Non-irradiated Cells Research Articles

The DNA repair function of CUX1 contributes to radioresistance.

Ionizing radiation generates a broad spectrum of oxidative DNA lesions, including oxidized base products, abasic sites, single-strand breaks and double-strand breaks. The CUX1 protein was recently shown to function as an auxiliary factor that stimulates enzymatic activities of OGG1 through its CUT domains. In the present study, we investigated the requirement for CUX1 and OGG1 in the resistance to radiation. Cancer cell survival following ionizing radiation is reduced by CUX1 knockdown and increased by higher CUX1 expression. However, CUX1 knockdown is sufficient by itself to reduce viability in many cancer cell lines that exhibit high levels of reactive oxygen species (ROS). Consequently, clonogenic results expressed relative to that of non-irradiated cells indicate that CUX1 knockdown confers no or modest radiosensitivity to cancer cells with high ROS. A recombinant protein containing only two CUT domains is sufficient for rapid recruitment to DNA damage, acceleration of DNA repair and increased survival following radiation. In agreement with these findings, OGG1 knockdown and treatment of cells with OGG1 inhibitors sensitize cancer cells to radiation. Together, these results validate CUX1 and more specifically the CUT domains as therapeutic targets.

A Light-Responsive Self-Assembly Formed by a Cationic Azobenzene Derivative and SDS as a Drug Delivery System

The structure of a self-assembly formed from a cationic azobenzene derivative, 4-cholesterocarbonyl-4′-(N,N,N-triethylamine butyloxyl bromide) azobenzene (CAB) and surfactant sodium dodecyl sulfate (SDS) in aqueous solution was studied by cryo-TEM and synchrotron radiation small-angle X-ray scattering (SAXS). Both unilamellar and multilamellar vesicles could be observed. CAB in vesicles were capable to undergo reversible trans-to-cis isomerization upon UV or visible light irradiation. The structural change upon UV light irradiation could be catched by SAXS, which demonstrated that the interlamellar spacing of the cis-multilamellar vesicles increased by 0.2–0.3 nm. Based on this microstructural change, the release of rhodamine B (RhB) and doxorubicin (DOX) could be triggered by UV irradiation. When incubated NIH 3T3 cells and Bel 7402 cells with DOX-loaded CAB/SDS vesicles, UV irradiation induced DOX release decreased the viability of both cell lines significantly compared with the non-irradiated cells. The in vitro experiment indicated that CAB/SDS vesicles had high efficiency to deliver loaded molecules into cells. The in vivo experiment showed that CAB/SDS vesicles not only have high drug delivery efficiency into rat retinas, but also could maintain high drug concentration for a longer time. CAB/SDS catanionic vesicles may find potential applications as a smart drug delivery system for controlled release by light.

IL-6 Mediates Macrophage Infiltration after Irradiation via Up-regulation of CCL2/CCL5 in Non-small Cell Lung Cancer.

Radiotherapy is effective in reducing primary tumors, however, it may enhance macrophage infiltration to tumor sites, accelerating tumor progression in several ways. We investigated whether radiation can increase macrophage infiltration into non-small cell lung carcinoma (NSCLC) cells. Analysis of in vitro macrophage (differentiated THP-1 cells) migration to either nonirradiated or irradiated tumor cells showed increased migration to the irradiated tumor cells. Because the IL-6 levels in A549 and H157 cells were significantly increased after irradiation, we then investigated whether this increased IL-6 level contributes to radiation-induced macrophage migration. Radiation-induced macrophage infiltration was reduced when IL-6 was knocked down in tumor cells, indicating a positive IL-6 role in this process. To validate this in vitro result, an orthotopic mouse model was developed using a luciferase-tagged H157siIL-6/scramble control (sc) cell set. After tumors developed, the lungs were irradiated, and infiltration of endogenous macrophages and tail-vein injected fluorescent macrophages to tumor sites was investigated. In both groups, increased macrophage infiltration was observed in H157sc cell-derived xenografts compared to H157siIL-6 cell-derived xenografts, confirming the positive IL-6 role in the radiation-induced macrophage infiltration process. In mechanistic dissection studies, radiation-induced up-regulation of CCL2 and CCL5 by IL-6 was detected, and blocking the action of CCL2/CCL5 molecules significantly reduced the number of migrated macrophages to tumor cells after irradiation. These results demonstrate that targeting the IL-6 signaling or CCL2/CCL5 molecules in combination with conventional radiotherapy potentially blocks undesired radiation-induced macrophage infiltration.

Characterization of biosurfactants produced by novel strains of Ochrobactrum anthropi HM-1 and Citrobacter freundii HM-2 from used engine oil-contaminated soil

Microbial surfactants are widely used for industrial, agricultural, food, cosmetics, pharmaceutical, and medical applications. In this study, two bacterial strains namely, Ochrobactrum anthropi HM-1 and Citrobacter freundii HM-2, previously isolated from used engine oil contaminated soil, and capable of producing biosurfactants, were used. Their cell-free culture broth showed positive results toward five screening tests (hemolysis in blood agar, drop collapse, oil displacement, emulsification activity (E24), and surface tension (ST) reduction). They reduced the ST of growth medium (70±0.9) to 30.8±0.6 and 32.5±1.3mN/m, respectively. The biosurfactants were classified as anionic biomolecules. Based on TLC pattern and FT-IR analysis, they were designated as glycolipids (rhamnolipid). Waste frying oil was feasibly used as a cheap and dominant carbon source for biosurfactants production; 4.9 and 4.1g/l were obtained after 96h of incubation, respectively. Compared with non-irradiated cells, gamma-irradiated cells (1.5kGy) revealed enhanced biosurfactant production by 56 and 49% for HM-1 and HM-2, respectively. The biosurfactants showed good stability after exposure to extreme conditions [temperatures (50–100°C for 30min), pH (2–12) and salinity (2–10% NaCl)], they retained 83 and 79.3% of their E24, respectively, after incubation for a month, under extreme conditions. Biosurfactants effectively recovered up to 70 and 67% of the residual oil, respectively, from oil-saturated sand pack columns. These biosurfactants are an interesting biotechnological product for many environmental and industrial applications.

Protective effect of mild endoplasmic reticulum stress on radiation-induced bystander effects in hepatocyte cells.

Radiation-induced bystander effect (RIBE) has important implications for secondary cancer risk assessment during cancer radiotherapy, but the defense and self-protective mechanisms of bystander normal cells are still largely unclear. The present study found that micronuclei (MN) formation could be induced in the non-irradiated HL-7702 hepatocyte cells after being treated with the conditioned medium from irradiated hepatoma HepG2 cells under either normoxia or hypoxia, where the ratio of the yield of bystander MN induction to the yield of radiation-induced MN formation under hypoxia was much higher than that of normoxia. Nonetheless, thapsigargin induced endoplasmic reticulum (ER) stress and dramatically suppressed this bystander response manifested as the decrease of MN and apoptosis inductions. Meanwhile, the interference of BiP gene, a major ER chaperone, amplified the detrimental RIBE. More precisely, thapsigargin provoked ER sensor of PERK to initiate an instantaneous and moderate ER stress thus defensed the hazard form RIBE, while BiP depletion lead to persistently destroyed homeostasis of ER and exacerbated cell injury. These findings provide new insights that the mild ER stress through BiP-PERK-p-eIF2α signaling pathway has a profound role in protecting cellular damage from RIBE and hence may decrease the potential secondary cancer risk after cancer radiotherapy.

Vav1, a Rho GTPase Guanine Exchange Factor (GEF) Is Required to Integrate gp130 Cytokine Signaling for Successful Engraftment of Murine Hematopoietic Stem Cells Following Irradiation

Successful engraftment of hematopoietic stem and progenitor cells (HSPCs) during bone marrow transplantation requires appropriate homing and retention of transplanted cells in the bone marrow (BM) and the activation of a proliferative program in response to signals from the hematopoietic microenvironment (HM). Molecular pathways regulating migration, homing and retention of HSPCs in the BM are integrated by RhoGTPasesincluding Rac and CDC42, however the complex cues that drive the proliferative response of these cells following transplantation are less clear.We have previously described the hematopoietic phenotype of adult mice lacking Vav1, a multi-domain, hematopoietic-specific GEF for Rac and CDC42. Deletion of Vav1 does not affect steady state hematopoiesis in adult mice, but severely compromises the engraftment potential of HSPCs. In the absence of Vav1, signal transduction from SDF1α is impaired in HSPCs, leading to abnormal localization and reduced retention of these cells in the HM, a phenotype similar to deficiency of Rac (Sanchez-Aguilera et al. PNAS, 2011). Here, we define an unexpected role for Vav1 in mediating post-irradiation proliferative responses of HSPCs.Surprisingly, we observed that deletion of Vav1 does not affect HSPC migration during ontogeny, a process largely mediated by SDF1α. The number of immunophenotypically and functionally defined HSPCs in Vav1-/- E13.5 fetal liver (FL) was comparable to WT (Table 1). Similarly, no difference was detected in HSPCs in the peripheral blood (PB) of E18.5 embryos or in the BM of newborn mice. However, similar to adult cells, Vav1-/- fetal HSCPs showed severely defective engraftment in lethally irradiated recipients (see Table 2). In marked contrast, both adult and fetal Vav1-/- HSCPs could engraft non-irradiated (Kit W/Wv Rag2- γc-) recipients, achieving successful correction of the macrocytic anemia and B cell leukopenia phenotype of recipient mice (Table 2, in red). Reduced proliferation of Vav1-/- HSPCs was also observed in vitro upon co-culture with primary irradiated stromal cells (Table 3). No differences among genotypes were detected when using non-irradiated stromal cells. These data suggest a distinct role for Vav1 in mediating responses of HSPCs to the HM after irradiation.To further clarify this phenotype, we investigated the role of individual soluble factors on proliferative responses of Vav1 HSPCs. Given their known role in expansion and proliferation of hematopoietic progenitors we focused on gp130 cytokines. We found that both IL-6 and IL-11, prominent members of this cytokine family, were increased in the BM of irradiated WT recipients, compared to both non-irradiated WT recipients (3x and 2x increase) and Kit W/Wv Rag2- γc- (2x and 3x increase) age- and sex-matched animals. To validate the potential role of IL-6 and IL-11 in Vav1 function, we stimulated HSPCs with both cytokines and observed that they induced phosphorylation of Vav1 and activation of Rac, but not CDC42. Using CFU assays, liquid culture experiments and BrdU analysis we confirmed that deletion of Vav1 abolishes the proliferative responses elicited by IL-6 and IL-11 on HSPCs in vitro.In summary, we show that Vav1 acts in HSPCs to mitigate responses to pro-inflammatory cytokines present in the HM during engraftment following irradiation. Manipulating the gp130-Vav-Rac axis in HSPCs could represent a strategy to enhance engraftment of normal cells in conditioned recipients. [Display omitted] [Display omitted] [Display omitted] DisclosuresWilliams:bluebird bio: Research Funding; Novartis: Consultancy; Orchard Therapeutics: Membership on an entity's Board of Directors or advisory committees.

178 - Oxidative, Morphological and Mechanical Changes in ARPE-19 Cells Induced by Lipofuscin-Mediated Photic Stress

Retinal pigment epithelium (RPE) provides important metabolic support for the entire retina and is involved in biological renewal of photoreceptor outer segments. It is believed that key changes involved in the pathology of age-related macular degeneration, the major cause of blindness in people over 60, occur in the RPE. Being exposed to high oxygen tension and intense visible light from focused irradiation, human RPR is at risk of oxidative stress, which is aggravated by the accumulating age pigment lipofuscin. In this work, we examined the effect of photic stress, induced by blue light irradiation of ARPE-19 cells containing phagocytized RPE lipofuscin granules isolated from human donors of different age, on cell survival, oxidation of cellular proteins, morphology of the cells and their mechanical properties, employing standard cell culture techniques, coumarin boronic acid (CBA) assay, immunofluorescence analysis with laser scanning confocal microscopy (LSCM), and atomic force microscopy (AFM) and spectroscopy. Photic stress mediated by lipofuscin from older donors reduced survival of ARPE-19 cells more efficiently than lipofuscin from younger donors. Sub-lethal stress induced oxidation of cellular proteins in a dose-dependent manner with the effect being stronger for lipofuscin from older donors. These biochemical changes correlated with modifications of the cell morphology, which indicated substantial decrease in the formation of actin stress fibers in lipofuscin-containing cells subjected to sub-lethal photic stress. In addition, nanomechanical analysis revealed that such cells were significantly softer than control non-irradiated cells, or irradiated cells without lipofuscin. Our study demonstrates that AFM analysis can be used for sensitive detection of early changes of cultured RPE cells subjected to sub-lethal oxidative stress. Supported by Poland National Science Centre (grant Maestro 2013/08/A/NZ1/00194).

FOXM1 and STAT3 interaction confers radioresistance in glioblastoma cells.

Glioblastoma multiforme (GBM) continues to be the most frequently diagnosed and lethal primary brain tumor. Adjuvant chemo-radiotherapy remains the standard of care following surgical resection. In this study, using reverse phase protein arrays (RPPAs), we assessed the biological effects of radiation on signaling pathways to identify potential radiosensitizing molecular targets. We identified subsets of proteins with clearly concordant/discordant behavior between irradiated and non-irradiated GBM cells in vitro and in vivo. Moreover, we observed high expression of Forkhead box protein M1 (FOXM1) in irradiated GBM cells both in vitro and in vivo. Recent evidence of FOXM1 as a master regulator of metastasis and its important role in maintaining neural, progenitor, and GBM stem cells, intrigued us to validate it as a radiosensitizing target. Here we show that FOXM1 inhibition radiosensitizes GBM cells by abrogating genes associated with cell cycle progression and DNA repair, suggesting its role in cellular response to radiation. Further, we demonstrate that radiation induced stimulation of FOXM1 expression is dependent on STAT3 activation. Co-immunoprecipitation and co-localization assays revealed physical interaction of FOXM1 with phosphorylated STAT3 under radiation treatment. In conclusion, we hypothesize that FOXM1 regulates radioresistance via STAT3 in GBM cells. We also, show GBM patients with high FOXM1 expression have poor prognosis. Collectively our observations might open novel opportunities for targeting FOXM1 for effective GBM therapy.

Numb/Notch signaling pathway modulation enhances human pancreatic cancer cell radiosensitivity

The present study aims to evaluate whether repression of the Numb/Notch signaling pathway affects the radiosensitivity of human pancreatic cancer cell lines. Different doses of X-rays (0, 2, 3, 4, and 5Gy) were applied to the PANC-1, SW1990, and MIA PaCa-2 human pancreatic cancer cell lines, and the Numb/Notch pathway inhibitor DAPT was added at different doses (0, 1, 3, and 5μmol/l). MTT assay, colony formation assay, flow cytometry, scratch assay, and Transwell experiments were performed, and qRT-PCR and Western blot were conducted for the detection of Numb expression. Tumorigenicity assay in nude mice was carried out to verify the influence of blocker of the Numb/Notch signaling pathway on the radiosensitivity of xenograft tumors. The MTT assay, colony formation assay and flow cytometry experiments revealed that proliferation decreased as radiation dose increased. The viability of PANC-1 cells at 5Gy, SW 1990 cells at 4Gy and 5Gy, and MIA PaCa-2 cells at 2-5Gy was significantly lower than that of non-irradiated cells (all P<0.05). The migration and invasion assays indicated that the PANC-1 cell line was least radiosensitive, while the MIA PaCa-2 cell line was the most radiosensitive. Numb expression significantly increased with increasing radiation dose, whereas the expression of Hes1, Notch1, and Hes5 significantly decreased compared to non-irradiated cells (P<0.05). Compared to untreated control cells, DAPT dose dependently increased Numb expression and inhibited Notch1, Hes1, and Hes5 expressions at 2Gy (P<0.05). Subcutaneous tumorigenicity assay in nude mice demonstrated that DAPT increased the radiosensitivity of PANC-1, SW 1990, and MIA PaCa-2 cells. These findings suggest that Numb/Notch signaling in pancreatic cancer cells is associated with X-ray radiation and that inhibition of the Numb/Notch signaling pathway can enhance radiosensitivity, suggesting that inhibition of the Numb/Notch signaling pathway may serve as a potential target for clinical improvement of the radiosensitivity of pancreatic cancer.

The effect of glucose-coated gold nanoparticles on radiation bystander effect induced in MCF-7 and QUDB cell lines.

Due to biocompatibility and relative non-toxic nature, gold nanoparticles (GNPs) have been studied widely to be employed in radiotherapy as radio-sensitizer. On the other hand, they may enhance radiation-induced bystander effect (RIBE), which causes radiation adverse effects in non-irradiated normal cells. The present study was planned to investigate the possibility of augmenting the RIBE consequence of applying glucose-coated gold nanoparticles (Glu-GNPs) to target cells. Glu-GNPs were synthesized and utilized to treat MCF7 and QUDB cells. The treated cells were irradiated with 100 kVp X-rays, and their culture media were transferred to non-irradiated bystander cells. Performing MTT cellular proliferation test and colony formation assay, percentage cell viability and survival fraction of bystander cells were determined, respectively, and were compared to control bystander cells which received culture medium from irradiated cells without Glu-GNPs. Glu-GNPs decreased the cell viability and survival fraction of QUDB bystander cells by as much as 13.2 and 11.5%, respectively (P<0.02). However, the same end points were not changed by Glu-GNPs in MCF-7 bystander cells. Different RIBE responses were observed in QUDB and MCF7 loaded with Glu-GNPs. Glu-GNPs increased the RIBE in QUDB cells, while they had no effects on RIBE in MCF7 cells. As opposed to QUDB cells, the RIBE in MCF7 cells did not change in the dose range of 0.5-10Gy. Therefore, it might be a constant effect and the reason of not being increased by Glu-GNPs.

Comparison of Radiation-Induced Bystander Effect in QU-DB Cells after Acute and Fractionated Irradiation: An In Vitro Study.

Radiation effects induced in non-irradiated cells are termed radiation-induced bystander effects (RIBE). The present study intends to examine the RIBE response of QU-DB bystander cells to first, second and third radiation fractions and compare their cumulative outcome with an equal, single acute dose. This experimental study irradiated three groups of target cells for one, two and three times with(60)Co gamma rays. One hour after irradiation, we transferred their culture media to non-irradiated (bystander) cells. We used the cytokinesis block micronucleus assay to evaluate RIBE response in the bystander cells. The numbers of micronuclei generated in bystander cells were determined. RIBE response to single acute doses increased up to 4 Gy, then decreased, and finally at the 8 Gy dose disappeared. The second and third fractions induced RIBE in bystander cells, except when RIBE reached to the maximum level at the first fraction. We split the 4 Gy acute dose into two fractions, which decreased the RIBE response. However, fractionation of 6 Gy (into two fractions of 3 Gy or three fractions of 2 Gy) had no effect on RIBE response. When we split the 8 Gy acute dose into two fractions we observed RIBE, which had disappeared following the single 8 Gy dose. The impact of dose fractionation on RIBE induced in QU-DB cells de- pended on the RIBE dose-response relationship. Where RIBE increased proportion- ally with the dose, fractionation reduced the RIBE response. In contrast, at high dos- es where RIBE decreased proportionally with the dose, fractionation either did not change RIBE (at 6 Gy) or increased it (at 8 Gy).

Intricate Macrophage-Colorectal Cancer Cell Communication in Response to Radiation.

Both cancer and tumour-associated host cells are exposed to ionizing radiation when a tumour is subjected to radiotherapy. Macrophages frequently constitute the most abundant tumour-associated immune population, playing a role in tumour progression and response to therapy. The present work aimed to evaluate the importance of macrophage-cancer cell communication in the cellular response to radiation. To address this question, we established monocultures and indirect co-cultures of human monocyte-derived macrophages with RKO or SW1463 colorectal cancer cells, which exhibit higher and lower radiation sensitivity, respectively. Mono- and co-cultures were then irradiated with 5 cumulative doses, in a similar fractionated scheme to that used during cancer patients’ treatment (2 Gy/fraction/day). Our results demonstrated that macrophages sensitize RKO to radiation-induced apoptosis, while protecting SW1463 cells. Additionally, the co-culture with macrophages increased the mRNA expression of metabolism- and survival-related genes more in SW1463 than in RKO. The presence of macrophages also upregulated glucose transporter 1 expression in irradiated SW1463, but not in RKO cells. In addition, the influence of cancer cells on the expression of pro- and anti-inflammatory macrophage markers, upon radiation exposure, was also evaluated. In the presence of RKO or SW1463, irradiated macrophages exhibit higher levels of pro-inflammatory TNF, IL6, CCL2 and CCR7, and of anti-inflammatory CCL18. However, RKO cells induce an increase of macrophage pro-inflammatory IL1B, while SW1463 cells promote higher pro-inflammatory CXCL8 and CD80, and also anti-inflammatory VCAN and IL10 levels. Thus, our data demonstrated that macrophages and cancer cells mutually influence their response to radiation. Notably, conditioned medium from irradiated co-cultures increased non-irradiated RKO cell migration and invasion and did not impact on angiogenesis in a chicken embryo chorioallantoic membrane assay. Overall, the establishment of primary human macrophage-cancer cell co-cultures revealed an intricate cell communication in response to ionizing radiation, which should be considered when developing therapies adjuvant to radiotherapy.

Diffusible Factors Secreted by Glioblastoma and Medulloblastoma Cells Induce Oxidative Stress in Bystander Neural Stem Progenitors.

Harmful effects that alter the homeostasis of neural stem or progenitor cells (NSPs) can affect regenerative processes in the central nervous system. We investigated the effect of soluble factors secreted by control or 137Cs-γ-irradiated glioblastoma or medulloblastoma cells on redox-modulated endpoints in recipient human NSPs. Growth medium harvested from the nonirradiated brain tumor cells, following 24 h of growth, induced prominent oxidative stress in recipient NSPs as judged by overall increases in mitochondrial superoxide radical levels (p < .001), activation of c-jun N-terminal kinase, and decrease in the active form of FoxO3a. The induced oxidative stress was associated with phosphorylation of p53 on serine 15, a marker of DNA damage, induction of the cyclin-cyclin dependent kinase inhibitors p21Waf1 and p27Kip1, and perturbations in cell cycle progression (p < .001). These changes were also associated with increased apoptosis as determined by enhanced annexin V staining (p < .001) and caspase 8 activation (p < .05) and altered expression of critical regulators of self-renewal, proliferation, and differentiation. Exposure of the tumor cells to radiation only slightly altered the induced oxidative changes in the bystander NSPs, except for medium from irradiated medulloblastoma cells that was more potent at inducing apoptosis in the NSPs than medium from nonirradiated cells (p < .001). The elucidation of such stressful bystander effects provides avenues to understand the biochemical events underlying the development or exacerbation of degenerative outcomes associated with brain cancers. It is also relevant to tissue culture protocols whereby growth medium conditioned by tumor cells is often used to support the growth of stem cells.

Red LED Photobiomodulates the Metabolic Activity of Odontoblast-Like Cells.

Phototherapy has been indicated as an adjunctive treatment for tissue repair, including the pulp tissue. However, there are no defined irradiation parameters, which is a great challenge to the clinical use of phototherapy. The aim of this study was to evaluate the effect of phototherapy with red LED on odontoblast-like MDPC-23 cells, using different parameter settings. Cells were seeded (104 cells/cm²), incubated for 12 h in complete DMEM and then the culture medium was replaced by DMEM supplemented with 0.5% FBS. After 12 h incubation, irradiations were performed (630±10 nm) using a LEDTable device with a 20 or 40 mW/cm² power density and 2 J/cm² energy dose. The cells were irradiated 1 or 3 times, at 1 min intervals. Non-irradiated cells served as control. The cells were evaluated for viability (MTT assay), total protein dosage (Lowry method) and number of viable cells (Trypan blue). The data (n=12 per group) were submitted to Kruskal-Wallis and Mann-Whitney tests (p=0.05). A single irradiation with 20 or 40 mW/cm² enhanced cell viability, which was negatively affected after 3 consecutive irradiations. Cells irradiated only once with 20 mW/cm² produced more proteins compared with those irradiated with 40 mW/cm². Reduction in the number of viable cells occurred only after 3 consecutive irradiations with 40 mW/cm². In conclusion, red LED was capable of biomodulating the metabolic activities of cultured MDPC-23 odontoblast-like cells. The best cell biostimulation was obtained when a single irradiation with 2 J/cm2 energy dose and 20 mW/cm2 power density was delivered to the pulp cells.

Plasmonic phototherapy of gold nanoparticles with Light Emitting Diode

Plasmonic Photo therapy (PPT) is a developing treatment modality for premalignant and malignant conditions. In this study, Gold nanospheres of 30 nm chose as potential sensitizer based on their pros and cons. Green Light Emitting Diode (LED) with 530nm of 30mW used as irradiation source. The cytotoxic effect of 30 nm GNPs based on the concentration and time was studied with MTT assay. In PPT, we study the cell death mechanism with non-coherent low power LED with GNP by photo irradiation study in Vero, Hela and Hep 2 cell lines. Post therapeutic changes in normal Vero and malignant Hela and Hep 2 cell lines were also observed for 2 ,24 and 48 hours. We observed localized apoptotic/secondary necrosis in irradiated spot, leading to irreversible cell. The viability and cell division of non-irradiated cells around irradiated spot was observed microscopically and by MTT assay. In PPT, fluence and GNP concentration were optimized since they perform crucial role in the mode of cell death. In this study we hypothesized that; plasmonic phototherapy leads to apoptosis with green LED of 30mW with 30nm GNPs.

Alteration In in -Vitro Infectivity of Leishmania donovani ExposedTo Gamma Radiation

At particular doses of gamma radiation from Co60 source suppresses the intracellular parasitism, a fact which raises the question of whether the phenomenon may find practical applications in the outcome of infectious diseases. In this study, stationary phase of promastigotes exposed to radiation doses in the range 10-20 krad (standard dose) resulted in significant parasitization of mononuclear phagocytic system in vitro. However, promastigotes irradiated with 20krad consistently resulted in higher parasitization and optimum infection after acquiring the shape of amastigote- like organism than those exposed to either higher or lower radiation doses. It was observed that 10 krad was necessary to immobilize immediately the organisms, whereas only 30 krad rendered them noninfective and 40-50 krad made promastigotes unable to recognize the binding ligand for attachment to macrophage cell. In comparison to the irradiated parasite, the rate of phagocytosis of 20 krad irradiated cells, were higher while considering the percentage of infected macrophages, the mean number of engulfed parasites by each macrophage cells and the statistics of the two. The rate of infected cells was approximately 8% greater in 20 krad irradiated cells than nonirradiated cells.

Biohydrogen production by purple non-sulfur bacteria Rhodobacter sphaeroides: Effect of low-intensity electromagnetic irradiation

The present work was focused on the effects of low-intensity (the flux capacity was of 0.06mWcm−2) electromagnetic irradiation (EMI) of extremely high frequencies or millimeter waves on the growth and hydrogen (H2) photoproduction by purple non-sulfur bacteria Rhodobacter sphaeroides MDC6521 (from Armenian mineral springs). After exposure of R. sphaeroides, grown under anaerobic conditions upon illumination, to EMI (51.8GHz and 53.0GHz) for 15min an increase of specific growth rate by ~1.2-fold, in comparison with control (non-irradiated cells), was obtained. However, the effect of EMI depends on the duration of irradiation: the exposure elongation up to 60min caused the delay of the growth lag phase and the decrease specific growth rate by ~1.3-fold, indicating the bactericidal effect of EMI. H2 yield of the culture, irradiated by EMI for 15min, determined during 72h growth, was ~1.2-fold higher than H2 yield of control cells, whereas H2 production by cultures, irradiated by EMI for 60min was not observed during 72h growth. This difference in the effects of extremely high frequency EMI indicates a direct effect of radiation on the membrane transfer and the enzymes of these bacteria. Moreover, EMI increased DCCD-inhibited H+ fluxes across the bacterial membrane and DCCD-sensitive ATPase activity of membrane vesicles, indicating that the proton FoF1-ATPase is presumably a basic target for extremely high frequency EMI related to H2 production by cultures.

Activation of the JNK-c-Jun pathway in response to irradiation facilitates Fas ligand secretion in hepatoma cells and increases hepatocyte injury.

BackgroundIt is well established that some irradiated liver non-parenchymal cells secrete pro-inflammatory cytokines to facilitate the development of radiation-induced liver disease. However, little is known on whether the irradiated hepatoma cells-mediated non-irradiated hepatocyte injury occurs in HCC patients. Here, we elucidated the roles of the irradiated hepatoma cells in driving non-irradiated hepatocyte injury and its underlying mechanism.MethodsSMMC7721 cells were cultured and divided into irradiated (4-Gy X-ray, R) and non-irradiated (NR) groups. At 24th hour after irradiation, conditioned medium (CM) from these cultures was mixed with normal culture medium in specific proportions, and termed as 7721-R-CM and 7721-NR-CM. Following incubation with these CM compound, the biological characteristics of L02 cells related to liver cell injury including viability, apoptosis and liver dysfunction indices were comparatively analyzed. Simultaneously, the levels of proliferation- and apoptosis-related cytokines in irradiated and non-irradiated SMMC7721 cells were also measured. FasL as a cytokine with significantly differential expression, was selected to clarify its effects on L02 apoptosis. Subsequently, FasL expression following irradiation was examined in SMMC7721 and other HCC cells with varying malignant potentials, as well as in HCC tissues, the related mechanism of higher expression of FasL in irradiated HCC cells was further investigated.ResultsApoptosis and liver dysfunction indices were all significantly enhanced in L02 cells treated with 7721-R-CM, whereas viability was suppressed, compared to those with 7721-NR-CM stimulation. FasL was identified as a leading differential cytokine in the irradiated SMMC7721 cells. Higher proportion of apoptosis was also found in L02 cells following FasL incubation. A recombinant Fas-Fc protein, which blocks Fas-FasL interaction, ameliorated 7721-R-CM-induced apoptosis in L02 cells. FasL was highly expressed in a dose-dependent manner, and peaked at the 24th hour post-irradiation in different HCC cells and their culture supernatant. Meanwhile, phosphorylation levels of JNK, ERK, Akt, and p38 were all upregulated significantly in irradiated HCC cells. But, only JNK inhibition was validated to block radiation-induced FasL expression in HCC cells. c-Jun, the target transcription factor of JNK, was also activated.ConclusionIn HCC cells, the JNK-c-Jun pathway plays an important role in mediating irradiation- induced FasL expression, which may be critical in determining non-irradiated hepatocyte injury.Electronic supplementary materialThe online version of this article (doi:10.1186/s13046-016-0394-z) contains supplementary material, which is available to authorized users.

Abstract 1981: Histone demethyalase JMJD1A promotes the DNA damage response of prostate cancer cells

Abstract DNA damage is a common feature of prostate cancer (PCa) therapies (e.g. radio-, chemo- and androgen deprivation therapies). Thus, the DNA damage response (DDR) is a key factor in determining the therapeutic response of PCa patients. JMJD1A regulates gene expression by demethylating H3K9. Here, we identified a new role for JMJD1A in the DDR of PCa cells. Inhibition of JMJD1A led to increased r-H2AX foci (marker for the double strand DNA breaks) in the non-irradiated cells, and the delayed clearance of r-H2AX foci in the irradiated cells. JMJD1A knockdown in PCa cells inhibited the DNA strand break repair in the reporter assays. We further found that phosphorylation and ubiquitination were key modifications that regulate the activity of JMJD1A in the DDR. Ectopic expression of the mutant JMJD1A at the phosphorylation or ubiquitination site attenuated the expression of DNA repair factors, DNA strand break repair, and PCa cell proliferation under irradiation and androgen deprivation conditions. Our results suggest that targeting JMJD1A may sensitize the response of PCa to the major anti-PCa therapies. Citation Format: Lingling Fan, Guihong Peng, Natasha Sahgal, Ladan Fazli, Martin Gleave, Yuji Zhang, Arif Hussain, Feyruz Rassool, Jianfei Qi. Histone demethyalase JMJD1A promotes the DNA damage response of prostate cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1981.

Mitotic genes are transcriptionally upregulated in the fibroblast irradiated with very low doses of UV-C.

Ultraviolet (UV) radiation induces a variety of biological effects, including DNA damage response and cell signaling pathways. We performed transcriptome analysis using microarray in human primary cultured fibroblasts irradiated with UV-C (0.5 or 5 J/m2) and harvested at 4 or 12 h following UV exposure. All transcript data were analyzed by comparison with the corresponding results in non-irradiated (control) cells. The number of genes with significantly altered expression (≥2-fold difference relative to the control) is higher in the sample irradiated with high dose of UV, suggesting that gene expression was UV dose-dependent. Pathway analysis on the upregulated genes at 12 h indicates that the expression of some cell cycle-related genes was predominantly induced irrespective of UV-dose. Interestingly, almost all the genes with significant altered expression were cell cycle-related genes designated as ‘Mitotic Genes’, which function in the spindle assembly checkpoint. Therefore, even a low dose of UV could affect the transcriptional profile.