Active Caspase-3 Protein Expression Research Articles

Modulation of Apoptotic and Akt/PI3K/mTOR pathways to target Glioblastoma Cells using synthetic compound PGEA-AN.

To investigate the anticancer potential of a novel synthetic derivative of a naturally occurring diterpenoid against glioblastoma. The in vitro study was conducted at the Ojha Campus of Dow University of Health Sciences, Karachi, from February to December 2021, and comprised U87 cells. The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine the growth inhibitory effect of 16(R and S) - phenylamino-cleroda3, 13(14) Zdiene- 15, 16 olide and standard drug temozolomide against glioblastoma cells, and half-maximal inhibitory concentration was calculated. Microscopy and immunocytochemistry were used to investigate apoptotic morphology and active caspase-3 and B-cell lymphoma 2 (Bcl-2) expression. Quantitative real time polymerase chain reaction was used to investigate the expression of proliferation markers. Data was analysed using SPSS 21. Both the synthetic derivative and the standard drug significantly inhibited growth of U87 cells (p<0.001) with half-maximal inhibitory concentration of 19μM and 185μM, respectively. Apoptotic morphology and upregulation of active caspase-3 protein expression was observed in cells treated with half-maximal inhibitory concentration doses of both the synthetic derivative (p<0.05) and the standard drug (p<0.001), and Bcl-2 was downregulated in both the synthetic derivative (p<0.01) and the standard drug (p=0.05). However, no significant difference was observed in the expression of proliferation markers (p>0.05). The synthetic diterpene derivative PGEA-AN showed growth inhibitory actiity against glioblastoma.

Opuntiol Inhibits Growth and Induces Apoptosis in Human Glioblastoma Cells by Upregulating Active Caspase 3 Expression.

Background:Glioblastoma Multiforme (GBM) is a deadly tumor with poor prognosis. Resistance to apoptosis considered as an important factor in treatment failure. Therefore, identification of new compounds that facilitates apoptosis is crucial. Natural Anti-inflammatory compounds have emerged as potential anti-cancer agents and should be explored for their apoptotic activity against GBM. Therefore, the present study aims to evaluate growth inhibitory and apoptotic activity of a natural anti-inflammatory compound “Opuntiol” against GBM cell line U87.Methods:MTT assay was performed to determine the effect of Temozolomide and Opuntiol on growth inhibition of U87 cell. While, TUNEL assay was used to assess their apoptotic activity. To further assess apoptosis, nuclear condensation and nuclear area factor (NAF) was evaluated through DAPI staining. Whereas, active caspase-3 protein expression determined using immunocytochemistry. Results:Significant growth inhibition was observed in U87 cells treated with Temozolomide (IC50 380 µM) and Opuntiol (IC50 357 µM). Temozolomide (p<0.001) and Opuntiol (p<0.001) significantly improved rate of apoptosis when compared to control group. A significant decrease in NAF was also observed in Temozolomide (p < 0.05) and Opuntiol (p < 0.05) treated cells. There was a significant increase in active caspase-3 expression when observed in Temozolomide (p<0.001) and Opuntiol (p<0.05) treated groups as compared to control. Conclusion:In conclusion our findings suggests, Opuntiol repress cell viability and possess strong apoptotic activity against GBM cell line U-87. However, further mechanistic studies will be required to confirm whether it can be develop as a potential drug against GBM.

APOPTOSIS INDUCING EFFECT OF SILVER NANOPARTICLES SYNTHESIZED USING MAGNOLIA CHAMPACA LEAF EXTRACT ON MCF-7 CELL LINE

Objective: To synthesize silver nanoparticle (AgNP) using the ethanolic leaf extract of Magnolia champaca (MC-AgNP) and to evaluate its cytotoxicity and apoptotic activity in MCF-7 cell line, and to analyse active Caspase-3 expression in inducing apoptosis.&#x0D; Methods: AgNP was green synthesized using ethanolic leaf extract of MC. Shape and size were analysed by SEM and particle size analyser. Cytotoxicity was tested to find IC50 value. Apoptosis was explored by mitochondrial membrane potential (ΔΨm) assay and active Caspase-3 expression study using flow cytometry.&#x0D; Results: AgNP synthesized was observed to be in spherical shape through SEM micrograph with 164.6 nm in size. IC50 value of 15.90 µg/ml was obtained after 24 h of drug treatment. Changes in ΔΨm and positive active Caspase-3 protein expression were observed.&#x0D; Conclusion: The present results suggest that MC-AgNP has potential anticancer property and also induced cell death via apoptosis through caspase dependent pathway in MCF-7 cells.

Perfluorocarbon Protects against Lipopolysaccharide-Induced Apoptosis of Endothelial Cells in Pulmonary Microvessels.

This study was aimed to explore the effect and mechanisms of action of perfluorocarbon on LPS-induced apoptosis of pulmonary microvascular endothelial cells (PMVEC) isolated from Sprague-Dawley rats. Apoptosis rates were assessed by flow cytometry. Ultrastructural characteristics of PMVEC were evaluated by transmission electron microscopy. The protein expression of cleaved caspase-3 was measured using Western blotting. LPS significantly increased the level of apoptosis, induced the appearance of ultrastructural changes typical of apoptosis, up-regulated the expression of active caspase-3 protein. These effects of LPS were attenuated by co-administration of perfluorocarbon. These results suggest that perfluorocarbon can attenuate LPS-induced apoptosis of PMVEC by inhibiting TLR-4 signaling and caspase-3 activation.

Z-Guggulsterone Induces Apoptosis in Gastric Cancer Cells through the Intrinsic Mitochondria-Dependent Pathway.

Background To study the effects of z-guggulsterone on gastric cancer cell apoptosis and the mechanism related. Materials and Methods Human gastric tumor SGC-7901 cells and GES-1 normal epithelial cells were treated with z-guggulsterone (0–75 μM) for 24 h. MTT assay was applied to evaluate cell proliferation. Flow cytometry and Hoechst staining were used to assess cell apoptosis. Western blotting was applied to evaluate FXR, small heterodimer partner (SHP), Bcl-2, and Bax protein expression. ELISA was applied to gain the levels of active caspase-3 and the contents of TNF-α, TGF-β1, and VEGF. Results The expression levels of FXR and SHP were higher in tumor cells than in normal epithelial cells. Inhibition of FXR signaling with z-guggulsterone dose-dependently inhibited SGC-7901 cell proliferation and promoted SGC-7901 cell apoptosis. Bcl-2 protein expression was significantly decreased, and active caspase-3 and Bax protein expression was increased in SGC-7901 cells incubated with z-guggulsterone. The content of TNF-α was significantly increased, and the contents of VEGF and TGF-β1 were decreased in SGC-7901 cells incubated with z-guggulsterone. Conclusions Inhibition of FXR signaling with z-guggulsterone induced anticancer effects in SGC-7901 cells by decreasing cell proliferation and promoting apoptosis. Z-guggulsterone induced cell apoptosis through the mitochondria-dependent pathway.

Correlation between the granulosa cell layer and active caspase-3 expression in ovarian follicles of Tropidurus hispidus and T. semitaeniatus (Squamata, Tropiduridae): immunohistochemical approach

The greatest threats to terrestrial reptiles are urban development and habitat modification. In this sense, a better understanding of folliculogenesis in these animals would be important to knowledge of reproductive biology. The aim of this study was to analyze the correlation between the thickness of the granulosa cell layer and the expression of the active caspase-3 protein in the previtellogenic and vitellogenic follicles of T. hispidus and T. semitaeniatus . Ovaries were used for histological (morphology and morphometry: thickness of granulosa layer) and immunohistochemical (active caspase-3 expression) analyses. The previtellogenic follicles of T. hispidus and T. semitaeniatus showed a thicker granulosa layer, with pyriform and small cells. The vitellogenic follicles had a monolayer of cuboid cells, and a thicker thecal layer. The thickness of the granulosa layer was significantly higher in the previtellogenic compared to the vitellogenic phase for both species. However, no differences were observed between the species. Active caspase-3 was observed in the pyriform and intermediate cells in previtellogenesis of T. hispidus and T. semitaeniatus . Nevertheless, no immunostaining was observed in the vitellogenic phase in both species. In conclusion, this study shows that the thickness of the granulosa cell layer is higher in the previtellogenic follicles compared to the vitellogenic follicles in the two Tropidurus species. Pyriform and intermediate cells from previtellogenic follicles show high expression of the protein, indicating that remodeling of the epithelium is associated with apoptosis. Finally, our results provide a scientific basis for assisted reproductive techniques and conservation actions to the reptiles in the future.

Alpha lipoic acid attenuates iron induced oxidative acute kidney injury in rats

ABSTRACT Iron has been implicated in oxidative tissue injury owing to its ability to generate reactive oxygen species (ROS). We investigated the reno-protective effects of alpha lipoic acid (ALA) by investigating its effects on the kidney isoform of NADPH oxidase (Nox4) and the specific signaling pathways, p38 MAPK and PI3K/Akt, which participate in apoptosis and survival, respectively. We established four groups of seven rats: control, 100 mg/kg ALA, 80 mg/kg iron sucrose (IS) and IS + ALA. IS and ALA were injected intravenously and rats were sacrificied after 6 h. The mRNA expression of the subunits of NADPH oxidase, Nox4 and p22phox; tumor necrosis factor-alpha (TNF-α); and kidney injury molecule-1 (KIM-1) were measured using quantitative real time polymerase chain reaction (qRT-PCR). Active caspase-3 protein expression was evaluated by immunostaining. Also, p38 MAPK and PI3K/Akt signaling pathways were analyzed using western blot. ALA suppressed the mRNA expression of Nox4, p22phox, TNF-α and KIM-1. Active caspase-3 protein expression induced by IS was decreased by ALA. ALA also suppressed p38 MAPK and activated the PI3K/Akt signaling pathway following IS administration. We found that ALA may be an effective strategy for preventing oxidative acute kidney injury caused by IS.

AMPK/mTOR/ULK1 Axis-Mediated Pathway Participates in Apoptosis and Autophagy Induction by Oridonin in Colon Cancer DLD-1 Cells.

BackgroundOridonin has been demonstrated to exert strong antitumor activities in various types of human cancers. Our previous study established that oridonin induced the apoptosis of and exerted an inhibitory effect on colon cancer cells in vitro and in vivo. However, the mechanisms behind the antitumor effects of oridonin on colorectal cancer are not clearly known. This study explored whether autophagy was involved in antitumorigenesis effects caused by the usage of oridonin in colon cancer and examined whether the AMPK/mTOR/ULK1 signaling pathway was involved in this process.MethodsCell viability was determined using CCK-8 assay. The distribution of cell apoptosis was evaluated using flow cytometry. RT-PCR and Western blotting analysis were conducted to identify the key target genes and proteins involved in the AMPK/mTOR cascade. AMPK siRNA was used to disturb AMPK expression. A DLD-1 cell orthotopic transplantation tumor model was established to explore the anti-cancer effects in vivo.ResultsOridonin exhibited a suppressive effect on DLD-1 cells in a concentration- and time-dependent manner. Additionally, in a dose-dependent manner, oridonin induced cell apoptosis via inducing the protein expression levels of cleaved caspase-3, cleaved PARP and stimulated autophagy by increasing protein expression levels of Becin1, LC3-II, decreasing protein expression levels of LC3-I, p62, which were respectively attenuated and elevated by autophagy inhibitor 3-MA. Furthermore, oridonin upregulated the expression level of p-AMPK and downregulated the expression levels of p-mTOR, p-ULK1 in the DLD-1 cells in a dose-dependent manner. Moreover, knockdown of AMPK by a specific siRNA reversed the expression levels of proteins involved in the AMPK/mTOR pathway, autophagy and apoptosis. In addition, outcomes from the in vivo experiments also showed that oridonin treatment significantly repressed tumorigenic growth of DLD-1 cells without any side effects, which was accompanied by the upregulation of p-AMPK, LC3-II, active caspase-3 protein expression levels and the downregulation of p-mTOR and p-ULK1 protein expression levels.ConclusionThis study demonstrated that oridonin induced apoptosis and autophagy of colon cancer DLD-1 cells via regulating the AMPK/mTOR/ULK1 pathway, which indicated that oridonin may be used as a novel therapeutic intervention for patients with colorectal cancer.

Lactobacillus reuteri ZJ617 Culture Supernatant Attenuates Acute Liver Injury Induced in Mice by Lipopolysaccharide

Lactobacillus rhamnosus GG culture supernatant (LGGs) promotes intestinal integrity and ameliorates acute liver injury induced by alcohol in mice. The aim of this study was to investigate the protective effects and molecular mechanisms of Lactobacillus reuteri ZJ617 culture supernatant (ZJ617s) on acute liver injury induced by lipopolysaccharide (LPS) in mice. Male C57BL/6 mice (20±2 g, 8 wk old) were randomly divided into 4 groups (6 mice/group): oral inoculation with phosphate-buffered saline (control), intraperitoneal injection of LPS (10 mg/kg body weight) (LPS), oral inoculation with ZJ617s 2 wk before intraperitoneal injection of LPS (ZJ617s+LPS), or oral inoculation with LGGs 2 wk before intraperitoneal injection of LPS (LGGs+LPS). Systemic inflammation, intestinal integrity, biomarkers of hepatic function, autophagy, and apoptosis signals in the liver were determined. Twenty-four hours after LPS injection, the activities of serum alanine transaminase and aspartate transaminase were 32.2% and 30.3% lower in the ZJ617s+LPS group compared with the LPS group, respectively (P<0.05). The ZJ617s+LPS group exhibited higher intestinal expression of claudin 3 (62.5%), occludin (60.1%), and zonula occludens 1 (60.5%) compared with the LPS group (P<0.05). The concentrations of hepatic interleukin-6 and tumor necrosis factor-α were 21.4% and 27.3% lower in the ZJ617s+LPS group compared with the LPS group, respectively (P<0.05). However, the concentration of interleukin-10 was 22.2% higher in the ZJ617s+LPS group. LPS increased the expression of Toll-like receptor 4 (TLR4; by 50.5%), phosphorylation p38 mitogen-activated protein kinase (p38MAPK; by 57.1%), extracellular signal-regulated kinase (by 77.8%), c-Jun N-terminal kinase (by 42.9%), and nuclear factor-κB (NF-κB; by 36.0%) compared with the control group. Supplementation with ZJ617s or LGGs ameliorated these effects (P<0.05). Moreover, the hepatic expression of active caspase-3 and microtubule-associated protein 1 light chain 3 II was 23.8% and 28.6% lower in the ZJ617s+LPS group compared with the LPS group, respectively (P<0.05). ZJ617s exerts beneficial effects on the mouse liver through suppression of hepatic TLR4/MAPK/NF-κB activation, apoptosis, and autophagy. This trial was registered at Zhejiang University (http://www.lac.zju.edu.cn) as NO.ZJU20170529.

Telbivudine Reduces Parvovirus B19-Induced Apoptosis in Circulating Angiogenic Cells.

Aims: Human parvovirus B19 (B19V) infection directly induces apoptosis and modulates CXCR4 expression of infected marrow-derived circulating angiogenic cells (CACs). This leads to dysfunctional endogenous vascular repair. Treatment for B19V-associated disease is restricted to symptomatic treatment. Telbivudine, a thymidine analogue, established in antiviral treatment for chronic hepatitis B, modulates pathways that might influence induction of apoptosis. Therefore, we tested the hypothesis of whether telbivudine influences B19V-induced apoptosis of CAC. Methods and Results: Pretreatment of two CAC-lines, early outgrowth endothelial progenitor cells (eo-EPC) and endothelial colony-forming cells (ECFC) with telbivudine before in vitro infection with B19V significantly reduced active caspase-3 protein expression (−39% and −40%, both p < 0.005). Expression of Baculoviral Inhibitor of apoptosis Repeat-Containing protein 3 (BIRC3) was significantly downregulated by in vitro B19V infection in ECFC measured by qRT-PCR. BIRC3 downregulation was abrogated with telbivudine pretreatment (p < 0.001). This was confirmed by single gene PCR (p = 0.017) and Western blot analysis. In contrast, the missing effect of B19V on angiogenic gene expression postulates a post-transcriptional modulation of CXCR4. Conclusions: We for the first time show a treatment approach to reduce B19V-induced apoptosis. Telbivudine reverses B19V-induced dysregulation of BIRC3, thus, intervening in the apoptosis pathway and protecting susceptible cells from cell death. This approach could lead to an effective B19V treatment to reduce B19V-related disease.

Inhibiting a spinal cord signaling pathway protects against ischemia injury in rats

ObjectiveThe aim of the study was to examine whether the cannabinoid agonist WIN55212-2 could attenuate ischemic spinal cord injury (SCI) in rats through inhibition of GAPDH/Siah1 signaling. MethodsMale Sprague-Dawley rats were distributed randomly into 5 groups: (1) sham group that received no aortic occlusion and injected intraperitoneally (i.p.) with vehicle control after reperfusion; (2) control group that received a 12-minute aortic occlusion and injected i.p. with vehicle control after reperfusion; (3) WIN55212-2 group (WIN) that received the aortic occlusion and injected i.p. with 1 mg/kg of WIN55212-2 after reperfusion; and (4) WIN55212-2 plus AM251 group and (5) WIN55212-2 plus AM630 group that received the same surgical operation as the WIN group, except that 1 mg/kg of AM251 or AM630 was injected i.p. 30 min before each dose of WIN55212-2 injection, respectively. Neurologic function was assessed 48 hours after reperfusion. Histopathologic examination was performed to determine the number of normal neurons in anterior spinal cord. Protein expression of active caspase-3, total caspase-3, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), inducible nitric oxide synthase (iNOS), nuclear factor kappa light chain enhancer of activated B cells (NF-κB), Siah1, tumor necrosis factor α, and interleukin 1β were determined with Western blot and enzyme-linked immunosorbent assay; coimmunoprecipitation assays were also used to determine GAPDH/Siah1 complexing. Finally, terminal deoxynucleotidyl transferase dUTP nick end labeling staining was used to determine neuronal apoptosis in the lumbar spinal cord. ResultsThe nuclear translocation of GAPDH and Siah1 in the spinal cord was initiated after ischemic spinal cord injury (SCI) along with the increased formation of GAPDH/Siah1 complexes. However, the activation of GAPDH/Siah1 was blocked by WIN. In addition, the treatment of WIN55212-2 promoted neuronal survival in the spinal cord, reduced apoptosis and inflammation, and improved neurologic scores. Furthermore, these beneficial effects of WIN55212-2 were abolished by the combined treatment of the CB2 antagonist AM630, but not the CB1 antagonist AM251. ConclusionsOur findings reveal GAPDH/Siah1 signaling cascades as a novel therapeutic target for ischemic SCI and identify WIN55212-2 with the potential to treat ischemic SCI by targeting this pathway.

Brain-derived neurotrophic factor modulates intestinal barrier by inhibiting intestinal epithelial cells apoptosis in mice.

We aimed to investigate the effects of brain-derived neurotrophic factor (BDNF) on apoptosis of intestinal epithelial cells (IECs) and alterations of intestinal barrier integrity using BDNF knock-out mice model. Colonic tissues from BDNF(+/+) mice and BDNF(+/-) mice were prepared for this study. The integrity of colonic mucosa was evaluated by measuring trans-mucosa electrical resistance and tissue conductance in Ussing chamber. The colonic epithelial structure was analyzed by transmission electron microscopy. Apoptosis involvement was determined with TUNEL staining, active caspase-3 immunostaining and Western blotting for the protein expression of active caspase-3, Bax and Bcl-2. The expression levels and distribution of tight junction proteins were evaluated by immunohistochemistry or Western blots. Compared with BDNF(+/+) mice, BDNF(+/-) mice displayed impaired integrity and ultrastructure alterations in their colonic mucosa, which was characterized by diminished microvilli, mitochondrial swelling and epithelial cells apoptosis. Altered intestinal barrier function was linked to excessive apoptosis of IECs demonstrated by the higher proportion of TUNEL-positive apoptotic cells and enhanced caspase activities in BDNF(+/-) mice. Increased expression of Bax and claudin-2 proteins and reduced Bcl-2 and tight junction proteins (occludin, ZO-1 and claudin-1) expression were also detected in the colonic mucosa of BDNF(+/-) mice. BDNF may play a role in the maintenance of intestinal barrier integrity via its anti-apoptotic properties.

Pipoxolan Exhibits Antitumor Activity Toward Oral Squamous Cell Carcinoma Through Reactive Oxygen Species-mediated Apoptosis.

Pipoxolan is frequently prescribed as a smooth muscle relaxant. Pipoxolan has also been shown to have anticancer activity. Our study investigated whether pipoxolan induced apoptosis in oral squamous cell carcinoma (OSCC). Cell cytotoxicity was evaluated by the MTT assay. Cell apoptosis and cell-cycle distribution were measured by annexin V/propidium iodide (PI) double staining and flow cytometry, respectively. Apoptotic-related proteins were assessed by western blotting. Reactive oxygen species (ROS) generation and mitochondrial membrane potential (MMP) were measured with fluorescent probes. Following exposure of TW206 OSCC cells to pipoxolan, a time-dependently decrease in MMP and an increase in ROS were observed. However, these effects were significantly abrogated by the free radical scavenger N-acetyl-L-cysteine. Since high levels of ROS were produced early in the treatment, intracellular ROS seemed to play a key role in pipoxolan-induced apoptosis. In HSC-3 OSCC cells, our results demonstrated that pipoxolan treatment caused a time-dependent increase of protein expression of active caspase-3 and -9, cytosolic cytochrome c, cleavage of poly (ADP-ribose) polymerase, and B-cell lymphoma 2 (BCL2)-like protein 4 (BAX). However, expression of BCL2 itself was reduced. Clearly, such an increase in BAX/BCL2 ratio would be associated with apoptosis. In addition, pipoxolan markedly suppressed the protein expression of phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) and phosphorylation of protein kinase B (AKT). These data suggest that pipoxolan acts against HSC-3 in vitro via intrinsic apoptotic signaling pathways, and inhibition of PI3K/AKT signaling.

Retraction Note to: The Crucial Role of Cyclin-Dependent Kinase-5-Ataxia-Telangiectasia Mutated Axis in ICH-Induced Neuronal Injury of Rat Model.

Cyclin-dependent kinase 5 (CDK5) and ataxia-telangiectasia mutated (ATM) are involved in normal human neurodevelopment and serves as a switch between neuronal survival and death. However, the molecular mechanisms underlying CDK5-ATM-induced neuronal injury caused by intracerebral hemorrhage (ICH) remain unclear. In this work, we used rat ICH models and thrombin-induced cell models to investigate the potential role of CDK5-ATM signals. Our findings revealed that CDK5 protein levels and kinase activities (p-histone H1 expression) were enforced in hematoma-surrounding neuron tissues following ICH. Besides, the expression of p25, p-ATM, and active caspase-3 protein was also upregulated after ICH. According to in vitro assays, the expression of CDK5, p-ATM, and active caspase-3 was all upregulated in cell viability-decreasing ICH cell models. However, blocking of either CDK5 or ATM suppressed the phosphorylation of ATM and the expression of active caspase-3, and attenuated the inhibition of neuronal survival. When p35/p25 was silenced, CDK5-ATM pathway was further inhibited, and cell viability was obviously ameliorated. In conclusion, this work suggested that ATM could be phosphorylated by CDK5 to induce the active caspase-3 and neuronal injury when intracerebral hemorrhage or ischemia occurred. Thus, the CDK5-AMT signal pathway has an important role in ICH process and may be a therapeutic target to prevent brain injury.

Effects of bufalin on the mTOR/p70S6K pathway and apoptosis in esophageal squamous cell carcinoma in nude mice.

The aim of this study was to investigate the effects of bufalin on the mammalian target of rapamycin (mTOR/p70S6 kinase (p70S6K) signaling pathway and cell apoptosis in orthotopically transplanted tumors in nude mice. The mice were inoculated with human esophageal squamous cell carcinoma (ESCC) ECA109 cells in order to establish a model of orthotopicall transplanted ESCC tumors. The mice are administered low, medium and high doses of bufalin (0.5, 1.0 and 1.5 mg/kg) or rapamycin, or a combination of both. After the tumors were removed, the mRNA expression levels of mTOR, p70S6K, eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1), cellular inhibitor of apoptosis protein 1 (cIAP1) and caspase-3 were detected by RT-PCR. In addition, we performed western blot analysis and immunohistochemical analysis to determine the protein expression of mTOR, p70S6K, 4EBP1, cIAP1, active caspase-3, Bcl-2 and Bad in the tumor tissue. The results revealed that bufalin exerted a significant anti-tumor effect in the nude mice with ESCC orthotopically transplanted tumors. This was shown by the decrease in the expression of mTOR, p70S6K and 4EBP1, which suggested that bufalin may possibly be used to inhibit tumor growth via the inhibition of the activation of p70S6K and 4EBP1. We also found that bufalin decreased the expression of cIAP1 and Bcl-2, and increased that of active caspase-3 and Bad, thus indicating that bufalin promoted apoptosis. Thus, our findings suggest that bufalin promotes tumor cell apoptosis, and this may be one of the important anti-tumor mechanisms of action of bufalin.

Porphyra-334, a mycosporine-like amino acid, attenuates UV-induced apoptosis in HaCaT cells.

The main aim of the current research was to study the effect of porphyra-334, one of mycosporine-like amino acids (MAAs), well known as UV-absorbing compounds, on UVinduced apoptosis in human immortalized keratinocyte (HaCaT) cells. Due to their UV-screening capacity and ability to prevent UV-induced DNA damage, MAAs have recently attracted considerable attention in both industry and research in pharmacology. Herein, human HaCaT cells were used to determine the biological activities of porphyra- 334 by various in vitro assays, including proliferation, apoptosis and Western blot assays. The proliferation rate of UV-irradiated HaCaT cells was significantly decreased compared to the control group. Pretreatment with porphyra- 334 markedly attenuated the inhibitory effect of UV and induced a dramatic decrease in the apoptotic rate. Expression of active caspase-3 protein was increased in response to UV irradiation, while caspase-3 levels were similar between cells treated with porphyra-334 and the non-irradiated control group. Taken together, our data suggest that porphyra-334 inhibits UV-induced apoptosis in HaCaT cells through attenuation of the caspase pathway.

Proliferation-apoptosis balance in Staphylococcus aureus chronically infected bovine mammary glands during involution.

The objective of this study was to determine whether Staphylococcus aureus chronic intramammary infection (IMI) influences expression of proteins related to regulation of proliferation and apoptosis processes and proliferation/apoptosis index during active involution in bovine mammary gland. Twenty-one Holstein non-pregnant cows in late lactation either uninfected or with chronic naturally acquired S. aureus IMI were included in this study. Cows were slaughtered at 7, 14 and 21 d after cessation of milking and samples for immunohistochemical analysis were taken. Protein expression of Bcl-2, Bax, Fas and active caspase-3 in mammary tissue was significantly affected by chronic S. aureus IMI, all showing increased immunoexpression in S. aureus-infected quarters at all involution stages. The percentage of apoptotic cells was increased by IMI in both mammary parenchyma and stroma, and the percentage of parenchymal and stromal cell proliferation was also increased. The proliferation/apoptosis ratio was significantly increased by IMI only in stromal cells. This imbalance to favour proliferation in S. aureus-infected mammary quarters could be one of the underlying causes that induce aberrant involution with permanence of nonsecretory tissue and increase of stromal components.

Inhibition of CYFIP2 promotes gastric cancer cell proliferation and chemoresistance to 5-fluorouracil through activation of the Akt signaling pathway.

Gastric cancer is a common gastrointestinal malignancy that accounts for a notable proportion of cancer-associated mortalities worldwide. Cytoplasmic fragile X mental retardation 1-interacting protein 2 (CYFIP2) is a novel p53-mediated pro-apoptotic protein whose expression is decreased in gastric cancer. However, whether decreased expression of CYFIP2 contributes to gastric carcinogenesis remains unclear. In order to mimic in vivo gastric tumor CYFIP2 expression levels, the present study used short hairpin RNA targeting CYFIP2 mRNA to silence CYFIP2 expression in MGC803 and SGC7901 gastric cancer cells. Gastric cancer cells with constitutively decreased CYFIP2 expression levels were successfully established. It was observed that CYFIP2 knockdown promoted proliferation and colony formation, and inhibited apoptosis in these cells. Furthermore, 5-fluorouracil (5-FU)-induced apoptosis was decreased following inhibition of CYFIP2 expression. In SGC7901 cells, protein expression of active caspase-3 and cleaved poly (ADP-ribose) polymerase was increased following treatment with 5-FU, while phosphorylated Akt serine/threonine kinase 1 (Akt) levels were decreased. These 5-FU-induced effects were reduced following CYFIP2 knockdown. In addition, inhibition of the Akt signaling pathway using the Akt inhibitor LY294002 restored CYFIP2-knockdown SGC7901 cell chemosensitivity to 5-FU. The results of the present study demonstrate that decreased CYFIP2 expression is associated with increased gastric tumor growth in vitro and that CYFIP2 knockdown-induced activation of the Akt pro-survival signaling pathway confers resistance to 5-FU-based chemotherapy in gastric cancer cells. Therefore, combined treatment with an Akt inhibitor and chemotherapeutic drugs may improve the efficacy of gastric cancer therapy in patients with low CYFIP2 expression.

The impact of neuronal Notch-1/JNK pathway on intracerebral hemorrhage-induced neuronal injury of rat model.

Notch signaling is a highly conserved pathway that regulates cell fate decisions during embryonic development. Notch activation endangers neurons by modulating NF-κB and HIF-1α pathways, however, the role of Notch signaling in activating JNK/c-Jun following intracerebral hemorrhage (ICH) has not been investigated. In this study, we used rat ICH models and thrombin-induced cell models to investigate the potential role of Notch-1/JNK signals. Our findings revealed that Notch-1 and JNK increased in hematoma-surrounding neurons tissues following ICH during ischemic conditions (all p<0.05). Besides, the expression of active caspase-3 protein was also up-regulated after ICH. According to in-vitro assays, the expression of Notch-1, p-JNK, and active caspase-3 were all up-regulated in cell viability-decreasing ICH cell models (all p<0.05). However, blocking of either Notch-1 or JNK suppressed the phosphorylation of JNK and the expression of active caspase-3, and cell viability was obviously ameliorated. In conclusion, this work suggested Notch-1 activates JNK pathway to induce the active caspase-3, leading to neuronal injury when intracerebral hemorrhage or ischemia occurred. Thus the Notch-1/JNK signal pathway has an important role in ICH process, and may be a therapeutic target to prevent brain injury.

1,6-Bis[4-(4-amino-3-hydroxyphenoxy)phenyl] diamantane potentiates in vitro and in vivo antitumor effects of irinotecan on human colorectal cancer cells.

1,6-Bis[4-(4-amino-3-hydroxyphenoxy)phenyl] diamantane (DPD), a diamantane derivative, was previously noted as an anticancer compound through anticancer drug screening with NCI-60 human tumor cells. Irinotecan (CPT-11), a semisynthetic derivative of camptothecin, is clinically active in the treatment of colorectal cancer, with no cross-resistance. The current study conducted a pharmacokinetic evaluation of DPD, an essential component of drug discovery. Subsequent pathway analysis of microarray gene expression data indicated that the anticancer mechanisms of DPD were associated with cell cycle progression and apoptosis. The combined effect of DPD and CPT-11 with regard to the mechanisms of apoptosis-related pathways in COLO 205 cells, and the antitumor effects in colon cancer xenograft mice, were investigated. The plasma concentration and pharmacokinetic parameters of DPD in male albino rats were analyzed following a single dose of DPD by injection. The protein expression of active caspase-3, procaspase-3 and poly ADP-ribose polymerase (PARP) in COLO 205 cells treated with DPD and CPT-11, alone or combined, was evaluated by western blotting. A trypan blue dye exclusion assay revealed that, whilst DPD alone demonstrated good antitumor effects, this effect was potentiated when combined with CPT-11. Combined treatment with DPD and CPT-11 upregulated the expression of cleaved PARP, procaspase-3, caspase-3 and active caspase-3 in COLO 205 cells. In the colon cancer xenograft model, compared with the control (vehicle-treated) mice, the sizes of the tumors were significantly lower in mice treated with DPD and CPT-11, alone or in combination. Thus, DPD may be a potential therapeutic agent for the treatment of colorectal cancer via upregulating apoptosis-related pathways.