Percentage Of Cell Death Research Articles

Free radical scavenging activity and cytotoxicity study of fermented oats (Avena sativa)

Oats (Avena sativa) is a cereal crop of utmost significance with rich therapeutic and nutritive value. Bioactive substances like tocopherols, phenolic acids, alkylresorcinols, beta-glucan, and avenanthramides present in Avena sativa significantly contribute towards its medicinal action. The current research study aims to assess the antioxidant and anti-cancer efficiency of fermented (FO) and non-fermented (NFO) samples of Avena sativa. In vitro anticancer studies on oats were assessed using colon malignant growth cell lines (HT29) by MTT assay. In vitro studies revealed that fermented and non-fermented oats displayed higher antioxidant activity, having a corresponding IC50 value of 201.03 µL and 236.46 µL, respectively. The cancer cell death percentage at 250 μg/mL concentration ranged between 58.19% and 51.85%, respectively.

Curcumin-induced cell death depends on the level of autophagic flux in A172 and U87MG human glioblastoma cells.

Glioblastoma is the deadliest neoplasm with the worst 5-year survival rate among all human cancers. Autophagy promotes autophagic cell death or blocks the induction of apoptosis in eukaryotic cells. Here, we investigated whether varying levels of autophagic flux in glioblastoma lead to different efficacies of curcumin treatment using U87MG and A172 human glioblastoma cells. The number of LC3 puncta, the number of cells with LC3 puncta and the level of LC3 II, Atg5 and Atg7 protein were higher in U87MG cells compared with A172 cells. When the cells were incubated with curcumin for 24 or 48 h, the percentage of cell death was higher in A172 cells compared with U87MG cells. Although the level of LC3 was lower, that of curcumin-induced LC3 was higher, in A172 cells than in U87MG cells. The relative increases in cell death and LC3-mediated autophagy were greater under serum starvation in A172 cells compared with U87MG cells. Curcumin-induced A172 cell death was reduced by serum starvation. When both types of cells were transfected with LC3-GFP, the percentage of cell death was higher in A172 cells than that in U87MG cells. Taken together, the data demonstrate that curcumin-mediated tumor cell death is regulated by the basal level of autophagic flux in different glioblastoma cells. This suggests that prior to the use of various curcumin therapeutics, the level of basal or induced autophagic flux should be carefully examined in tumor cells for the best efficacy.

Necroptosis of osteoblasts was induced by breast cancer cells in vitro.

BackgroundBone metastasis of breast cancer could lead to serious osteolysis and severe pain. This study is aimed to investigate the existence of necroptosis, a new type of programmed cell necrosis pathway, in breast cancer-induced osteoblast cell death.MethodsIn this study, conditioned medium (CM) of breast cancer cells was prepared to simulate the micro-environment of bone metastasis in breast cancer in vitro and co-cultured with osteoblast. Then the percentage of cell survival and death was detected via cell viability and flow cytometry. Western blot and PCR were taken to measure protein and mRNA expression level of RIPK 3, MLKL and caspase 3 respectively.ResultsCM could induce osteoblasts death, including apoptosis and necroptosis and necrostatin-1 plus Z-IETD-FMK could decrease the percentage of death cells significantly in the flow cytometry detection. Moreover, CM could increase cleaved caspase 3, RIPK 3 and p-MLKL significantly, while RIPK 3 and p-MLKL was reduced statistically when osteoblasts were treated with Necrostatin-1 (Nec-1). In addition, the mRNA level of three proteins was not consistent with the change of their corresponding protein level.ConclusionsIn conclusion, the necroptosis pathway exists in osteoblast cell death pathway induced by breast cancer cells and could be inhibited by Necrostatin-1 (Nec-1).

Investigation of cell death mechanism and activity of esculetin-loaded PLGA nanoparticles on insulinoma cells in vitro.

The purpose of this studywas to prepare targeted cancer therapy formulation against insulinoma INS-1 cells and to study its effect on cell death with related mechanisms in vitro. Polylactide-co-glycolide (PLGA) nano-micelles were used for preparation of esculetin nano-formulation (nano-esculetin). The cells were treated with nano-esculetin and free esculetin. Apoptotic and necrotic cell death percentages, cell proliferation, ATP and GTP reductions and insulin levels were investigated on insulinoma INS-1 cells for both free and nano-esculetin formulations. About 50mg of PLGA was able to carry 20mg esculetin in 20ml of formulation. The obtained optimized formulation was 150nm, with 92% encapsulation efficiency and a slow-release behaviour was observed during release studies. Nano-esculetin bearing 25, 50 and 100μg esculetin and free esculetinin equivalent doses successfully decreased cell viability. The prevailing cell death mechanism was necrosis. Along with cell proliferation, intracellular insulin and the ratio of ATP and GTP were decreased even with 12.5, 25 and 50μg esculetin bearing nano-formulation and its equivalent free esculetin. The results revealed that esculetin is able to show its anti-tumor afficacy after loading to PLGA nano-micelles and nano-encapsulation intensifies its cytotoxic activity in vitro. Current study shows that esculetin and its nano formulations are promising agents in treatment of insulinoma.

Bioactive Compounds Isolated From In Vitro Callus and Wild Plant of Hibiscus Sabdariffa Linn. And Its Anticancer Activities

Bioactive compounds were isolated from in vitro callus as well as wild plant of Hibiscus sabdariffa Linn. is an annual shrub belonging to the family Malvaceae. The bioactive compounds were isolated from two different organic extracts are methanolic crude and acidified aqueous acetone. These extracts were analyzed antioxidant potential by free radical scavenging activity of DPPH and Total antioxidant activities. The strong DPPH free radical scavenging activity of the acidified aqueous acetone and methanolic extracts of wild plant and in vitro callus of H. sabdariffa showed maximum of 94.03 and 94.50% of inhibition, respectively. IC50 value of acidified aqueous acetone and methanolic extracts of wild plant and in vitro callus was 35.77 and 30.47 µg/mL concentrations, respectively. Based on the antioxidant potential, the isolated compounds were studied the antiviral, anticancer activities. The antiviral activity of H. sabdariffa show evidence of antiviral activity for H1N1 and FLU B viruses by using Vero cell line. The good antiviral activity was observed both extracts as well as isolated compounds. In vitro cytotoxicity study was carried out for the extract and isolated compounds of extracts of plant and callus by used human cervical carcinoma cells (HeLa) and human colon carcinoma cells (HT 29). Apoptosis cell death percentage was observed in and human carcinoma cancer cells (HT 29) with H. sabdariffa and its isolated compounds by DNA fragmentation method. We could observe distinct ladder pattern in the compounds treated cells. The DNA fragmentation induced by the compounds indicating programmed cell death. The present work strongly justifies that the isolated compounds of Hibiscus sabdariffa is a good candidate for anticancer.

Determination of Infrared Laser Energy Dose for Cancer Cells Inactivation as a Candidate of Photodynamic Therapy

The aim of this research is to find out the effect of GaAlAs diode laser 808 nm exposure on MCF-7 breast cancer cells in vitro with and without the addition of a photosensitizer. Methylene blue (C16H18N3SCl) with concentration of 2 µM is used as the photosensitizer based on the preliminary results of cytotoxicity assay. Energy dose is set in the range of 23, 043 to 322, 062 J/cm2. Laser exposure with the addition of the photosensitizer generates the highest percentage of cell death of 20.80% at energy dose of 184, 344 J/cm2 and cell death begin to decrease at energy dose above this value. This behavior is likely caused by photodegradation and photobleaching effect of the photosensitizer due to the longer exposure time. However, the percentage of cell death without the addition of photosensitizer is increased proportionally to the increase of energy dose and achieved 32, 45% cell mortality at 299, 559 J/cm2. This study not only shows that the exposure of infrared laser can be used to inactivate cancer cells but also determines its optimum energy dose, makes it a possible candidate for photodynamic therapy in the future.

Preventing necroptosis by scavenging ROS production alleviates heat stress-induced intestinal injury

Background Worldwide heat stroke incidence has increased in recent years and is associated with high morbidity and mortality. Therefore, it is critical to identify mechanisms that mediate heat stroke. Previous studies suggested that damage to the small intestine may be a major factor in heat stroke-related morbidity and mortality. However, the mechanism underlying heat stroke related small intestine injury remains unclear. Methods To explore how heat stroke promotes intestinal damage, we applied two well established models: mouse and IEC-6 cells heat stress (HS) to mimic heat stroke both in vivo and in vitro. The percentages of viability and cell death were assessed by WST-1 and LDH release assays. Induction of HS-induced cell death was analyzed by flow cytometry with Annexin V-FITC/PI staining. Flow cytometry was used to analyze HS-induced mitochondrial superoxide with MitoSOX staining. Malondialdehyde (MDA) levels and superoxide dismutase (SOD) levels were detected by ELISA. Flow cytometry was used to analyze HS-induced mitochondrial depolarization (low ΔΨm) with JC-1 staining. Histopathology changes in the ileum were detected by H&E staining.The ileum ultrastructure was observed by transmission electron microscopy (TEM). RIPK1, RIPK3, phosphorylated MLKL, and MLKL levels were detected by Western blot. RIPK1-RIPK3 complexes were measured by immunoprecipitation assay. Results HS increased both necrotic cell rate and RIPK1, RIPK3, and phosphorylated MLKL expression levels in IEC-6 cells. These increased expression levels promoted higher RIPK1-RIPK3 complex formation, leading to necrosome formation both in vivo and in vitro. Moreover, HS caused dyshomeostasis, an oxidative stress response, and mitochondrial damage, along with small intestinal tissue injury and cell death. However, IEC-6 cells or mice pretreated with the RIPK1 activity chemical inhibitor Nec-1 or RIPK3 activity chemical inhibitor GSK'872 significantly reversed these phenomena and promoted balance in oxidative stress response homeostasis. More importantly, the reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine (NAC) pretreatment significantly inhibited HS-induced RIPK1/RIPK3-dependent necroptosis formation both in vivo and in vitro, suggesting that preventing necroptosis via scavenging ROS production might alleviate HS-induced small intestinal tissue injury and cell death. Conclusion This study provides strong evidence that HS causes damage to both the small intestine and intestinal epithelial cells, scavenging ROS production can significantly alleviate such RIPK1/RIPK3-dependent necroptosis, mediating HS-induced intestinal damage both in vitro and in vivo. These findings provide a clear target for future mechanism-based therapeutic strategies for patients diagnosed with heat stroke.

Comparison of different zinc precursors for the construction of zeolitic imidazolate framework-8 artificial shells on living cells.

The robust cell-in-shell structure is highly desirable for endowing living cells with an artificial exoskeleton to defend them from many environmental factors such as osmotic pressure, shear force, heat, UV radiation, and enzymes. Cell encapsulation has shown potential applications in many fields and attracted increasing interest. However, the influences of the precursors on the cell viability during the shell formation process are not clear and seldom investigated. Here, zinc nitrite, zinc acetate and zinc sulfate were applied individually to synthesize zeolitic imidazolate framework-8 (ZIF-8) shells on living cells. All the zinc salt precursors could convert to a ZIF-8 layer on the living cell surface. The zinc salts and organic ligand did not exhibit obvious toxicity to yeast cells when applied individually. However, dead cells were observed during the living cell encapsulation process using different zinc precursors. Compared with zinc nitrate and zinc acetate, ZIF-8 formed by zinc sulfate led to a higher percentage of cell death, especially under high concentrations of zinc sulfate. Cell division was suppressed by the ZIF-8 shell but restored fully upon shell removal by EDTA solution or pH 4.0 buffer. Escherichia coli (E. coli) cells showed a lower percentage of cell death, indicating excellent tolerance to the ZIF-8 encapsulation process. This work illustrates the cell toxicity during the formation of ZIF-8 cell shells by different zinc salts and engineering of the cell growth by MOF coating, which could provide a foundation for further quantitative analysis and potential applications in biomedicine and bioengineering.

Amifostine Prophylaxis in Irradiated Breast Reconstruction: A Study of Oncologic Safety In Vitro.

Indications for adjuvant radiation therapy (XRT) in breast cancer have expanded. Although highly effective, XRT damages surrounding tissues and vasculature, often resulting in delayed or compromised breast reconstruction. Thus, effective yet safe methods of radiation injury prophylaxis would be desirable. Amifostine is a Food and Drug Administration-approved radioprotectant; however, concerns about its potential to also protect cancer remain. The purpose of this study was to evaluate the oncologic safety of amifostine (AMF) in vitro and determine its effect on human breast cancer cells in the setting of XRT. One ER+/PR+/Her2- (MCF-7) and two ER-/PR-Her2- (MDA-MB-231, MDA-MB-468) breast cancer cell lines were investigated. Female fibroblasts were used as controls. Cells were treated with WR-1065, the active metabolite of AMF, 20 minutes before 0Gy, 10Gy, or 20Gy XRT. Live and dead cells were quantified; percent cell death was calculated. WR-1065 treatment significantly preserved viability and reduced healthy female fibroblasts death after XRT compared with untreated controls. All three breast cancer cells lines exhibited radiosensitivity with substantial cell death. Cancer cells retained their radiosensitivity despite WR-1065 pretreatment, achieving the same degree of cell death as untreated controls. This study demonstrated the proficiency of AMF to selectively protect healthy cells from XRT while breast cancer cells remained radiosensitive. These results support the oncologic safety of AMF in breast cancer in vitro. Further investigation is now warranted in vivo to ascertain the translational potential of using AMF as a radioprotectant to improve breast reconstruction after radiation treatment.

Ifenprodil and Flavopiridol Identified by Genomewide RNA Interference Screening as Effective Drugs To Ameliorate Murine Acute Lung Injury after Influenza A H5N1 Virus Infection.

Due to the limitations of effective treatments, avian influenza A H5N1 virus is the most lethal influenza virus strain that causes severe acute lung injury (ALI). To develop effective drugs ameliorating H5N1-induced ALI, we explore an RNA interference (RNAi) screening method to monitor changes in cell death induced by H5N1 infection. We performed RNAi screening on 19,424 genes in A549 lung epithelial cells and examined cell death induced by H5N1 infection. These screens identified 1,137 host genes for which knockdown altered cell viability by over 20%. DrugBank searches of these 1,137 host genes identified 146 validated druggable target genes with 372 drug candidates. We obtained 104 commercially available drugs with 65 validated target genes and examined their improvement of cell viability following H5N1 infection. We identified 28 drugs that could significantly recover cell viability following H5N1 infection and tested 10 in an H5N1-induced-ALI mouse model. The neurological drug ifenprodil and the anticancer drug flavopiridol markedly decreased leukocyte infiltration and lung injury scores in infected mouse lungs, significantly ameliorated edema in infected mouse lung tissues, and significantly improved the survival of H5N1-infected mice. Ifenprodil is an antagonist of the N-methyl-d-aspartate (NMDA) receptor, which is linked to inflammation and lung injury. Flavopiridol is an inhibitor of cyclin-dependent kinase 4 (CDK4), which is linked to leukocyte migration and lung injury. These results suggest that ifenprodil and flavopiridol represent novel remedies against potential H5N1 epidemics in addition to their proven indications. Furthermore, our strategy for identifying repurposable drugs could be a general approach for other diseases.IMPORTANCE Drug repurposing is a quick and economical strategy for developing new therapies with approved drugs. H5N1 is a highly pathogenic avian influenza virus subtype that can cause severe acute lung injury (ALI) and a high mortality rate due to limited treatments. The use of RNA interference (RNAi) is a reliable approach to identify essential genes in diseases. In most genomewide RNAi screenings, virus replication is the readout of interference. Since H5N1 virus infection could induce significant cell death and the percentage of cell death is associated with virus lethality, we designed a genomewide RNAi screening method to identify repurposable drugs against H5N1 virus with cell death as the readout. We discovered that the neurological drug ifenprodil and the anticancer drug flavopiridol could effectively ameliorate murine ALI after influenza A H5N1 virus infection, suggesting that they might be novel remedies for H5N1 virus-induced ALI in addition to the traditional indications.

Gastric mucosal devitalization (GMD): translation to a novel endoscopic metabolic therapy.

Background and study aims The metabolic effects of bariatric surgery may partially result from removal of the gastric mucosa, an often underappreciated endocrine organ. Using argon plasma coagulation (APC), we may be able to selectively devitalize (ablate) the mucosa. The aim of this study was to identify the optimal tissue color that would correspond to selective gastric mucosal devitalization (GMD) using ex-vivo human stomach specimens. Patients and methods Stomach specimens were obtained at sleeve gastrectomy. Prior to APC application, a submucosal fluid cushion was created. APC was then applied over a 2 × 2-cm area to the fundus and body, aiming for the three indicator colors (white, golden, brown). Pathological analysis was then performed independently and in a blinded fashion by two pathologists to determine the depth of mucosal and submucosal percent thermal injury and mucosal percent cell death. Results Six patients were enrolled. There was a significant correlation between tissue color and mucosal percent thermal injury. The highest percent mucosal thermal injury was seen with brown (99.6 %, 95 % CI: 98.7, 100), followed by golden (92.5 %, 95 % CI: 85.5, 99.5), and then white (75.2 %, 95 % CI: 58.3, 92.1, P < 0.01). Submucosal thermal injury was seen in 88.9 % of the slides. Greater than minimal submucosal injury (> 10 % depth) was found significantly more with brown tissue color (91.6 %) than golden (75 %) or white (33.3 %, P < 0.05). However, 91.7 % of the entire sample set < 50 % injury. Conclusion GMD is achievable using APC without thermal injury to muscularis propria. A golden color results in sufficient mucosal injury with only superficial injury to the submucosa.

The cryoprotective effect of Ficoll 70 on the post-warming survival and quality of Cryotop-vitrified donkey embryos

Many domestic donkey breeds are at risk of extinction, there is a critical urgency for genome resource banking. In the present study, we examined whether the use of Ficoll 70 added to the vitrification medium containing ethylene glycol (EG), dimethyl sulfoxide (DMSO) and sucrose improves the cryotolerance of donkey in vivo derived embryos. Day 7–8, grade 1–2 donkey embryos were measured and morphologically evaluated and then vitrified-warmed using the Cryotop technique. Before vitrification, embryos were randomly distributed into two groups: (i) VS1 (n = 14): vitrified using 15% EG + 15% DMSO + 0.5 M sucrose; and (ii) VS2 (n = 10): vitrified in the same medium supplemented also with 18% of Ficoll 70. After 24 h of warming, the embryos were measured and evaluated for their morphology, development and viability (Propidium Iodide-Hoechst 33342 dyes). Post-warming survival was numerically higher but not significantly different (P > 0.05) when embryos were vitrified in VS2 (70%) compared to VS1 (57.1%). Embryo rupture was only observed in the VS1 group (21.4%, 3/14). Higher embryo diameter was observed in all groups after 24 h culture (P < 0.05). No significant differences (P > 0.05) were observed among treatments in terms of percentages of cell death. These results demonstrate that the addition of Ficoll 70 to the vitrification medium is not a pre-requisite for successful vitrification of donkey embryos. However, its addition seems to enhance some of the post-warming embryo quality characteristics. Since no statistically significant evidence was found, further studies should be conducted in order to confirm our findings.

In vitro cytotoxicity study and anti-Brucella activity of Tarenna asiatica (L)

Tarenna asiatica (L), widely used medicinal plants in the treatment of eye infections, skin problems and abdominal pain as a traditional medicine within India and the across the globe. Tarenna asiatica has been used to treat a number of disorders, including boils, external ulcers and wounds. The present study aims to evaluate the phytochemical properties and the effects of Tarenna asiatica through In vitro studies. In addition, our study aims to evaluate the anti-cancer activity of the plant extracts against lung cancer cell line (A549) and measure the Anti-Brucella activity of the plant extracts. The plant solvent was extracted for its active chemical components with three different polar solvents using soxhlet apparatus. The quantitative estimation revealed that the ethanol extract of the plant possessed higher phenolics and flavonoids. In vitro studies revealed that the ethanol extract retains higher activity compared to that of the aqueous and petroleum ether extracts. The cancer cell death percentage at 100 mg/ml concentrations of the ethanol and aqueous extracts of T. asiatica ranged between 60% and 67% on lung cancer cell line, respectively.

Regulatory T cells promote corneal endothelial cell survival following transplantation via interleukin-10.

The functional competence of corneal endothelial cells (CEnCs) is critical for survival of corneal allografts, but these cells are often targets of the immune response mediated by graft-attacking effector T cells. Although regulatory T cells (Tregs) have been studied for their role in regulating the host's alloimmune response towards the graft, the cytoprotective function of these cells on CEnCs has not been investigated. The aim of this study was to determine whether Tregs suppress effector T cell-mediated and inflammatory cytokine-induced CEnC death, and to elucidate the mechanism by which this cytoprotection occurs. Using 2 well-established models of corneal transplantation (low-risk and high-risk models), we show that Tregs derived from low-risk graft recipients have a superior capacity in protecting CEnCs against effector T cell-mediated and interferon-γ and tumor necrosis factor-α-induced cell death compared to Tregs derived from high-risk hosts. We further demonstrate that the cytoprotective function of Tregs derived from low-risk hosts occurs independently of direct cell-cell contact and is mediated by the immunoregulatory cytokine IL-10. Our study is the first to report that Tregs provide cytoprotection for CEnCs through secretion of IL-10, indicating potentially novel therapeutic targets for enhancing CEnC survival following corneal transplantation.

R5 HIV-1 gp120 Activates p38 MAPK to Induce Rat Cardiomyocyte Injury by the CCR5 Coreceptor

Background: Effective antiretroviral therapy extends the survival of patients with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome, but these patients remain at higher risk for heart diseases compared with the general population. Previous studies have suggested that HIV-1 glycoprotein 120 (gp120) may be associated with heart disease. However, the underlying mechanisms by which HIV-1 gp120-mediated myocardial injury occurs remain unknown. Objective: The current study aimed to uncover the mechanism of C-C chemokine receptor 5 (CCR5) coreceptor (R5) HIV-1 gp120-induced myocardial injury. Methods: Morphology analysis, determination of the percentage of cell apoptosis, as well as lactate dehydrogenase (LDH) and creatine kinase (CK) assays were used to analyze whether R5 HIV-1 gp120 induced myocardial cell injury. We analyzed the phosphorylation of p38 mitogen-activated protein kinase (MAPK) with the CCR5 antagonist D-Ala-peptide T-amide (DAPTA) and NMDA receptor antagonist MK801, detected LDH and CK assays with p38 MAPK antagonist SB203580 (SB), and detected the percentage of cell apoptosis and death with DAPTA to investigate the mechanism of R5 HIV-1 gp120-induced myocardial cell injury. Results: R5 HIV-1 gp120 damaged myocardial cells and induced p38 MAPK phosphorylation. SB blocked R5 HIV-1 gp120-induced myocardial cell injury. DAPTA blocked R5 HIV-1 gp120-mediated p38 MAPK phosphorylation, while MK801 did not. DAPTA inhibited R5 HIV-1 gp120-induced myocardial cell injury. Conclusion: Our data indicate that R5 HIV-1 gp120 activated p38 MAPK to trigger myocardial cell injury by the CCR5 coreceptor.

Cellular accumulation and cytotoxic effects of zinc oxide nanoparticles in microalga Haematococcus pluvialis.

BackgroundZinc oxide nanoparticles (ZnO NPs) are widely used in household and cosmetic products which imply an increased releasing of these particles into the environment, especially aquatic ecosystems, resulting in the need of assessing the potential toxic effects of ZnO NPS on the aquatic organisms, particularly on microalgae which form the base for food chain of aquatic biota. The present study has investigated the dose- and time-dependent cellular accumulation and the corresponding cytotoxic effects of increasing concentrations of ZnO NPs from 10–200 μg/mL on microalga Haematococcus pluvialis at an interval of 24 h for 96 h.MethodsThe scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) was used to qualitatively detect the cellular accumulation of ZnO NPs in algal cells, while inductively coupled plasma optical emission spectrometry (ICP OES) was performed to quantify the cell associated-zinc in algal cells. The percentage of cell death, reduction in algal biomass, and loss in photosynthetic pigments were measured to investigate the cytotoxic effects of ZnO NPs on H. pluvialis. Extracellular and intracellular changes in algal cells resulted from the treatment of ZnO NPs were demonstrated through optical, scanning, and transmission electron microscopic studies.ResultsSEM-EDX spectrum evidenced the accumulation of ZnO NPs in algal biomass and ICP OES results reported a significant (p < 0.05) dose- and time-dependent accumulation of zinc in algal cells from 24 h for all the tested concentrations of ZnO NPs (10–200 μg/mL). Further, the study showed a significant (p < 0.05) dose- and time-dependent growth inhibition of H. pluvialis from 72 h at 10–200 μg/mL of ZnO NPs. The morphological examinations revealed substantial surface and intracellular damages in algal cells due to the treatment of ZnO NPs.DiscussionThe present study reported the significant cellular accumulation of ZnO NPs in algal cells and the corresponding cytotoxic effects of ZnO NPs on H. pluvialis through the considerable reduction in algal cell viability, biomass, and photosynthetic pigments together with surface and intracellular damages.

Gene Expression Profiling in HeLa Cells After Proton and X-Ray Irradiation with Cisplatin

Our previous study demonstrated that cisplatin had more potent radiosensitizing effects and yielded a significantly higher percentage of apoptotic cell death when combined with proton beams than with X-ray irradiation. Although such results may be explained by differences in the DNA repair mechanisms, factors other than cell death may possibly be involved. In this study, we carried out the gene expression profiling in HeLa cells after proton and X-ray irradiation in combination with cisplatin. HeLa cells were provided by the RIKEN BioResource Center. We evaluated differences in the gene expression profile by cDNA microarray activated in response to proton and X-ray irradiation with or without cisplatin in HeLa. The cells were exposed to the medium containing 0 or 2.5 μmol/L cisplatin and were irradiated with single doses of 6 Gy with proton beams or X rays under the same biological conditions. One hour after irradiation, cisplatin was washed out from the medium. Each sample was cryopreserved at 2 h and 24 h after irradiation. Total RNA was further purified using a micro kit and amplified and labeled with Cyanine 3 using Agilent Low Input Quick Amp Labeling Kit (one-color) according to the manufacturer’s instructions. For each hybridization, 0.60 μg of Cyanine 3 labeled cRNA were fragmented, and hybridized at 65 °C for 17 h to an Agilent SurePrint G3 Human GE v3 8x60K Microarray. After washing, microarrays were scanned using an Agilent DNA microarray scanner. Intensity values of each scanned feature were quantified using feature extraction software. The Gene oncology (GO) analysis on microarray data was performed using a data analysis software. The data were then processed with Fisher’s exact test and multiple test correction to identify significant overrepresentation of GO annotations belonging to molecular functions. In addition, the pathway statistical analysis was performed on a pathway collection of WikiPathways database using PathVisio tool to determine pathways that contained the greatest change in expression. Gene expression profiling pathway analyses showed that the activation of different signaling and molecular networks was dependent on the radiation type, time, and presence/absence of cisplatin. In the 24-h samples irradiated with proton beams in combination with cisplatin, particularly, alterations in expression of many genes such as JAK-STAT cascade and MHC class I receptor activity were observed in GO analysis. In pathway analysis, there were significant differences in such as MAPK signaling and NRF2 between protons and X rays combined with cisplatin. In the microarray analysis, proton beam irradiation combined with cisplatin resulted in different gene expression alterations as compared with X rays and cisplatin. These differences suggested the possibility of leading to further development of irradiation methods and new therapeutic strategies using proton therapy.

Hypoxia-Induced Autophagy Promotes EGFR Loss in Specific Cell Contexts, Which Leads to Cell Death and Enhanced Radiosensitivity

Treatment failure through radio resistance of tumors is associated with activation of the epidermal growth factor receptor (EGFR). Tumor cell proliferation, DNA-repair, hypoxia and metastases-formation are four mechanisms in which EGFR signalling has an important role. However, the effect of hypoxia on EGFR expression is still controversial. In this study, we evaluated the in vitro and in vivo effects of hypoxia on EGFR and its mechanism, as well as its relationship with radiosensitivity. Treatment failure through radio resistance of tumors is associated with activation of the epidermal growth factor receptor (EGFR). Tumor cell proliferation, DNA-repair, hypoxia and metastases-formation are four mechanisms in which EGFR signalling has an important role. However, the effect of hypoxia on EGFR expression is still controversial. In this study, we evaluated the in vitro and in vivo effects of hypoxia on EGFR and its mechanism, as well as its relationship with radio sensitivity. In a panel of cancer cells with low or high cell density under hypoxia, viable cell counting assay was used to calculate the percentage of cell death. Western blot was used to detect the levels of proteins involved in EGFR signaling and autophagy. The localization of EGFR and autophagy-related molecules was observed by confocal microscopy. The xenograft model in nude mice was used to elucidate the in vivo correlation of hypoxia with EGFR and p62. Colony formation assay was performed to assess the radiosensitivity. In this study, we demonstrated that hypoxia enhanced EGFR expression and sustained cell survival in SiHa, CAL 27 and A549 cells at both low and high cell densities, while in MCF-7, MDA-MB-231 and HeLa cells, EGFR and cell survival were regulated by hypoxic treatment in a cell-density dependent manner: upregulated at low cell density and down regulated at high cell density. In MCF-7 and HeLa xenografts in nude mice, EGFR expression varied inversely with the pimonidazole level that was used as an indicator of hypoxia, accordant with the effect of hypoxia at high cell density in vitro. Hypoxia induced more remarkable cell autophagy at high cell density than at low cell density. Autophagy inhibitor 3MA, rather than proteasome inhibitor MG132 inhibited hypoxia-mediated EGFR loss and shifted cell death to cell survival in HeLa cells. The MCF7 cells’ sensitivity to ionizing radiation (IR) under hypoxia was also conditional on the cell densities when the hypoxia treatment was introduced, inversely associated with the expression levels of EGFR. Hypoxia can decrease EGFR expression in some cell lines by enhancing autophagy at high cell density, leading to cell death and hypersensitivity to radiotherapy. This study may help understand how hypoxia influences EGFR expression and radiosensitivity.

Physico-chemical, antimicrobial and anticancer properties of silver nanoparticles synthesised from organ-specific extracts of Bidens pilosa L.

There is an increasing commercial demand for nanoparticles synthesis by green as opposed to chemical methods, given the toxicity and contamination risks associated with the latter. This study compared the physico-chemical, antimicrobial and anticancer activities of silver nanoparticles (AgNPs) synthesised using organ-specific plant extracts in Bidens pilosa. Leaf, stem and root extracts were used as the reducing agent with varying concentrations of AgNO3 (1 mM and 2 mM, respectively). The synthesised AgNPs were subsequently characterised by UV–vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FT-IR). UV–vis spectroscopy showed a surface plasmon resonance peak for the synthesised AgNPs at 410 nm using all organ extracts. TEM studies indicated that nanoparticles ranged from 1.00 to 62.01 nm, with an average particle size of 17.00 nm. Average particle size was larger at the higher AgNO3 concentration. The FTIR analysis confirmed the presence of carbonyl groups, proteins and aldehydes on nanoparticles produced using all extract types. The leaf extract derived nanoparticles displayed maximum percentage cell death (76.0 ± 4.5%) against bacteria and superior antifungal activity (94.8 ± 0.5%) at 200 μg/ml. Leaf extract derived NPs also displayed maximum anticancer potency (38.1 ± 2.3%). The differential bioactivities of NPs across the three organ extracts investigated here suggests that comparative studies on plant organ-specific synthesised NPs can help us maximize the antimicrobial and anticancer benefits of plant-derived NPs.

Amyloid β and Tumorigenesis: Amyloid β-Induced Telomere Dysfunction in Tumor Cells

Amyloid β and Tumorigenesis: Amyloid β-Induced Telomere Dysfunction in Tumor Cells