In vivo activated caspase-3 cleaves PARP-1 in rat liver after administration of the hepatocarcinogenN-nitrosomorpholine (NNM) generating the 85 kDa fragment

Longitudinal and simultaneous profiling of 11 modes of cell death in mouse retina post-optic nerve injury

Retinal ganglion cell (RGC) death is a critical pathological trigger leading to irreversible visual impairment and blindness after optic nerve (ON) injury. Yet, there is still no effective clinical treatment to rescue RGC death after ON injury. Understanding the involvement of different modes of cell death post-ON injury could facilitate the development of targeting treatments against RGC death. Herein we aimed to characterize the regulation of 11 modes of cell death simultaneously and longitudinally in mouse retina post-ON injury. The number of RGCs gradually decreased from Day 3-14 in mice post-ON injury. Increase in the apoptosis (cleaved caspase-3), autolysis (cleaved cathespin B) and pyroptosis (cleaved caspase-1) marker expression in the retina began at Day 3 post-ON injury. Meanwhile, the markers for autophagy (Atg7 and Becn1) and phagocytosis (Mfge8 and Mertk) were downregulated from Day 1 to Day 5. Additionally, the expression of ferroptosis marker (4-hydroxynonenal) was upregulated from Day 7 to Day 14 post-ON injury following the early reduction of Gpx4. Yet, the reduction of parthanatos, sarmoptosis, and mitochondrial permeable transition could be related to autophagy and apoptosis. The markers for necroptosis did not show significant changes post-ON injury. In summary, this study revealed that the activation of apoptosis, autolysis, pyroptosis and ferroptosis, together with the early downregulation of autophagy and phagocytosis, are the major modes of cell death involved in the RGC death post-ON injury. Simultaneously targeting multiple modes of cell death at different time courses could be a potential treatment approach against RGC death for traumatic optic neuropathy.

Effect of Methyl Gallate on 1-Nitropyrene-Induced Keratinocyte Toxicity in a Human and Canine Skin Model

The skin, which is the largest organ of the human body, is in direct contact with pollutants in the surrounding atmosphere. Meanwhile, 1-nitropyrene (1-NP), the most abundant nitro-polycyclic aromatic hydrocarbon found in particulate matter, is known to have carcinogenic effects; however, studies on its toxicity in human and canine skin are still needed. In this study, we investigated 1-NP-induced apoptosis and inflammatory pathways in HaCaT cells. In addition, we also measured the cytoprotective effect of methyl gallate (MG), which is widely distributed in medicinal and edible plants and is well known for its anti-inflammatory and antioxidant properties. MG inhibited 1-NP-induced cell death and apoptosis pathways, including the cleavage of PARP and activation of caspase-3, -7, and -9. MG also suppressed 1-NP-induced COX-2 expression and phosphorylation of mitogen-activated protein kinases (MAPKs) and MAPK kinases (MAPKKs). Our findings suggest that 1-NP induces skin toxicity in human and canine through apoptosis and inflammatory responses, and moreover, that this can be prevented by treatment with MG.

Understanding the mechanism of amygdalin's multifunctional anti-cancer action using computational approach

Amygdalin possesses anticancer properties and induces apoptosis. Based on experimental studies the presence of amygdalin with cancer cells led to activate the caspase-3 and BAX and inhibits Bcl-2 and Poly (ADP-ribose) polymerase-1 (PARP-1) but without deep information on action mode of these activities. Herein, we leaped forward to examine the molecular dynamics of the bound amygdalin and free ligand proteins, to identify precise action (conformation changes in targeted proteins) of amygdalin through using double docking and molecular dynamics (MD) simulations for 50 ns time scale. The MD simulations revealed that the binding of amygdalin led to disrupting the interaction between the Bcl-2/BAX complex. We furthermore conducted MD simulation for Bcl-2/amygdalin to investigate the stability of the complex which is responsible for inhibition of Bcl-2. It has been obtained a stable Bcl-2/amygdalin complex during the 50 ns. The results give a detail explanation of how amygdalin activates BAX and inhibits Bcl-2. For caspase-3, the matter is different, we found that amygdalin led to disrupting the interaction of caspase-3's two chains for intervals during 50 ns and then bind together repeatedly. The mechanism of caspase-3's activation through switching by disrupt the interacts for periodic intervals manner. For PARP-1, the dynamics simulations results indicated amygdalin interacts with PARP-1's binding site and forms stable interaction during simulation to render it inactive. Hence, amygdalin revealed a supernatural behavior through the MD simulations: it revealed a further clarification of the mystery amygdalin's experimental action which can act as a multifunctional drug in the cancer therapeutics.Communicated by Ramaswamy H. Sarma.

Effects Of Adenosine On Apoptosis Of Ovarian Cancer A2780 Cells Via ROS And Caspase Pathways

Background

Ovarian cancer is the second most common malignant tumor of the female genital tract and the main cause of death of gynecological malignant tumors. Exogenous adenosine has been shown to induce apoptosis in tumor cells.

Materials and methods

The current study aimed to investigate the inhibitory effect and underlying mechanism of adenosine on the proliferation of ovarian cancer cells. The inhibitory effects of adenosine on ovarian cancer cells were assessed through MTT assay. The adenosine-induced apoptosis was determined by Hoechst 33342 staining and flow cytometry. The effect of adenosine on the intracellular reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) was assessed according to the DCFH-DA and JC-1 methods, respectively. Expression of apoptosis-related proteins and mitochondrial proteins was measured using Western blotting.

Results

MTT suggested that adenosine inhibited A2780 and SKOV3 cells viability in a dose- and time-dependent manner (P<0.05). Hoechst 33342 staining had demonstrated pronounced changes in cell morphology; to be specific, cells treated with 0 mmol/L adenosine showed a light blue color, while those in treatment groups had nuclear pyknosis and apoptotic body formation. Besides, the apoptosis rate was positively correlated with adenosine concentration (P<0.05). Flow cytometry results revealed that adenosine increased the intracellular ROS level and decreased MMP. Western blotting indicated that, the expression of Bax, cleaved-caspase-3 and cleaved-poly (ADP-ribose) polymerase was up-regulated with the increase in adenosine concentration, while that of Bcl-2 protein and apoptosis-related protein caspase-3 was down-regulated.

Conclusion

With the increase in drug concentration, the CytoC expression in mitochondria was gradually reduced, while that in the cytoplasm was gradually increased. In conclusion, Ado may inhibit the proliferation and induce the apoptosis of ovarian cancer cells by increasing ROS, up-regulating the pro-apoptotic protein Bax and activating the caspase-3 expression in vitro.

The protective effects of total paeony glycoside on ischemia/reperfusion injury in H9C2 cells via inhibition of the PI3K/Akt signaling pathway

At present, cardiovascular disease is the global leading cause of mortality. Total paeony glycoside (TPG) is a traditional Chinese medicine, which serves a pivotal role in the cardiovascular system. In the present study, the effects and underlying mechanisms of TPG on ischemia/reperfusion (I/R) injury-induced apoptosis of cardiomyocytes were investigated in vitro. Cell Counting kit-8 and flow cytometry were used to assess the viability, reactive oxygen species (ROS) content and apoptosis of H9C2 cells. The activities of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPX) were analyzed by commercial detection kits. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were conducted to evaluate the expression levels of various factors. The results demonstrated that the viability of H9C2 cells was not significantly altered in response to various concentrations of TPG. However, following I/R injury, TPG markedly enhanced cell viability in a time- and dose-dependent manner. Furthermore, TPG decreased the rate of apoptosis and ROS levels, and reduced the activities of MDA and LDH. Conversely, TPG increased SOD and GPX activities. In addition, TPG upregulated the expression levels of pro-caspase-3 and B-cell lymphoma2 (Bcl-2), whereas it downregulated cleaved-caspase-3, poly (ADP-ribose) polymerase 1, Bcl-2-associated X protein, phosphorylated (p)-phosphatidylinositol 3 kinase (PI3K) and p-protein kinase B (Akt) expression. Treatment with insulin-like growth factor-1 increased the apoptosis of H9C2 cells, thus suggesting that activation of the PI3K/Akt signaling pathway reversed the protective effects of TPG. Taken together, TPG may suppress I/R-induced apoptosis and oxidative stress of H9C2 cells possibly by inhibiting the PI3K/Akt signaling pathway; such a phenomenon may have a therapeutic effect on cardiovascular disease.

The HSP90 inhibitor, NVP-AUY922, attenuates intrinsic PI3K inhibitor resistance in KRAS-mutant non-small cell lung cancer

More than 25% of non-small cell lung cancers (NSCLCs) carry mutations in KRAS, one of the most common oncogenic drivers in this disease. KRAS-mutant NSCLC responds poorly to currently available therapies; therefore, novel treatment strategies are needed. Here, we describe a particularly promising targeted therapeutic strategy against KRAS mutation-harboring NSCLC intrinsically resistant to treatment by PI3K inhibition. We found that intrinsic resistance to PI3K inhibition derived from RAF/MEK/ERK and RSK activation, bypassing blockage of the PI3K/AKT/mTOR pathway. The HSP90 inhibitor AUY922 suppressed both PI3K/AKT/mTOR and RAF/MEK/ERK signaling, rendering cells sensitive to a PI3K inhibitor (omipalisib, GSK458). Combining these two drugs achieved a synergistic effect, even using only sub-therapeutic concentrations. Dual inhibition of the HSP90 and PI3K signaling pathways with sub-therapeutic doses of these combined anticancer drugs may represent a potent treatment strategy for KRAS-mutant NSCLC with intrinsic resistance to PI3K inhibition.

Novel N-Substituted 2-(2-(Adamantan-1-yl)-1H-Indol-3-yl)-2-Oxoacetamide Derivatives: Synthesis and Biological Evaluation

In this study, a series of novel N-substituted 2-(2-(adamantan-1-yl)-1H-indol-3-yl)-2-oxoacetamide derivatives were synthesized, and evaluated for their cytotoxicity in human cell lines including Hela (cervical cancer), MCF7 (breast cancer ) and HepG2 (liver cancer). Several compounds were found to have potent anti-proliferative activity against those human cancer cell lines and compound 5r showed the most potent biological activity against HepG2 cells with an IC50 value of 10.56 ± 1.14 μΜ. In addition, bioassays showed that compound 5r induced time-dependent and dose-dependent cleavage of poly ADP-ribose polymerase (PARP), and also induced a dose-dependent increase in caspase-3 and caspase-8 activity, but had little effect on caspase-9 protease activity in HepG2 cells. These results provide evidence that 5r-induced apoptosis in HepG2 cell is caspase-8-dependent.

Thymoquinone as an anticancer agent: evidence from inhibition of cancer cells viability and invasion in vitro and tumor growth in vivo

Phytochemical compounds are emerging as a new generation of anticancer agents with limited toxicity in cancer patients. The purpose of this study was to investigate the potential impact of thymoquinone (TQ), the major constituent of black seed, on survival, invasion of cancer cells in vitro, and tumor growth in vivo. Exposure of cells derived from lung (LNM35), liver (HepG2), colon (HT29), melanoma (MDA-MB-435), and breast (MDA-MB-231 and MCF-7) tumors to increasing TQ concentrations resulted in a significant inhibition of viability through the inhibition of Akt phosphorylation leading to DNA damage and activation of the mitochondrial-signaling proapoptotic pathway. We provide evidence that TQ at non-toxic concentrations inhibited the invasive potential of LNM35, MDA-MB-231, and MDA-MB231-1833 cancer cells. Moreover, we demonstrate that TQ synergizes with DNA-damaging agent cisplatin to inhibit cellular viability. The anticancer activity of thymoquinone was also investigated in athymic mice inoculated with the LNM35 lung cells. Administration of TQ (10 mg/kg/i.p.) for 18 days inhibited the LNM35 tumor growth by 39% (P < 0.05). Tumor growth inhibition was associated with significant increase in the activated caspase-3. The in silico target identification suggests several potential targets of TQ mainly HDAC2 proteins and the 15-hydroxyprostaglandin dehydrogenase. In this context, we demonstrated that TQ treatment resulted in a significant inhibition of HDAC2 proteins. In view of the available experimental findings, we contend that thymoquinone and/or its analogues may have clinical potential as an anticancer agent alone or in combination with chemotherapeutic drugs such as cisplatin.

Insulin-like growth factor receptor-1 and nuclear factor κB are crucial survival signals that regulate caspase-3-mediated lens epithelial cell differentiation initiation

It is now known that the function of the caspase family of proteases is not restricted to effectors of programmed cell death. For example, there is a significant non-apoptotic role for caspase-3 in cell differentiation. Our own studies in the developing lens show that caspase-3 is activated downstream of the canonical mitochondrial death pathway to act as a molecular switch in signaling lens cell differentiation. Importantly, for this function, caspase-3 is activated at levels far below those that induce apoptosis. We now have provided evidence that regulation of caspase-3 for its role in differentiation induction is dependent on the insulin-like growth factor-1 receptor (IGF-1R) survival-signaling pathway. IGF-1R executed this regulation of caspase-3 by controlling the expression of molecules in the Bcl-2 and inhibitor of apoptosis protein (IAP) families. This effect of IGF-1R was mediated through NFκB, demonstrated here to function as a crucial downstream effector of IGF-1R. Inhibition of expression or activation of NFκB blocked expression of survival proteins in the Bcl-2 and IAP families and removed controls on the activation state of caspase-3. The high level of caspase-3 activation that resulted from inhibiting this IGF-1R/NFκB signaling pathway redirected cell fate from differentiation toward apoptosis. These results provided the first evidence that the IGF-1R/NFκB cell survival signal is a crucial regulator of the level of caspase-3 activation for its non-apoptotic function in signaling cell differentiation.

Synergistic effects of erlotinib and everolimus on bronchial carcinoids and large-cell neuroendocrine carcinomas with activated EGFR/AKT/mTOR pathway

BACKGROUND

Epidermal growth factor receptor (EGFR) and mammalian target of rapamycin (mTOR) are crucial targets in cancer therapy. Combined inhibition of both targets yielded synergistic effects in vitro and in vivo in several cancer entities. However, the impact of EGFR and mTOR expression and combined inhibition in neuroendocrine lung tumors other than small-cell lung cancer remains unclear.

MATERIAL AND METHODS

Expression and activation of EGFR/AKT/mTOR pathway constituents were investigated in typical and atypical bronchial carcinoid (AC) tumors and large-cell neuroendocrine lung carcinomas (LCNEC) by immunohistochemistry in 110 tumor samples, and correlated with clinicopathological parameters and patient survival. Cytotoxicity of mTOR inhibitor everolimus and EGFR inhibitor erlotinib alone and in combination was assessed using growth inhibition assay in NCI-H720 AC and SHP-77 LCNEC cells. Cell cycle phase distribution was determined by FACS. Apoptosis-associated activation of caspase-3/7 was measured by Caspase-Glo® assay. Activity status of EGFR and mTOR pathway components was analyzed by immunoblotting.

RESULTS

Activation of the EGFR/AKT/mTOR axis could be demonstrated in all entities and was significantly increased in higher grade tumors. Neoadjuvant chemotherapy correlated significantly with p-AKT expression and p-ERK loss. Erlotinib combined with everolimus exerted synergistic combination effects in AC and LCNEC cells by induction of apoptosis, while cell cycle phase distribution remained unaffected. These effects could be explained by synergistic downregulation of phospho-mTOR, phospho-p70S6 kinase and phospho-AKT expression by everolimus and erlotinib.

CONCLUSIONS

Our study indicates that EGFR and mTOR are clinically important targets in bronchial neuroendocrine tumors, and further in vivo and clinical exploration of combined inhibition is warranted.

Pituitary adenylate cyclase-activating polypeptide ameliorates cisplatin-induced acute kidney injury

Cisplatin nephrotoxicity involves DNA damage, proinflammatory responses and apoptosis/necrosis of renal proximal tubular epithelial cells. Pituitary adenylate cyclase-activating polypeptide (PACAP) has been shown to protect kidneys from ischemic injury and light chain-induced damage by modulating inflammation. Confluent monolayer of HK-2 human renal cells were exposed to 50 microM cisplatin in the presence or absence of either PACAP38 or p53 siRNA. Mice injected with cisplatin were also treated with PACAP38 daily for 3 days. The damage to HK-2 cells caused by cisplatin involved the activation of p53, caspase-7, and poly (ADP-ribose) polymerase-1 (PARP-1). PACAP38 prevented the decrease in the apurinic/apyrimidinic endonuclease-1 by suppressing p53 activation and blocked the cleavage of caspase-7 and PARP-1 in cisplatin-exposed cells. PACAP also markedly inhibited cisplatin-induced apoptotic tubule cell death. Exposure to cisplatin significantly suppressed the expression of fibronectin and collagens I and IV, and altered the integrin repertoire of human renal tubule cells, while PACAP partially reversed the reduction of fibronectin, collagen IV, and the integrin subunits in cells exposed to cisplatin. Experiments with PACAP receptor antagonists and siRNA silencing of p53 showed that the renoprotection with PACAP was mediated by the PAC(1) receptor and through both p53-dependent and -independent suppression of apoptosis. PACAP was renoprotective in vivo and prevented the rise in blood urea nitrogen and creatinine in mice treated with cisplatin. These results suggest that p53 plays a pivotal role in decreased integrin-mediated extracellular matrix component expression in cisplatin-induced tubule cell apoptosis, and reveal a novel aspect of PACAP-mediated renoprotection.

Calpain plays a central role in 1-methyl-4-phenylpyridinium (MPP+)-induced neurotoxicity in cerebellar granule neurons

1-Methyl-4-phenylpyridinium (MPP(+))-induced neurotoxicity has previously been attributed to either caspase-dependent apoptosis or caspase-independent cell death. In the current study, we found that MPP(+) induces a unique, non-apoptotic nuclear morphology coupled with a caspase-independent but calpain-dependent mechanism of cell death in primary cultures of rat cerebellar granule neurons (CGNs). Using a terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) assay in CGNs exposed to MPP(+), we observed that these neurons are essentially devoid of caspase-dependent DNA fragments indicative of apoptosis. Moreover, proteolysis of a well recognized caspase-3 substrate, poly (ADP ribose) polymerase (PARP), was not observed in CGNs exposed to MPP(+). In contrast, calpain-dependent proteolysis of fodrin and pro-caspases-9 and -3 occurred in this model coupled with inhibition of caspase-3/-7 activities. Notably, several key members of the Bcl-2 protein family appear to be prominent calpain targets in MPP(+)-treated CGNs. Bid and Bax were proteolyzed to truncated forms thought to have greater pro-death activity at mitochondria. Moreover, the pro-survival Bcl-2 protein was degraded to a form predicted to be inactive at mitochondria. Cyclin E was also cleaved by calpain to an active low MW fragment capable of facilitating cell cycle re-entry. Finally, MPP(+)-induced neurotoxicity in CGNs was significantly attenuated by a cocktail of calpain and caspase inhibitors in combination with the antioxidant glutathione. Collectively, these results demonstrate that caspases do not play a central role in CGN toxicity induced by exposure to MPP(+), whereas calpain cleavage of key protein targets, coupled with oxidative stress, plays a critical role in MPP(+)-induced neurotoxicity. Our findings underscore the complexity of MPP(+)-induced neurotoxicity and suggest that calpain may play a fundamental role in causing neuronal death downstream of mitochondrial oxidative stress and dysfunction.

Combined treatment of Caco-2 cells with butyrate and mesalazine inhibits cell proliferation and reduces Survivin protein level

There is epidemiological evidence, that mesalazine can inhibit colon cancer development by affecting proliferation and apoptosis. Several studies suggest that supplementary intake of butyrate may yield to improved efficacy of mesalazine. However, the underlying molecular mechanisms of such interaction remain unknown. This study addressed the combinatory effect of both substances on the growth of Caco-2 cells. Challenging of cells with mesalazine and butyrate provoked a time-dependent decrease in both cell counts and proliferation. Co-treatment with the substances could further intensify these effects. The growth-inhibitory action of mesalazine and butyrate was accompanied by a significant increase in caspase-3 activity, cleavage of PARP and caspase-8, while decreasing the expression of Xiap and Survivin simultaneously. Co-incubation of both substances exaggerated effects on all examined apoptosis-regulatory proteins except for Xiap. Our data demonstrate that co-treatment of mesalazine and butyrate evoked additive effects on inhibition of cell growth and induction of apoptosis in Caco-2 cells.

Paraquat-induced apoptosis in human neuroblastoma SH-SY5Y cells: involvement of p53 and mitochondria

The herbicide paraquat is a suspected etiologic factor in the development of Parkinson's disease (PD). Paraquat was therefore used to reproduce Parkinsonian syndromes in lab animals, in which it produces dopaminergic pathogenesis. However, the factors or mechanisms by which paraquat kills dopaminergic neurons are not fully understood. Based on reported evidence that paraquat increases p53 protein levels and inhibits mitochondrial function, it was hypothesized that paraquat induces cell death in dopaminergic neurons through a mechanism in which p53 and mitochondrial apoptotic pathway are linked. To explore this possibility, dopaminergic SY5Y cells were treated with paraquat for 48 h and p53 responses were investigated, as well as biomarkers of the mitochondrial intrinsic pathway of apoptosis. Paraquat significantly increased protein levels of p53 and one of its target genes, Bax. By 24 h, paraquat decreased mitochondrial complex I activity and mitochondrial transmembrane potential and induced the release of cytochrome c from mitochondria. In addition, paraquat increased the activities of caspases 9 and 3. Finally, nuclear condensation and DNA fragmentation occurred 48 h after treatment. The decrease of mitochondrial functions, the release of cytochrome c, the increase of caspase 9 and 3 activities, and DNA damage that were produced by paraquat were inhibited by a specific p53 inhibitor, pifithrin-alpha. These findings support the conclusion that paraquat produced apoptosis in SY5Y cells through the mitochondrial intrinsic pathway associated with p53.

PPARgamma is a key target of butyrate-induced caspase-3 activation in the colorectal cancer cell line Caco-2

BACKGROUND

Butyrate, a potent histone deacetylase inhibitor, belongs to a promising new class of antineoplastic agents with the capacity to induce apoptosis of cancer cells. However, the underlying mechanisms of action have yet not been elucidated.

AIM

To further investigate the molecular events involved in butyrate-induced caspase-3 activation in Caco-2 wild-type, empty-vector and dominant-negative PPARgamma mutant cells along the signalling pathway. In this context, the involvement and up-regulation of PPARgamma was examined.

RESULTS

Stimulation of cells with butyrate resulted in increased expression of PPARgamma mRNA, protein, and activity as well as phospho-p38 MAPK protein expression and caspase-3 activity. Arsenite, a direct stimulator of p38 MAPK, also led to an increased PPARgamma expression, thereby mimicking the effects of butyrate. In contrast, butyrate-mediated up-regulation of PPARgamma was counteracted by co-incubation with the p38 MAPK inhibitor SB203580. Treatment of cells with butyrate resulted in both increased caspase-8 and -9 activity and reduced expression of XIAP and survivin. However, butyrate-mediated effects on these apoptosis-regulatory proteins leading to caspase-3 activation were almost completely abolished in Caco-2 dominant-negative PPARgamma mutant cells.

CONCLUSIONS

Our data clearly unveil PPARgamma as a key target in the butyrate-induced signalling cascade leading to apoptosis via caspase-3 in Caco-2 cells.

IFNgamma expression inhibits LHBs storage disease and ground glass hepatocyte appearance, but exacerbates inflammation and apoptosis in HBV surface protein-accumulating transgenic livers

BACKGROUND/AIMS

Interferon gamma (IFNgamma) controls hepatitis B virus replication. As systemic application may cause severe adverse effects, approaches of liver-directed IFNgamma gene therapy may represent an attractive alternative for treatment of chronic viral hepatitis B and thus needs testing in vivo in suitable animal models.

METHODS

We therefore crossbred Alb-1HBV transgenic mice overexpressing the large HBV surface protein (LHBs) in their livers and developing LHBs storage disease and ground glass hepatocyte appearance with SAP-IFNgamma transgenic animals previously shown to exhibit constitutive hepatic IFNgamma expression, and analyzed the resulting double-transgenic offspring.

RESULTS

We found that IFNgamma coexpression significantly reduced hepatic LHBs expression and thereby inhibited hepatocellular LHBs storage disease and ground glass hepatocyte appearance. The beneficial antiviral IFNgamma effects as observed in Alb1-HBV SAP-IFNgamma double-transgenic livers were associated with significantly elevated serum ALT concentrations, massive mononuclear cell infiltrates, appearance of Councilman bodies, and increased alpha-PARP (poly(ADP-ribose) polymerase cleavage).

CONCLUSIONS

Exacerbation of hepatic necroinflammation and increased hepatocellular apoptosis rate in IFNgamma-expressing Alb1-HBV transgenic livers suggest that special precautions be taken for testing approaches of liver-specific IFNgamma expression in patients with chronic hepatitis B.

Proteomic approach to study the cytotoxicity of dioscin (saponin)

Dioscin, extracted from the root of Polygonatum zanlanscianense pamp, exhibits cytotoxicity towards human myeloblast leukemia HL-60 cells. Proteomic analysis revealed that the expression of mitochondrial associated proteins was substantially altered in HL-60 cells corresponding to the dioscin treatment, suggesting that mitochondria are the major cellular target of dioscin. Mitochondrial functional studies validated that mitochondrial apoptotic pathway was initiated by dioscin treatment. Changes in proteome other than mitochondrial related proteins implicate that other mechanisms were also involved in dioscin-induced apoptosis in HL-60 cells, including the activity impairment in protein synthesis, alterations of phosphatases in cell signaling, and deregulation of oxidative stress and cell proliferation. Current study of protein alterations in dioscin-treated HL-60 cells suggested that dioscin exerts cytotoxicity through multiple apoptosis-inducing pathways.

A new multiplex assay allowing simultaneous detection of the inhibition of cell proliferation and induction of cell death

The efficacy of distinct anti-cancer drugs used in the chemotherapy of human malignancies varies between tumor tissues and depends largely on the ability of the therapeutic agents to simultaneously inhibit cell proliferation and to eliminate malignant cells by apoptosis. Especially, detection of early apoptotic changes seems to be important because early stages of apoptosis differ from those of necrosis. Therefore, the development of a novel test allowing fast and concomitant screening of the anti-proliferative and pro-apoptotic action of a number of anti-cancer drugs is of great interest. For this purpose, we choose as an experimental model a well characterized anti-proliferative and pro-apoptotic effect of cisplatin (CP) on human cervical carcinoma HeLaS3 cells. As previously reported, exposure of HeLaS3 to CP resulted in a concomitant inhibition of cell proliferation and induction of apoptosis in a dose- and time-dependent manner. In the present study we performed two independent approaches. In the first approach, we examined the cell proliferation and activity of caspases-3/7 in two separate microtiter plates using the CellTiter-Glo Luminescent Cell Viability Assay and the Caspase-Glo 3/7 Assay, respectively. In the second approach, we determined the same parameters sequentially in one microtiter plate by a mutiplexing assay using CellTiter-Blue Cell Viability Assay and Caspase-Glo 3/7 Assay. The both approaches gave very similar results indicating that this new multiplexing assay offers an important advantage for simultaneous detection of cell number and activation of caspases-3/7. The new multiplexing assay offers a range of benefits over standard assays.