S phase arrest along with significant down-regulation of S phase-associated proteins, such as cyclin A, cyclin E, cyclin D1 and cdk2. Transplanted U14 cervical cancer mouse model was used to evaluate the antitumor effect of DPF in vivo. Compared with control, DPF treatment markedly prolonged survival of tumor-bearing mice and dose-dependently reduced the tumor weight. DPF could induce apoptosis in tumor tissues as evidenced by increased TUNEL-positive cells, activation of caspase-3, up-regulation of Bax and down-regulation of Bcl-2. In addition, DPF significantly decreased the expression of cell proliferation markers PCNA and ki67 in tumors. All together, these data sustain our contention that DPF has anticancer properties and merits further investigation as a potential therapeutic agent.

hKSR-2, a vitamin D-regulated gene, inhibits apoptosis in arabinocytosine-treated HL60 leukemia cells

Ras signaling can be modulated by the scaffolding activity of kinase suppressor of Ras-1 (KSR-1) and by the hKSR-2 protein, resulting in diverse phenotypic outcomes. The mitogen-activated protein kinase cascade downstream from Ras and KSRs includes Raf-1 and extracellular signal-regulated kinase 1/2 kinases, known to enhance survival potential of a range of cell types. Because the molecular events that increase survival of HL60 cells induced to differentiate toward monocytic phenotype by 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] are not known, we investigated if KSR proteins provide a survival function in these cells. We found that whereas kinase suppressor of Ras-1 had no detectable effect on cell survival in the system studied here, 1,25-(OH)2D3-induced up-regulation of hKSR-2 enhanced the resistance of HL60 cells to arabinocytosine. Knockdown of hKSR-2 by either small interfering RNA or antisense oligonucleotides increased arabinocytosine-induced apoptosis, which was accompanied by reduced Bcl-2/Bax and Bcl-2/Bad ratios, and increased caspase-3 activating cleavage. In contrast, up-regulation of Mcl-1 was not abrogated by anti-sense (AS) AS-hKSR-2, pointing to a specific role of Bcl-2 in control of 1,25-(OH)2D3-induced increased cell survival. These findings are consistent with the previously shown lack of fully differentiated monocytic cells in HL60 cultures exposed to 1,25-(OH)2D3 in which hKSR-2 was knocked down, suggesting that optimal differentiation of these cells requires enhanced antiapoptotic mechanisms provided, at least in part, by hKSR-2. Collectively, these results suggest that hKSR-2 may offer a new target for novel therapies of acute myelogenous leukemia.